Section: 6.1.3.2.2.3 Handling of network rejection due to SM cause other than SM cause #26
Content: If the SM cause value is different from #26 "insufficient resources" and #65 "maximum number of PDP contexts reached", and the Back-off timer value IE is included, the MS takes different actions depending on the timer value received in the Back-off timer value IE (if the MS is an MS configured to use AC11 – 15 in selected PLMN, exceptions are specified in subclause 6.1.3.13): i) if the timer value indicates neither zero nor deactivated, the MS shall start the back-off timer with the value provided in the Back-off timer value IE for the secondary PDP context activation procedure and PLMN and combination and not send another ACTIVATE SECONDARY PDP CONTEXT REQUEST message in the PLMN for the same until the back-off timer expires, the MS is switched off or the /USIM is removed; ii) if the timer value indicates that this timer is deactivated, the MS shall not send another ACTIVATE SECONDARY PDP CONTEXT REQUEST message in the PLMN for the same until the MS is switched off or the /USIM is removed; and iii) if the timer value indicates that this timer is zero, the MS may send an ACTIVATE SECONDARY PDP CONTEXT REQUEST message in the PLMN for the same . If the Back-off timer value IE is not included, then the MS shall ignore the Re-attempt indicator IE provided by the network, if any. i) Additionally, if the SM cause value is #32 "service option not supported", or #33 "requested service option not subscribed", the MS shall proceed as follows: - if the MS is registered in its HPLMN or in a PLMN that is within the EHPLMN list (if the EHPLMN list is present), the MS shall behave as described above in the present subclause, using the configured SM_RetryWaitTime value as specified in 3GPP TS 24.368[ Non-Access Stratum (NAS) configuration Management Object (MO) ]  [135] or in USIM file NASCONFIG as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [112], if available, as back-off timer value; and - otherwise, if the MS is not registered in its HPLMN or in a PLMN that is within the EHPLMN list (if the EHPLMN list is present), or if the SM_RetryWaitTime value is not configured, the MS shall behave as described above in the present subclause using the default value of 12 minutes for the back-off timer. ii) For SM cause values different from #32 "service option not supported", or #33 "requested service option not subscribed", the MS behaviour regarding the start of a back-off timer is unspecified. The MS shall not stop any back-off timer upon a PLMN change or inter-system change. If the network indicates that a back-off timer for the secondary PDP context activation procedure and PLMN and APN combination is deactivated, then it remains deactivated upon a PLMN change or inter-system change. NOTE 1: This means the back-off timer can still be running or be deactivated for the given SM procedure and PLMN and APN combination when the MS returns to the PLMN or when it performs inter-system change back from S1 mode to A/Gb or Iu mode. Thus the MS can still be prevented from sending another ACTIVATE SECONDARY PDP CONTEXT REQUEST message in the PLMN for the same APN. If the back-off timer is started upon receipt of an ACTIVATE SECONDARY PDP CONTEXT REJECT message (i.e. the timer value was provided by the network, a configured value is available or the default value is used as explained above) or the back-off timer is deactivated, the MS behaves as follows: i) after a PLMN change the MS may send an ACTIVATE SECONDARY PDP CONTEXT REQUEST message for the same in the new PLMN, if the back-off timer is not running and is not deactivated for the secondary PDP context activation procedure and the combination of new PLMN and APN; Furthermore as an implementation option, for the SM cause values #32 "service option not supported" or #33 "requested service option not subscribed", if the network does not include a Re-attempt indicator IE, the MS may decide not to automatically send another ACTIVATE SECONDARY PDP CONTEXT REQUEST message for the same APN, if the MS registered to a new PLMN which is in the list of equivalent PLMNs. ii) if the network does not include the Re-attempt indicator IE to indicate whether re-attempt in S1 mode is allowed, or the MS ignores the Re-attempt indicator IE, e.g. because the Back-off timer value IE is not included, then: - if the MS is registered in its HPLMN or in a PLMN that is within the EHPLMN list (if the EHPLMN list is present), the MS shall apply the configured SM_RetryAtRATChange value as specified in 3GPP TS 24.368[ Non-Access Stratum (NAS) configuration Management Object (MO) ]  [135] or in USIM file NASCONFIG as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [112], if available, to determine whether the MS may attempt a bearer resource allocation procedure for the same PLMN and APN combination in S1 mode; and - if the MS is not registered in its HPLMN or in a PLMN that is within the EHPLMN list (if the EHPLMN list is present), or if the NAS configuration MO as specified in 3GPP TS 24.368[ Non-Access Stratum (NAS) configuration Management Object (MO) ]  [135] is not available and the value for inter-system change is not configured in the USIM file NASCONFIG, then the MS behaviour regarding a bearer resource allocation procedure for the same PLMN and APN combination in S1 mode is unspecified; and iii) if the network includes the Re-attempt indicator IE indicating that re-attempt in an equivalent PLMN is not allowed, then depending on the timer value received in the Back-off timer value IE, for each combination of a PLMN from the equivalent PLMN list and the APN the MS shall start a back-off timer for the secondary PDP context activation procedure with the value provided by the network, or deactivate the respective back-off timer as follows: - If the Re-attempt indicator IE additionally indicates that re-attempt in S1 mode is allowed, the MS shall start or deactivate the back-off timer for A/Gb and Iu mode only; and - otherwise the MS shall start or deactivate the back-off timer for A/Gb, Iu, and S1 mode. If the back-off timer for a PLMN and APN combination was started or deactivated in S1 mode upon receipt of a BEARER RESOURCE ALLOCATION REJECT message (see 3GPP TS 24.301[ Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3 ]  [120]) and the network indicated that re-attempt in A/Gb or Iu mode is allowed, then this back-off timer does not prevent the MS from sending an ACTIVATE SECONDARY PDP CONTEXT REQUEST message in this PLMN for the same APN in A/Gb or Iu mode. If the network indicated that re-attempt in A/Gb or Iu mode is not allowed, the MS shall not send any ACTIVATE SECONDARY PDP CONTEXT REQUEST message in this PLMN for the same APN in A/Gb or Iu mode, until the timer expires, the MS is switched off or the USIM is removed. NOTE 2: The back-off timer is used to describe a logical model of the required MS behaviour. This model does not imply any specific implementation, e.g. as a timer or timestamp. NOTE 3: Reference to back-off timer in this section can either refer to use of timer T3396 or to use of a different packet system specific timer within the MS. Whether the MS uses T3396 as a back-off timer or it uses different packet system specific timers as back-off timers is left up to MS implementation. This back-off timer is stopped when the MS is switched off or the SIM/USIM is removed. If the SM cause value is #65 "maximum number of PDP contexts reached", the MS shall determine the PLMN's maximum number of PDP contexts in A/Gb or Iu mode (see subclause 6.1.3.0) as the number of active PDP contexts it has. The MS shall ignore the Back-off timer value IE and Re-attempt indicator IE provided by the network, if any. NOTE 4: In some situations, when attempting to establish multiple PDP contexts, the number of active PDP contexts that the MS has when cause #65 is received is not equal to the maximum number of PDP contexts reached in the network. The PLMN's maximum number of PDP context in A/Gb or Iu mode applies to the PLMN in which the SM cause #65 "maximum number of PDP contexts reached" is received. When the MS is switched off or when the USIM is removed, the MS shall clear all previous determinations representing any PLMN's maximum number of PDP contexts in A/Gb or Iu mode (see subclause 6.1.3.0). Upon successful registration with a new PLMN, the MS may clear previous determinations representing any PLMN's maximum number of PDP contexts in A/Gb or Iu mode.