11.1.5 MO MMTEL voice call setup from NR RRC_CONNECTED / EPS Fallback with redirection / Single registration mode without N26 interface / E-UTRAN cell selection using cell status reservation / Success

38.523-13GPP5GSPart 1: ProtocolRelease 17TSUser Equipment (UE) conformance specification

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

11.1.5.1 Test Purpose (TP)

(1)

with {UE supporting both S1 mode and N1 mode and operating in single-registration mode, and, the Network has indicated "interworking without N26 interface supported", and, the UE is in in NR RRC_CONNECTED state }

ensure that {

when {User initiates a MMTEL call, the MO IMS voice session establishment has been initiated and the UE receives a RRCRelease message which includes redirectedCarrierInfo indicating redirection to eutra, and, an E-UTRA cell on the frequency indicated by redirectedCarrierInfo is found with cell status "reserved for operator use" and another E-UTRA cell is found on another frequency which is not "reserved for operator use" both cells belonging to the UE’s HPLMN}

then { UE selects the E-UTRA cell respecting the UE Access Class, performs an ATTACH or a TAU procedure, and the UE successfully completes the MO MMTEL call in EPS}

}

11.1.5.2 Conformance requirements

References: The conformance requirements covered in the current TC are specified in: TS23.502, clauses 4.11.2.2, 4.13.6.1; TS 24.501, clause 6.1.4.2; TS 38.331, clause 5.3.11, TS 38.304, clause 5.2.6. Unless otherwise stated these are Rel-15 requirements.

[TS 23.502, clause 4.11.2.2]

The following procedure is used by UEs in single-registration or dual registration mode on mobility from 5GS to EPS.

In the case of network sharing the UE selects the target PLMN ID according to clause 5.18.3 of TS 23.501 [2].

Figure 4.11.2.2-1: Mobility procedure from 5GS to EPS without N26 interface

The UE operating in single-registration mode can start the procedure from Step 1 or Step 5. The UE operating in dual-registration mode starts the procedure from Step 5.

NOTE 1: The network has indicated the " Interworking without N26" to the UE. To support IP address preservation, the UE in single-registration mode starts the procedure from Step 5. If the UE in single-registration mode starts the procedure from Step 1, the IP address preservation is not provided.

0. UE is registered in 5GS and established PDU sessions. The FQDN for the S5/S8 interface of the PGW-C+SMF is also stored in the UDM by the PGW-C+SMF during PDU Session setup in addition to what is specified in clause 4.3.2.2.1 and clause 4.3.2.2.2.

NOTE 2: At 5GS to EPS mobility, the MME use the FQDN for the S5/S8 interface of the PGW-C+SMF to find the PGW-C+SMF, and when UE moves back from EPS to 5GS, the AMF uses FQDN for the S5/S8 interface of the PGW-C+SMF to find the PGW-C+SMF.

1. Step 1 as in clause 5.3.3.1 (Tracking Area Update) in TS 23.401 [13].

2. Step 2 as in clause 5.3.3.1 (Tracking Area Update) in TS 23.401 [13] with the following modifications:

The UE shall provide a EPS-GUTI that is mapped from the 5G-GUTI following the mapping rules specified in TS 23.501 [2]. The UE indicates that it is moving from 5GC.

3. Step 3 as in clause 5.3.3.1 (Tracking Area Update) in TS 23.401 [13].

4. If the MME determined that the old node is an AMF based on UE’s GUTI mapped from 5G-GUTI and the MME is configured to support 5GS-EPS interworking without N26 procedure, the MME sends a TAU Reject to the UE.

5. Step 1 as in clause 5.3.2.1 (E-UTRAN Initial Attach) in TS 23.401 [13] with the modifications captured in clause 4.11.2.4.1.

6. Step 2 as in clause 5.3.2.1 (E-UTRAN Initial Attach) in TS 23.401 [13].

7. Steps 4-7 as in clause 5.3.2.1 (E-UTRAN Initial Attach) in TS 23.401 [13], with the modifications captured in clause 4.11.2.4.1.

8. Step 8 as in clause 5.3.2.1 (E-UTRAN Initial Attach) in TS 23.401 [13], with the modifications captured in clause 4.11.2.4.1.

9. Step 11 as in clause 5.3.2.1 (E-UTRAN Initial Attach) in TS 23.401 [13], with the following modifications:

The subscription profile the MME receives from HSS+UDM includes per DNN/APN at most one PGW-C+SMF FQDN as described in in clause 5.17.2.1 in TS 23.501 [2].

10. Steps 12-24 as in clause 5.3.2.1 (E-UTRAN Initial Attach) in TS 23.401 [13], with the modifications as described in clause 4.11.2.4.1.

11. Step 25 as in clause 5.3.2.1 (E-UTRAN Initial Attach) in TS 23.401 [13].

12. Step 26 as in clause 5.3.2.1 (E-UTRAN Initial Attach) in TS 23.401 [13].

13. If the UE has remaining PDU Sessions in 5GS which it wants to transfer to EPS and maintain the same IP address/prefix, the UE performs the UE requested PDN Connectivity Procedure as specified in TS 23.401 [13] clause 5.10.2 and sets the Request Type to "handover" in Step 1 of the procedure with modification captured in clause 4.11.2.4.2. UE provides an APN and the PDU Session ID corresponding to the PDU Session it wants to transfer to EPS. The UE provides the PDU Session ID in PCO as described in clause 4.11.1.1.

UEs in single-registration mode performs this step for each PDU Session immediately after completing the E-UTRAN Initial Attach procedure. UEs in dual-registration mode may perform this step any time after the completing of E-UTRAN Initial Attach procedure. Also, UEs in dual-registration mode may perform this step only for a subset of PDU Sessions.

The MME determines the PGW-C+SMF address for the Create Session Request based on the APN received from the UE and the subscription profile received from the HSS+UDM in Step 9 or when the HSS+UDM notifies the MME for the new PGW-C+SMF ID in the updated subscription profile.

The PGW-C+SMF uses the PDU Session ID to correlate the transferred PDN connection with the PDU Session in 5GC.

As a result of the procedure the PGW-U+UPF starts routing DL data packets to the Serving GW for the default and any dedicated EPS bearers established for this PDN connection.

14. The PGW-C+SMF initiates release of the PDU Session(s) in 5GS transferred to EPS as specified in clause 4.3.4.2 with the following clarification:

In step 2, the PGW-C+SMF shall not release IP address/prefix(es) allocated for the PDU Session.

If UP connection of the PDU Session is not active, step 3b is not executed, thus the steps triggered by step 3b are not executed;

If UP connection of the PDU Session is active, the SMF invokes the Namf_Communication_N1N2MessageTransfer service operation without including N1 SM container (PDU Session Release Command).

[TS 23.502, clause 4.13.6.1]

Figure 4.13.6.1-1 describes the EPS fallback procedure for IMS voice.

When the UE is served by the 5G System, the UE has one or more ongoing PDU Sessions each including one or more QoS Flows. The serving PLMN AMF has sent an indication towards the UE during the Registration procedure that IMS voice over PS session is supported, see clause 5.16.3.10 in TS 23.501 [2] and the UE has registered in the IMS. If N26 is not supported, the serving PLMN AMF sends an indication towards the UE during the Registration procedure that interworking without N26 is supported, see clause 5.17.2.3.1 in TS 23.501 [2].

Figure 4.13.6.1-1: EPS Fallback for IMS voice

1. UE camps on NG-RAN in the 5GS and an MO or MT IMS voice session establishment has been initiated.

2. Network initiated PDU Session modification to setup QoS flow for voice reaches the NG-RAN (see N2 PDU Session Request in clause 4.3.3).

3. NG-RAN is configured to support EPS fallback for IMS voice and decides to trigger fallback to EPS, taking into account UE capabilities, indication from AMF that "Redirection for EPS fallback for voice is possible" (received as part of initial context setup as defined in TS 38.413 [10]), network configuration (e.g. N26 availability configuration) and radio conditions. If NG-RAN decides not to trigger fallback to EPS, then the procedure stops here and following steps are not executed.

NG-RAN may initiate measurement report solicitation from the UE including E-UTRAN as target.

NOTE 1: If AMF has indicated that "Redirection for EPS fallback for voice is not possible", then AN Release via inter-system redirection to EPS is not performed in step 5.

4. NG-RAN responds indicating rejection of the PDU Session modification to setup QoS flow for IMS voice received in step 2 by PDU Session Response message towards the PGW-C+SMF (or H-SMF+P-GW-C via V-SMF, in case of roaming scenario) via AMF with an indication that mobility due to fallback for IMS voice is ongoing. The PGW-C+SMF maintains the PCC rule(s) associated with the QoS Flow(s).

5. NG-RAN initiates either handover (see clause 4.11.1.2.1), or AN Release via inter-system redirection to EPS (see clause 4.2.6 and clause 4.11.1.3.2), taking into account UE capabilities. The PGW-C+SMF reports change of the RAT type if subscribed by PCF as specified in clause 4.11.1.2.1, or clause 4.11.1.3.2.6. When the UE is connected to EPS, either 6a or 6b is executed

6a. In the case of 5GS to EPS handover, see clause 4.11.1.2.1, and in the case of inter-system redirection to EPS with N26 interface, see clause 4.11.1.3.2. In either case the UE initiates TAU procedure; or

6b. In the case of inter-system redirection to EPS without N26 interface, see clause 4.11.2.2. If the UE supports Request Type flag "handover" for PDN connectivity request during the attach procedure as described in clause 5.3.2.1 of TS 23.401 [13] and has received the indication that interworking without N26 is supported, then the UE initiates Attach with PDN connectivity request with request type "handover".

In inter-system redirection, the UE uses the emergency indication in the RRC message as specified in clause 6.2.2 of TS 36.331 [16] and E-UTRAN provides the emergency indication to MME during Tracking Area Update or Attach procedure. For the handover procedure see clause 4.11.1.2.1, step 1.

7. After completion of the mobility procedure to EPS or as part of the 5GS to EPS handover procedure (see clause 4.11.1.2.1), the SMF/PGW re-initiates the setup of the dedicated bearer for IMS voice, mapping the 5G QoS to EPC QoS parameters. The PGW-C+SMF behaves as specified in clause 4.9.1.3.1. The PGW-C+SMF reports about Successful Resource Allocation and Access Network Information if subscribed by PCF.

8. The IMS voice session establishment is continued.

At least for the duration of the voice call in EPS the E-UTRAN is configured to not trigger any handover to 5GS.

[TS 24.501, clause 6.1.4.2]

When the network does not support N26 interface, the SMF does not provide the UE with the mapped EPS bearer context for a PDU session.

NOTE 1: Since the SMF does not provide the UE with the mapped EPS bearer context for a PDU session, the UE does not know whether interworking with EPS is supported for a PDU session before attempting to transfer the PDU session from N1 mode to S1 mode.

NOTE 2: It is up to UE implementation to decide which PDU session(s) to be attempted to transfer from N1 mode to S1 mode, e.g. based on UE policy or user preference.

Upon inter-system change from N1 mode to S1 mode in EMM-IDLE mode, the UE shall use the parameters from each PDU session which the UE intends to transfer to EPS to create the contents of a PDN CONNECTIVITY REQUEST message as follows:

a) if the PDU session is an emergency PDU session, the request type shall be set to "handover of emergency bearer services". Otherwise the request type shall be set to "handover";

b) the PDU session type of the PDU session shall be mapped to the PDN type of the default EPS bearer context as follows:

1) the PDN type shall be set to "non-IP" if the PDU session type is "Ethernet" or "Unstructured";

2) the PDN type shall be set to "IPv4" if the PDU session type is "IPv4";

3) the PDN type shall be set to "IPv6" if the PDU session type is "IPv6"; and

4) the PDN type shall be set to "IPv4v6" if the PDU session type is "IPv4v6";

c) the DNN of the PDU session shall be mapped to the APN of the default EPS bearer context; and

d) the PDU session ID parameter in the PCO IE shall be set to the PDU session identity of the PDU session.

After inter-system change from N1 mode to S1 mode, the UE shall associate the PDU session identity with the default EPS bearer context.

Upon successful completion of an EPS attach procedure after inter-system change from N1 mode to S1 mode (see 3GPP TS 24.301 [15]), the UE shall delete any UE derived QoS rules.

The UE shall locally release the PDU session(s) and QoS flow(s) associated with the 3GPP access which have not been transferred to EPS.

…

[TS 38.331, clause 5.3.11]

UE shall:

1> reset MAC;

1> if T302 is running:

2> stop timer T302;

2> perform the actions as specified in 5.3.14.4;

1> stop all timers that are running except T320 and T325;

1> discard the UE Inactive AS context;

1> set the variable pendingRnaUpdate to false, if that is set to true;

1> discard the K_gNB, the K_RRCenc key, the K_RRCint, the K_UPint key and the K_UPenc key, if any;

1> release all radio resources, including release of the RLC entity, the MAC configuration and the associated PDCP entity and SDAP for all established RBs;

1> indicate the release of the RRC connection to upper layers together with the release cause;

1> enter RRC_IDLE and perform cell selection as specified in TS 38.304 [20], except if going to RRC_IDLE was triggered by selecting an inter-RAT cell while T311 was running;

1> if going to RRC_IDLE was triggered by reception of the RRCRelease message including a waitTime:

2> start timer T302 with the value set to the waitTime;

2> inform the upper layer that access barring is applicable for all access categories except categories ‘0’ and ‘2’.

[TS 38.304, clause 5.2.6]

At reception of RRCRelease message to transition the UE to RRC_IDLE or RRC_INACTIVE, UE shall attempt to camp on a suitable cell according to redirectedCarrierInfo if included in the RRCRelease message. If the UE cannot find a suitable cell, the UE is allowed to camp on any suitable cell of the indicated RAT. If the RRCRelease message does not contain the redirectedCarrierInfo, UE shall attempt to select a suitable cell on an NR carrier. If no suitable cell is found according to the above, the UE shall perform cell selection using stored information in order to find a suitable cell to camp on.

When returning to RRC_IDLE state after UE moved to RRC_CONNECTED state from camped on any cell state, UE shall attempt to camp on an acceptable cell according to redirectedCarrierInfo, if included in the RRCRelease message. If the UE cannot find an acceptable cell, the UE is allowed to camp on any acceptable cell of the indicated RAT. If the RRCRelease message does not contain redirectedCarrierInfo UE shall attempt to select an acceptable cell on an NR frequency. If no acceptable cell is found according to the above, the UE not in SNPN Access Mode shall continue to search for an acceptable cell of any PLMN in state any cell selection.

11.1.5.3 Test description

11.1.5.3.1 Pre-test conditions

System Simulator:

– 3 cells

– NR Cell 1 as defined in TS 38.508-1 [4] Table 4.4.2-3. System information combination NR-6 as defined in TS 38.508-1 [4], sub-clause 4.4.3.1.2.

– E-UTRA Cell 1 as defined in TS 36.508 [7] Table 4.4.2-2. System information combination 31 as defined in TS 36.508 [7], sub-clause 4.4.3.1.1.

– E-UTRA Cell 3 as defined in TS 36.508 [7] Table 4.4.2-2. System information combination 1 as defined in TS 36.508 [7], sub-clause 4.4.3.1.1. Cell 3 is set as "reserved for operator use" in SIB1.

– Power levels are constant and as defined in Tables 11.1.5.3.1-1/2.

Table 11.1.5.3.1-1: Time instances of cell power level and parameter changes for conducted test environment

	Parameter name	Unit	NR Cell 1	E-UTRA Cell 1	E-UTRA Cell 3	Remark
T0	SS/PBCH SSS EPRE	dBm/SCS	-88	–	–
T0	RS EPRE	dBm/15kHz	–	-85	-73

Table 11.1.5.3.1-2: Time instances of cell power level and parameter changes for OTA test environment

	Parameter name	Unit	NR Cell 1	E-UTRA Cell 1	E-UTRA Cell 3	Remark
T0	SS/PBCH SSS EPRE	dBm/SCS	-82	–	–
T0	RS EPRE	dBm/15kHz	–	-96	-96

UE:

– The UE fitted with a USIM with access class 0..9

Preamble:

– With E-UTRA Cell 1 "Serving cell", E-UTRA Cell 3 "Non-suitable "Off" cell" and NR Cell 1 "Non-suitable "Off" cell" in accordance with TS 38.508-1 [4], Table 6.2.2.1-3, the UE is brought to state RRC_IDLE using generic procedure parameters Connectivity (E-UTRA/EPC) and Unrestricted nr PDN (On) in accordance with the procedure described in TS 38.508-1 [4], clause 4.5.2. 4G GUTI and eKSI are assigned and security context established.

– The UE is switched-off.

– With E-UTRA Cell 1 "Non-suitable "Off" cell", E-UTRA Cell 3 "Non-suitable "Off" cell" and NR Cell 1 "Serving cell" in accordance with TS 38.508-1 [4], Table 6.2.2.1-3, the UE is brought to state 1N-A, RRC_IDLE Connectivity (NR), with at least one IMS PDU session on NR Cell 1, in accordance with the procedure described in TS 38.508-1 [4], Table 4.5.2.2-2. 5G-GUTI and ngKSI are assigned.

11.1.5.3.2 Test procedure sequence

Table 11.1.5.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
0	Void	–	–	–	–
–	EXCEPTION: The following messages are to be observed on NR Cell 1 unless explicitly stated otherwise.	–	–	–	–
1	The SS transmits a Paging message.	<–	NR RRC: Paging	–	–
2	The UE transmits an RRCSetupRequest message.	–>	NR RRC: RRCSetupRequest	–	–
3-9a2	Steps 3 to 9a2 of the NR RRC_CONNECTED procedure in TS 38.508-1 [4] Table 4.5.4.2-3 are executed to successfully complete the service request procedure.	–	–	–	–
9A	Set the power levels according to “T0” as per Table 11.1.5.3.1-1/2.	–	–	–	–
10	Make the UE attempt an MTSI MO Speech Call.	–	–	–	–
11	The UE transmits an INVITE message.	–	–	–	–
12	Void	–	–	–	–
12a1	Void	–		–	–
13	The SS transmits an RRCRelease message.	<–	NR RRC: RRCRelease	–	–
–	EXCEPTION: The following messages are to be observed on E-UTRA Cell 1 unless explicitly stated otherwise.	–	–	–	–
14	Check: Does the UE send an RRCConnectionRequest message on E-UTRA cell 1?	–>	RRC: RRCConnectionRequest	1	P
15	SS transmits an RRCConnectionSetup message.	<–	RRC: RRCConnectionSetup	–	–
–	EXCEPTION: Steps 15Aa1 to 15Ab3 describe behaviour that depends on the UE implementation; the "lower case letter" identifies a step sequence that take place depending on the UE implementation.	–	–	–	–
15a1-15b3	Void	–	–	–	–
15Aa1	If the UE tries to preserve the IP address of the PDN connection then check does the UE transmits an ATTACH REQUEST message?	–>	RRC: RRCConnectionSetupComplete NAS: ATTACH REQUEST	1	P
15Ab1	Else check: does the UE transmit a TRACKING AREA UPDATE REQUEST message?	–>	RRC: RRCConnectionSetupComplete NAS: TRACKING AREA UPDATE REQUEST	1	P
15Ab2	The SS transmites a TRACKING AREA UPDATE REJECT message to UE.	<–	RRC: DLInformationTransfer NAS: TRACKING AREA UPDATE REQUEST REJECT	–	–
15Ab3	The UE transmits an ATTACH REQUEST message.	–>	RRC: ULInformationTransfer NAS: ATTACH REQUEST	–	–
16-27	Steps 5 to 16 of the generic test procedure for UE registration (TS 36.508 [2] Table 4.5.2.3-1).	–	–	–	–
–	EXCEPTION: In parallel to the events described in steps 28 to 36 the steps specified in Table 11.1.5.3.2-2 may take place to transfer other PDU sessions to EPS.	–	–	–	–
–	EXCEPTION: In parallel to the events described in steps 28 to 37 the UE may perform IMS re-registration on EUTRAN as per steps 3-11 as defined in 34.229-1 [35] subclause C.46 using the message “REGISTER” with condition A31.	–	–	–	–
28-32	Steps 9a1-13 from the Generic Test Procedure for MTSI MO speech call establishment (TS 36.508 [2] table 4.5A.6.3-1) are performed.	–	–	–	–
33-34	Void	–	–	–	–
35	Check: Does the UE transmit an ACTIVATE DEDICATED EPS BEARER CONTEXT ACCEPT message?	–>	RRC: ULInformationTransfer NAS:ACTIVATE DEDICATED EPS BEARER CONTEXT ACCEPT	1	P
36	The SS waits 1 second.	–	–	–	–
36a1	Void	–	–	–	–
37	Release IMS Call as specified in the generic procedure in TS 34.229-1 [35] subclause C.32.	–	–	–	–

Table 11.1.5.3.2-2: Parallel behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1	Check: Does the UE transmit a PDN CONNECTIVITY REQUEST message to request an additional PDN.	–>	RRC: ULInformationTransfer NAS: PDN CONNECTIVITY REQUEST	1	P
2	The SS configures a new data radio bearer, associated with the additional default EPS bearer context. RRCConnectionReconfiguration message contains the ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message.	<–	RRC: RRCConnectionReconfiguration NAS: ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST
3	The UE transmits an RRCConnectionReconfigurationComplete message to confirm the establishment of additional default bearer.	–>	RRC: RRCConnectionReconfigurationComplete
–	EXCEPTION: In parallel to the event described in step 4 below, if initiated by the UE the generic procedure for IP address allocation in the U-plane specified in TS 36.508 subclause 4.5A.1 takes place performing IP address allocation in the U-plane.	–	–
4	The UE transmits an ACTIVATE DEFAULT EPS BEARER CONTEXT ACCEPT message.	–>	RRC: ULInformationTransfer NAS: ACTIVATE DEFAULT EPS BEARER CONTEXT ACCEPT

11.1.5.3.3 Specific message contents

Table 11.1.5.3.3-0: REGISTRATION ACCEPT (preamble)

Derivation path: TS 38.508-1 [4] Table 4.7.1-7
Information Element	Value/remark	Comment	Condition
Extended protocol discriminator	‘0111 1110’B	5GS mobility management messages
Security header type	’0000’B	Plain 5GS NAS message, not security protected
Spare half octet	‘0000’B
5GS network feature support	‘0100 0001 0000 0000’B	Interworking without N26 interface supported

Table 11.1.5.3.3-1: RRCRelease (step 13, table 11.1.5.3.2-1)

Derivation path: TS 38.508-1 [4] Table Table 4.6.1-16
Information Element	Value/Remark	Comment	Condition
RRCRelease ::= SEQUENCE {
criticalExtensions CHOICE {
rrcRelease SEQUENCE {
redirectedCarrierInfo CHOICE {
eutra SEQUENCE {
eutraFrequency	Downlink EARFCN of E-UTRA cell 3
cnType	epc
}
}
}
}
}
}

Table 11.1.5.3.3-2: ATTACH REQUEST (step 15a1, table 11.1.5.3.2-1)

Derivation Path: TS 36.508 [7], Table 4.7.2-4
Information Element	Value/Remark	Comment	Condition
NAS key set identifier	KSI_ASMEthat was created when the UE last registered to EPC E-UTRA
EPS mobile identity	GUTI, assigned by E-UTRA Cell 1 at the initial registration when the UE entered S1
Last visited registered TAI	The TAI the last visited E-UTRA Cell belonged to, if any. Not included if the UE does not have last stored EPC TAI.
Old GUTI type	"Native GUTI"
ESM message container	PDN CONNECTIVITY REQUEST message to active PDU sessions which the UE intends to transfer to EPS.

Table 11.1.5.3.3-3: PDN CONNECTIVITY REQUEST (Table 11.1.5.3.3-2)

Derivation Path: TS 36.508 [7], Table 4.7.3-20
Information Element	Value/remark	Comment	Condition
EPS bearer identity	0	No EPS bearer identity assigned, for coding see Table 9.11.4.8.1 in TS 24.501 [22]
Procedure transaction identity	Any value from 1 to 254
PDN connectivity request message identity	‘1101 0000’B	PDN connectivity request
Request type	‘010’B	Handover
PDN type	Any value between ‘001’B, ‘010’B, ‘011’B and ‘100’B	The allowed values are respectively IPv4, IPv6, IPv4v6 and "unused but interpreted as IPv6 by the network"
Protocol configuration options	PDU session ID of IMS PDU session

Table 11.1.5.3.3-4: TRACKING AREA UPDATE REQUEST (step 15b1, table 11.1.5.3.2-1)

Derivation Path: TS 36.508 [7], Table 4.7.2-27, condition NR.
Information Element	Value/Remark	Comment	Condition
"Active" flag	0001	Bearer Establishment requested
EPS bearer context status	Present	EBI corresponding to active PDU Sessions need to be set to 1
NAS key set identifier	KSI_ASMEthat was created when the UE last registered to EPC E-UTRA
Old GUTI	GUTI, mapped from the 5G-GUTI assigned at the initial registration when the UE entered N1
Last visited registered TAI	The TAI the last visited E-UTRA Cell belonged to, if any. Not included if the UE does not have last stored EPC TAI.
Old GUTI type	"Native GUTI"
UE status	"UE is in 5GMM-REGISTERED state"

Table 11.1.5.3.3-5: TRACKING AREA UPDATE REJECT (step 15b2, table 11.1.5.3.2-1)

Derivation Path: TS 36.508 [7], Table 4.7.2-26.
Information Element	Value/Remark	Comment	Condition
EMM cause	‘0000 1001’B	#9 "UE identity cannot be derived by the network"

Table 11.1.5.3.3-6: ATTACH REQUEST (step 15b3, table 11.1.5.3.2-1)

Derivation Path: TS 36.508 [7], Table 4.7.2-4.
Information Element	Value/Remark	Comment	Condition
IMSI	IMSI of the UE

Table 11.1.5.3.3-7: PDN CONNECTIVITY REQUEST (step 1, table 11.1.5.3.2-2)

Derivation Path: TS 36.508 [7], Table 4.7.3-20
Information Element	Value/remark	Comment	Condition
EPS bearer identity	0	No EPS bearer identity assigned, for coding see Table 9.11.4.8.1 in TS 24.501 [22]
Procedure transaction identity	Any value from 1 to 254
PDN connectivity request message identity	‘1101 0000’B	PDN connectivity request
Request type	‘010’B	Handover
PDN type	Any value between ‘001’B, ‘010’B, ‘011’B and ‘100’B	The allowed values are respectively IPv4, IPv6, IPv4v6 and "unused but interpreted as IPv6 by the network"
Protocol configuration options	PDU session ID of internet PDU session

Table 11.1.5.3.3-8: SystemInformationBlockType1 of E-UTRA Cell 3 (all steps, table 11.1.5.3.2-1)

Derivation Path: 36.508 [7] Table 4.4.3.2-3
Information Element	Value/remark	Comment	Condition
SystemInformationBlockType1 ::= SEQUENCE {
cellAccessRelatedInfo SEQUENCE {
plmn-IdentityList SEQUENCE (SIZE (1..6)) OF SEQUENCE {	1 entry
cellReservedForOperatorUse[1]	reserved
}
}
}

Table 11.1.5.3.3-9: ATTACH ACCEPT (preamble, step 25; step 14, TS 36.508-1 [7], Table 4.5.2.3-1)

Derivation path: TS 36.508-1 [7] Table 4.7.2-1

Information Element

Value/remark

Comment

Condition

EPS network feature support

‘0000 0011 0100 1000’B

– IMS voice over PS session in S1 mode supported

– emergency bearer services in S1 mode supported

– ePCO supported

– Interworking without N26 interface supported

Table 11.1.5.3.3-10: ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST (preamble, step 25; step 14, TS 36.508-1 [7], Table 4.5.2.3-1)

Derivation Path: TS 36.508-1 [7] Table 4.7.3-6
Information Element	Value/remark	Comment	Condition
Protocol configuration options
Container ID n+2	Not present	Session-AMBR are not present
Container ID n+3	Not present	QoS rules are not present
Container ID n+4	Not present	Qos flow descriptions are not present