Section: 6.1.3.3.1 Network initiated PDP Context Modification
Content: In order to initiate the procedure, the network sends the MODIFY PDP CONTEXT REQUEST message to the MS and starts timer T3386. The message shall contain the new QoS and the radio priority level and LLC SAPI that shall be used by the MS in A/Gb mode at the lower layers for the transmission of data related to the PDP context. The MODIFY PDP CONTEXT REQUEST message may also contain packet filters in the TFT information element. If the selected Bearer Control Mode is 'MS/NW' and the TFT information element is included in the MODIFY PDP CONTEXT REQUEST message, the network shall include packet filter(s), or if no packet filters are proposed to be either added, replaced or deleted, it shall set TFT operation code to "No TFT operation" and include packet filter identifier(s) in the Packet filter identifier parameter in the parameters list to indicate which packet filter(s) in the TFT is associated with the QoS change. If the TFT information element is included in the MODIFY PDP CONTEXT REQUEST message and packet filter(s) is proposed to be added, the network shall allocate packet filter identifier(s) for all packet filters to be added to the TFT. The network shall allocate packet filter identifier value s which are currently not allocated to any existing packet filter of the same TFT. The network informs the MS about the Bearer Control Mode to be applied for all active PDP contexts sharing the same PDP Address and APN by including the selected Bearer Control Mode parameter in the protocol configuration options information element. This information is either explicitly given in the MODIFY PDP CONTEXT REQUEST message or implicitly given by not being present. The MS shall act according to the presence of the protocol configuration options information element and the value of the selected Bearer Control Mode parameter in the MODIFY PDP CONTEXT REQUEST message: - if the protocol configuration options information element is not present, the MS shall apply Bearer Control Mode 'MS only' for all active PDP contexts sharing the same PDP Address and APN. - if 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 selected Bearer Control Mode parameter is present in the protocol configuration options information element, the MS shall apply Bearer Control Mode according to the value of this parameter for all active PDP contexts sharing the same PDP Address and APN. If a WLAN offload indication information element is included in the MODIFY PDP CONTEXT REQUEST message, the MS shall replace stored WLAN offload acceptability values for this PDN connection with the newly received offload indications and use the UTRAN offload acceptability value to determine whether this PDN connection is offloadable to WLAN or not. Upon receipt of the MODIFY PDP CONTEXT REQUEST message, if the MS sent an APN for the establishment of the PDN connection, the MS shall stop the timer T3396 if it is running for the APN sent by the MS.If the MS did not send an APN for the establishment of the PDN connection and the request type was different from "emergency", the MS shall stop the timer T3396 associated with no APN if it is running. If the MODIFY PDP CONTEXT REQUEST message was received for an emergency PDN connection, the MS shall not stop the timer T3396 associated with no APN if it is running. For any case, the MS shall then reply with the MODIFY PDP CONTEXT ACCEPT message, if the MS accepts the new QoS and the indicated LLC SAPI. The network shall upon receipt of the MODIFY PDP CONTEXT ACCEPT message stop timer T3386. In A/Gb mode, the network shall establish, reconfigure or continue using the logical link with the new QoS for the LLC SAPI indicated in the MODIFY PDP CONTEXT REQUEST message. In Iu mode, if the Radio Access Bearer supporting the PDP context is active, then the network shall reconfigure and continue using the Radio Access Bearer with the new QoS indicated in the MODIFY PDP CONTEXT REQUEST message; if the PDP context is preserved, then the network may re-establish a Radio Access Bearer with the new QoS indicated in the MODIFY PDP CONTEXT REQUEST message.