Section: 6.4.4.3 EPS bearer context deactivation accepted by the UE
Content: Upon receipt of the DEACTIVATE EPS BEARER CONTEXT REQUEST message, the UE shall delete the EPS bearer context identified by the EPS bearer identity. After deactivating the identified EPS bearer context, the UE shall respond to the MME with the DEACTIVATE EPS BEARER CONTEXT ACCEPT. If the EPS bearer identity indicated in the DEACTIVATE EPS BEARER CONTEXT REQUEST is that of the default bearer to a PDN, the UE shall delete all EPS bearer contexts associated to the PDN. After deactivating all EPS bearer contexts, the UE shall respond to the MME with the DEACTIVATE EPS BEARER CONTEXT ACCEPT. Upon sending the DEACTIVATE EPS BEARER CONTEXT ACCEPT message, the UE shall enter the state BEARER CONTEXT INACTIVE. If due to the EPS bearer context deactivation only the PDN connection for emergency bearer services remains established, the UE shall consider itself attached for emergency bearer services only. If the DEACTIVATE EPS BEARER CONTEXT REQUEST includes ESM cause #39 "reactivation requested" and the EPS bearer context is a default EPS bearer context, and the UE provided an APN for the establishment of the PDN connection, the UE shall stop timer T3396 if it is running for the APN provided by the UE. The UE should then re-initiate the UE requested PDN connectivity procedure for the same APN as the deactivated default EPS bearer context to reactivate the EPS bearer context. If the UE did not provide an APN for the establishment of the PDN connection and the request type was different from "emergency" and from "handover of emergency bearer services", the UE shall stop the timer T3396 associated with no APN if it is running, and should re-initiate the UE requested PDN connectivity procedure without including an APN. Additionally, the UE should re-initiate the request(s) for dedicated bearer resources that have been activated on request of the UE and released as a result of this EPS bearer context deactivation procedure. If the DEACTIVATE EPS BEARER CONTEXT REQUEST message was received for an emergency PDN connection, the UE shall not stop the timer T3396 associated with no APN if it is running. The UE should then re-initiate the UE requested PDN connectivity procedure for the emergency PDN connection. NOTE 1: User interaction is necessary in some cases when the UE cannot re-activate the EPS bearer context(s) automatically. NOTE 2: The UE behaviour is not specified for the case where the DEACTIVATE EPS BEARER CONTEXT REQUEST includes ESM cause #39 "reactivation requested" and the deactivated EPS bearer context was a dedicated EPS bearer context. If the DEACTIVATE EPS BEARER CONTEXT REQUEST message contains a PTI value other than "no procedure transaction identity assigned" and "reserved" (see 3GPP TS 24.007[ Mobile radio interface signalling layer 3; General Aspects ]  [12]), the UE uses the PTI to identify the UE requested bearer resource modification procedure or UE requested PDN disconnect procedure to which the EPS bearer context deactivation is related (see clause 6.5.4). If the DEACTIVATE EPS BEARER CONTEXT REQUEST message contains a PTI value other than "no procedure transaction identity assigned" and "reserved" (see 3GPP TS 24.007[ Mobile radio interface signalling layer 3; General Aspects ]  [12]), the UE shall release the traffic flow aggregate description associated to the PTI value provided. If the ESM cause value is #26 "insufficient resources", the network may include a value for timer T3396 in the DEACTIVATE EPS BEARER CONTEXT REQUEST message. The UE shall take different actions depending on the timer value received for timer T3396 (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, the UE shall stop timer T3396 associated with the corresponding APN, if it is running. The UE shall start timer T3396 with received value and 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 timer T3396 expires or the timer T3396 is stopped. If the UE did not provide an APN for the establishment of the PDN connection 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 start timer T3396 with the received value and 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, 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. If the UE did not provide an APN for the establishment of the PDN connection and the request type was different from "emergency" and from "handover of emergency bearer services", the UE 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 APN provided 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, 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 the UE did not provide an APN for the establishment of the PDN connection 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. 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, the UE shall behave as follows when the UE is switched on and the USIM in the UE remains the same: - 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 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 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. If the T3396 IE is not included, the UE shall proceed with deactivation procedure and then send DEACTIVATE EPS BEARER CONTEXT ACCEPT message. Upon receipt of the DEACTIVATE EPS BEARER CONTEXT ACCEPT message, the MME shall enter the state BEARER CONTEXT INACTIVE and stop the timer T3495.