6.1.3 MAC Control Elements (CEs)

38.3213GPPMedium Access Control (MAC) protocol specificationNRRelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

6.1.3.1 Buffer Status Report MAC CEs

Buffer Status Report (BSR) MAC CEs consist of either:

– Short BSR format (fixed size); or

– Extended Short BSR format (fixed size); or

– Long BSR format (variable size); or

– Extended Long BSR format (variable size); or

– Short Truncated BSR format (fixed size); or

– Extended Short Truncated BSR format (fixed size); or

– Long Truncated BSR format (variable size); or

– Extended Long Truncated BSR format (variable size).

Pre-emptive BSR MAC CE consists of:

– Pre-emptive BSR format (variable size); or

– Extended Pre-emptive BSR format (variable size).

The BSR formats are identified by MAC subheaders with LCIDs as specified in Table 6.2.1-2.

The Extended BSR formats and Pre-emptive BSR format are identified by MAC subheaders with eLCIDs as specified in Table 6.2.1-2b.

The fields in the BSR MAC CE are defined as follows:

– LCG ID: The Logical Channel Group ID field identifies the group of logical channel(s) whose buffer status is being reported. The length of the field is 3 bits for the case of Short BSR and Short Truncated BSR formats, and 8 bits for the case of Extended Short BSR and Extended Short Truncated BSR formats;

– LCG_i: For the Long BSR format, Extended Long BSR format, Pre-emptive BSR format, and Extended Pre-emptive BSR format, this field indicates the presence of the Buffer Size field for the logical channel group i. The LCG_i field set to 1 indicates that the Buffer Size field for the logical channel group i is reported. The LCG_i field set to 0 indicates that the Buffer Size field for the logical channel group i is not reported. For the Long Truncated BSR format and the Extended Long Truncated BSR format, this field indicates whether logical channel group i has data available. The LCG_i field set to 1 indicates that logical channel group i has data available. The LCG_i field set to 0 indicates that logical channel group i does not have data available;

– Buffer Size: The Buffer Size field identifies the total amount of data available according to the data volume calculation procedure in TSs 38.322 [3] and 38.323 [4] across all logical channels of a logical channel group after the MAC PDU has been built (i.e. after the logical channel prioritization procedure, which may result the value of the Buffer Size field to zero). The amount of data is indicated in number of bytes. The size of the RLC headers and MAC subheaders are not considered in the buffer size computation. The length of this field for the Short BSR format and the Short Truncated BSR format is 5 bits. The length of this field for the Extended Short BSR format and the Extended Short Truncated BSR format is 8 bits. The length of this field for the Long BSR format, the Long Truncated BSR format, the Extended Long BSR format, and the Extended Long Truncated format is 8 bits. The values for the 5-bit and 8-bit Buffer Size fields are shown in Tables 6.1.3.1-1 and 6.1.3.1-2, respectively. For the Long BSR format, the Long Truncated BSR format, the Extended Long BSR format, and the Extended Long Truncated format, the Buffer Size fields are included in ascending order based on the LCG_i. For the Long Truncated BSR format and the Extended Long Truncated format the number of Buffer Size fields included is maximised, while not exceeding the number of padding bits. For the Pre-emptive BSR format and the Extended Pre-emptive BSR format, the Buffer Size field identifies the total amount of the data expected to arrive at the IAB-MT of the node where the Pre-emptive BSR/Extended Pre-emptive BSR is triggered and does not include the volume of data currently available in the IAB-MT. Pre-emptive BSR format is identical to the Long BSR format. Extended Pre-emptive BSR format is identical to the Extended Long BSR format.

NOTE 1: For the Pre-emptive BSR, if configured, the LCGs to be reported, the expected data volume calculation, the exact time to report Pre-emptive BSR and the associated LCH are left to implementation.

NOTE 2: The mapping of LCGs between the ingress and egress links of an IAB node for purposes of determining expected change in occupancy of IAB-MT buffers (to be reported as Pre-emptive BSR) is left to implementation.

NOTE 3: The number of the Buffer Size fields in the Long BSR, Extended Long BSR, Long Truncated BSR, and Extended Long Truncated BSR format can be zero.

NOTE 4: The Extended versions of the BSR formats can only be used by IAB nodes.

Figure 6.1.3.1-1: Short BSR and Short Truncated BSR MAC CE

Figure 6.1.3.1-2: Long BSR, Long Truncated BSR, and Pre-emptive BSR MAC CE

Figure 6.1.3.1-3: Extended Short BSR and Extended Short Truncated BSR MAC CE

Figure 6.1.3.1-4: Extended Long BSR, Extended Long Truncated BSR, and Extended Pre-emptive BSR MAC CE

Table 6.1.3.1-1: Buffer size levels (in bytes) for 5-bit Buffer Size field

Index	BS value	Index	BS value	Index	BS value	Index	BS value
0	0	8	≤ 102	16	≤ 1446	24	≤ 20516
1	≤ 10	9	≤ 142	17	≤ 2014	25	≤ 28581
2	≤ 14	10	≤ 198	18	≤ 2806	26	≤ 39818
3	≤ 20	11	≤ 276	19	≤ 3909	27	≤ 55474
4	≤ 28	12	≤ 384	20	≤ 5446	28	≤ 77284
5	≤ 38	13	≤ 535	21	≤ 7587	29	≤ 107669
6	≤ 53	14	≤ 745	22	≤ 10570	30	≤ 150000
7	≤ 74	15	≤ 1038	23	≤ 14726	31	> 150000

Table 6.1.3.1-2: Buffer size levels (in bytes) for 8-bit Buffer Size field

Index	BS value	Index	BS value	Index	BS value	Index	BS value
0	0	64	≤ 560	128	≤ 31342	192	≤ 1754595
1	≤ 10	65	≤ 597	129	≤ 33376	193	≤ 1868488
2	≤ 11	66	≤ 635	130	≤ 35543	194	≤ 1989774
3	≤ 12	67	≤ 677	131	≤ 37850	195	≤ 2118933
4	≤ 13	68	≤ 720	132	≤ 40307	196	≤ 2256475
5	≤ 14	69	≤ 767	133	≤ 42923	197	≤ 2402946
6	≤ 15	70	≤ 817	134	≤ 45709	198	≤ 2558924
7	≤ 16	71	≤ 870	135	≤ 48676	199	≤ 2725027
8	≤ 17	72	≤ 926	136	≤ 51836	200	≤ 2901912
9	≤ 18	73	≤ 987	137	≤ 55200	201	≤ 3090279
10	≤ 19	74	≤ 1051	138	≤ 58784	202	≤ 3290873
11	≤ 20	75	≤ 1119	139	≤ 62599	203	≤ 3504487
12	≤ 22	76	≤ 1191	140	≤ 66663	204	≤ 3731968
13	≤ 23	77	≤ 1269	141	≤ 70990	205	≤ 3974215
14	≤ 25	78	≤ 1351	142	≤ 75598	206	≤ 4232186
15	≤ 26	79	≤ 1439	143	≤ 80505	207	≤ 4506902
16	≤ 28	80	≤ 1532	144	≤ 85730	208	≤ 4799451
17	≤ 30	81	≤ 1631	145	≤ 91295	209	≤ 5110989
18	≤ 32	82	≤ 1737	146	≤ 97221	210	≤ 5442750
19	≤ 34	83	≤ 1850	147	≤ 103532	211	≤ 5796046
20	≤ 36	84	≤ 1970	148	≤ 110252	212	≤ 6172275
21	≤ 38	85	≤ 2098	149	≤ 117409	213	≤ 6572925
22	≤ 40	86	≤ 2234	150	≤ 125030	214	≤ 6999582
23	≤ 43	87	≤ 2379	151	≤ 133146	215	≤ 7453933
24	≤ 46	88	≤ 2533	152	≤ 141789	216	≤ 7937777
25	≤ 49	89	≤ 2698	153	≤ 150992	217	≤ 8453028
26	≤ 52	90	≤ 2873	154	≤ 160793	218	≤ 9001725
27	≤ 55	91	≤ 3059	155	≤ 171231	219	≤ 9586039
28	≤ 59	92	≤ 3258	156	≤ 182345	220	≤ 10208280
29	≤ 62	93	≤ 3469	157	≤ 194182	221	≤ 10870913
30	≤ 66	94	≤ 3694	158	≤ 206786	222	≤ 11576557
31	≤ 71	95	≤ 3934	159	≤ 220209	223	≤ 12328006
32	≤ 75	96	≤ 4189	160	≤ 234503	224	≤ 13128233
33	≤ 80	97	≤ 4461	161	≤ 249725	225	≤ 13980403
34	≤ 85	98	≤ 4751	162	≤ 265935	226	≤ 14887889
35	≤ 91	99	≤ 5059	163	≤ 283197	227	≤ 15854280
36	≤ 97	100	≤ 5387	164	≤ 301579	228	≤ 16883401
37	≤ 103	101	≤ 5737	165	≤ 321155	229	≤ 17979324
38	≤ 110	102	≤ 6109	166	≤ 342002	230	≤ 19146385
39	≤ 117	103	≤ 6506	167	≤ 364202	231	≤ 20389201
40	≤ 124	104	≤ 6928	168	≤ 387842	232	≤ 21712690
41	≤ 132	105	≤ 7378	169	≤ 413018	233	≤ 23122088
42	≤ 141	106	≤ 7857	170	≤ 439827	234	≤ 24622972
43	≤ 150	107	≤ 8367	171	≤ 468377	235	≤ 26221280
44	≤ 160	108	≤ 8910	172	≤ 498780	236	≤ 27923336
45	≤ 170	109	≤ 9488	173	≤ 531156	237	≤ 29735875
46	≤ 181	110	≤ 10104	174	≤ 565634	238	≤ 31666069
47	≤ 193	111	≤ 10760	175	≤ 602350	239	≤ 33721553
48	≤ 205	112	≤ 11458	176	≤ 641449	240	≤ 35910462
49	≤ 218	113	≤ 12202	177	≤ 683087	241	≤ 38241455
50	≤ 233	114	≤ 12994	178	≤ 727427	242	≤ 40723756
51	≤ 248	115	≤ 13838	179	≤ 774645	243	≤ 43367187
52	≤ 264	116	≤ 14736	180	≤ 824928	244	≤ 46182206
53	≤ 281	117	≤ 15692	181	≤ 878475	245	≤ 49179951
54	≤ 299	118	≤ 16711	182	≤ 935498	246	≤ 52372284
55	≤ 318	119	≤ 17795	183	≤ 996222	247	≤ 55771835
56	≤ 339	120	≤ 18951	184	≤ 1060888	248	≤ 59392055
57	≤ 361	121	≤ 20181	185	≤ 1129752	249	≤ 63247269
58	≤ 384	122	≤ 21491	186	≤ 1203085	250	≤ 67352729
59	≤ 409	123	≤ 22885	187	≤ 1281179	251	≤ 71724679
60	≤ 436	124	≤ 24371	188	≤ 1364342	252	≤ 76380419
61	≤ 464	125	≤ 25953	189	≤ 1452903	253	≤ 81338368
62	≤ 494	126	≤ 27638	190	≤ 1547213	254	> 81338368
63	≤ 526	127	≤ 29431	191	≤ 1647644	255	Reserved

6.1.3.2 C-RNTI MAC CE

The C-RNTI MAC CE is identified by MAC subheader with LCID as specified in Table 6.2.1-2.

It has a fixed size and consists of a single field defined as follows (Figure 6.1.3.2-1):

– C-RNTI: This field contains the C-RNTI of the MAC entity. The length of the field is 16 bits.

Figure 6.1.3.2-1: C-RNTI MAC CE

6.1.3.3 UE Contention Resolution Identity MAC CE

The UE Contention Resolution Identity MAC CE is identified by MAC subheader with LCID as specified in Table 6.2.1-1.

It has a fixed 48-bit size and consists of a single field defined as follows (Figure 6.1.3.3-1):

– UE Contention Resolution Identity: This field contains the UL CCCH SDU. If the UL CCCH SDU is longer than 48 bits, this field contains the first 48 bits of the UL CCCH SDU.

Figure 6.1.3.3-1: UE Contention Resolution Identity MAC CE

6.1.3.4 Timing Advance Command MAC CE

The Timing Advance Command MAC CE is identified by MAC subheader with LCID as specified in Table 6.2.1-1.

It has a fixed size and consists of a single octet defined as follows (Figure 6.1.3.4-1):

– TAG Identity (TAG ID): This field indicates the TAG Identity of the addressed TAG. The TAG containing the SpCell has the TAG Identity 0. The length of the field is 2 bits;

– Timing Advance Command: This field indicates the index value T_A (0, 1, 2… 63) used to control the amount of timing adjustment that MAC entity has to apply (as specified in TS 38.213 [6]). The length of the field is 6 bits.

Figure 6.1.3.4-1: Timing Advance Command MAC CE

6.1.3.4a Absolute Timing Advance Command MAC CE

The Absolute Timing Advance Command MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-1b.

It has a fixed size and consists of two octets defined as follows (Figure 6.1.3.4a-1):

– Timing Advance Command: This field indicates the index value TA used to control the amount of timing adjustment that the MAC entity has to apply in TS 38.213 [6]. The size of the field is 12 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.4a-1: Absolute Timing Advance Command MAC CE

6.1.3.5 DRX Command MAC CE

The DRX Command MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1.

It has a fixed size of zero bits.

6.1.3.6 Long DRX Command MAC CE

The Long DRX Command MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1.

It has a fixed size of zero bits.

6.1.3.7 Configured Grant Confirmation MAC CE

The Configured Grant Confirmation MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-2.

It has a fixed size of zero bits.

6.1.3.8 Single Entry PHR MAC CE

The Single Entry PHR MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-2.

It has a fixed size and consists of two octets defined as follows (figure 6.1.3.8-1):

– R: Reserved bit, set to 0;

– P: If mpe-Reporting-FR2 is configured and the Serving Cell operates on FR2, the MAC entity shall set this field to 0 if the applied P-MPR value, to meet MPE requirements, as specified in TS 38.101-2 [15], is less than P-MPR_00 as specified in TS 38.133 [11] and to 1 otherwise. If mpe-Reporting-FR2 is not configured or the Serving Cell operates on FR1, this field indicates whether power backoff is applied due to power management (as allowed by P-MPR_c as specified in TS 38.101-1 [14], TS 38.101-2 [15], and TS 38.101-3 [16]). The MAC entity shall set the P field to 1 if the corresponding P_CMAX,f,c field would have had a different value if no power backoff due to power management had been applied;

– P_CMAX,f,c: This field indicates the P_CMAX,f,c (as specified in TS 38.213 [6]) used for calculation of the preceding PH field. The reported P_CMAX,f,c and the corresponding nominal UE transmit power levels are shown in Table 6.1.3.8-2 (the corresponding measured values in dBm are specified in TS 38.133 [11]);

– MPE: If mpe-Reporting-FR2 is configured, and the Serving Cell operates on FR2, and if the P field is set to 1, this field indicates the applied power backoff to meet MPE requirements, as specified in TS 38.101-2 [15]. This field indicates an index to Table 6.1.3.8-3 and the corresponding measured values of P-MPR levels in dB are specified in TS 38.133 [11]. The length of the field is 2 bits. If mpe-Reporting-FR2 is not configured, or if the Serving Cell operates on FR1, or if the P field is set to 0, R bits are present instead.

Figure 6.1.3.8-1: Single Entry PHR MAC CE

Table 6.1.3.8-1: Power Headroom levels for PHR

PH	Power Headroom Level
0	POWER_HEADROOM_0
1	POWER_HEADROOM_1
2	POWER_HEADROOM_2
3	POWER_HEADROOM_3
…	…
60	POWER_HEADROOM_60
61	POWER_HEADROOM_61
62	POWER_HEADROOM_62
63	POWER_HEADROOM_63

Table 6.1.3.8-2: Nominal UE transmit power level for PHR

P_CMAX,f,c	Nominal UE transmit power level
0	PCMAX_C_00
1	PCMAX_C_01
2	PCMAX_C_02
…	…
61	PCMAX_C_61
62	PCMAX_C_62
63	PCMAX_C_63

Table 6.1.3.8-3: Effective power reduction for MPE P-MPR

MPE	Measured P-MPR value
0	P-MPR_00
1	P-MPR_01
2	P-MPR_02
3	P-MPR_03

6.1.3.9 Multiple Entry PHR MAC CE

The Multiple Entry PHR MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-2.

It has a variable size, and includes the bitmap, a Type 2 PH field and an octet containing the associated P_CMAX,f,c field (if reported) for SpCell of the other MAC entity, a Type 1 PH field and an octet containing the associated P_CMAX,f,c field (if reported) for the PCell. It further includes, in ascending order based on the ServCellIndex, one or multiple of Type X PH fields and octets containing the associated P_CMAX,f,c fields (if reported) for Serving Cells other than PCell indicated in the bitmap. X is either 1 or 3 according to TS 38.213 [6] and TS 36.213 [17].

The presence of Type 2 PH field for SpCell of the other MAC entity is configured by phr-Type2OtherCell with value true.

A single octet bitmap is used for indicating the presence of PH per Serving Cell when the highest ServCellIndex of Serving Cell with configured uplink is less than 8, otherwise four octets are used.

The MAC entity determines whether PH value for an activated Serving Cell is based on real transmission or a reference format by considering the configured grant(s) and downlink control information which has been received until and including the PDCCH occasion in which the first UL grant for a new transmission that can accommodate the MAC CE for PHR as a result of LCP as defined in clause 5.4.3.1 is received since a PHR has been triggered if the PHR MAC CE is reported on an uplink grant received on the PDCCH or until the first uplink symbol of PUSCH transmission minus PUSCH preparation time as defined in clause 7.7 of TS 38.213 [6] if the PHR MAC CE is reported on a configured grant.

For a band combination in which the UE does not support dynamic power sharing, the UE may omit the octets containing Power Headroom field and P_CMAX,f,c field for Serving Cells in the other MAC entity except for the PCell in the other MAC entity and the reported values of Power Headroom and P_CMAX,f,c for the PCell are up to UE implementation.

The PHR MAC CEs are defined as follows:

– C_i: This field indicates the presence of a PH field for the Serving Cell with ServCellIndex i as specified in TS 38.331 [5]. The C_i field set to 1 indicates that a PH field for the Serving Cell with ServCellIndex i is reported. The C_i field set to 0 indicates that a PH field for the Serving Cell with ServCellIndex i is not reported;

– R: Reserved bit, set to 0;

– V: This field indicates if the PH value is based on a real transmission or a reference format. For Type 1 PH, the V field set to 0 indicates real transmission on PUSCH and the V field set to 1 indicates that a PUSCH reference format is used. For Type 2 PH, the V field set to 0 indicates real transmission on PUCCH and the V field set to 1 indicates that a PUCCH reference format is used. For Type 3 PH, the V field set to 0 indicates real transmission on SRS and the V field set to 1 indicates that an SRS reference format is used. Furthermore, for Type 1, Type 2, and Type 3 PH, the V field set to 0 indicates the presence of the octet containing the associated P_CMAX,f,c field and the MPE field, and the V field set to 1 indicates that the octet containing the associated P_CMAX,f,c field and the MPE field is omitted;

– Power Headroom (PH): This field indicates the power headroom level. The length of the field is 6 bits. The reported PH and the corresponding power headroom levels are shown in Table 6.1.3.8-1 (the corresponding measured values in dB for the NR Serving Cell are specified in TS 38.133 [11] while the corresponding measured values in dB for the E-UTRA Serving Cell are specified in TS 36.133 [12]);

– P_CMAX,f,c: If present, this field indicates the P_CMAX,f,c (as specified in TS 38.213 [6]) for the NR Serving Cell and the P_CMAX,c or P̃_CMAX,c (as specified in TS 36.213 [17]) for the E-UTRA Serving Cell used for calculation of the preceding PH field. The reported P_CMAX,f,c and the corresponding nominal UE transmit power levels are shown in Table 6.1.3.8-2 (the corresponding measured values in dBm for the NR Serving Cell are specified in TS 38.133 [11] while the corresponding measured values in dBm for the E-UTRA Serving Cell are specified in TS 36.133 [12]);

Figure 6.1.3.9-1: Multiple Entry PHR MAC CE with the highest ServCellIndex of Serving Cell with configured uplink is less than 8

Figure 6.1.3.9-2: Multiple Entry PHR MAC CE with the highest ServCellIndex of Serving Cell with configured uplink is equal to or higher than 8

6.1.3.10 SCell Activation/Deactivation MAC CEs

The SCell Activation/Deactivation MAC CE of one octet is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a fixed size and consists of a single octet containing seven C-fields and one R-field. The SCell Activation/Deactivation MAC CE with one octet is defined as follows (Figure 6.1.3.10-1).

The SCell Activation/Deactivation MAC CE of four octets is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a fixed size and consists of four octets containing 31 C-fields and one R-field. The SCell Activation/Deactivation MAC CE of four octets is defined as follows (Figure 6.1.3.10-2).

– C_i: If there is an SCell configured for the MAC entity with SCellIndex i as specified in TS 38.331 [5], this field indicates the activation/deactivation status of the SCell with SCellIndex i, else the MAC entity shall ignore the C_i field. The C_i field is set to 1 to indicate that the SCell with SCellIndex i shall be activated. The C_i field is set to 0 to indicate that the SCell with SCellIndex i shall be deactivated;

– R: Reserved bit, set to 0.

Figure 6.1.3.10-1: SCell Activation/Deactivation MAC CE of one octet

Figure 6.1.3.10-2: SCell Activation/Deactivation MAC CE of four octets

NOTE: If UE receives the SCell Activation/Deactivation MAC CE for an SCell configured with TRS for fast activation of the SCell, such TRS is not used for the corresponding SCell.

6.1.3.11 Duplication Activation/Deactivation MAC CE

The Duplication Activation/Deactivation MAC CE of one octet is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a fixed size and consists of a single octet containing eight D-fields. The Duplication Activation/Deactivation MAC CE is defined, for a MAC entity, as follows (Figure 6.1.3.11-1).

– D_i: This field indicates the activation/deactivation status of the PDCP duplication of DRB i where i is the ascending order of the DRB ID among the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity. The D_i field is set to 1 to indicate that the PDCP duplication of DRB i shall be activated. The D_i field is set to 0 to indicate that the PDCP duplication of DRB i shall be deactivated.

Figure 6.1.3.11-1: Duplication Activation/Deactivation MAC CE

NOTE: The Duplication Activation/Deactivation MAC CE is not used if a DRB is configured with more than two RLC entities, i.e. with moreThanTwoRLC-DRB.

6.1.3.12 SP CSI-RS/CSI-IM Resource Set Activation/Deactivation MAC CE

The SP CSI-RS/CSI-IM Resource Set Activation/Deactivation MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a variable size and consists of the following fields:

– A/D: This field indicates whether to activate or deactivate indicated SP CSI-RS and CSI-IM resource set(s). The field is set to 1 to indicate activation, otherwise it indicates deactivation;

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– BWP ID: This field indicates a DL BWP for which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9]. The length of the BWP ID field is 2 bits;

– SP CSI-RS resource set ID: This field contains an index of NZP-CSI-RS-ResourceSet containing Semi Persistent NZP CSI-RS resources, as specified in TS 38.331 [5], indicating the Semi Persistent NZP CSI-RS resource set, which shall be activated or deactivated. The length of the field is 6 bits;

– IM: This field indicates the presence of the octet containing SP CSI-IM resource set ID field. If the IM field is set to 1, the octet containing SP CSI-IM resource set ID field is present. If IM field is set to 0, the octet containing SP CSI-IM resource set ID field is not present;

– SP CSI-IM resource set ID: This field contains an index of CSI-IM-ResourceSet containing Semi Persistent CSI-IM resources, as specified in TS 38.331 [5], indicating the Semi Persistent CSI-IM resource set, which shall be activated or deactivated. The length of the field is 6 bits;

– TCI State ID_i: This field contains TCI-StateId, as specified in TS 38.331 [5], of a TCI State, which is used as QCL source for the resource within the Semi Persistent NZP CSI-RS resource set indicated by SP CSI-RS resource set ID field. TCI State ID₀ indicates TCI State for the first resource within the set, TCI State ID₁ for the second one and so on. The length of the field is 7 bits. If the A/D field is set to 0, the octets containing TCI State ID field(s) are not present;

– R: Reserved bit, set to 0.

Figure 6.1.3.12-1: SP CSI-RS/CSI-IM Resource Set Activation/Deactivation MAC CE

6.1.3.13 Aperiodic CSI Trigger State Subselection MAC CE

The Aperiodic CSI Trigger State Subselection MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a variable size consisting of following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– T_i: This field indicates the selection status of the Aperiodic Trigger States configured within aperiodicTriggerStateList, as specified in TS 38.331 [5]. T₀ refers to the first trigger state within the list, T₁ to the second one and so on. If the list does not contain entry with index i, MAC entity shall ignore the T_i field. The T_i field is set to 1 to indicate that the Aperiodic Trigger State i shall be mapped to the codepoint of the DCI CSI request field, as specified in TS 38.214 [7]. The codepoint to which the Aperiodic Trigger State is mapped is determined by its ordinal position among all the Aperiodic Trigger States with T_i field set to 1, i.e. the first Aperiodic Trigger State with T_i field set to 1 shall be mapped to the codepoint value 1, second Aperiodic Trigger State with T_i field set to 1 shall be mapped to the codepoint value 2 and so on. The maximum number of mapped Aperiodic Trigger States is 63;

– R: Reserved bit, set to 0.

Figure 6.1.3.13-1: Aperiodic CSI Trigger State Subselection MAC CE

6.1.3.14 TCI States Activation/Deactivation for UE-specific PDSCH MAC CE

The TCI States Activation/Deactivation for UE-specific PDSCH MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a variable size consisting of following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits. If the indicated Serving Cell is configured as part of a simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2 as specified in TS 38.331 [5], this MAC CE applies to all the Serving Cells configured in the set simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2, respectively;

– T_i: If there is a TCI state with TCI-StateId i as specified in TS 38.331 [5], this field indicates the activation/deactivation status of the TCI state with TCI-StateId i, otherwise MAC entity shall ignore the T_i field. The T_i field is set to 1 to indicate that the TCI state with TCI-StateId i shall be activated and mapped to the codepoint of the DCI Transmission Configuration Indication field, as specified in TS 38.214 [7]. The T_i field is set to 0 to indicate that the TCI state with TCI-StateId i shall be deactivated and is not mapped to the codepoint of the DCI Transmission Configuration Indication field. The codepoint to which the TCI State is mapped is determined by its ordinal position among all the TCI States with T_i field set to 1, i.e. the first TCI State with T_i field set to 1 shall be mapped to the codepoint value 0, second TCI State with T_i field set to 1 shall be mapped to the codepoint value 1 and so on. The maximum number of activated TCI states is 8. The activated TCI states can be associated with at most one PCI different from the Serving Cell PCI at a time;

– CORESET Pool ID: This field indicates that mapping between the activated TCI states and the codepoint of the DCI Transmission Configuration Indication set by field T_i is specific to the ControlResourceSetId configured with CORESET Pool ID as specified in TS 38.331 [5]. This field set to 1 indicates that this MAC CE shall be applied for the DL transmission scheduled by CORESET with the CORESET pool ID equal to 1, otherwise, this MAC CE shall be applied for the DL transmission scheduled by CORESET pool ID equal to 0. If the coresetPoolIndex is not configured for any CORESET, MAC entity shall ignore the CORESET Pool ID field in this MAC CE when receiving the MAC CE. If the Serving Cell in the MAC CE is configured in a cell list that contains more than one Serving Cell, the CORSET Pool ID field shall be ignored when receiving the MAC CE.

Figure 6.1.3.14-1: TCI States Activation/Deactivation for UE-specific PDSCH MAC CE

6.1.3.15 TCI State Indication for UE-specific PDCCH MAC CE

The TCI State Indication for UE-specific PDCCH MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a fixed size of 16 bits with following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits. If the indicated Serving Cell is configured as part of a simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2 as specified in TS 38.331 [5], this MAC CE applies to all theServing Cells in the set simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2, respectively;

– CORESET ID: This field indicates a Control Resource Set identified with ControlResourceSetId as specified in TS 38.331 [5], for which the TCI State is being indicated. In case the value of the field is 0, the field refers to the Control Resource Set configured by controlResourceSetZero as specified in TS 38.331 [5]. The length of the field is 4 bits;

– TCI State ID: This field indicates the TCI state identified by TCI-StateId as specified in TS 38.331 [5] applicable to the Control Resource Set identified by CORESET ID field. If the field of CORESET ID is set to 0, this field indicates a TCI-StateId for a TCI state of the first 64 TCI-states configured by tci-StatesToAddModList and tci-StatesToReleaseList in the PDSCH-Config in the active BWP. If the field of CORESET ID is set to the other value than 0, this field indicates a TCI-StateId configured by tci-StatesPDCCH-ToAddList and tci-StatesPDCCH-ToReleaseList in the controlResourceSet identified by the indicated CORESET ID. The length of the field is 7 bits.

Figure 6.1.3.15-1: TCI State Indication for UE-specific PDCCH MAC CE

6.1.3.16 SP CSI reporting on PUCCH Activation/Deactivation MAC CE

The SP CSI reporting on PUCCH Activation/Deactivation MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a fixed size of 16 bits with following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– BWP ID: This field indicates a UL BWP for which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9]. The length of the BWP ID field is 2 bits;

– S_i: This field indicates the activation/deactivation status of the Semi-Persistent CSI report configuration within csi-ReportConfigToAddModList, as specified in TS 38.331 [5]. S₀ refers to the report configuration which includes PUCCH resources for SP CSI reporting in the indicated BWP and has the lowest CSI-ReportConfigId within the list with type set to semiPersistentOnPUCCH, S₁ to the report configuration which includes PUCCH resources for SP CSI reporting in the indicated BWP and has the second lowest CSI-ReportConfigId and so on. If the number of report configurations within the list with type set to semiPersistentOnPUCCH in the indicated BWP is less than i + 1, MAC entity shall ignore the S_i field. The S_i field is set to 1 to indicate that the corresponding Semi-Persistent CSI report configuration shall be activated. The S_i field is set to 0 to indicate that the corresponding Semi-Persistent CSI report configuration i shall be deactivated;

– R: Reserved bit, set to 0.

Figure 6.1.3.16-1: SP CSI reporting on PUCCH Activation/Deactivation MAC CE

6.1.3.17 SP SRS Activation/Deactivation MAC CE

The SP SRS Activation/Deactivation MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a variable size with following fields:

– A/D: This field indicates whether to activate or deactivate indicated SP SRS resource set. The field is set to 1 to indicate activation, otherwise it indicates deactivation;

– SRS Resource Set’s Cell ID: This field indicates the identity of the Serving Cell, which contains activated/deactivated SP SRS Resource Set. If the C field is set to 0, this field also indicates the identity of the Serving Cell which contains all resources indicated by the Resource ID_i fields. The length of the field is 5 bits;

– SRS Resource Set’s BWP ID: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], which contains activated/deactivated SP SRS Resource Set. If the C field is set to 0, this field also indicates the identity of the BWP which contains all resources indicated by the Resource ID_i fields. The length of the field is 2 bits;

– C: This field indicates whether the octets containing Resource Serving Cell ID field(s) and Resource BWP ID field(s) are present. If this field is set to 1, the octets containing Resource Serving Cell ID field(s) and Resource BWP ID field(s) are present, otherwise they are not present;

– SUL: This field indicates whether the MAC CE applies to the NUL carrier or SUL carrier configuration. This field is set to 1 to indicate that it applies to the SUL carrier configuration, and it is set to 0 to indicate that it applies to the NUL carrier configuration;

– SP SRS Resource Set ID: This field indicates the SP SRS Resource Set ID identified by SRS-ResourceSetId as specified in TS 38.331 [5], which is to be activated or deactivated. The length of the field is 4 bits;

– F_i: This field indicates the type of a resource used as a spatial relationship for SRS resource within SP SRS Resource Set indicated with SP SRS Resource Set ID field. F₀ refers to the first SRS resource within the resource set, F₁ to the second one and so on. The field is set to 1 to indicate NZP CSI-RS resource index is used, and it is set to 0 to indicate either SSB index or SRS resource index is used. The length of the field is 1 bit. This field is only present if MAC CE is used for activation, i.e. the A/D field is set to 1;

– Resource ID_i: This field contains an identifier of the resource used for spatial relationship derivation for SRS resource i. Resource ID₀ refers to the first SRS resource within the resource set, Resource ID₁ to the second one and so on. If F_i is set to 0, and the first bit of this field is set to 1, the remainder of this field contains SSB-Index as specified in TS 38.331 [5]. If F_i is set to 0, and the first bit of this field is set to 0, the remainder of this field contains SRS-ResourceId as specified in TS 38.331 [5]. The length of the field is 7 bits. This field is only present if MAC CE is used for activation, i.e. the A/D field is set to 1;

– Resource Serving Cell ID_i: This field indicates the identity of the Serving Cell on which the resource used for spatial relationship derivation for SRS resource i is located. The length of the field is 5 bits;

– Resource BWP ID_i: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], on which the resource used for spatial relationship derivation for SRS resource i is located. The length of the field is 2 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.17-1: SP SRS Activation/Deactivation MAC CE

6.1.3.18 PUCCH spatial relation Activation/Deactivation MAC CE

The PUCCH spatial relation Activation/Deactivation MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a fixed size of 24 bits with following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– PUCCH Resource ID: This field contains an identifier of the PUCCH resource ID identified by PUCCH-ResourceId as specified in TS 38.331 [5]. The length of the field is 7 bits;

– S_i: If, in PUCCH-Config in which the PUCCH Resource ID is configured, there is a PUCCH Spatial Relation Info with PUCCH-SpatialRelationInfoId as specified in TS 38.331 [5], configured for the uplink bandwidth part indicated by BWP ID field, S_i indicates the activation status of PUCCH Spatial Relation Info with PUCCH-SpatialRelationInfoId equal to i + 1, otherwise MAC entity shall ignore this field. The S_i field is set to 1 to indicate PUCCH Spatial Relation Info with PUCCH-SpatialRelationInfoId equal to i + 1 shall be activated. The S_i field is set to 0 to indicate PUCCH Spatial Relation Info with PUCCH-SpatialRelationInfoId equal to i + 1 shall be deactivated. Only a single PUCCH Spatial Relation Info can be active for a PUCCH Resource at a time;

– R: Reserved bit, set to 0.

Figure 6.1.3.18-1: PUCCH spatial relation Activation/Deactivation MAC CE

6.1.3.19 SP ZP CSI-RS Resource Set Activation/Deactivation MAC CE

The SP ZP CSI-RS Resource Set Activation/Deactivation MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.1-1. It has a fixed size of 16 bits with following fields:

– A/D: This field indicates whether to activate or deactivate indicated SP ZP CSI-RS resource set. The field is set to 1 to indicate activation, otherwise it indicates deactivation;

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– BWP ID: This field indicates a DL BWP for which the MAC CE applies as the codepoint value of the DCI bandwidth part indicator field as specified in TS 38.212 [9]. The length of the BWP ID field is 2 bits;

– SP ZP CSI-RS resource set ID: This field contains an index of sp-ZP-CSI-RS-ResourceSetsToAddModList, as specified in TS 38.331 [5], indicating the Semi Persistent ZP CSI-RS resource set, which shall be activated or deactivated. The length of the field is 4 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.19-1: SP ZP CSI-RS Resource Set Activation/Deactivation MAC CE

6.1.3.20 Recommended bit rate MAC CE

The Recommended bit rate MAC CE is identified by a MAC subheader with LCID as specified in Tables 6.2.1-1 and 6.2.1-2 for bit rate recommendation message from the gNB to the UE and bit rate recommendation query message from the UE to the gNB, respectively. It has a fixed size and consists of two octets defined as follows (Figure 6.1.3.20-1):

– LCID: This field indicates the identity of the logical channel for which the recommended bit rate or the recommended bit rate query is applicable. The length of the field is 6 bits;

– Uplink/Downlink (UL/DL): This field indicates whether the recommended bit rate or the recommended bit rate query applies to uplink or downlink. The length of the field is 1 bit. The UL/DL field set to 0 indicates downlink. The UL/DL field set to 1 indicates uplink;

– Bit Rate: This field indicates an index to Table 6.1.3.20-1. The length of the field is 6 bits. For bit rate recommendation the value indicates the recommended bit rate. For bit rate recommendation query the value indicates the desired bit rate;

– X: Bit rate multiplier. For UEs supporting recommended bit rate multiplier, when bitRateMultiplier is configured for the logical channel indicated by LCID field, X field set to 1 indicates the actual value of bit rate is the value corresponding to the index indicated by the Bit Rate field multiplied by bitRateMultiplier as specified in TS 38.331 [5].

– R: reserved bit, set to 0.

Figure 6.1.3.20-1: Recommended bit rate MAC CE

Table 6.1.3.20-1: Values (kbit/s) for Bit Rate field

Index	NR Recommended Bit Rate value [kbit/s]	Index	NR Recommended Bit Rate value [kbit/s]
0	Note 1	32	700
1	0	33	800
2	9	34	900
3	11	35	1000
4	13	36	1100
5	17	37	1200
6	21	38	1300
7	25	39	1400
8	29	40	1500
9	32	41	1750
10	36	42	2000
11	40	43	2250
12	48	44	2500
13	56	45	2750
14	72	46	3000
15	88	47	3500
16	104	48	4000
17	120	49	4500
18	140	50	5000
19	160	51	5500
20	180	52	6000
21	200	53	6500
22	220	54	7000
23	240	55	7500
24	260	56	8000
25	280	57	Reserved
26	300	58	Reserved
27	350	59	Reserved
28	400	60	Reserved
29	450	61	Reserved
30	500	62	Reserved
31	600	63	Reserved
Note 1: For bit rate recommendation message this index is used for indicating that no new recommendation on bit rate is given.

6.1.3.21 Timing Delta MAC CE

The Timing Delta MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-1b.

It has a fixed size and consists of two octets defined as follows (Figure 6.1.3.21-1):

– R: Reserved bit, set to 0;

– T_delta: This field indicates the value (0, 1, …, 2047) used to control the amount of timing adjustment that MAC entity indicates (as specified in TS 38.213 [6]). The length of the field is 11 bits.

Figure 6.1.3.21-1: Timing Delta MAC CE

6.1.3.22 Guard Symbols MAC CEs

The Guard Symbols MAC CEs (i.e. Provided Guard Symbols MAC CE and Desired Guard Symbols MAC CE) for Case-1 timing mode are identified by the MAC subheader with eLCID as specified in Table 6.2.1-1b for DL-SCH and in Table 6.2.1-2b for UL-SCH.

It has fixed size and consists of four octets defined as follows (Figure 6.1.3.22-1):

– R: Reserved bit, set to 0;

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– Sub-carrier spacing (SCS): This field indicates the subcarrier spacing used as reference for the guard spacing. The length of this field is 2bits. The values for the SCS field are shown in Table 6.1.3.22-2;

– Number of Guard Symbols (NmbGS_i): This field indicates the number of guard symbols for the switching scenario shown in Table 5.18.19-1. The number of guard symbols can take values within the range of 0 to 4. Higher values 5 to 7 are reserved.

Figure 6.1.3.22-1: Guard Symbols MAC CEs

Table 6.1.3.22-2: Subcarrier spacing for Guard Symbols MAC CEs

Subcarrier spacing	SCS value
15kHz	00
30kHz	01
60kHz	10
120kHz	11

6.1.3.23 BFR MAC CEs

The MAC CEs for BFR consists of either:

– BFR MAC CE; or

– Truncated BFR MAC CE.

The BFR MAC CE and Truncated BFR MAC CE are identified by a MAC subheader with LCID/eLCID as specified in Table 6.2.1-2 and Table 6.2.1-2b.

The BFR MAC CE and Truncated BFR MAC CE have a variable size. They include a bitmap and in ascending order based on the ServCellIndex, beam failure recovery information i.e. octets containing candidate beam availability indication (AC) for SCells indicated in the bitmap. For BFR MAC CE, a single octet bitmap is used when the highest ServCellIndex of this MAC entity’s SCell for which beam failure is detected and the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed is less than 8, otherwise four octets are used. A MAC PDU shall contain at most one BFR MAC CE.

For Truncated BFR MAC CE, a single octet bitmap is used for the following cases, otherwise four octets are used:

– the highest ServCellIndex of this MAC entity’s SCell for which beam failure is detected and the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed is less than 8; or

– beam failure is detected for SpCell (as specified in Clause 5.17) and the SpCell is to be indicated in a Truncated BFR MAC CE and the UL-SCH resources available for transmission cannot accommodate the Truncated BFR MAC CE with the four octets bitmap plus its subheader as a result of LCP.

The fields in the BFR MAC CEs are defined as follows:

– SP: This field indicates beam failure detection (as specified in clause 5.17) for the SpCell of this MAC entity. The SP field is set to 1 to indicate that beam failure is detected for SpCell only when BFR MAC CE or Truncated BFR MAC CE is to be included into a MAC PDU as part of Random Access Procedure (as specified in 5.1.3a and 5.1.4), otherwise, it is set to 0;

– C_i(BFR MAC CE): This field indicates beam failure detection (as specified in clause 5.17) and the presence of an octet containing the AC field for the SCell with ServCellIndex i as specified in TS 38.331 [5]. The C_i field set to 1 indicates that beam failure is detected, the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed, and the octet containing the AC field is present for the SCell with ServCellIndex i. The C_i field set to 0 indicates that the beam failure is either not detected or the beam failure is detected but the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has not been completed, and the octet containing the AC field is not present for the SCell with ServCellIndex i. The octets containing the AC field are present in ascending order based on the ServCellIndex;

– C_i(Truncated BFR MAC CE): This field indicates beam failure detection (as specified in clause 5.17) for the SCell with ServCellIndex i as specified in TS 38.331 [5]. The C_i field set to 1 indicates that beam failure is detected, the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed, and the octet containing the AC field for the SCell with ServCellIndex i may be present. The C_i field set to 0 indicates that the beam failure is either not detected or the beam failure is detected but the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has not been completed, and the octet containing the AC field is not present for the SCell with ServCellIndex i. The octets containing the AC field, if present, are included in ascending order based on the ServCellIndex. The number of octets containing the AC field included is maximised, while not exceeding the available grant size;

NOTE: The number of the octets containing the AC field in the Truncated BFR MAC CE can be zero.

– AC: This field indicates the presence of the Candidate RS ID field in this octet. If at least one of the SSBs with SS-RSRP above rsrp-ThresholdBFR amongst the SSBs in candidateBeamRSSCellList or the CSI-RSs with CSI-RSRP above rsrp-ThresholdBFR amongst the CSI-RSs in candidateBeamRSSCellList is available, the AC field is set to 1; otherwise, it is set to 0. If the AC field set to 1, the Candidate RS ID field is present. If the AC field set to 0, R bits are present instead;

– Candidate RS ID: This field is set to the index of an SSB with SS-RSRP above rsrp-ThresholdBFR amongst the SSBs in candidateBeamRSSCellList or to the index of a CSI-RS with CSI-RSRP above rsrp-ThresholdBFR amongst the CSI-RSs in candidateBeamRSSCellList. Index of an SSB or CSI-RS is the index of an entry in candidateBeamRSSCellList corresponding to the SSB or CSI-RS. Index 0 corresponds to the first entry in the candidateBeamRSSCellList, index 1 corresponds to the second entry in the list and so on. The length of this field is 6 bits.

– R: Reserved bit, set to 0.

Figure 6.1.3.23-1: BFR and Truncated BFR MAC CE with one octet C_i field

Figure 6.1.3.23-2: BFR and Truncated BFR MAC CE with four octets C_i field

6.1.3.24 Enhanced TCI States Activation/Deactivation for UE-specific PDSCH MAC CE

The Enhanced TCI States Activation/Deactivation for UE-specific PDSCH MAC CE is identified by a MAC PDU subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size consisting of following fields:

– C_i: This field indicates whether the octet containing TCI state ID_i,2 is present. If this field is set to 1, the octet containing TCI state ID_i,2 is present. If this field is set to 0, the octet containing TCI state ID_i,2 is not present;

– TCI state ID_i,j: This field indicates the TCI state identified by TCI-StateId as specified in TS 38.331 [5], where i is the index of the codepoint of the DCI Transmission configuration indication field as specified in TS 38.212 [9] and TCI state ID_i,j denotes the j^th TCI state indicated for the i^th codepoint in the DCI Transmission Configuration Indication field. The TCI codepoint to which the TCI States are mapped is determined by its ordinal position among all the TCI codepoints with sets of TCI state ID_i,j fields, i.e. the first TCI codepoint with TCI state ID_0,1 and TCI state ID_0,2 shall be mapped to the codepoint value 0, the second TCI codepoint with TCI state ID_1,1 and TCI state ID_1,2 shall be mapped to the codepoint value 1 and so on. The TCI state ID_i,2 is optional based on the indication of the C_i field. The maximum number of activated TCI codepoint is 8 and the maximum number of TCI states mapped to a TCI codepoint is 2.

– R: Reserved bit, set to 0.

Figure 6.1.3.24-1: Enhanced TCI States Activation/Deactivation for UE-specific PDSCH MAC CE

6.1.3.25 Enhanced PUCCH Spatial Relation Activation/Deactivation MAC CE

The Enhanced PUCCH Spatial Relation Activation/Deactivation MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size with following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– BWP ID: This field indicates a UL BWP for which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9]. The length of the BWP ID field is 2 bits;

– PUCCH Resource ID: This field contains an identifier of the PUCCH resource ID identified by PUCCH-ResourceId as specified in TS 38.331 [5], which is to be activated with a spatial relation indicated by Spatial Relation Info ID field in the subsequent octet. The length of the field is 7 bits. If the indicated PUCCH Resource ID is included in a PUCCH Resource Group (configured via resourceGroupToAddModList as specified in TS 38.331 [5]) of the indicated UL BWP, no other PUCCH Resources within the same PUCCH Resource group are indicated in the MAC CE, and this MAC CE applies to all the PUCCH Resources in the PUCCH Resource group;

– Spatial Relation Info ID: This field contains PUCCH-SpatialRelationInfoId – 1 where PUCCH-SpatialRelationInfoId is the identifier of the PUCCH Spatial Relation Info in PUCCH-Config in which the PUCCH Resource ID is configured, as specified in TS 38.331 [5]. The length of the field is 6 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.25-1: Enhanced PUCCH spatial relation Activation/Deactivation MAC CE

6.1.3.26 Enhanced SP/AP SRS Spatial Relation Indication MAC CE

The Enhanced SP/AP SRS Spatial Relation Indication MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size with following fields:

– A/D: This field indicates whether to activate or deactivate indicated SP SRS resource set. The field is set to 1 to indicate activation, otherwise it indicates deactivation. If the indicated SRS resource set ID is for the AP SRS resource set, MAC entity shall ignore this field;

– SRS Resource Set’s Cell ID: This field indicates the identity of the Serving Cell, which contains the indicated SP/AP SRS Resource Set. If the C field is set to 0, this field also indicates the identity of the Serving Cell which contains all resources indicated by the Resource ID_i fields. The length of the field is 5 bits;

– SRS Resource Set’s BWP ID: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], which contains the indicated SP/AP SRS Resource Set. If the C field is set to 0, this field also indicates the identity of the BWP which contains all resources indicated by the Resource ID_i fields. The length of the field is 2 bits;

– C: This field indicates whether the octets containing Resource Serving Cell ID field(s) and Resource BWP ID field(s) are present. If this field is set to 1, Resource Serving Cell ID field(s) and Resource BWP ID field(s) are present, otherwise they are not present so MAC entity shall ignore Resource Serving Cell ID field(s) and Resource BWP ID field(s);

– SRS Resource Set ID: This field indicates the SP/AP SRS Resource Set ID identified by SRS-ResourceSetId as specified in TS 38.331 [5]. The length of the field is 4 bits;

– F_i: This field indicates the type of a resource used as a spatial relationship for SRS resource within SP/AP SRS Resource Set indicated with SP/AP SRS Resource Set ID field. F₀ refers to the first SRS resource within the resource set, F₁ to the second one and so on. The field is set to 1 to indicate NZP CSI-RS resource index is used, and it is set to 0 to indicate either SSB index or SRS resource index is used. The length of the field is 1 bit. This field is only present if MAC CE is used for activation of SP SRS resource set, i.e. the A/D field is set to 1, or for AP SRS resource set;

– Resource ID_i: This field contains an identifier of the resource used for spatial relationship derivation for SRS resource i. Resource ID₀ refers to the first SRS resource within the resource set, Resource ID₁ to the second one and so on. If F_i is set to 0, the first bit of this field is always set to 0. If F_i is set to 0, and the second bit of this field is set to 1, the remainder of this field contains SSB-Index as specified in TS 38.331 [5]. If F_i is set to 0, and the second bit of this field is set to 0, the remainder of this field contains SRS-ResourceId as specified in TS 38.331 [5]. The length of the field is 8 bits. This field is only present if MAC CE is used for activation of SP SRS resource set, i.e. the A/D field is set to 1, or for AP SRS resource set;

– R: Reserved bit, set to 0.

Figure 6.1.3.26-1: Enhanced SP/AP SRS spatial relation Indication MAC CE

6.1.3.27 SRS Pathloss Reference RS Update MAC CE

The SRS Pathloss Reference RS Update MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a fixed size of 24 bits:

– Serving Cell ID: This field indicates the identity of the Serving Cell, which contains activated SRS Resource Set. The length of the field is 5 bits;

– BWP ID: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], which contains activated SRS Resource Set. The length of the field is 2 bits;

– SRS Resource Set ID: This field indicates the SRS Resource Set ID identified by SRS-ResourceSetId as specified in TS 38.331 [5]. The length of the field is 4 bits;

– Pathloss Reference RS ID: This field indicates the Pathloss Reference RS ID identified by srs-PathlossReferenceRS-Id as specified in TS 38.331 [5]. It updates the pathloss reference RS for an SRS-resource set indicated by SRS Resource Set ID field. The length of the field is 6 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.27-1: SRS Pathloss Reference RS Update MAC CE

6.1.3.28 PUSCH Pathloss Reference RS Update MAC CE

The PUSCH Pathloss Reference RS Update MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size and consists of the following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell, which contains activated PUSCH Pathloss Reference RS. The length of the field is 5 bits;

– BWP ID: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], which contains activated PUSCH Pathloss Reference RS. The length of the field is 2 bits;

– T: If the UE is configured with two SRS resources sets for codebook or non-codebook, as specified in TS 38.331 [5], in the indicated bandwidth part of the indicated Serving Cell, if this field is set to 0, SRI ID(s) to be updated are the ones associated with the first SRS resource set, and if is set to 1 the SRI ID(s) to be updated are the ones associated with the second SRS resource set. Otherwise, this field is a reserved bit set to 0;

– PUSCH Pathloss Reference RS ID: This field indicates the PUSCH Pathloss Reference RS ID identified by PUSCH-PathlossReferenceRS-Id as specified in TS 38.331 [5], which is to be updated in the SRI PUSCH power control mappings indicated by SRI ID fields indicated in the same MAC CE. The length of the field is 6 bits;

– C: This field indicates the presence of the additional SRI ID in the last octet of this MAC CE. If this field is set to 1, two SRI ID(s) are present in the last octet. Otherwise only one SRI ID (i.e. the first SRI ID) is present in the last octet;

– SRI ID: This field indicates the SRI PUSCH power control ID identified by sri-PUSCH-PowerControlId as specified in TS 38.331 [5]. The length of the field is 4 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.28-1: PUSCH Pathloss Reference RS Update MAC CE

6.1.3.29 Serving Cell Set based SRS Spatial Relation Indication MAC CE

The Serving Cell Set based SRS Spatial Relation indication MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size and consists of the following fields:

– SRS Resource’s Cell ID: This field indicates the identity of the Serving Cell, which contains the indicated SP/AP SRS Resource. If the C field is set to 0, this field also indicates the identity of the Serving Cell which contains all resources indicated by the Resource IDi fields. The length of the field is 5 bits. The indicated Serving Cell is configured as part of a simultaneousSpatial-UpdatedList1 or simultaneousSpatial-UpdatedList2 as specified in TS 38.331 [5], and this MAC CE applies to all the Serving Cells configured in the set simultaneousSpatial-UpdatedList1 or simultaneousSpatial-UpdatedList2, respectively;

– SRS Resource’s BWP ID: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], which contains the indicated AP/SP SRS Resource. If the C field is set to 0, this field also indicates the identity of the BWP which contains all resources indicated by the Resource ID_i fields. The length of the field is 2 bits;

– C: This field indicates whether the octets containing Resource Serving Cell ID field(s) and Resource BWP ID field(s) are present. If this field is set to 1, the Resource Serving Cell ID field(s) and Resource BWP ID field(s) are present, otherwise they are not present so MAC entity shall ignore Resource Serving Cell ID field(s) and Resource BWP ID field(s);

– SRS Resource ID_i: This field indicates the SP/AP SRS Resource ID identified by SRS-ResourceId as specified in TS 38.331 [5]. The length of the field is 6 bits;

– F_i: This field indicates the type of a resource used as a spatial relationship for SRS resource indicated with SRS Resource ID_i field. F₀ refers to the first SRS resource which is indicated SRS Resource ID₁, F₁ to the second one and so on. The field is set to 1 to indicate NZP CSI-RS resource index is used, and it is set to 0 to indicate either SSB index or SRS resource index is used. The length of the field is 1 bit;

– Resource Serving Cell ID_i: This field indicates the identity of the Serving Cell on which the resource used for spatial relationship derivation for SRS Resource ID_i is located. The length of the field is 5 bits;

– Resource BWP ID_i: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], on which the resource used for spatial relationship derivation for SRS Resource ID_i is located. The length of the field is 2 bits;

– Resource ID_i: This field contains an identifier of the resource used for spatial relationship derivation for SRS resource i. Resource ID₀ refers to the first SRS resource which is indicated SRS Resource ID₀, Resource ID₁ to the second one and so on. If F_i is set to 0, the first bit of this field is always set to 0. If F_i is set to 0, and the second bit of this field is set to 1, the remainder of this field contains SSB-Index as specified in TS 38.331 [5]. If F_i is set to 0, and the second bit of this field is set to 0, the remainder of this field contains SRS-ResourceId as specified in TS 38.331 [5]. The length of the field is 8 bits.

– R: Reserved bit, set to 0.

Figure 6.1.3.29-1: Serving Cell set based SRS Spatial Relation Indication MAC CE

6.1.3.30 LBT failure MAC CEs

The LBT failure MAC CE of one octet is identified by a MAC subheader with LCID as specified in Table 6.2.1-2. It has a fixed size and consists of a single octet containing 8 C-fields as follows (Figure 6.1.3.30-1).

The LBT failure MAC CE of four octets is identified by a MAC subheader with LCID as specified in Table 6.2.1-2. It has a fixed size and consists of four octets containing 32 C-fields as follows (Figure 6.1.3.30-2).

A single octet format is used when the highest ServCellIndex of this MAC entity’s Serving Cell for which LBT failure is detected is less than 8, otherwise four octets format is used.

– C_i: If there is a Serving Cell configured for the MAC entity with ServCellIndex i as specified in TS 38.331 [5] and if consistent LBT failure have been triggered and not cancelled in this Serving Cell, the field is set to 1, otherwise the field is set to 0.

Figure 6.1.3.30-1: LBT failure MAC CE of one octet

Figure 6.1.3.30-2: LBT failure MAC CE of four octets

6.1.3.31 Multiple Entry Configured Grant Confirmation MAC CE

The Multiple Entry Configured Grant Confirmation MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-2b. It has a fixed size and consists of a four octets containing 32 CG-fields. The Multiple Entry Configured Grant Confirmation MAC CE is defined as follows (Figure 6.1.3.31-1).

– CG_i: This field indicates whether PDCCH indicating activation or deactivation of configured uplink grant with ConfiguredGrantConfigIndexMAC i has been received. The CG_i field is set to 1 to indicate that PDCCH indicating activation or deactivation of type 2 configured uplink grant with ConfiguredGrantConfigIndexMAC i has been received. The CG_i field is set to 0 to indicate that PDCCH indicating activation or deactivation of type 2 configured uplink grant with ConfiguredGrantConfigIndexMAC i has not been received.

Figure 6.1.3.31-1: Multiple Entry Configured Grant Confirmation MAC CE

6.1.3.32 Duplication RLC Activation/Deactivation MAC CE

The Duplication RLC Activation/Deactivation MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a fixed size and consists of a single octet defined as follows (Figure 6.1.3.32-1).

– DRB ID: This field indicates the identity of DRB for which the MAC CE applies. The length of the field is 5 bits;

– RLC_i: This field indicates the activation/deactivation status of PDCP duplication for the RLC entity i where i is ascending order of logical channel ID of secondary RLC entities in the order of MCG and SCG, for the DRB. The RLC_i field is set to 1 to indicate that the PDCP duplication for the RLC entity i shall be activated. The RLC_i field is set to 0 to indicate that the PDCP duplication for the RLC entity i shall be deactivated.

Figure 6.1.3.32-1: Duplication RLC Activation/Deactivation MAC CE

6.1.3.33 Sidelink Buffer Status Report MAC CEs

Sidelink Buffer Status Report (SL-BSR) MAC CEs consist of either:

– SL-BSR format (variable size); or

– Truncated SL-BSR format (variable size).

SL-BSR and Truncated SL-BSR MAC control elements consist of one Destination Index field, one LCG ID field and one corresponding Buffer Size field per reported target group.

The SL-BSR formats are identified by MAC subheaders with LCIDs as specified in in Table 6.2.1-2.

The fields in the SL-BSR MAC CE are defined as follows:

– Destination Index: The Destination Index field identifies the destination. The length of this field is 5 bits. The value is set to one index corresponding to SL destination identity associated to same destination reported in sl-TxResourceReqList, sl-TxResourceReqListDisc and sl-TxResourceReqListCommRelay, if present. The value is indexed sequentially from 0 in the same ascending order of SL destination identity in sl-TxResourceReqList, sl-TxResourceReqListDisc and sl-TxResourceReqListCommRelay as specified in TS 38.331 [5]. When multiple lists are reported, the value is indexed sequentially across all the lists in the same order as presented in SidelinkUEInformaitonNR message;

– LCG ID: The Logical Channel Group ID field identifies the group of logical channel(s) whose SL buffer status is being reported. The length of the field is 3 bits;

Buffer Sizes of LCGs are included in decreasing order of the highest priority of the sidelink logical channel having data avaialble for transmission in each of the LCGs irrespective of the value of the Destination Index field.

NOTE: Void.

Figure 6.1.3.33-1: SL-BSR and Truncated SL-BSR MAC control element

6.1.3.34 Sidelink Configured Grant Confirmation MAC CE

The Sidelink Configured Grant Confirmation MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-2b. The Sidelink Configured Grant Confirmation MAC CE is defined as follows (Figure 6.1.3.34-1):

– C_i: If there is a configured grant Type 2 with sl-ConfigIndexCG i configured for the MAC entity as specified in TS 38.331 [5], this field indicates the confirmation to activation/deactivation of the configured grant with sl-ConfigIndexCG i, else the MAC entity shall ignore the C_i field. The C_i field is set to 1 to confirm that the configured grant with sl-ConfigIndexCG i shall be activated. The C_i field is set to 0 to indicate that the configured grant with sl-ConfigIndexCG i shall be deactivated.

Figure 6.1.3.34-1: Sidelink Configured Grant Confirmation MAC CE

6.1.3.35 Sidelink CSI Reporting MAC CE

The Sidelink CSI Reporting MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.4-1. The priority of the Sidelink CSI Reporting MAC CE is fixed to ‘1’. The Sidelink CSI Reporting MAC CE is defined as follows (Figure 6.1.3.35-1):

– RI: This field indicates the derived value of the Rank Indicator for sidelink CSI reporting as specified in clause 8.5 of TS 38.214 [7]. The length of the field is 1 bit;

– CQI: This field indicates the derived value of the Channel Quality Indicator for sidelink CSI reporting as specified in clause 8.5 of TS 38.214 [7]. The length of the field is 4 bit;

– R: Reserved bit, set to 0.

Figure 6.1.3.35-1: Sidelink CSI Reporting MAC CE

6.1.3.36 SP Positioning SRS Activation/Deactivation MAC CE

The SP Positioning SRS Activation/Deactivation MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size with following fields:

– A/D: This field indicates whether to activate or deactivate indicated SP Positioning SRS resource set. The field is set to 1 to indicate activation, otherwise it indicates deactivation;

– Positioning SRS Resource Set’s Cell ID: This field indicates the identity of the Serving Cell, which contains activated/deactivated SP Positioning SRS Resource Set. If the C field is set to 0, this field also indicates the identity of the Serving Cell which contains all resources indicated by the Spatial Relation for Resource ID_i fields, if present. The length of the field is 5 bits;

– Positioning SRS Resource Set’s BWP ID: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], which contains activated/deactivated SP Positioning SRS Resource Set. If the C field is set to 0, this field also indicates the identity of the BWP which contains all resources indicated by the Spatial Relation for Resource ID_i fields, if present. The length of the field is 2 bits;

– C: This field indicates whether the octets containing Resource Serving Cell ID field(s) and Resource BWP ID field(s) withn the field Spatial Relation for Resource ID_i are present, except for Spatial Relation Resource ID_i with DL-PRS or SSB. When A/D is set to 1, if this field is set to 1, the octets containing Resource Serving Cell ID field(s) and Resource BWP ID field(s) in the field Spatial Relation for Resource ID_i are present, otherwise if this field is set to 0, they are not present. When A/D is set to 0, this field is always set to 0 that they are not present;

– Positoining SRS Resource Set ID: This field indicates the SP Positioning SRS Resource Set identified by SRS-PosResourceSetId as specified in TS 38.331 [5], which is to be activated or deactivated. The length of the field is 4 bits;

– Spatial Relation for Resource ID_i: The field Spatial Relation for Resource ID_i is only present if MAC CE is used for activation, i.e. the A/D field is set to 1. M is the total number of Positioning SRS resource(s) configured under the SP Positioning SRS resource set indicated by the field Positioning SRS Resource Set ID. There are 4 types of Spatial Relation for Resource ID_i, which is indicated by the F (F₀ and F₁) field within. The fields within Spatial Relation for Resource ID_i are shown in Figures 6.1.3.36-2 to 6.1.3.36-5 for the 4 types of Spatial Relations for Resource ID_i;

– S: This field indicates whether the fields Spatial Relation for Resource ID_i for the positioning SRS resource i within the positioning SRS resource set are present. If the field is set to 1, the fields Spatial Relation for Resource IDi are present; otherwise, they are absent;

– R: Reserved bit, set to 0.

Figure 6.1.3.36-1: SP Positioning SRS Activation/Deactivation MAC CE

Figure 6.1.3.36-2: Spatial Relation for Resource ID_i with NZP CSI-RS

Figure 6.1.3.36-3: Spatial Relation for Resource ID_i with SSB

Figure 6.1.3.36-4: Spatial Relation for Resource ID_i with SRS

Figure 6.1.3.36-5: Spatial Relation for Resource ID_i with DL-PRS

The field Spatial Relation for Resource ID_i consists of the following fields:

– F₀: This field indicates the type of a resource used as a spatial relation for the i^th Positioning SRS resource within the Positioning SRS Resource Set indicated with the field Positioning SRS Resource Set ID. The field is set to 00 to indicate NZP CSI-RS resource index is used; it is set to 01 to indicate SSB index is used; it is set to 10 to indicate SRS resource index is used; it is set to 11 to indicate DL-PRS index is used. The length of the field is 2 bits;

– F₁: This field indicates the type of SRS resource used as spatial relation for the i^th Positioning SRS resource within the SP Positioning SRS Resource Set indicated with the field Positioning SRS Resource Set ID when F₀ is set to 10. The field is set to 0 to indicate SRS resource index SRS-ResourceId as defined in TS 38.331 [5] is used; the field is set to 1 to indicate Positioning SRS resource index SRS-PosResourceId as defined in TS 38.331 [5] is used;

– NZP CSI-RS Resource ID: This field contains an index of NZP-CSI-RS-ResourceID, as specified in TS 38.331 [5], indicating the NZP CSI-RS resource, which is used to derive the spatial relation for the positioning SRS. The length of the field is 8 bits;

– SSB index: This field contains an index of SSB SSB-Index as specified in TS 38.331 [5] and/or TS 37.355 [23]. The length of the field is 6 bits;

– PCI: This field contains physical cell identity PhysCellId as specified in TS 38.331 [5] and/or TS 37.355 [23]. The length of the field is 10 bits;

– SRS resource ID: When F₁ is set to 0, the field indicates an index for SRS resource SRS-ResourceId as defined in TS 38.331 [5]; When F₁ is set to 1, the field indicates an index for Positioning SRS resource SRS-PosResourceId as defined in TS 38.331 [5]. The length of the field is 5 bits representing the index from 0 to 31;

– E: This field indicates the extension of SRS resource ID as the MSB of SRS resource ID. The total length of the extended SRS resource ID is 6 bits. If E bit is set to 1, the SRS resource ID value is 5-bit SRS resource ID field + 32;

– DL-PRS Resource Set ID: This field contains an index for DL-PRS Resource Set nr-DL-PRS-ResourceSetId as defined in TS 37.355 [23]. The length of the field is 3 bits;

– DL-PRS Resource ID: This field contains an index for DL-PRS resource nr-DL-PRS-Resource-Id as defined in TS 37.355 [23]. The length of the field is 6 bits;

– DL-PRS ID: This field contains an identity for DL-PRS resource dl-PRS-ID as defined in TS 37.355 [23]. The length of the field is 8 bits;

– PI: This field indicates whether the field DL-PRS resource ID is present within the Spatial Relation for Resource ID_i with DL-PRS. If the field is set to 1, the octet containing the field DL-PRS resource ID is present; otherwise, the octet is omitted;

– SI: This field indicates whether the field SSB index is present within the Spatial Relation for Resource ID_i with SSB. If the field is set to 1, the octet containing the field SSB index is present; otherwise, the octet is omitted;

– Resource Serving Cell ID_i: This field indicates the identity of the Serving Cell on which the resource used for spatial relationship derivation for the i^th Positioning SRS resource is located. The length of the field is 5 bits;

– Resource BWP ID_i: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], on which the resource used for spatial relationship derivation for the i^th Positioning SRS resource is located. The length of the field is 2 bits.

6.1.3.37 Guard Symbols MAC CEs for Case-6 and Case-7 timing modes

The Guard Symbols MAC CEs (i.e. Provided Guard Symbols MAC CE and Desired Guard Symbols MAC CE) for Case-6 and Case-7 timing modes are identified by the MAC subheader with eLCIDs as specified in Table 6.2.1-1b for DL-SCH and in Table 6.2.1-2b for UL-SCH.

The MAC CEs have fixed size and consist of four octets each, defined as follows (Figure 6.1.3.37-1 and Figure 6.1.3.37-2):

– R: Reserved bit, set to 0;

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– Number of Guard Symbols (NmbGS_i): This field indicates the number of guard symbols for the switching scenario shown in Table 5.18.19-2.

Figure 6.1.3.37-1: Case-6 timing Guard Symbols MAC CEs

Figure 6.1.3.37-2: Case-7 timing Guard Symbols MAC CEs

6.1.3.38 Case-7 Timing advance offset MAC CE

The Case-7 Timing advance offset MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-1b.

The Case-7 Timing advance offset MAC CE is related to the Case-7 timing mode, has a fixed size and consists of two octets defined as follows (Figure 6.1.3.21-2):

– R: Reserved bit, set to 0;

– T_offset,2: This field indicates the value (-3072, -3071, …, 1023) used to control the amount of timing adjustment that MAC entity indicates (as specified in TS 38.213 [6]). The length of the field is 12 bits.

Figure 6.1.3.38-1: Case-7 Timing advance offset MAC CE

6.1.3.39 Case-6 Timing Request MAC CE

The Case-6 Timing Request MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-2b. This MAC CE is used by the IAB-MT node to inform its parent node whether Case-6 timing is required for simultaneous operation.

It has a fixed size of zero bits.

6.1.3.40 Positioning Measurement Gap Activation/Deactivation Request MAC CE

The Positioning Measurement Gap Activation/deactivation request MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-2b.

It has a fixed 8-bit size defined as follows (Figure 6.1.3.40-1):

– Positioning MG ID: This field indicates the identifier for the pre-configured positioning measurement gap. The length of the field is 4 bits;

– A/D: This field indicates the activation or deactivation of the Positioning Measurement Gap. The field is set to 1 to indicate activation, otherwise it indicates deactivation. The length of the field is 1 bit;

– R: Reserved bit, set to 0.

Figure 6.1.3.40-1: Positioning Measurement Gap Activation/Deactivation Request MAC CE

6.1.3.41 Positioning Measurement Gap Activation/Deactivation Command MAC CE

The Positioning Measurement Gap Activation/Deactivation Command MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-1b.

It has a fixed 8-bit size defined as follows (Figure 6.1.3.41-1):

– Positioning MG ID: This field indicates the identifier for the preconfigured positioning measurement gap. The length of the field is 4 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.41-1: Positioning Measurement Gap Activation/Deactivation Command MAC CE

6.1.3.42 PPW Activation/Deactivation Command MAC CE

The PPW Activation/Deactivation Command MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-1b.

It has variable size defined as follows (Figure 6.1.3.42-1):

– numEntry: This field indicates the number of entries N-1 in the MAC CE. 00 indicates that N equals to 2; 01 indicates that N equals to 3 and so on. The length of the field is 2 bits;

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– PPW ID: This field indicates the PPW configured on active DL BWP of the Serving Cell identified by the above Serving Cell ID. Index 0 corresponds to the first entry within the list of the PPW configuration in this BWP, index 1 corresponds to the second entry in the list and so on. The length of the field is 2 bits;

– A/D: This field indicates the activation or deactivation of the PPW. The field is set to 1 to indicate activation, otherwise it indicates deactivation. The length of the field is 1 bit;

– R: Reserved bit, set to 0.

Figure 6.1.3.42-1: PPW Activation/Deactivation Command MAC CE

6.1.3.43 Enhanced BFR MAC CEs

The Enhanced MAC CEs for BFR consists of either:

– Enhanced BFR MAC CE; or

– Truncated Enhanced BFR MAC CE.

The Enhanced BFR MAC CE and Truncated Enhanced BFR MAC CE are identified by a MAC subheader with eLCID/LCID as specified in Table 6.2.1-2 and Table 6.2.1-2b.

The Enhanced BFR MAC CE and Truncated Enhanced BFR MAC CE have a variable size. They include a SP field, C_i bitmap (single octet or four octets), S_j bitmap (0 to 4 octets), beam failure recovery information i.e. octets containing candidate beam availability indication (AC) for BFD-RS set(s) of SpCell configured with two BFD-RS sets, and in ascending order based on ServCellIndex, beam failure recovery information i.e. octets containing candidate beam availability indication (AC) for BFD-RS set(s) of SCells indicated in the C_i bitmap. For Enhanced BFR MAC CE, a single octet C_i bitmap is used when the highest ServCellIndex of this MAC entity’s SCell for which beam failure is detected for SCell or for at least one BFD-RS set of SCell and the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed is less than 8, otherwise four octets C_i bitmap is used. A MAC PDU shall contain at most one MAC CE for BFR.

For Truncated Enhanced BFR MAC CE, a single octet C_i bitmap is used for the following cases, otherwise four octets C_i bitmap is used:

– the highest ServCellIndex of this MAC entity’s SCell for which beam failure is detected for SCell or for at least one BFD-RS set of SCell and the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed is less than 8; or

– beam failure is detected for SpCell (as specified in Clause 5.17) not configured with two BFD-RS sets, and the SpCell is to be indicated in a Truncated Enhanced BFR MAC CE and the UL-SCH resources available for transmission cannot accommodate the Truncated Enhanced BFR MAC CE with the four octets C_i bitmap plus its subheader as a result of LCP; or

– Random Access procedure is initiated for beam failure recovery of both BFD-RS sets of SpCell (as specified in Clause 5.17) configured with two BFD-RS sets and the SpCell is to be indicated in a Truncated Enhanced BFR MAC CE and the UL-SCH resources available for transmission cannot accommodate the Truncated Enhanced BFR MAC CE with the four octets Ci bitmap plus its subheader as a result of LCP.

For Enhanced BFR MAC CE and Truncated Enhanced BFR MAC CE, a single octet S_k bitmap is included if the total number of Serving Cells configured with two BFD-RS sets for which SP/Ci field set to 1 is greater than 0 and less than 9; a two octets S_k bitmap is included if the total number of Serving Cells configured with two BFD-RS sets for which SP/C_i field set to 1 is greater than 8 and less than 17; a three octets S_k bitmap is included if the total number of Serving Cells configured with two BFD-RS sets for which SP/C_i field is set to 1 is greater than 16 and less than 25; a four octets S_k bitmap is included if the total number of Serving Cells configured with two BFD-RS sets for which SP/Ci field set to 1 is greater than 24; S_k bitmap is not included if the total number of Serving Cells configured with two BFD-RS sets for which SP/C_i field is set to 1 is zero.

For Truncated Enhanced BFR MAC CE, octet(s) containing the AC field, if any, are included for SpCell first, then one octet containing the AC field is included for SCell(s) (in ascending order of the ServCellIndex) and then the second octet containing the AC field, if any, is included for SCell(s) (in ascending order of the ServCellIndex), while not exceeding the available grant size. The number of the octets containing the AC field in the Truncated Enhanced BFR MAC CE can be zero.

The fields in the Enhanced BFR MAC CEs are defined as follows:

– SP (Enhanced BFR MAC CE): This field indicates beam failure detection (as specified in clause 5.17) for the SpCell of this MAC entity and the presence of octet(s) containing the AC field if the SpCell is configured with multiple BFD-RS sets. For the SpCell configured with two BFD-RS sets, this field set to 1 indicates that beam failure is detected for at least one BFD-RS set, the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed, and the octet(s) containing the AC field is present for the SpCell; otherwise, it is set to 0. The octet(s) containing the AC field for SpCell are included before those of SCell(s). For the SpCell not configured with multiple BFD-RS sets, the SP field is set to 1 to indicate that beam failure is detected for SpCell when Enhanced BFR MAC CE is to be included into a MAC PDU as part of Random Access Procedure (as specified in 5.1.3a and 5.1.4); otherwise, it is set to 0;

– SP (Truncated Enhanced BFR MAC CE): This field indicates beam failure detection (as specified in clause 5.17) for the SpCell of this MAC entity. For the SpCell configured with two BFD-RS sets, this field set to 1 indicates that beam failure is detected for at least one BFD-RS set, the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed, and the octet(s) containing the AC field may be present for the SpCell; otherwise, it is set to 0. For the SpCell not configured with multiple BFD-RS sets, the SP field is set to 1 to indicate that beam failure is detected for SpCell when Truncated Enhanced BFR MAC CE is to be included into a MAC PDU as part of Random Access Procedure (as specified in 5.1.3a and 5.1.4); otherwise, it is set to 0;

– C_i (Enhanced BFR MAC CE): This field indicates beam failure detection (as specified in clause 5.17) and the presence of octet(s) containing the AC field for the SCell with ServCellIndex i as specified in TS 38.331 [5]. The Ci field set to 1 indicates that beam failure is detected for at least one BFD-RS set, the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed, and the octet(s) containing the AC field is present for the SCell with ServCellIndex i. The Ci field set to 0 indicates that the beam failure is either not detected for any BFD-RS set or the beam failure is detected for at least one BFD-RS set but the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has not been completed, and the octets containing the AC field is not present for the SCell with ServCellIndex i. The octets containing the AC field are present in ascending order based on the ServCellIndex and are included after the octets containing the AC field for SpCell, if any;

– C_i (Truncated Enhanced BFR MAC CE): This field indicates beam failure detection (as specified in clause 5.17) for the SCell with ServCellIndex i as specified in TS 38.331 [5]. The C_i field set to 1 indicates that beam failure is detected for at least one BFD-RS set, the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed, and the octet(s) containing the AC field for the SCell with ServCellIndex i may be present. The C_i field set to 0 indicates that the beam failure is either not detected for any BFD-RS set or the beam failure is detected for at least one BFD-RS set but the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has not been completed, and the octet(s) containing the AC field is not present for the SCell with ServCellIndex i;

– S_k (Enhanced BFR MAC CE): This field corresponds to the k^th Serving Cell for which SP/C_i field is set to 1 and is configured with two BFD-RS sets. The Serving Cells for which SP/C_i field is set to 1 and are configured with two BFD-RS sets, are indexed sequentially starting with SpCell and followed by SCells in ascending order of ServCellIndex i. This field indicates whether beam failure is detected for one or both BFD-RS sets and presence of one or two octets containing the AC field of the Serving Cell. The S_k field set to 1 indicates that beam failure is detected for both the BFD-RS sets, the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed for both the BFD-RS sets, and the octets containing the AC field is present for both the BFD-RS sets, of the Serving Cell. The S_k field set to 0 indicates that beam failure is either detected for one of the BFD-RS sets and the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed or beam failure is detected for both the BFD-RS sets but the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has not been completed for both the BFD-RS sets, and the octet containing the AC field is present for only one BFD-RS set of the Serving Cell. The S_k field not mapped to any Serving Cell is set to 0;

– S_k (Truncated Enhanced BFR MAC CE): This field corresponds to the k^th Serving Cell for which SP/C_i field is set to 1 and is configured with two BFD-RS sets. The Serving Cells for which SP/C_i field is set to 1 and are configured with two BFD-RS sets, are indexed sequentially starting with SpCell and followed by SCells in ascending order of ServCellIndex i. This field indicates whether beam failure is detected for one or both BFD-RS sets of the Serving Cell. The S_k field set to 1 indicates that beam failure is detected for both the BFD-RS sets, the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed for both the BFD-RS sets, and the octet containing the AC field is present for zero, one or two BFD-RS sets of the Serving Cell. The S_k field set to 0 indicates that beam failure is either detected for one of the BFD-RS sets and the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has been completed or beam failure is detected for both the BFD-RS sets but the evaluation of the candidate beams according to the requirements as specified in TS 38.133 [11] has not been completed for both the BFD-RS sets or the octet containing the AC field is present for zero or one BFD-RS set of the Serving Cell. The S_k field not mapped to any Serving Cell is set to 0;

– AC: This field indicates the presence of the Candidate RS ID field in this octet. If at least one of the SSBs with SS-RSRP above rsrp-ThresholdBFR amongst the SSBs in list of candidate beams (i.e. candidateBeamRS-List-r16 for the SCell not configured with two BFD-RS sets, candidateBeamRS-List-r16 or candidateBeamRS-List2-r17 for Serving Cell configured with two BFD-RS sets) or the CSI-RSs with CSI-RSRP above rsrp-ThresholdBFR amongst the CSI-RSs in list of candidate beams is available, the AC field is set to 1; otherwise, it is set to 0. If the AC field set to 1, the Candidate RS ID field is present. If the AC field set to 0, R bits are present instead;

– ID: This field indicates the identity of the BFD-RS set. It is set to 0 if this octet corresponds to BFD-RS set one, failureDetectionSet1-r17. It is set to 1 if this octet corresponds to BFD-RS set two, failureDetectionSet2-r17. For the Serving cell not configured with two BFD-RS sets, this field is set to 0;

– Candidate RS ID: This field is set to the index of an SSB with SS-RSRP above rsrp-ThresholdBFR amongst the SSBs in list of candidate beams (i.e. candidateBeamRS-List-r16 for the SCell not configured with two BFD-RS sets, candidateBeamRS-List-r16 or candidateBeamRS-List2-r17 for Serving Cell configured with two BFD-RS sets) or to the index of a CSI-RS with CSI-RSRP above rsrp-ThresholdBFR amongst the CSI-RSs in the list of candidate beams. Index of an SSB or CSI-RS is the index of an entry in the list of candidate beams corresponding to the SSB or CSI-RS. Index 0 corresponds to the first entry in the list of candidate beams, index 1 corresponds to the second entry in the list and so on. The length of this field is 6 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.43-1: Enhanced BFR and Truncated Enhanced BFR MAC CE with one octet Ci field

Figure 6.1.3.43-2: Enhanced BFR and Truncated Enhanced BFR MAC CE with four octets Ci field

6.1.3.44 Enhanced TCI States Indication for UE-specific PDCCH MAC CE

The Enhanced TCI States Indication for UE-specific PDCCH MAC CE is identified by a MAC PDU subheader with eLCID as specified in Table 6.2.1-1b. It has a fixed size of 24 bits with following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits. If the indicated Serving Cell is configured as part of a simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2 as specified in TS 38.331 [5], this MAC CE applies to all theServing Cells in the set simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2, respectively;

– TCI state IDi: This field indicates the TCI state identified by TCI-StateId as specified in TS 38.331 [5] applicable to the Control Resource Set identified by CORESET ID field. If the field of CORESET ID is set to the other value than 0, this field indicates a TCI-StateId configured by tci-StatesPDCCH-ToAddList and tci-StatesPDCCH-ToReleaseList in the controlResourceSet identified by the indicated CORESET ID. The length of the field is 7 bits.

NOTE 1: The Enhanced TCI State Indication for UE specific PDCCH MAC CE is not applicable to any of the configured CORESETs in a BWP if the CORESETs are configured with different CORESETPoolindex values in the BWP.

NOTE 2: The Enhanced TCI State Indication for UE specific PDCCH MAC CE is applied only if sfnSchemePdcch is configured.

Figure 6.1.3.44-1: Enhanced TCI States Indication for UE-specific PDCCH MAC CE

6.1.3.45 PUCCH spatial relation Activation/Deactivation for multiple TRP PUCCH repetition MAC CE

The PUCCH Spatial Relation Activation/Deactivation for multiple TRP PUCCH repetition MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size with following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– C: This field indicates whether single or two spatial relation info(s) is activated for the indicated PUCCH Resource ID. If this field is set to 1, octet containing the second spatial relation info for the indicated PUCCH Resource is present. If this field is set to 0, octet containing the second spatial relation info for the indicated PUCCH Resource is not present;

– PUCCH Resource ID: This field contains an identifier of the PUCCH resource ID identified by PUCCH-ResourceId as specified in TS 38.331 [5], which is to be activated with a spatial relations indicated by Spatial Relation Info IDi fields in the subsequent octet(s). The length of the field is 7 bits. If the indicated PUCCH Resource ID is included in a PUCCH Resource Group (configured via resourceGroupToAddModList as specified in TS 38.331 [5]) of the indicated UL BWP, no other PUCCH Resources within the same PUCCH Resource group are indicated in the MAC CE, and this MAC CE applies to all the PUCCH Resources in the PUCCH Resource group;

– Spatial Relation Info IDi: This field contains PUCCH-SpatialRelationInfoId–r16 where PUCCH-SpatialRelationInfoId is the identifier of the PUCCH Spatial Relation Info in PUCCH-Config in which the PUCCH Resource ID is configured, as specified in TS 38.331 [5], where i is the index of the activated spatial relation info ID. The length of the field is 6 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.45-1: PUCCH spatial relation Activation/Deactivation for multiple TRP PUCCH repetition MAC CE

6.1.3.46 PUCCH Power Control Set Update for multiple TRP PUCCH repetition MAC CE

The PUCCH Power Control Set Update for multiple TRP PUCCH repetition MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size with following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– C: This field indicates whether single or two power control set(s) is activated for the indicated PUCCH Resource ID. If this field is set to 1, the second power control set index (i.e. Power Control Set ID1) for the indicated PUCCH Resource is present. If this field is set to 0, the second power control set index (i.e. Power Control Set ID1) for the indicated PUCCH Resource is not present;

– PUCCH Resource ID: This field contains an identifier of the PUCCH resource ID identified by PUCCH-ResourceId as specified in TS 38.331 [5], which is to be activated with a power control set(s) indicated by Power Control Set IDi fields in the subsequent octet. The length of the field is 7 bits. If the indicated PUCCH Resource ID is included in a PUCCH Resource Group (configured via resourceGroupToAddModList as specified in TS 38.331 [5]) of the indicated UL BWP, no other PUCCH Resources within the same PUCCH Resource group are indicated in the MAC CE, and this MAC CE applies to all the PUCCH Resources in the PUCCH Resource group;

– Power Control Set ID_i: This field contains PUCCH-PowerControlSetInfoId where PUCCH-PowerControlSetInfoId is the identifier of the PUCCH Power Control Set in PUCCH-Config in which the PUCCH Resource ID is configured, as specified in TS 38.331 [5], where i is the index of the power control set ID. The length of the field is 3 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.46-1: PUCCH power control set update for multiple TRP PUCCH repletion MAC CE

6.1.3.47 Unified TCI States Activation/Deactivation MAC CE

The Unified TCI States Activation/Deactivation MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size consisting of following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits. If the indicated Serving Cell is configured as part of a simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3 or simultaneousU-TCI-UpdateList4 as specified in TS 38.331 [5], this MAC CE applies to all theServing Cells in the set simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3 or simultaneousU-TCI-UpdateList4, respectively;

– DL BWP ID: This field indicates a DL BWP for which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9]. The length of the BWP ID field is 2 bits;

– UL BWP ID: This field indicates a UL BWP for which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9]. The length of the BWP ID field is 2 bits;

– P_i: This field indicates whether each TCI codepoint has multiple TCI states or single TCI state. If P_i field is set to 1, it indicates that i^th TCI codepoint includes the DL TCI state and the UL TCI state. If P_i field is set to 0, it indicates that i^th TCI codepoint includes only the DL/joint TCI state or the UL TCI state. The codepoint to which a TCI state is mapped is determined by its ordinal position among all the TCI state ID fields;

– D/U: This field indicate whether the TCI state ID in the same octet is for joint/downlink or uplink TCI state. If this field is set to 1, the TCI state ID in the same octet is for joint/downlink. If this field is set to 0, the TCI state ID in the same octet is for uplink;

– TCI state ID: This field indicates the TCI state identified by TCI-StateId as specified in TS 38.331 [5]. If D/U is set to 1, 7-bits length TCI state ID i.e. TCI-StateId as specified in TS 38.331 [5] is used. If D/U is set to 0, the most significant bit of TCI state ID is considered as the reserved bit and remainder 6 bits indicate the UL-TCIState-Id as specified in TS 38.331 [5]. The maximum number of activated TCI states is 16;

– R: Reserved bit, set to 0.

Figure 6.1.3.47-1: Unified TCI state activation/deactivation MAC CE

6.1.3.48 Enhanced Single Entry PHR MAC CE

The Enhanced Single Entry PHR MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-2b. It has a variable size with following fields:

– R: Reserved bit, set to 0;

– B_i: This field indicates whether the candidate beam information identified by Resource_i is present or not. If the B₁ field is set to 1, the first octet containing Resource₁ is present and if the B₂ field is set to 1, the second octet containing Resource₂ is present, and so on;

– P_i: If mpe-Reporting-FR2-r17 is configured and the Serving Cell operates on FR2, the MAC entity shall set this field to 0 if the applied P-MPR value, to meet MPE requirements, as specified in TS 38.101-2 [15], is less than P-MPR_00 as specified in TS 38.133 [11] and to 1 otherwise;

– MPE_i: If mpe-Reporting-FR2-r17 is configured, and the Serving Cell operates on FR2, and if the corresponding P_i field is set to 1, this field indicates the applied power backoff to meet MPE requirements, as specified in TS 38.101-2 [15]. This field indicates an index to Table 6.1.3.8-3 and the corresponding measured values of P-MPR levels in dB are specified in TS 38.133 [11]. The length of the field is 2 bits. If mpe-Reporting-FR2-r17 is not configured, or if the Serving Cell operates on FR1, or if the P_i field is set to 0, R bits are present instead;

– Resource_i: This field indicates the candidate beam identified by the number of entries in the corresponding mpe-ResourcePoolToAddModList as specified in TS 38.331 [5]. The length of this field 6 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.48-1: Enhanced Single Entry PHR MAC CE

6.1.3.49 Enhanced Multiple Entry PHR MAC CE

The Enhanced Multiple Entry PHR MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-2b. It has a variable size with following fields:

– C_i: This field indicates the presence of PH field(s) for the Serving Cell with ServCellIndex i as specified in TS 38.331 [5]. The C_i field set to 1 indicates that PH field(s) for the Serving Cell with ServCellIndex i is reported. The C_i field set to 0 indicates that a PH field for the Serving Cell with ServCellIndex i is not reported;

– R: Reserved bit, set to 0;

– B_i: This field indicates whether the candidate beam information identified by either Resource_i is present or not. If the B₁ field is set to 1, the first octet containing Resource₁ is present and if the B₂ field is set to 1, the second octet containing Resource₂ is present, and so on.

– MPE_i: If mpe-Reporting-FR2-r17 is configured, and the Serving Cell operates on FR2, and if the corresponding P i field is set to 1, this field indicates the applied power backoff to meet MPE requirements, as specified in TS 38.101-2 [15]. This field indicates an index to Table 6.1.3.8-3 and the corresponding measured values of P-MPR levels in dB are specified in TS 38.133 [11]. The length of the field is 2 bits. If mpe-Reporting-FR2-r17 is not configured, or if the Serving Cell operates on FR1, or if the P _i field is set to 0, R bits are present instead;

– Resource_i: This field indicates the candidate beam identified by by the number of entries in the corresponding mpe-ResourcePoolToAddModList as specified in TS 38.331 [5]. The length of this field 6 bits.

– R: Reserved bit, set to 0.

Figure 6.1.3.49-1: Enhanced Multiple Entry PHR MAC CE with the highest ServCellIndex of Serving Cell with configured uplink is less than 8

Figure 6.1.3.49-2: Enhanced Multiple Entry PHR MAC CE with the highest ServCellIndex of Serving Cell with configured uplink is equal to or higher than 8

6.1.3.50 Enhanced Single Entry PHR for multiple TRP MAC CE

The Enhanced Single Entry PHR for multiple TRP MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-2b.

The two PHs together with one P_CMAX,f,c for the Serving Cell are reported if UE is configured with twoPHRMode with the multiple TRP PUSCH repetition feature is configured.

It has a fixed size and consists of three octets defined as follows (Figure 6.1.3.50-1):

– R: Reserved bit, set to 0;

– Power Headroom i (PH i): This field indicates the power headroom level, where PH 1 is associated with the SRS-ResourceSet with a lower srs-ResourceSetId and PH 2 is associated with the SRS-ResourceSet with a higher srs-ResourceSetId. PH fields for a Serving Cell are included in ascending order based on i. The length of the field is 6 bits. The reported PH and the corresponding power headroom levels are shown in Table 6.1.3.8-1 (the corresponding measured values in dB are specified in TS 38.133 [11]);

– P: If mpe-Reporting-FR2 is configured and the Serving Cell operates on FR2, the MAC entity shall set this field to 0 if the applied P-MPR value, to meet MPE requirements, as specified in TS 38.101-2 [15], is less than P-MPR_00 as specified in TS 38.133 [11] and to 1 otherwise. If mpe-Reporting-FR2 is not configured or the Serving Cell operates on FR1, this field indicates whether power backoff is applied due to power management (as allowed by P-MPRc as specified in TS 38.101-1 [14], TS 38.101-2 [15], and TS 38.101-3 [16]). The MAC entity shall set the P field to 1 if the corresponding P_CMAX,f,c field would have had a different value if no power backoff due to power management had been applied;

– V: This field indicates if the PH value for the corresponding TRP is based on a real transmission or a reference format. For Type 1 PH, the V field set to 0 indicates real transmission on PUSCH and the V field set to 1 indicates that a PUSCH reference format is used;

Figure 6.1.3.50-1: Enhanced Single Entry PHR for multiple TRP MAC CE

6.1.3.51 Enhanced Multiple Entry PHR for multiple TRP MAC CE

The Enhanced Multiple Entry PHR for multiple TRP MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-2b.

It has a variable size, and includes the bitmaps, a Type 2 PH field and an octet containing the associated P_CMAX,f,c field (if reported) for SpCell of the other MAC entity, a Type 1 PH field and an octet containing the associated P_CMAX,f,c field (if reported) for the PCell. It further includes, in ascending order based on the ServCellIndex, one or multiple of Type X PH fields and octets containing the associated P_CMAX,f,c fields (if reported) for Serving Cells other than PCell indicated in the bitmap for indicating the presence of PH(s). X is either 1 or 3 according to TS 38.213 [6] and TS 36.213 [17].

The presence of Type 2 PH field for SpCell of the other MAC entity is configured by phr-Type2OtherCell with value true.

A single octet bitmap is used for indicating the presence of PH(s) per Serving Cell when the highest ServCellIndex of Serving Cell with configured uplink is less than 8, otherwise four octets are used.

The two PHs together with one P_CMAX,f,c for the Serving Cell configured with the multiple TRP PUSCH repetition feature is configured are reported if the MAC entity is configured with twoPHRMode.

The Enhanced Multiple Entry PHR for multiple TRP MAC CEs are defined as follows:

– R: Reserved bit, set to 0;

– V: This field indicates if the PH value is based on a real transmission or a reference format. For Type 1 PH, the V field set to 0 indicates real transmission on PUSCH and the V field set to 1 indicates that a PUSCH reference format is used. For Type 2 PH, the V field set to 0 indicates real transmission on PUCCH and the V field set to 1 indicates that a PUCCH reference format is used. For Type 3 PH, the V field set to 0 indicates real transmission on SRS and the V field set to 1 indicates that an SRS reference format is used. Furthermore, for Type 1, Type 2, and Type 3 PH, the V field set to 0 indicates the presence of the octet containing the associated P_CMAX,f,c field and the MPE field, and all of the V field(s) for the Serving Cell set to 1 indicates that the octet containing the associated P_CMAX,f,c field and the MPE field is omitted;

– P: If mpe-Reporting-FR2 is configured and the Serving Cell operates on FR2, the MAC entity shall set this field to 0 if the applied P-MPR value, to meet MPE requirements, as specified in TS 38.101-2 [15], is less than P-MPR_00 as specified in TS 38.133 [11] and to 1 otherwise. If mpe-Reporting-FR2 is not configured or the Serving Cell operates on FR1, this field indicates whether power backoff is applied due to power management (as allowed by P-MPRc as specified in TS 38.101-1 [14], TS 38.101-2 [15], and TS 38.101-3 [16]). The MAC entity shall set the P field to 1 if the corresponding P_CMAX,f,c field would have had a different value if no power backoff due to power management had been applied;

Figure 6.1.3.51-1: Enhanced Multiple Entry PHR for multiple TRP MAC CE with the highest ServCellIndex of Serving Cell with configured uplink is less than 8

Figure 6.1.3.51-2: Enhanced Multiple Entry PHR for multiple TRP MAC CE with the highest ServCellIndex of Serving Cell with configured uplink is equal to or higher than 8

6.1.3.52 Sidelink DRX Command MAC CE

The Sidelink DRX Command MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.4-1. The priority of the Sidelink DRX Command MAC CE is fixed to ‘1’.

It has a fixed size of zero bits.

SL DRX Command MAC CE is only supported in sidelink unicast.

6.1.3.53 Inter-UE Coordination Information MAC CE

The Inter-UE Coordination Information MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.4-1. The priority of the Inter-UE Coordination Information MAC CE is fixed to ‘1’. It has a variable size with following fields:

– RT: This field indicates the resource set type, i.e., preferred resource set or non-preferred resource set, as the codepoint value of the SCI format 2-C resourceSetType field as specified in TS 38.212 [9].

– RSL: This field indicates the location of reference slot, as the codepoint value of the SCI format 2-C referenceSlotLocation field as specified in TS 38.212 [9]. The length of the field is 17 bits. If the length of referenceSlotLocation field in SCI format 2-C as specified in TS 38.212 [9] is shorter than 17 bit, this field contains referenceSlotLocation field using the LSB bits;

– LSI_i: This field indicates lowest subchannel indices for the first resource location of each TRIV, as the codepoint value of the SCI format 2-C lowestIndices field as specified in TS 38.212 [9]. LSI₀ indicates lowest subchannel indices for the first resource location of TRIV within the first resource combination, LSI₁ indicates lowest subchannel indices for the first resource location of TRIV within the second resource combination and so on. The length of the field is 5 bits. If the length of lowestIndices field in SCI format 2-C as specified in TS 38.212 [9] is shorter than 5 bit, this field contains lowestIndices field using the LSB bits;

– RC_i: This field indicates resource combination, as the codepoint value of the SCI format 2-C resourceCombination field as specified in TS 38.212 [9]. RC₀ indicates the first resource combination, RC₁ indicates the second resource combination and so on. The length of the field is 26 bits. If the length of resourceCombination field in SCI format 2-C as specified in TS 38.212 [9] is shorter than 26 bit, this field contains resourceCombination field using the LSB bits;

– First resource location_i-1: This field indicates first resource location, as the codepoint value of the SCI format 2-C firstResourceLocation field as specified in TS 38.212 [9]. First Resource Location₀ indicates the first resource location for the second resource combination, First Resource Location₁ indicates the first resource location for the third resource combination and so on. The length of the field is 13 bits. If the length of firstResourceLocation field in SCI format 2-C as specified in TS 38.212 [9] is shorter than 13 bit, this field contains firstResourceLocation field using the LSB bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.53-1: Inter-UE Coordination Information MAC CE

6.1.3.54 Inter-UE Coordination Request MAC CE

The Inter-UE Coordination request MAC CE is identified by a MAC subheader with LCID as specified in Table 6.2.4-1. The priority of the Inter-UE Coordination Request MAC CE is fixed to ‘1’. It has a fixed size of 48 bits with following fields:

– RT: If the value of sl-DetermineResourceType (as specified in TS 38.331 [5] clause 6.3.5) is set to ueb, this field indicates the resource set type, i.e., preferred resource set or non-preferred resource set, as the codepoint value of the SCI format 2-C resourceSetType field as specified in TS 38.212 [9]. This field is ignored if the value of sl-DetermineResourceType is set to uea;

– RP: This field indicates the resource reservation period, as the codepoint value of the SCI format 2-C resourceReservationPeriod field as specified in TS 38.212 [9]. The length of the field is 4 bits. If the length of resourceReservationPeriod field in SCI format 2-C as specified in TS 38.212 [9] is shorter than 4 bit, this field contains resourceReservationPeriod field using the LSB bits;

– Priority: This field indicates the priority, as the codepoint value of the SCI format 2-C priority field as specified in TS 38.212 [9]. The length of the field is 3 bits;

– RSWL: This field indicates resource selection window location, as the codepoint value of the SCI format 2-C resourceSelectionWindowLocation field as specified in TS 38.212 [9]. The length of the field is 34 bits. If the length of resourceSelectionWindowLocation field in SCI format 2-C as specified in TS 38.212 [9] is shorter than 34 bit, this field contains resourceSelectionWindowLocation field using the LSB bits;

– Number of Subchannel: This field indicates the number of subchannels, as the codepoint value of the SCI format 2-C numberOfSubchannel field as specified in TS 38.212 [9]. The length of the field is 5 bits. If the length of numberOfSubchannel field in SCI format 2-C as specified in TS 38.212 [9] is shorter than 5 bit, this field contains numberOfSubchannel field using the LSB bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.54-1: Inter-UE Coordination Request MAC CE

6.1.3.55 Enhanced SCell Activation/Deactivation MAC CEs

The Enhanced SCell Activation/Deactivation MAC CE with one octet C_i field is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size and consists of seven C-fields, one R-field and zero or more TRS ID_j fields in ascending order based on the ScellIndex for SCells indicated by the C_i field(s) to be activated. The Enhanced SCell Activation/Deactivation MAC CE of with one octet C_i field is defined as follows (Figure 6.1.3.55-1).

The Enhanced SCell Activation/Deactivation MAC CE with four octet C_i field is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size and consists of 31 C-fields, one R-field and zero or more TRS ID_j fields in ascending order based on the ScellIndex for SCells indicated by the C_i field(s) to be activated. The Enhanced SCell Activation/Deactivation MAC CE with four octet C_i field is defined as follows (Figure 6.1.3.55-2).

– C_i: If there is an SCell configured for the MAC entity with SCellIndex i as specified in TS 38.331 [5], this field indicates the activation/deactivation status of the SCell with SCellIndex i, else the MAC entity shall ignore the C_i field. The C_i field is set to 1 to indicate that the SCell with SCellIndex i shall be activated and that a TRS ID_j field is included for the SCell. The C_ifield is set to 0 to indicate that the SCell with SCellIndex i shall be deactivated and that no TRS ID field is included for this SCell;

– TRS ID_j: If TRS ID_j is set to a non-zero value, it indicates the corresponding TRS address by scellActivationRS-Id as specified in TS 38.331 [5] is activated. If TRS ID_j is set to zero, it indicates that no TRS is used for the corresponding SCell;

– R: Reserved bit, set to 0.

Figure 6.1.3.55-1: Enhanced SCell Activation/Deactivation MAC CE with one octet C_i field

Figure 6.1.3.55-2: Enhanced SCell Activation/Deactivation MAC CE with four octet C_i field

6.1.3.56 Timing Advance Report MAC CE

The Timing Advance Report MAC CE is identified by MAC subheader with LCID as specified in Table 6.2.1-2. It has a fixed size and consists of two octets defined as follows (Figure 6.1.3.56-1):

– R: Reserved bit, set to 0;

– Timing Advance: In FR1, the Timing Advance field indicates the least integer number of slots greater than or equal to the Timing Advance value (see TS 38.211 [8], clause 4.3.1). The length of the field is 14 bits.

Figure 6.1.3.56-1: Timing Advance Report MAC CE

6.1.3.57 Differential Koffset MAC CE

The Differential Koffset MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a fixed size and consists of a single octet defined as follows (Figure 6.1.3.57-1):

– R: Reserved bit, set to 0;

– Differential Koffset: This field contains the differential Koffset. The length of the field is 6 bits.

Figure 6.1.3.57-1: Differential Koffset MAC CE

6.1.3.58 BFD-RS Indication MAC CE

The BFD-RS Indication MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size, and includes a BFD-RS-ID₀ field and a BFD-RS-ID₁ field (optional) of failureDetectionSet1, and a BFD-RS-ID₀ field and a BFD-RS-ID₁ field (optional) of failureDetectionSet2.

It has a variable size consisting of following fields:

– Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits;

– BWP ID: This field indicates a DL BWP for which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.213 [6]. The length of the BWP ID field is 2 bits;

– S: This field indicates the presence of the octet containing the BFD-RS ID₁ of the same BFD-RS set. The S field set to 1 indicates that the octet containing BFD-RS ID₁ is included. The S field set to 0 indicates that the octet containing the BFD-RS ID₁ of the same BFD-RS set is not included;

– BFD-RS ID_i: This field indicates the BFD-RS resource from failureDetectionSet1 or failureDetectionSet2 as specified in TS 38.331 [5];

– R: Reserved bit, set to 0.

Figure 6.1.3.58-1: BFD-RS Indication MAC CE

6.1.3.59 SP/AP SRS TCI State Indication MAC CE

The SP/AP SRS TCI State Indication MAC CE is identified by a MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size with following fields:

– SRS Resource Set’s Cell ID: This field indicates the identity of the Serving Cell, which contains the indicated SP/AP SRS Resource Set. If the C field is set to 0, this field also indicates the identity of the Serving Cell associated with all TCI states indicated by the TCI State ID_i fields. The length of the field is 5 bits;

– SRS Resource Set’s BWP ID: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], which contains the indicated SP/AP SRS Resource Set. If the C field is set to 0, this field also indicates the identity of the BWP associated with all TCI states indicated by the TCI State ID_i fields. The length of the field is 2 bits;

– C: This field indicates whether the octets containing TCI State Serving Cell ID field(s) and TCI State BWP ID field(s) are present. If this field is set to 1, TCI State Serving Cell ID field(s) and TCI State BWP ID field(s) are present, otherwise they are not present so MAC entity shall ignore TCI State Serving Cell ID field(s) and TCI State BWP ID field(s);

– SRS Resource Set ID: This field indicates the SP/AP SRS Resource Set ID identified by SRS-ResourceSetId as specified in TS 38.331 [5]. The length of the field is 4 bits;

– TCI State Serving Cell ID_i: This field indicates the identity of the Serving Cell on which the TCI State used for SRS resource i is located. The length of the field is 5 bits;

– TCI State BWP ID_i: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], on which the TCI State used for SRS resource i is located. The length of the field is 2 bits;

– TCI State ID_i: This field contains an identifier of the TCI state used for SRS resource i. TCI State ID₀ refers to the first SRS resource within the resource set, TCI State ID₁ refers to the second one and so on. If joint/downlink TCI State is used, 7-bits length TCI state ID i.e. TCI-StateId as specified in TS 38.331 [5] is used. If separate downlink and uplink TCI State is used, the most significant bit of TCI state ID is considered as a reserved bit and the remaining 6 bits indicate the UL-TCIState-Id as specified in TS 38.331 [5]. The length of the field is 7 bits. This field is only present if MAC CE is used for activation of SP SRS resource set, i.e. the A/D field is set to 1, or for AP SRS resource set;

– R: Reserved bit, set to 0.

Figure 6.1.3.59-1: SP/AP SRS TCI State Indication MAC CE

6.1.3.60 Serving Cell Set based SRS TCI State Indication MAC CE

The Serving Cell Set based SRS TCI State Indication MAC CE is identified by a MAC subheader with eLCID as specified. It has a variable size with following fields:

– SRS Resource’s Cell ID: This field indicates the identity of the Serving Cell, which contains the indicated SP/AP SRS Resource. If the C field is set to 0, this field also indicates the identity of the Serving Cell associated with all TCI States indicated by the TCI State IDi fields. The length of the field is 5 bits. The indicated Serving Cell is configured as part of simultaneousSpatial-UpdatedList1 or simultaneousSpatial-UpdatedList2 in TS 38.331 [5], and this MAC CE applies to all the Serving Cells configured in the set simultaneousSpatial-UpdatedList1 or simultaneousSpatial-UpdatedList2, respectively;

– SRS Resource’s BWP ID: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], which contains the indicated AP/SP SRS Resource. If the C field is set to 0, this field also indicates the identity of the BWP associated with all TCI States indicated by the TCI State IDi fields. The length of the field is 2 bits;

– C: This field indicates whether the octets containing TCI State Serving Cell ID field(s) and TCI State BWP ID field(s) are present. If this field is set to 1, the TCI State Serving Cell ID field(s) and TCI State BWP ID field(s) are present, otherwise they are not present so MAC entity shall ignore TCI State Serving Cell ID field(s) and TCI State BWP ID field(s);

– SRS Resource ID_i: This field indicates the SP/AP SRS Resource ID identified by SRS-ResourceId as specified in TS 38.331 [5]. The length of the field is 6 bits;

– TCI State Serving Cell ID_i: This field indicates the identity of the Serving Cell on which the TCI State used for SRS Resource ID_i is located. The length of the field is 5 bits;

– TCI State BWP ID_i: This field indicates a UL BWP as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9], on which the TCI State used for SRS Resource ID_i is located. The length of the field is 2 bits;

– TCI State ID_i: This field contains an identifier of the TCI state used for SRS resource i. TCI State ID₀ refers to the first SRS resource which is indicated SRS Resource ID₀, TCI State ID₁ refers to the second one and so on. If joint/downlink TCI State is used, 7-bits length TCI state ID i.e. TCI-StateId as specified in TS 38.331 [5] is used. If separate downlink and uplink TCI State is used, the most significant bit of TCI state ID is considered as a reserved bit and the remaining 6 bits indicate the UL-TCIState-Id as specified in TS 38.331 [5]. The length of the field is 7 bits;

– R: Reserved bit, set to 0.

Figure 6.1.3.60-1: Serving Cell Set based SRS TCI State Indication MAC CE

6.1.3.61 Child IAB-DU Restricted Beam Indication MAC CE

The Child IAB-DU Restricted Beam Indication MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size with following fields (Figure 6.1.3.61-1):

– Resource Configuration ID: This fields indicates the RRC configuration which applies to this MAC CE and corresponds to iab-ResourceConfigID parameter in IAB-ResourceConfig as specified in TS 38.331 [5]. The length of the field is 16 bits;

– Number of child IAB-DU beams ID: This field indicates the number of restricted child IAB-DU beams included in the MAC CE. The length of the field is 8 bits;

– IAB-DU restricted beams type ID_i: This field determines the type of information used as an indication of a set of child IAB-DU’s restricted beams, indicated with the Child IAB-DU Resource set ID_i field. IAB-DU restricted beams type ID₀ refers to the first restricted beam within the resource set, IAB-DU restricted beams type ID₁ to the second one and so on. If the value of the field is 00, SSB index is used (contained in the 6 rightmost bits of the Child IAB-DU Resource set ID_i field, with the two leftmost bits being set to zero). If the value of the field is 01, SSB index (contained in the 6 rightmost bits of the Child IAB-DU Resource set ID_i field) and STC index (contained in the two leftmost bits of the Child IAB-DU Resource set ID_i field) are both used. If the value of the field is set to 11, CSI-RS index is used (comprising all 8 bits of the Child IAB-DU Resource set ID_i field). The length of the field is 2 bits;

– C_i1: This field indicates whether the octet containing the Number of cell configurations ID_i field is included or not. C₀₁refers to the first restricted beam within the resource set, C₁₁ to the second one and so on. The field is set to 0 to indicate the octet is not included (and subsequently, that no cell information is included for the relevant restricted beam). The field is set to 1 to indicate that Number of cell configurations ID_i field is included. The length of the field is 1 bits;

– C_i2: This field indicates whether the child IAB-DU beam indicated with the Child IAB-DU Resource set ID_i field is associated with one or more uplink or downlink IAB-MT beams, indicated with the IAB-MT Resource set ID_ij fields. C₀₂ refers to the first restricted beam within the resource set, C₁₂ to the second one and so on. The field is set to 1 to indicate that at least one IAB-MT Resource set ID_ij field is included (and that Number of associated IAB-MT beams ID_i is included), and it is set to 0 to indicate that no IAB-MT Resource set ID_ij field is present (and that the Number of associated IAB-MT beams ID_i is absent). The length of the field is 1 bit;

– R: Reserved bit, set to 0;

– Child IAB-DU Resource set ID_i:an indication of the child IAB-DU’s beam in the direction of which simultaneous operation is restricted. The length of the field is 8 bits;

– Number of cell configurations ID_i: This field indicates the number of cell configurations associated with the beam restriction indicated in Child IAB-DU Resource set ID_i. Number of cell configurations ID₀ refers to the first restricted beam within the resource set, Number of cell configurations ID₁ to the second one and so on. The length of the field is 8 bits;

– Cell info type ID_ij: indicates the type of information included in the Cell info ID_ij field. If the value of the field is set to zero, the combination of {MT CC, DU cell} is included in the Cell info ID_ij field, by including the IAB-DU cell in the first nine bits of the field, and the IAB-MT Serving Cell index into the next 5 bits of the field,. If the value of the field is set to one, only DU cell is included in the Cell info ID_ij field, by including the IAB-DU cell in the first nine bits of the field, and by setting the remaining five bits to zero. The length of the field is 1 bit;

– M_ij: This field indicates whether the octet containing multiplexing mode info (containing the Multiplexing mode info ID_ij field) is included or not. M_i0 refers to the first combination of {MT CC, DU cell} associated with Child IAB-DU Resource set ID_i, M_i1 to the second one and so on. The field is set to 1 to indicate that multiplexing mode info is included, and it is set to 0 to indicate that multiplexing mode info is not present. The length of the field is 1 bit;

– Cell info ID_ij: indicates the cell configuration associated with beam restriction indicated in Child IAB-DU Resource set ID_i. Cell info ID_i0field refers to the first cell configuration associated with the beam restriction indicated in Child IAB-DU Resource set ID_i, Cell info ID_i1field refers to the second cell configuration associated with the beam restriction indicated in Child IAB-DU Resource set ID_i, and so on. The length of the field is 15 bits;

– Multiplexing mode info ID_ij: The two rightmost bits indicate which of the four multiplexing modes defined in TS 38.473 [27] is applicable. The third rightmost bit of this field indicates whether multiplexing restrictions mode information contained in the two rightmost bits of the field are applicable to non-overlapping frequency resources. This bit is set to 1 when multiplexing mode information contained in the two rightmost bits of the Multiplexing mode info ID_ij field is applicable to non-overlapping frequency resources. This field is set to 0 when multiplexing mode information contained in the two rightmost bits of the Multiplexing mode info ID_ij field is not applicable to non-overlapping frequency resources. The remaining 5 bits of this field are set to zero. The length of the field is 8 bits;

– Number of associated IAB-MT beams ID_i: This field indicates the number of IAB-MT beams associated with the beam indicated in Child IAB-DU Resource set ID_i. Number of associated IAB-MT beams ID₀ refers to the first restricted beam within the resource set, Number of associated IAB-MT beams ID₁ to the second one and so on. The length of the field is 8 bits;

– Associated IAB-MT’s beams type ID_ij: This field determines the type of information used as an indication of an uplink or downlink IAB-MT beam associated with the child IAB-DU’s restricted beams, indicated with the IAB-MT Resource set ID_ij. If the value of the field is 00, the information included in the IAB-MT Resource set ID_ij field is the TCI state ID (contained in the 7 rightmost bits of the field). If the value of the field is 01, the information included in the IAB-MT Resource set ID_ij field is the SSB ID (contained in the 6 rightmost bits of the field). If the value of the field is 10, the information included in the IAB-MT Resource set ID_ij field is the CSI-RS index (comprising all 8 bits). If the value of the field is 11, the information included in the IAB-MT Resource set ID_ij field is the SRI (contained in the 4 rightmost bits of the field). The length of the field is 2 bits;

– IAB-MT Resource set ID_ij:an indication of the IAB-MTs downlink or uplink beams which are associated with the child IAB-DU restricted beam indicated in Child IAB-DU Resource set ID_i field. IAB-MT Resource set ID_i0 field refers to the first IAB-MT’s beam associated with the child IAB-DU’s restricted beam indicated in Child IAB-DU Resource set ID_i field, IAB-MT Resource set ID_i1 field refers to the second IAB-MT’s beam associated with the child IAB-DU’s restricted beam indicated in Child IAB-DU Resource set ID_i field, and so on. The length of the field is 8 bits.

Figure 6.1.3.61-1: Child IAB-DU Restricted Beam Indication MAC CE

6.1.3.62 IAB-MT Recommended Beam Indication MAC CE

The IAB-MT Recommended Beam Indication MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-2b. It has a variable size with following fields (Figure 6.1.3.62-1):

– Resource Configuration ID: This field indicates the RRC configuration which applies to this MAC CE and corresponds to iab-ResourceConfigID parameter in IAB-ResourceConfig as specified in TS 38.331 [5]. The length of the field is 16 bits;

– Number of IAB-MT beams ID: This field indicates the number of recommended IAB-MT beams included in the MAC CE. The length of the field is 8 bits;

– IAB-MT beam type ID_i: This field determines the type of information used as an indication of an uplink or downlink IAB-MT beam, indicated with the IAB-MT Resource set ID_i. If the value of the field is 00, the information included in the IAB-MT Resource set ID_i field is the TCI state ID (contained in the 7 rightmost bits of the field). If the value of the field is 01, the information included in the IAB-MT Resource set ID_i field is the SSB ID (contained in the 6 rightmost bits of the field). If the value of the field is 10, the information included in the IAB-MT Resource set ID_i field is the CSI-RS index (comprising all 8 bits). If the value of the field is 11, the information included in the IAB-MT Resource set ID_i field is the SRI (contained in the 4 rightmost bits of the field). The length of the field is 2 bits;

– IAB-MT Resource set ID_i: an indication of the IAB-MTs recommended downlink or uplink beams. IAB-MT Resource set ID₀ field refers to the first IAB-MT’s beam, IAB-MT Resource set ID₁ field refers to the second IAB-MT’s beam, and so on. The length of the field is 8 bits;

– C_i1: This field indicates whether the octet containing the Number of cell configurations ID_i field is included or not. C₀₁ refers to the first recommended beam within the resource set, C₁₁ to the second one and so on. The field is set to 0 to indicate the octet is not included (and subsequently, that no cell information is included for the relevant recommended beam). The field is set to 1 to indicate that Number of cell configurations ID_i field is included. The length of the field is 1 bits;

– R: Reserved bit, set to 0;

– Number of cell configurations ID_i: This field indicates the number of cell configurations associated with the beam indicated in IAB-MT Resource set ID_i. Number of cell configurations ID₀ refers to the first recommended beam within the resource set, Number of cell configurations ID₁ to the second one and so on. The length of the field is 8 bits;

– Cell info type ID_ij: indicates the type of information included in the Cell info ID_ij field. If the value of the field is set to zero, the combination of {MT CC, DU cell} is included in the Cell info ID_ij field, by including the IAB-DU cell in the first nine bits of the field, and the IAB-MT Serving Cell index into the next 5 bits of the field. If the value of the field is set to one, only MT CC information is included in the Cell info ID_ij field, by including the IAB-MT Serving Cell index in the first 5 bits of the field, and by setting the remaining nine bits to zero. The length of the field is 1 bit;

– M_ij: This field indicates whether the octet containing multiplexing mode info (containing the Multiplexing mode info ID_ij field) is included or not. M_i0 refers to the first combination of {MT CC, DU cell} associated with IAB-MT Resource set ID_i, M_i1 to the second one and so on. The field is set to 1 to indicate that multiplexing mode info is included, and it is set to 0 to indicate that multiplexing mode info is not present. The length of the field is 1 bit;

– Cell info ID_ij: indicates the cell configuration associated with beam recommendation indicated in IAB-MT Resource set ID_i. Cell info ID_i0 field refers to the first cell configuration associated with the beam recommendation indicated in IAB-MT Resource set ID_i, Cell info ID_i1 field refers to the second cell configuration associated with the beam recommendation indicated in IAB-MT Resource set ID_i, and so on. The length of the field is 14 bits.

Figure 6.1.3.62-1: IAB-MT Recommended Beam Indication MAC CE

6.1.3.63 DL TX Power Adjustment and Desired DL TX Power Adjustment MAC CEs

The DL TX Power Adjustment MAC CE and Desired DL TX Power Adjustment MAC CEs are identified by MAC subheaders with eLCIDs as specified in Table 6.2.1-1b and Table 6.2.1-1b, respectively. Otherwise the format of the two MAC CEs is identical. Each has a variable size with following fields (Figure 6.1.3.63-1):

– DL Tx Power adjustment: For the case of the Desired DL TX Power Adjustment MAC CE, this field contains desired DL TX power adjustment sent by an IAB-MT to assist with the parent node’s DL TX power allocation. For the case of the DL TX Power Adjustment MAC CE, this fields contains adjustment to a node’s DL TX power sent by its parent node. The value of the power adjustment is in both cases contained in the 5 right-most bits of the field, while the remaining 3 bits are set to zero. The length of the field is 8 bits;

– Reference CSI-RS ID: This field indicates the CSI-RS used as reference for power adjustment, which is identified by NZP-CSI-RS-ResourceId as specified in TS 38.331 [5]. The indicated DL TX power adjustment is in terms of a relative offset to the CSI-RS TX power of the indicated CSI-RS.The length of this field is 8bits;

– C₀: This field indicates whether the octet containing multiplexing mode info (containing the Multiplexing mode info ID field) is included or not. The field is set to 1 to indicate that multiplexing mode info is included, and it is set to 0 to indicate that multiplexing mode info is not present. The length of the field is 1 bit;

– C₁: This field indicates whether the two octets containing the Cell info ID are included or not. The field is set to 0 to indicate the two octets are not included (and subsequently, that no cell information is included). The field is set to 1 to indicate that the two octets are included. The length of the field is 1 bits;

– C₂: This field indicates whether any information on IAB-MT DL beams is included or not. The field is set to 1 to indicate that at least one IAB-MT Resource set ID_i field is included, and it is set to 0 to indicate that no IAB-MT Resource set ID_i field is present. The length of the field is 1 bit;

– R: Reserved bit, set to 0.

– Multiplexing mode info ID: The two rightmost bits indicate which of the four multiplexing modes defined in TS 38.473 [27] is applicable. The third rightmost bit of this field indicates whether multiplexing restrictions mode information contained in the two rightmost bits of the field are applicable to non-overlapping frequency resources. This bit is set to 1 when multiplexing mode information contained in the two rightmost bits of the Multiplexing mode info ID field is applicable to non-overlapping frequency resources. This field is set to 0 when multiplexing mode information contained in the two rightmost bits of the Multiplexing mode info ID field is not applicable to non-overlapping frequency resources. The remaining 5 bits of this field are set to zero. The length of the field is 8 bits;

– Number of IAB-MT DL beams ID: This field indicates the number of IAB-MT beams included in the MAC CE. The length of the field is 8 bits;

– IAB-MT beam type ID_i: This field determines the type of information used as an indication of a downlink IAB-MT beam, indicated with the IAB-MT Resource set ID_i. If the value of the field is 00, the information included in the IAB-MT Resource set ID_i field is the TCI state ID (contained in the 7 rightmost bits of the field). If the value of the field is 01, the information included in the IAB-MT Resource set ID_i field is the SSB ID (contained in the 6 rightmost bits of the field). If the value of the field is 10, the information included in the IAB-MT Resource set ID_i field is the CSI-RS index (comprising all 8 bits). The length of the field is 2 bits;

– IAB-MT Resource set ID_i: an indication of the IAB-MTs downlink beams. IAB-MT Resource set ID₀ field refers to the first IAB-MT downlink beam, IAB-MT Resource set ID1 field refers to the second IAB-MT downlink beam, and so on. The length of the field is 8 bits;

– DU resource configuration ID: when this field is set to 00, the provided power adjustment is applied on FDM resources where the simultaneous MT and DU signals are non-overlapping in the frequency-domain; when this field is set to 01, the provided power adjustment is applied on non-FDM resources where the simultaneous MT and DU signals may overlap in the frequency-domain for a given (MT CC, DU cell); when this field is set to 10, the provided power adjustment is applied on FDM resources where the simultaneous MT and DU signals are non-overlapping in the frequency-domain, and on non-FDM resources where the simultaneous MT and DU signals may overlap in the frequency-domain for a given (MT CC, DU cell). The length of the field is 2 bits;

– Cell info ID: indicates the cell configuration associated with the information contained in the MAC CE. The length of the field is 14 bits. IAB-DU cell is contained in the first nine bits of the field, while the Child IAB-MT Serving Cell index into the next 5 bits of the field. The length of the field is 14 bits.

Figure 6.1.3.63-1: DL TX Power Adjustment and Desired DL TX Power Adjustment MAC CEs

6.1.3.64 Desired IAB-MT PSD range MAC CE

The Desired IAB-MT PSD range MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-2b. It has a variable size with following fields (Figure 6.1.3.64-1):

– PSD range: This field contains the desired PSD range a node sends to its parent node to help with the sending node’s MT UL TX power control. The 4 left-most bits of the field indicate the offset, while the next 7 left-most bits indicate the Pmax range. The remaining 5 bits are set to zero. The length of the field is 16 bits;

– C₂: This field indicates whether any information on IAB-MT UL beams is included or not. The field is set to 1 to indicate that at least one IAB-MT Resource set ID_i field is included, and it is set to 0 to indicate that no IAB-MT Resource set ID_i field is present. The length of the field is 1 bit;

– R: Reserved bit, set to 0;

– Number of IAB-MT UL beams ID: This field indicates the number N of IAB-MT UL beams included in the MAC CE. The length of the field is 8 bits;

– IAB-MT Resource set ID_i: an indication of the IAB-MTs uplink beams. IAB-MT Resource set ID₀ field refers to the first IAB-MT uplink beam, IAB-MT Resource set ID₁ field refers to the second IAB-MT uplink beam, and so on. If the total number N of beams included in the MAC CE is odd, the 4 right-most bits in the final octet of the IAB-MT Resource set are disregarded by the UE. The length of the field is 4 bits;

– Cell info ID: indicates the cell configuration associated with the information contained in the MAC CE. IAB-DU cell is contained in the first nine bits of the field, while the Child IAB-MT Serving Cell index into the next 5 bits of the field. The length of the field is 14 bits.

Figure 6.1.3.64-1: Desired IAB-MT PSD range MAC CE

6.1.3.65 Timing Case Indication MAC CE

The Timing Case Indication MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-1b. It has a variable size with following fields (Figure 6.1.3.65-1):

– Timing mode ID_i: when this field is set to 00, the timing mode applied to the i^th slot in the list of slots slotList provided via RRC in IAB-ResourceConfig is Case-1; when this field is set to 01, the timing mode applied to the i^th slot in the list of slots slotList provided via RRC in IAB-ResourceConfig is Case-6; when this field is set to 10, the timing mode applied to the i^th slot in the list of slots slotList provided via RRC in IAB-ResourceConfig is Case-7. The total number N of Timing mode ID_i fields corresponds to the size of slotList provided via RRC in IAB-ResourceConfig. If number N is not divisible by 4, (4 – N mod 4) of the final Timing mode ID_i fields are disregarded by the receiving IAB node. The length of the field is 2 bits.

Figure 6.1.3.65-1: Timing Case Indication MAC CE