Section: 6.1.3.1.1 Successful PDP context activation initiated by the mobile station
Content: In order to request a PDP context activation, the MS sends an ACTIVATE PDP CONTEXT REQUEST message to the network, enters the state PDP-ACTIVE-PENDING and starts timer T3380. The message contains the selected NSAPI, PDP type number and requested QoS. The MS shall ensure that the selected NSAPI is not currently being used by another Session Management entity in the MS. The MS may indicate the support of Network Requested Bearer Control procedures, the support of local IP address in TFTs or the 3GPP PS data off UE status in the protocol configuration options information element. The MS supporting S1 mode shall indicate subscribed, interactive or background traffic class in the QoS requested. The MS not supporting S1 mode should indicate subscribed, interactive or background traffic class in the QoS requested. If there is a subscribed QoS profile available for the MS, the network may ignore the requested QoS and apply the subscribed QoS profile (see 3GPP TS 23.060[ General Packet Radio Service (GPRS); Service description; Stage 2 ]  [74]). The MS shall set the request type to "initial request" when the MS is establishing connectivity to an additional PDN for the first time, i.e. when it is an initial attach to that PDN. The MS shall set the request type to "handover" when the connectivity to a PDN is established upon handover from a non-3GPP access network and the MS was connected to that PDN before the handover to the 3GPP access network. If the MS is establishing connectivity for emergency bearer services it shall set the request type to "emergency" and not include an APN in the ACTIVATE PDP CONTEXT REQUEST message. Upon receipt of the ACTIVATE PDP CONTEXT REQUEST message with request type set to "emergency" the network shall use the APN or the GGSN/PDN GW configured for emergency bearer services. Upon receipt of an ACTIVATE PDP CONTEXT REQUEST message with a PDP type number "IPv4v6 address" in the Requested PDP address information element, the network shall on sending the ACTIVATE PDP CONTEXT ACCEPT message: - include the SM cause information element with cause #50 "PDP type IPv4 only allowed", if the requested PDN connectivity is accepted with the restriction that only PDP type IPv4 is allowed; or - include the SM cause information element with cause #51 "PDP type IPv6 only allowed", if the requested PDN connectivity is accepted with the restriction that only PDP type IPv6 is allowed; or - include the SM cause information element with cause #52 "single address bearers only allowed", if the requested PDN connectivity is accepted with the restriction that only single IP version bearers are allowed. If the MS receives the SM cause value #50 "PDP type IPv4 only allowed" or #51 "PDP type IPv6 only allowed" in the ACTIVATE PDP CONTEXT ACCEPT message, the MS shall not subsequently request another PDP context to get a PDP Type different from the one allowed by the network, until: - all PDP contexts to the given APN are deactivated either explicitly between the MS and the network, i.e. PDP context deactivation procedure, or implicitly (without peer to peer signalling between the MS and the network) as a result of: i) PDP context synchronization during routing area updating or service request procedure; ii) PDP context deactivation initiated by the network, iii) detach from GPRS services; or; iv) a service request procedure is rejected with a cause which results in the MS entering state GMM-DEREGISTERED; or - the PDP type which is used to access to the APN is changed. NOTE 1: Request to send another ACTIVATE PDP CONTEXT REQUEST message with a specific PDP type comes from upper layers. If the MS receives the SM cause value #52 "single address bearers only allowed" in the ACTIVATE PDP CONTEXT ACCEPT message, the MS should subsequently request another PDP context for the other PDP type to the same APN with a single address PDP type (IPv4 or IPv6) other than the one already activated. NOTE 2: If the MT and TE are separated, the MS might not be able to use SM cause #52 "single address bearers only allowed" as a trigger for activating a second single-IP-stack PDP context. Upon receipt of an ACTIVATE PDP CONTEXT REQUEST message, the network selects a radio priority level based on the QoS negotiated and may reply with an ACTIVATE PDP CONTEXT ACCEPT message. If the ACTIVATE PDP CONTEXT REQUEST message included a low priority indicator set to "MS is configured for NAS signalling low priority", the network shall store the NAS signalling low priority indication within the default PDP context. If the network receives an ACTIVATE PDP CONTEXT REQUEST message with the same combination of APN and PDP type as an already existing PDN connection, and multiple PDN connections for a given APN are allowed, the network may retain the existing PDP contexts and proceed with the requested PDP context activation procedure. Upon receipt of the message ACTIVATE PDP CONTEXT ACCEPT the MS shall stop timer T3380, shall enter the state PDP-ACTIVE. If the protocol configuration options information element is present, the network may indicate the Bearer Control Mode that shall be used, the network support of local IP address in TFTs, or the 3GPP PS data off support indication. If the protocol configuration options information element is not present or the Selected Bearer Control Mode parameter is not present in the protocol configuration options information element, the MS shall apply Bearer Control Mode 'MS only' for all active PDP contexts sharing the same PDP Address and APN. If the 3GPP PS data off UE status is "activated", the MS behaves as described in subclause 4.7.1.10. If the offered QoS parameters received from the network differ from the QoS requested by the MS, the MS shall either accept the negotiated QoS or initiate the PDP context deactivation procedure. If the Request type information element is not present, the network shall assume that the request type is "initial request". NOTE 3: If the MS requested a value for a QoS parameter that is not within the range specified by 3GPP TS 23.107[ Quality of Service (QoS) concept and architecture ]  [81], the network should negotiate the parameter to a value that lies within the specified range. If the lower layers provide a L-GW Transport Layer Address value together with the ACTIVATE PDP CONTEXT REQUEST message and a PDN connection is established as a LIPA PDN connection due to the ACTIVATE PDP CONTEXT REQUEST message, then the SGSN shall store the L-GW Transport Layer Address value as the GGSN address in the PDP context of the LIPA PDN connection. If connectivity with the requested APN is accepted and the network considers this PDN connection a LIPA PDN connection, then subject to operator policy the SGSN shall include in the ACTIVATE PDP CONTEXT ACCEPT message the Connectivity type IE indicating "the PDN connection is considered a LIPA PDN connection". If the lower layers provide a SIPTO L-GW Transport Layer Address value identifying a L-GW together with the ACTIVATE PDP CONTEXT REQUEST message and a PDN connection is established as a SIPTO at the local network PDN connection due to the ACTIVATE PDP CONTEXT REQUEST message, then the SGSN shall store the SIPTO L-GW Transport Layer Address value as the P-GW address in the PDP context of the SIPTO at the local network PDN connection. If the lower layers provide a LHN-ID value together with the ACTIVATE PDP CONTEXT REQUEST message and a PDN connection is established as a SIPTO at the local network PDN connection due to the ACTIVATE PDP CONTEXT REQUEST message, then the SGSN shall store the LHN-ID value in the PDP context of the SIPTO at the local network PDN connection. NOTE 4: The receipt of a LHN-ID value during the establishment of the PDN connection, during routing area updating procedure or during inter-SGSN handover can be used as an indication by the SGSN that the SIPTO at the local network PDN connection is established to a stand-alone GW (see 3GPP TS 23.060[ General Packet Radio Service (GPRS); Service description; Stage 2 ]  [74]). In A/Gb mode, the MS shall initiate establishment of the logical link for the LLC SAPI indicated by the network with the offered QoS and selected radio priority level if no logical link has been already established for that SAPI. If the offered QoS parameters received from the network differ from the QoS requested by the MS, the MS shall either accept the negotiated QoS or initiate the PDP context deactivation procedure. If the LLC SAPI indicated by the network can not be supported by the MS, the MS shall initiate the PDP context deactivation procedure. In Iu mode, both the network and the MS shall store the LLC SAPI and the radio priority in the PDP context. If a Iu mode to A/Gb mode system change is performed, the new SGSN shall initiate establishment of the logical link using the negotiated QoS profile, the negotiated LLC SAPI, and selected radio priority level stored in the PDP context as in a A/Gb mode to A/Gb mode Routing Area Update. An MS, which is capable of operating in A/Gb mode, shall use a valid LLC SAPI, while an MS which is not capable of operating in A/Gb mode shall indicate the LLC SAPI value as "LLC SAPI not assigned" in order to avoid unnecessary value range checking and any other possible confusion in the network. When the MS uses a valid LLC SAPI, the network shall return a valid LLC SAPI. The network shall return the "LLC SAPI not assigned" value only when the MS uses the "LLC SAPI not assigned" value. NOTE 5: The radio priority level and the LLC SAPI parameters, though not used in Iu mode, shall be included in the messages, in order to support handover between Iu mode and A/Gb mode networks. If a WLAN offload indication information element is included in the ACTIVATE PDP CONTEXT ACCEPT message, the MS shall store the WLAN offload acceptability values for this PDN connection and use the UTRAN offload acceptability value to determine whether this PDN connection is offloadable to WLAN or not. At inter-system change from Iu mode to A/Gb mode, SM shall locally deactivate the active PDP context(s) if SM does not have the following parameters: - LLC SAPI; and - radio priority. Upon receipt of the ACTIVATE PDP CONTEXT ACCEPT message with the Connectivity type IE indicating "the PDN connection is considered a LIPA PDN connection", the MS provides an indication to the upper layers that the connectivity is provided by a LIPA PDN connection.