6.1.3 MAC Control Elements

36.3213GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Medium Access Control (MAC) protocol specificationRelease 17TS

6.1.3.1 Buffer Status Report MAC Control Elements

Buffer Status Report (BSR) MAC control elements consist of either:

– Short BSR and Truncated BSR format: one LCG ID field and one corresponding Buffer Size field (figure 6.1.3.1-1); or

– Long BSR format: four Buffer Size fields, corresponding to LCG IDs #0 through #3 (figure 6.1.3.1-2).

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

The fields LCG ID and Buffer Size are defined as follow:

– LCG ID: The Logical Channel Group ID field identifies the group of logical channel(s) which buffer status is being reported. The length of the field is 2 bits. For NB-IoT, the LCG ID is set to #0.

– Buffer Size: The Buffer Size field identifies the total amount of data available across all logical channels of a logical channel group after all MAC PDUs for the TTI have been built. The amount of data is indicated in number of bytes. It shall include all data that is available for transmission in the RLC layer and in the PDCP layer; the definition of what data shall be considered as available for transmission is specified in TS 36.322 [3] and TS 36.323 [4] or TS 38.323 [17] respectively. The size of the RLC and MAC headers are not considered in the buffer size computation. The length of this field is 6 bits. If extendedBSR-Sizes is not configured, the values taken by the Buffer Size field are shown in Table 6.1.3.1-1. If extendedBSR-Sizes is configured, the values taken by the Buffer Size field are shown in Table 6.1.3.1-2.

Figure 6.1.3.1-1: Short BSR and Truncated BSR MAC control element

Figure 6.1.3.1-2: Long BSR MAC control element

Table 6.1.3.1-1: Buffer size levels for BSR

Index

Buffer Size (BS) value [bytes]

Index

Buffer Size (BS) value [bytes]

0

BS = 0

32

1132 < BS <= 1326

1

0 < BS <= 10

33

1326 < BS <= 1552

2

10 < BS <= 12

34

1552 < BS <= 1817

3

12 < BS <= 14

35

1817 < BS <= 2127

4

14 < BS <= 17

36

2127 < BS <= 2490

5

17 < BS <= 19

37

2490 < BS <= 2915

6

19 < BS <= 22

38

2915 < BS <= 3413

7

22 < BS <= 26

39

3413 < BS <= 3995

8

26 < BS <= 31

40

3995 < BS <= 4677

9

31 < BS <= 36

41

4677 < BS <= 5476

10

36 < BS <= 42

42

5476 < BS <= 6411

11

42 < BS <= 49

43

6411 < BS <= 7505

12

49 < BS <= 57

44

7505 < BS <= 8787

13

57 < BS <= 67

45

8787 < BS <= 10287

14

67 < BS <= 78

46

10287 < BS <= 12043

15

78 < BS <= 91

47

12043 < BS <= 14099

16

91 < BS <= 107

48

14099 < BS <= 16507

17

107 < BS <= 125

49

16507 < BS <= 19325

18

125 < BS <= 146

50

19325 < BS <= 22624

19

146 < BS <= 171

51

22624 < BS <= 26487

20

171 < BS <= 200

52

26487 < BS <= 31009

21

200 < BS <= 234

53

31009 < BS <= 36304

22

234 < BS <= 274

54

36304 < BS <= 42502

23

274 < BS <= 321

55

42502 < BS <= 49759

24

321 < BS <= 376

56

49759 < BS <= 58255

25

376 < BS <= 440

57

58255 < BS <= 68201

26

440 < BS <= 515

58

68201 < BS <= 79846

27

515 < BS <= 603

59

79846 < BS <= 93479

28

603 < BS <= 706

60

93479 < BS <= 109439

29

706 < BS <= 826

61

109439 < BS <= 128125

30

826 < BS <= 967

62

128125 < BS <= 150000

31

967 < BS <=1132

63

BS > 150000

Table 6.1.3.1-2: Extended Buffer size levels for BSR

Index

Buffer Size (BS) value [bytes]

Index

Buffer Size (BS) value [bytes]

0

BS = 0

32

4940 < BS <= 6074

1

0 < BS <= 10

33

6074 < BS <= 7469

2

10 < BS <= 13

34

7469 < BS <= 9185

3

13 < BS <= 16

35

9185 < BS <= 11294

4

16 < BS <= 19

36

11294 < BS <= 13888

5

19 < BS <= 23

37

13888 < BS <= 17077

6

23 < BS <= 29

38

17077 < BS <= 20999

7

29 < BS <= 35

39

20999 < BS <= 25822

8

35 < BS <= 43

40

25822 < BS <= 31752

9

43 < BS <= 53

41

31752 < BS <= 39045

10

53 < BS <= 65

42

39045 < BS <= 48012

11

65 < BS <= 80

43

48012 < BS <= 59039

12

80 < BS <= 98

44

59039 < BS <= 72598

13

98 < BS <= 120

45

72598 < BS <= 89272

14

120 < BS <= 147

46

89272 < BS <= 109774

15

147 < BS <= 181

47

109774 < BS <= 134986

16

181 < BS <= 223

48

134986 < BS <= 165989

17

223 < BS <= 274

49

165989 < BS <= 204111

18

274 < BS <= 337

50

204111 < BS <= 250990

19

337 < BS <= 414

51

250990 < BS <= 308634

20

414 < BS <= 509

52

308634 < BS <= 379519

21

509 < BS <= 625

53

379519 < BS <= 466683

22

625 < BS <= 769

54

466683 < BS <= 573866

23

769 < BS <= 945

55

573866 < BS <= 705666

24

945 < BS <= 1162

56

705666 < BS <= 867737

25

1162 < BS <= 1429

57

867737 < BS <= 1067031

26

1429 < BS <= 1757

58

1067031 < BS <= 1312097

27

1757 < BS <= 2161

59

1312097 < BS <= 1613447

28

2161 < BS <= 2657

60

1613447 < BS <= 1984009

29

2657 < BS <= 3267

61

1984009 < BS <= 2439678

30

3267 < BS <= 4017

62

2439678 < BS <= 3000000

31

4017 < BS <=4940

63

BS > 3000000

6.1.3.1a Sidelink BSR MAC Control Elements

Sidelink BSR and Truncated Sidelink 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 Sidelink BSR MAC control elements are identified by MAC PDU subheaders with LCIDs as specified in table 6.2.1-2. They have variable sizes.

For each included group, the fields are defined as follows (figures 6.1.3.1a-1 and 6.1.3.1a-2):

– Destination Index: The Destination Index field identifies the ProSe Destination or the destination for V2X sidelink communication. The length of this field is 4 bits. The value is set to the index of the destination reported in destinationInfoList for sidelink communication or is set to one index among index(es) associated to same destination reported in v2x-DestinationInfoList for V2X sidelink communication. If multiple such lists are reported, the value is indexed sequentially across all the lists in the same order as specified in TS 36.331 [8];

– LCG ID: The Logical Channel Group ID field identifies the group of logical channel(s) which buffer status is being reported. The length of the field is 2 bits;

– Buffer Size: The Buffer Size field identifies the total amount of data available across all logical channels of a LCG of a ProSe Destination after all MAC PDUs for the TTI have been built. The amount of data is indicated in number of bytes. It shall include all data that is available for transmission in the RLC layer and in the PDCP layer; the definition of what data shall be considered as available for transmission is specified in TS 36.322 [3] and TS 36.323 [4] respectively. The size of the RLC and MAC headers are not considered in the buffer size computation. The length of this field is 6 bits. The values taken by the Buffer Size field are shown in Table 6.1.3.1-1;

– R: Reserved bit, set to "0".

Buffer Sizes of LCGs are included in decreasing order of the highest priority of the sidelink logical channel belonging to the LCG irrespective of the value of the Destination Index field.

Figure 6.1.3.1a-1: Sidelink BSR and Truncated Sidelink BSR MAC control element for even N

Figure 6.1.3.1a-2: Sidelink BSR and Truncated Sidelink BSR MAC control element for odd N

6.1.3.2 C-RNTI MAC Control Element

The C-RNTI MAC control element is identified by MAC PDU 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 control element

6.1.3.3 DRX Command MAC Control Element

The DRX Command MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-1.

It has a fixed size of zero bits.

6.1.3.4 UE Contention Resolution Identity MAC Control Element

The UE Contention Resolution Identity MAC control element is identified by MAC PDU subheader with LCID as specified in table 6.2.1-1. This control element has a fixed 48-bit size and consists of a single field defined as follows (figure 6.1.3.4-1)

– UE Contention Resolution Identity: If this MAC control element is included in response to an uplink CCCH transmission, then this field contains the uplink CCCH SDU if the uplink CCCH SDU is 48 bits long. If the CCCH SDU is longer than 48 bits, this field contains the first 48 bits of the uplink CCCH SDU. If this MAC control element is included in response to an uplink DCCH transmission (i.e. the MAC entity is configured with rach-Skip or rach-SkipSCG), then the MAC entity shall ignore the contents of this field.

Figure 6.1.3.4-1: UE Contention Resolution Identity MAC control element

6.1.3.5 Timing Advance Command MAC Control Element

The Timing Advance Command MAC control element is identified by MAC PDU 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 6.1.3.5-1):

– 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 TA (0, 1, 2… 63) used to control the amount of timing adjustment that MAC entity has to apply (see clause 4.2.3 of TS 36.213 [2]). The length of the field is 6 bits.

Figure 6.1.3.5-1: Timing Advance Command MAC control element

6.1.3.6 Power Headroom Report MAC Control Element

The Power Headroom Report (PHR) MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-2. It has a fixed size and consists of a single octet defined as follows (figure 6.1.3.6-1):

– R: reserved bit, set to "0";

– 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 6.1.3.6-1 below (the corresponding measured values in dB can be found in clause 9.1.8.4 of TS 36.133 [9]).

Figure 6.1.3.6-1: PHR MAC control element

Table 6.1.3.6-1: 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

6.1.3.6a Extended Power Headroom Report MAC Control Elements

For extendedPHR, the Extended Power Headroom Report (PHR) MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-2. It has a variable size and is defined in Figure 6.1.3.6a-2. When Type 2 PH is reported, the octet containing the Type 2 PH field is included first after the octet indicating the presence of PH per SCell and followed by an octet containing the associated PCMAX,c field (if reported). Then follows an octet with the Type 1 PH field and an octet with the associated PCMAX,c field (if reported), for the PCell. If SRS-ConfigAdd-r16 is configured for the PCell then follows an octet with the Type 3 PH field and an octet with the associated PCMAX,c field (if reported), for the PCell. And then follows in ascending order based on the ServCellIndex, as specified in TS 36.331 [8] an octet with the Type x PH field, wherein x is equal to 3 when the ul-Configuration-r14 or SRS-ConfigAdd-r16 is configured for this SCell, x is equal to 1 otherwise, and an octet with the associated PCMAX,c field (if reported), for each SCell indicated in the bitmap.

For extendedPHR2, the Extended Power Headroom Report (PHR) MAC control elements are identified by a MAC PDU subheader with LCID as specified in table 6.2.1-2. They have variable sizes and are defined in Figure 6.1.3.6a1-3, Figure 6.1.3.6a2-4 and Figure 6.1.3.6a3-5. One octet with C fields is used for indicating the presence of PH per SCell when the highest SCellIndex of SCell with configured uplink is less than 8, otherwise four octets are used. When Type 2 PH is reported for the PCell, the octet containing the Type 2 PH field is included first after the octet(s) indicating the presence of PH per SCell and followed by an octet containing the associated PCMAX,c field (if reported). Then follows the Type 2 PH field for the PUCCH SCell (if PUCCH on SCell is configured and Type 2 PH is reported for the PUCCH SCell), followed by an octet containing the associated PCMAX,c field (if reported). Then follows an octet with the Type 1 PH field and an octet with the associated PCMAX,c field (if reported), for the PCell. If SRS-ConfigAdd-r16 is configured for the PCell then follows an octet with the Type 3 PH field and an octet with the associated PCMAX,c field (if reported), for the PCell. Then follows in ascending order based on the ServCellIndex, as specified in TS 36.331 [8] an octet with the Type x PH field, wherein, x is equal to 3 when the ul-Configuration-r14 or SRS-ConfigAdd-r16 is configured for this SCell, x is equal to 1 otherwise, and an octet with the associated PCMAX,c field (if reported), for each SCell indicated in the bitmap.

The Extended PHR MAC Control Elements are defined as follows:

– Ci: this field indicates the presence of a PH field for the SCell with SCellIndex i as specified in TS 36.331 [8]. The Ci field set to "1" indicates that a PH field for the SCell with SCellIndex i is reported. The Ci field set to "0" indicates that a PH field for the SCell with SCellIndex 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, V=0 indicates real transmission on PUSCH and V=1 indicates that a PUSCH reference format is used. For Type 2 PH, V=0 indicates real transmission on PUCCH/SPUCCH and V=1 indicates that a PUCCH/SPUCCH reference format is used. For Type 3 PH, V=0 indicates real transmission on SRS and V=1 indicates that an SRS reference format is used. Furthermore, for Type 1, Type 2 and Type 3 PH, V=0 indicates the presence of the octet containing the associated PCMAX,c field, and V=1 indicates that the octet containing the associated PCMAX,c 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 6.1.3.6-1 (the corresponding measured values in dB can be found in clause 9.1.8.4 of TS 36.133 [9]);

– P: this field indicates whether the MAC entity applies power backoff due to power management (as allowed by P-MPRc, see TS 36.101 [10]). The MAC entity shall set P=1 if the corresponding PCMAX,c field would have had a different value if no power backoff due to power management had been applied;

– PCMAX,c: if present, this field indicates the PCMAX,c or , as specified in TS 36.213 [2] used for calculation of the preceding PH field. The reported PCMAX,c and the corresponding nominal UE transmit power levels are shown in Table 6.1.3.6a-1 (the corresponding measured values in dBm can be found in clause 9.6.1 of TS 36.133 [9]).

Figure 6.1.3.6a-1: Void

Figure 6.1.3.6a-2: Extended PHR MAC Control Element

Figure 6.1.3.6a1-3: Extended PHR MAC Control Element supporting PUCCH on SCell

Figure 6.1.3.6a2-4: Extended PHR MAC Control Element supporting 32 serving cells with configured uplink

Figure 6.1.3.6a3-5: Extended PHR MAC Control Element supporting 32 serving cells with configured uplink and PUCCH on SCell

Table 6.1.3.6a-1: Nominal UE transmit power level for Extended PHR and for Dual Connectivity PHR

PCMAX,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

6.1.3.6b Dual Connectivity Power Headroom Report MAC Control Element

The Dual Connectivity Power Headroom Report (PHR) MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-2. It has a variable size and is defined in Figure 6.1.3.6b-1 and Figure 6.1.3.6b-2. One octet with Ci fields is used for indicating the presence of PH per serving cell other than PCell, when the highest SCellIndex of SCell with configured uplink is less than 8, otherwise four octets are used. In case EN-DC, NE-DC or NGEN-DC is configured, four octets with Ci fields is always used. When Type 2 PH is reported for the PCell, the octet containing the Type 2 PH field is included first after the octet(s) indicating the presence of PH per cell (PSCell and all SCells of all MAC entities) and followed by an octet containing the associated PCMAX,c field (if reported). Then after that, when Type 2 PH is reported for the PSCell, the octet containing the Type 2 PH field is included followed by an octet containing the associated PCMAX,c field (if reported). Then follows an octet with the Type 1 PH field and an octet with the associated PCMAX,c field (if reported), for the PCell. If SRS-ConfigAdd-r16 is configured for the PCell then follows an octet with the Type 3 PH field and an octet with the associated PCMAX,c field (if reported), for the PCell. And then follows in ascending order based on the ServCellIndex, as specified in TS 36.331 [8], an octet with the Type x PH field, wherein x is either 1 or 3 according to TS 36.213 [2] and TS 38.213 [18] and an octet with the associated PCMAX,c field (if reported), for all serving cells of all MAC entities indicated in the bitmap. In case of EN-DC and NGEN-DC, for serving cells in the other MAC entity in which the UE does not support dynamic power sharing or dynamic power sharing is not applicable (clause 4.2.7.9, TS 38.306 [22]), the UE may omit the octets containing Power Headroom field and PCMAX,c field for those serving cells. In case of NE-DC, for serving cells in the other MAC entity in which the UE does not support dynamic power sharing or dynamic power sharing is not applicable, the UE may omit the octets containing Power Headroom field and PCMAX,f,c field for those serving cells except for the PCell in the other MAC entity and the reported values of Power Headroom and PCMAX,f,c for the PCell are up to UE implementation.

The Dual Connectivity PHR MAC Control Element is defined as follows:

– Ci: this field indicates the presence of a PH field for the serving cell of any MAC entity, except the PCell, with ServCellIndex (for EN-DC, NE-DC or NGEN-DC case) or SCellIndex i as specified in TS 36.331 [8]. The Ci field set to "1" indicates that a PH field for the serving cell with ServCellIndex (for EN-DC, NE-DC or NGEN-DC case) or SCellIndex i is reported. The Ci field set to "0" indicates that a PH field for the serving cell with ServCellIndex (for EN-DC, NE-DC or NGEN-DC case) or SCellIndex 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, V=0 indicates real transmission on PUSCH and V=1 indicates that a PUSCH reference format is used. For Type 2 PH, V=0 indicates real transmission on PUCCH and V=1 indicates that a PUCCH reference format is used. For Type 3 PH, V=0 indicates real transmission on SRS and V=1 indicates that an SRS reference format is used. Furthermore, for Type 1 ,Type 2 and Type 3 PH, V=0 indicates the presence of the octet containing the associated PCMAX,c field, and V=1 indicates that the octet containing the associated PCMAX,c field is omitted. Whether the reported PH value for an activated NR Serving Cell is based on real transmission or a reference format is determined based on UL transmissions that have been scheduled or configured until 4 ms prior to the TTI in which this PHR MAC CE is transmitted;

– 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 6.1.3.6-1 (the corresponding measured values in dB for the E-UTRA Serving Cell are specified in clause 9.1.8.4 of TS 36.133 [9] while the corresponding measured values in dB for the NR Serving Cell are specified in TS 38.133 [19]);

– P: this field indicates whether power backoff due to power management is applied (as allowed by P-MPRc, see TS 36.101 [10] and TS 38.101-3 [21]). The MAC entity shall set P=1 if the corresponding PCMAX,c field would have had a different value if no power backoff due to power management had been applied;

– PCMAX,c: if present, this field indicates the PCMAX,c or , as specified in TS 36.213 [2] for the E-UTRA Serving Cell and the PCMAX,f,c or P̃CMAX,f,c, as specified in TS 38.213 [18]) for the NR Serving Cell used for calculation of the preceding PH field. The reported PCMAX,c and the corresponding nominal UE transmit power levels are shown in Table 6.1.3.6a-1 (the corresponding measured values in dBm for the E-UTRA Serving Cell can be found in TS 36.133 [9] while the corresponding measured values in dBm for the NR Serving Cell can be found in TS 38.133 [19]).

Figure 6.1.3.6b-1: Dual Connectivity PHR MAC Control Element

Figure 6.1.3.6b-2: Dual Connectivity PHR MAC Control Element supporting 32 serving cells with configured uplink

6.1.3.7 MCH Scheduling Information MAC Control Element

The MCH Scheduling Information MAC Control Element illustrated in Figure 6.1.3.7-1 is identified by a MAC PDU subheader with LCID as specified in Table 6.2.1-4. This control element has a variable size. For each MTCH the fields below are included:

– LCID: this field indicates the Logical Channel ID of the MTCH. The length of the field is 5 bits;

– Stop MTCH: this field indicates the ordinal number of the subframe within the MCH scheduling period, counting only the subframes allocated to the MCH, where the corresponding MTCH stops. Value 0 corresponds to the first subframe. The length of the field is 11 bits. The special Stop MTCH value 2047 indicates that the corresponding MTCH is not scheduled. The value range 2043 to 2046 is reserved.

Figure 6.1.3.7-1: MCH Scheduling Information MAC control element

6.1.3.7a Extended MCH Scheduling Information MAC Control Element

The Extended MCH Scheduling Information MAC control element illustrated in Figure 6.1.3.7-2 is identified by a MAC PDU subheader with LCID as specified in Table 6.2.1-4. This control element has a variable size.

For each MTCH the fields below are included:

– LCID: this field indicates the Logical Channel ID of the MTCH. The length of the field is 5 bits;

– Stop MTCH: this field indicates the ordinal number of the subframe within the MCH scheduling period, counting only the subframes allocated to the MCH, where the corresponding MTCH stops. Value 0 corresponds to the first subframe. The length of the field is 11 bits. The special Stop MTCH value 2047 indicates that the corresponding MTCH is not scheduled. The value range 2043 to 2046 is reserved.

For each MTCH the fields below may be included:

– LCID: this field indicates the Logical Channel ID of the MTCH. The length of the field is 5 bits. LCIDs x…x+y shall be equal to or a subset of the LCIDs 1…n;

– S: this field indicates that the transmission of the corresponding MTCH is to be suspended. The S field is set to 000. All other values are reserved.

Figure 6.1.3.7a-1: Extended MCH Scheduling Information MAC control element

6.1.3.8 Activation/Deactivation MAC Control Elements

The Activation/Deactivation MAC control element of one octet is identified by a MAC PDU 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 Activation/Deactivation MAC control element with one octet is defined as follows (figure 6.1.3.8-1).

The Activation/Deactivation MAC control element of four octets is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-1. It has a fixed size and consists of a four octets containing 31 C-fields and one R-field. The Activation/Deactivation MAC control element of four octets is defined as follows (figure 6.1.3.8-2).

For the case with no serving cell with a ServCellIndex, as specified in TS 36.331 [8] larger than 7, Activation/Deactivation MAC control element of one octet is applied, otherwise Activation/Deactivation MAC control element of four octets is applied.

For the case that Activation/Deactivation MAC control element is received and Hibernation MAC control element is not received:

– Ci: if there is an SCell configured with SCellIndex i as specified in TS 36.331 [8], this field indicates the activation/deactivation status of the SCell with SCellIndex i, else the MAC entity shall ignore the Ci field. When the Ci field is set to "1", SCell with SCellIndex i shall be activated if it is in already activated state or deactivated state, otherwise the Ci field set to "1" shall be ignored. The Ci field is set to "0" to indicate that the SCell with SCellIndex i shall be deactivated;

– R: Reserved bit, set to "0".

For the case that both Activation/Deactivation MAC control element and Hibernation MAC control element are received, see clause 6.1.3.15.

Figure 6.1.3.8-1: Activation/Deactivation MAC control element of one octet

Figure 6.1.3.8-2: Activation/Deactivation MAC control element of four octets

6.1.3.9 Long DRX Command MAC Control Element

The Long DRX Command MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-1.

It has a fixed size of zero bits.

6.1.3.10 Data Volume and Power Headroom Report MAC Control Element

The Data Volume and Power Headroom Report (DPR) MAC control element is identified by the MAC PDU subheader used for the CCCH MAC SDU, as specified in table 6.2.1-2. It does not add any additional subheader and is always placed before the CCCH MAC SDU. DPR MAC control element is not included in the calculation of the L field in the MAC PDU subheader for the CCCH MAC SDU.

It has a fixed size and consists of a single octet defined as follows (figures 6.1.3.10-1 and 6.1.3.10-1a):

– Data Volume (DV): The Data Volume field identifies the total amount of data available across all logical channels and of data not yet associated with a logical channel after all MAC PDUs for the TTI have been built. The amount of data is indicated in number of bytes. It shall include all data that is available for transmission in the RLC layer, in the PDCP layer, and in the RRC layer; the definition of what data shall be considered as available for transmission is specified in TS 36.322 [3], TS 36.323 [4] and TS 36.331 [8] respectively. The size of the RLC and MAC headers are not considered in the buffer size computation. The length of this field is 4 bits. The values taken by the Data Volume field are shown in Table 6.1.3.10-1;

– Power Headroom (PH): This field indicates the power headroom level. The length of the field is 2 bits or 4 bits. The reported PH and the corresponding power headroom and extended power headroom levels are shown in Table 6.1.3.10-2 and Table 6.1.3.10-2a, respectively, below (the corresponding measured values in dB can be found in TS 36.133 [9]);

– R: reserved bit, set to "0".

Figure 6.1.3.10-1: Data Volume and Power Headroom Report MAC control element

Figure 6.1.3.10-1a: Data Volume and Power Headroom Report MAC control element for Extended Power Headroom level reporting

Table 6.1.3.10-1: Data Volume levels for DV

Index

Data Volume (DV) value [bytes]

Index

Data Volume (DV) value [bytes]

0

DV = 0

8

67 < DV <= 91

1

0 < DV <= 10

9

91 < DV <= 125

2

10 < DV <= 14

10

125 < DV <= 171

3

14 < DV <= 19

11

171 < DV <= 234

4

19 < DV <= 26

12

234 < DV <= 321

5

26 < DV <= 36

13

321 < DV <= 768

6

36 < DV <= 49

14

768 < DV <= 1500

7

49 < DV <= 67

15

DV > 1500

Table 6.1.3.10-2: Power Headroom levels for PH

PH

Power Headroom Level

0

POWER_HEADROOM_0

1

POWER_HEADROOM_1

2

POWER_HEADROOM_2

3

POWER_HEADROOM_3

Table 6.1.3.10-2a: Extended Power Headroom levels for PH

PH

Extended Power Headroom Level

0

EXTENDED_POWER_HEADROOM_0

1

EXTENDED_POWER_HEADROOM_1

2

EXTENDED_POWER_HEADROOM_2

3

EXTENDED_POWER_HEADROOM_3

4

EXTENDED_POWER_HEADROOM_4

5

EXTENDED_POWER_HEADROOM_5

6

EXTENDED_POWER_HEADROOM_6

7

EXTENDED_POWER_HEADROOM_7

8

EXTENDED_POWER_HEADROOM_8

9

EXTENDED_POWER_HEADROOM_9

10

EXTENDED_POWER_HEADROOM_10

11

EXTENDED_POWER_HEADROOM_11

12

EXTENDED_POWER_HEADROOM_12

13

EXTENDED_POWER_HEADROOM_13

14

EXTENDED_POWER_HEADROOM_14

15

EXTENDED_POWER_HEADROOM_15

6.1.3.11 SPS confirmation MAC Control Element

The SPS confirmation MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-2.

It has a fixed size of zero bits.

6.1.3.12 SC-PTM Stop Indication MAC Control Element

The SC-PTM Stop Indication MAC control element is applicable to NB-IoT UEs and BL UEs or UEs in enhanced coverage and indicates that the SC-MTCH transmission for a specific G-RNTI is stopped. It is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-1.

It has a fixed size of zero bits.

6.1.3.13 Recommended bit rate MAC Control Element

The recommended bit rate MAC control element is identified by a MAC PDU subheader with LCID as specified in tables 6.2.1-1 and 6.2.1-2 for bit rate recommendation message from the eNB to the UE and bit rate recommendation query message from the UE to the eNB, respectively. It has a fixed size and consists of two octets defined as follows (figure 6.1.3.13-1):

– LCID: This field indicates the identity of the logical channel (as described in Table 6.1.3.13-2) for which the recommended bit rate or the recommended bit rate query is applicable. The length of the field is 4 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 6.1.3.13-1. 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 36.331 [8];

– R: reserved bit, set to "0".

Figure 6.1.3.13-1: Recommended bit rate MAC control element

Table 6.1.3.13-1: Values (kbit/s) for Bit Rate field

Index

Recommended Bit Rate value [kbit/s]

Index

Recommended Bit Rate value [kbit/s]

0

Note 1

32

700

1

0

33

800

2

8

34

900

3

10

35

1000

4

12

36

1100

5

16

37

1200

6

20

38

1300

7

24

39

1400

8

28

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

Note1: For bit rate recommendation message this index is used for indicating that no recommendation on bit rate is given.

Table 6.1.3.13-2: Values of identity of the logical channel for LCID field

Codepoint/Index

Identity of the logical channel (i.e. logicalChannelIdentity as specified in TS 36.331 [8])

0000

Reserved

0001

32

0010

33

0011-1010

3-10

1011

34

1100

35

1101

36

1110

37

1111

38

6.1.3.14 Activation/Deactivation of CSI-RS resources MAC Control Element

The Activation/Deactivation of CSI-RS resources MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-1. It has variable size as the number of CSI process configured with csi-RS-NZP-Activation by RRC, see TS 36.331 [8], (N) and the N number of octets with A fields are included in ascending order of CSI process ID, i.e., CSI-ProcessId, as defined in Figure 6.1.3.14-1. Activation/Deactivation CSI-RS command is defined in Figure 6.1.3.14-2 and activates or deactivates CSI-RS resources for a CSI process. For a UE configured with transmission mode 9, N equals 1. Activation/Deactivation of CSI-RS resources MAC control element applies to the serving cell on which the UE receives the Activation/Deactivation of CSI-RS resources MAC control element.

The Activation/Deactivation of CSI-RS resources MAC control elements is defined as follows:

– Ai: this field indicates the activation/deactivation status of the CSI-RS resources configured by upper layers for the CSI process. A1 corresponds to the 1st entry in the list of CSI-RS specified by csi-RS-ConfigNZP-ApList as configured by upper layers, A2 corresponds to the 2nd entry in this list and so on. The Ai field is set to "1" to indicate that ith entry in the list of CSI-RS specified by csi-RS-ConfigNZP-ApList shall be activated. The Ai field is set to "0" to indicate that ith entry in the list shall be deactivated. For each CSI process, the number of Ai fields (i=1, 2,…, 8) which are set to "1" shall be equal to the value of the higher-layer parameter activatedResources in TS 36.331 [8].

Figure 6.1.3.14-1: Activation/Deactivation of CSI-RS resources MAC Control Element

Figure 6.1.3.14-2: Activation/Deactivation CSI-RS command

6.1.3.15 Hibernation MAC Control Elements

The Hibernation MAC control element of one octet is identified by a MAC PDU 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 Hibernation MAC control element with one octet is defined as follows (figure 6.1.3.15-1).

The Hibernation MAC control element of four octets is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-1. It has a fixed size and consists of a four octets containing 31 C-fields and one R-field. The Hibernation MAC control element of four octets is defined as follows (figure 6.1.3.15-2).

For the case with no serving cell with a ServCellIndex (TS 36.331 [8]) larger than 7, Hibernation MAC control element of one octet is applied, otherwise Hibernation MAC control element of four octets is applied.

For the case that Hibernation MAC control element is received and Activation/Deactivation MAC control element is not received:

– Ci: if there is an SCell configured with SCellIndex i as specified in TS 36.331 [8], this field indicates the dormant/activated status of the SCell with SCellIndex i, else the MAC entity shall ignore the Ci field. The Ci field is set to "1" to indicate that the SCell with SCellIndex i shall enter dormant state. When the Ci field is set to "0", the SCell with SCellIndex i shall be activated if it is in already activated state or dormant state, otherwise the Ci field set to "0" shall be ignored.

– R: Reserved bit, set to "0".

For the case that both Activation/Deactivation MAC control element and Hibernation MAC control element are received:

– R: Reserved bit, set to "0".

– Ci: if there is an SCell configured with SCellIndex i as specified in TS 36.331 [8], these fields indicate possible state transitions of the SCell with SCellIndex i, else the MAC entity shall ignore the Ci fields. The Ci fields of the two MAC control elements are interpreted according to Table 6.1.3.15-1.

Figure 6.1.3.15-1: Hibernation MAC control element of one octet

Figure 6.1.3.15-2: Hibernation MAC control element of four octets

Table 6.1.3.15-1: MAC control elements for SCell state transitions

Hibernation MAC control element Ci

Activation/Deactivation MAC control element Ci

SCell shall be

0

0

Deactivated

0

1

Activated

1

0

Reserved MAC control element combination

1

1

Dormant

6.1.3.16 AUL confirmation MAC Control Element

The AUL confirmation MAC control element of one octet is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-2. It has a fixed size and consists of a single octet containing seven C-fields and one R-field. The AUL confirmation MAC control element with one octet is defined as follows (figure 6.1.3.16-1).

The AUL confirmation MAC control element of four octets is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-2. It has a fixed size and consists of a four octets containing 31 C-fields and one R-field. The AUL confirmation MAC control element of four octets is defined as follows (figure 6.1.3.16-2).

For the case with no serving cell with a ServCellIndex (TS 36.331 [8]) larger than 7, AUL confirmation MAC control element of one octet is applied, otherwise AUL confirmation MAC control element of four octets is applied.

– Ci: if there is an SCell configured with SCellIndex i as specified in TS 36.331 [8], this field indicates whether a PDCCH containing AUL activation or AUL release of the autonomous uplink configuration in the SCell with SCellIndex i has been received, else the MAC entity shall ignore the Ci field. The Ci field is set to "1" to indicate that a PDCCH containing AUL activation or AUL release of the autonomous uplink configuration in the SCell with SCellIndex i has been received in the TTI in which AUL confirmation has been triggered. The Ci field is set to "0" to indicate that a PDCCH containing AUL activation or AUL release of the autonomous uplink configuration in the SCell with SCellIndex i has not been received in the TTI in which AUL confirmation has been triggered;

– R: Reserved bit, set to "0".

Figure 6.1.3.16-1: AUL confirmation MAC Control Element of one octet

Figure 6.1.3.16-2: AUL confirmation MAC Control Element of four octets

6.1.3.17 PDCP Duplication Activation/Deactivation MAC Control Element

PDCP Duplication Activation/Deactivation MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-1. It has a fixed size, consists of a single octet containing eight D-fields, and is defined, for a MAC entity, as follows (figure 6.1.3.17-1):

– Di: this field refers to the i-th DRB in the ascending order of the DRB identity among the established DRB(s) configured with duplication and with RLC entity(ies) associated with this MAC entity. Di field set to "1" indicates that the duplication shall be activated and Di field set to "0" indicates that the duplication shall be deactivated.

Figure 6.1.3.17-1: PDCP Duplication Activation/Deactivation MAC Control Element

6.1.3.18 Downlink Channel Quality Report Command MAC Control Element

DCQR Command MAC control element is identified by a MAC PDU subheader with LCID as specified in Table 6.2.1-1.

It has a fixed size of zero bits.

6.1.3.19 Downlink Channel Quality Report and AS RAI MAC Control Element

DCQR and AS RAI MAC control element is identified by a MAC PDU subheader with LCID as specified in Table 6.2.1-2. A MAC PDU shall contain at most one DCQR and AS RAI MAC control element.

It has a fixed size and consists of a single octet defined as follows (Figure 6.1.3.19-1):

– R: Reserved bit, set to "0";

– AS RAI: The field corresponds to Access Stratum Release Assistance Indication as shown in Table 6.1.3.19-1. The length of the field is 2 bits;

– Quality Report: For a NB-IoT UE, if npdsch-16QAM-Config is not configured, the report mapping is defined in Table 9.1.22.15-1 in TS 36.133 [9] and if npdsch-16QAM-Config is configured the report mapping is defined in Table 9.1.22.17-1 in TS 36.133 [9]. For a BL UE or UE in CE, the field corresponds to DL channel quality report as defined in TS 36.133 [9]. The length of the field is 4 bits.

Figure 6.1.3.19-1: DCQR and AS RAI MAC control element

Table 6.1.3.19-1: Values for AS RAI

Codepoint/Index

Value

00

No RAI information

01

No subsequent DL and UL data transmission is expected

10

A single subsequent DL transmission is expected

11

Reserved

6.1.3.20 Timing Advance Report MAC Control Element

The Timing Advance 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 6.1.3.20-1):

– R: Reserved bit, set to 0;

– Timing Advance: The Timing Advance field indicates the least integer number of subframes greater than or equal to the Timing Advance value (see TS 36.211 [7] clause 8.1). The length of the field is 14 bits.

Figure 6.1.3.20-1: Timing Advance MAC CE

6.1.3.21 Differential Koffset MAC Control Element

The Differential Koffset 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 field defined as follows (Figure 6.1.3.21-1):

– R: Reserved bit, set to 0;

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

Figure 6.1.3.21-1: Differential Koffset MAC CE