Section: 6.5.1.4.2 Handling of network rejection due to ESM cause #26
Content: If the ESM cause value is #26 "insufficient resources" and the Back-off timer value IE is included, the UE shall ignore the Re-attempt indicator IE provided by the network, if any, and behave as follows: 1) if the PDN CONNECTIVITY REQUEST message was sent standalone, the UE shall take different actions depending on the timer value received for timer T3396 in the Back-off timer value IE (if the UE is configured for dual priority, exceptions are specified in clause 6.5.5; if the UE is a UE configured to use AC11 – 15 in selected PLMN, exceptions are specified in clause 6.3.5): i) if the timer value indicates neither zero nor deactivated and an APN was included in the PDN CONNECTIVITY REQUEST message, the UE shall stop timer T3396 associated with the corresponding APN, if it is running. If the timer value indicates neither zero nor deactivated, no APN was included in the PDN CONNECTIVITY REQUEST message and the request type was different from "emergency" and from "handover of emergency bearer services", the UE shall stop timer T3396 associated with no APN if it is running. The UE shall then start timer T3396 with the value provided in the Back-off timer value IE and: - shall not send another PDN CONNECTIVITY REQUEST, BEARER RESOURCE MODIFICATION REQUEST with exception of those identified in clause 6.5.4.1, or BEARER RESOURCE ALLOCATION REQUEST message for the same APN that was sent by the UE, until timer T3396 expires or timer T3396 is stopped; and - shall not send another PDN CONNECTIVITY REQUEST message without an APN and with request type different from "emergency" and from "handover of emergency bearer services", or another BEARER RESOURCE MODIFICATION REQUEST with exception of those identified in clause 6.5.4.1, or BEARER RESOURCE ALLOCATION REQUEST for a non-emergency PDN connection established without an APN provided by the UE, if no APN was included in the PDN CONNECTIVITY REQUEST message and the request type was different from "emergency" and from "handover of emergency bearer services", until timer T3396 expires or timer T3396 is stopped. The UE shall not stop timer T3396 upon a PLMN change or inter-system change; ii) if the timer value indicates that this timer is deactivated, the UE: - shall not send another PDN CONNECTIVITY REQUEST, BEARER RESOURCE MODIFICATION REQUEST with exception of those identified in clause 6.5.4.1, or BEARER RESOURCE ALLOCATION REQUEST message for the same APN until the UE is switched off or the USIM is removed, or the UE receives an ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST, ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST or MODIFY EPS BEARER CONTEXT REQUEST message for the same APN from the network or a DEACTIVATE EPS BEARER CONTEXT REQUEST message including ESM cause #39 "reactivation requested" for a default EPS bearer context for the same APN from the network; and - shall not send another PDN CONNECTIVITY REQUEST message without an APN and with request type different from "emergency" and from "handover of emergency bearer services", or another BEARER RESOURCE MODIFICATION REQUEST with exception of those identified in clause 6.5.4.1, or BEARER RESOURCE ALLOCATION REQUEST message for a non-emergency PDN connection established without an APN provided by the UE, if no APN was included in the PDN CONNECTIVITY REQUEST message and the request type was different from "emergency" and from "handover of emergency bearer services", until the UE is switched off or the USIM is removed, or the UE receives an ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST, ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST or MODIFY EPS BEARER CONTEXT REQUEST message for a non-emergency PDN connection established without an APN provided by the UE, or a DEACTIVATE EPS BEARER CONTEXT REQUEST message including ESM cause #39 "reactivation requested" for a default EPS bearer context of a non-emergency PDN connection established without an APN provided by the UE. The timer T3396 remains deactivated upon a PLMN change or inter-system change; and iii) if the timer value indicates zero, the UE: - shall stop timer T3396 associated with the corresponding APN, if running, and may send another PDN CONNECTIVITY REQUEST, BEARER RESOURCE MODIFICATION REQUEST or BEARER RESOURCE ALLOCATION REQUEST message for the same APN; and - if no APN was included in the PDN CONNECTIVITY REQUEST message and the request type was different from "emergency" and from "handover of emergency bearer services", the UE shall stop timer T3396 associated with no APN, if running, and may send another PDN CONNECTIVITY REQUEST message without an APN, or another BEARER RESOURCE MODIFICATION REQUEST or BEARER RESOURCE ALLOCATION REQUEST message for a non-emergency PDN connection established without an APN provided by the UE; and 2) if the PDN CONNECTIVITY REQUEST message was sent together with an ATTACH REQUEST, the UE shall take different actions depending on the timer value received for timer T3396 in the Back-off timer value IE and on the integrity protection of the ATTACH REJECT message (if the UE is configured for dual priority, exceptions are specified in clause 6.5.5; if the UE is a UE configured to use AC11 – 15 in selected PLMN, exceptions are specified in clause 6.3.5): i) if the ATTACH REJECT message is not integrity protected and an APN was sent by the UE during the attach procedure, the UE shall stop timer T3396 associated with the corresponding APN if it is running. If the ATTACH REJECT message is not integrity protected, the request type was different from "emergency" and from "handover of emergency bearer services", and an APN was not sent by the UE, the UE shall stop timer T3396 associated with no APN if it is running. The UE shall then start timer T3396 with a random value from a default range specified in table 11.2.3 defined in 3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  [13], and: a) shall not initiate a new attach procedure with the same APN or send another PDN CONNECTIVITY REQUEST with the same APN that was sent by the UE, until timer T3396 expires or timer T3396 is stopped; and b) shall not initiate a new attach procedure without an APN and with request type different from "emergency" and from "handover of emergency bearer services" or send another PDN CONNECTIVITY REQUEST without an APN and with request type different from "emergency" and from "handover of emergency bearer services", if the UE did not provide any APN during the attach procedure and the request type was different from "emergency" and from "handover of emergency bearer services", until timer T3396 expires. The UE shall not stop timer T3396 upon a PLMN change or inter-system change; ii) if the ATTACH REJECT message is integrity protected, the UE shall proceed as follows: a) if the timer value indicates neither zero nor deactivated and an APN was sent by the UE during the attach procedure, the UE shall stop timer T3396 associated with the corresponding APN if it is running. If the timer value indicates neither zero nor deactivated, the request type was different from "emergency" and from "handover of emergency bearer services", and an APN was not sent by the UE during the attach procedure, the UE shall stop timer T3396 associated with no APN if it is running. The UE shall then start timer T3396 with the value provided in the Back-off timer value IE and: - shall not initiate a new attach procedure with the same APN or send another PDN CONNECTIVITY REQUEST with the same APN that was sent by the UE, until timer T3396 expires or timer T3396 is stopped; and - shall not initiate a new attach procedure without an APN and with request type different from "emergency" and from "handover of emergency bearer services" or send another PDN CONNECTIVITY REQUEST without an APN and with request type different from "emergency" and from "handover of emergency bearer services", if the UE did not provide any APN during the attach procedure and the request type was different from "emergency" and from "handover of emergency bearer services", until timer T3396 expires. The UE shall not stop timer T3396 upon a PLMN change or inter-system change; b) if the timer value indicates that this timer is deactivated, the UE: - shall not initiate a new attach procedure with the same APN or send another PDN CONNECTIVITY REQUEST with the same APN that was sent by the UE, until the UE is switched off or the USIM is removed, or the UE receives an ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message for the same APN from the network; and - shall not initiate a new attach procedure without an APN and with request type different from "emergency" and from "handover of emergency bearer services" or send another PDN CONNECTIVITY REQUEST without an APN and with request type different from "emergency" and from "handover of emergency bearer services", if the UE did not provide any APN during the attach procedure and the request type was different from "emergency" and from "handover of emergency bearer services", until the UE is switched off or the USIM is removed, or the UE receives an ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message for a non-emergency PDN connection established without an APN provided by the UE. The timer T3396 remains deactivated upon a PLMN change or inter-system change; and c) if the timer value indicates that this timer is zero, the UE shall proceed as specified in clause 5.5.1.2.6 item d. If the Back-off timer value IE is not included and the PDN CONNECTIVITY REQUEST was sent standalone, then the UE may send another PDN CONNECTIVITY REQUEST, BEARER RESOURCE MODIFICATION REQUEST or BEARER RESOURCE ALLOCATION REQUEST message for the same APN. When the timer T3396 is running or the timer is deactivated, the UE is allowed to initiate an attach procedure or PDN connectivity procedure if the procedure is for emergency bearer services. If the timer T3396 is running when the UE enters state EMM-DEREGISTERED, the UE remains switched on, and the USIM in the UE remains the same, then timer T3396 is kept running until it expires or it is stopped. If the UE is switched off when the timer T3396 is running, and if the USIM in the UE remains the same when the UE is switched on, the UE shall behave as follows: - let t1 be the time remaining for T3396 timeout at switch off and let t be the time elapsed between switch off and switch on. If t1 is greater than t, then the timer shall be restarted with the value t1 – t. If t1 is equal to or less than t, then the timer need not be restarted. If the UE is not capable of determining t, then the UE shall restart the timer with the value t1; - if prior to switch off, timer T3396 was running for a specific APN, because a PDN CONNECTIVITY REQUEST, BEARER RESOURCE MODIFICATION REQUEST or BEARER RESOURCE ALLOCATION REQUEST message containing the low priority indicator set to "MS is configured for NAS signalling low priority" was rejected with a timer value for timer T3396, and if timer T3396 is restarted at switch on, then the UE configured for dual priority shall handle session management requests as indicated in clause 6.5.5; and - if prior to switch off timer T3396 was running because a PDN CONNECTIVITY REQUEST without APN sent together with an ATTACH REQUEST message containing the low priority indicator set to "MS is configured for NAS signalling low priority" was rejected with a timer value for timer T3396, and if timer T3396 is restarted at switch on, then the UE configured for dual priority shall handle session management requests as indicated in clause 6.5.5.