The PDN-GW uses the QoS policy to assign the EPS Bearer QoS, i.e., it assigns the values to the bearer level QoS parameters QCI, ARP, GBR and MBR; see TS 23.401
. The PDN-GW may have interacted with PCRF beforehand (refer to TS 23.203
). The PDN-GW sends a Create Bearer Request message (Bearer QoS, TFT, S5/S8 TEID, LBI, Protocol Configuration Options) to the Serving GW, the Linked EPS Bearer Identity (LBI) is the EPS Bearer Identity of a bearer for this MS and PDN connection.
The TFT shall contain uplink packet filter(s) and should contain downlink packet filter(s).
The Serving GW sends the Create Bearer Request (EPS Bearer QoS, TFT, UL TEID, LBI, CGI/SAI/RAI change report required, Protocol Configuration Options) message to the SGSN.
If the MS is in IDLE state and extended idle mode DRX is enabled for the MS, the SGSN will trigger Network Initiated Service Request Procedure from step 2 (which is specified in clause 6.12.2
), and start a timer which is configured to a value smaller than the GTP re-transmission timer. If the SGSN receives no response from the MS before the timer expires, the SGSN sends a Create Bearer Response with a rejection cause indicating that the MS is temporarily not reachable due to power saving and, if a Delay Tolerant Connection indication was set for the PDN connection, the SGSN sets the internal flag Pending Network Initiated PDN Connection Signalling. The rejection is forwarded by the Serving GW to the PDN-GW. In this case, the steps 3-9 are skipped.
Same as step 2 in clause 22.214.171.124
, where Linked NSAPI equals LBI. The LBI is received from the S-GW in the Create Bearer Request message.
The SGSN may include an indication whether the traffic of this PDP context is allowed to be offloaded to WLAN as described in clause 5.3.21
The MS initiates the Secondary PDP Context activation procedure as described in clause 126.96.36.199.1
The MS shall maintain the previously negotiated Bearer Control Mode for the PDP Address/APN pair (see clause 9.2
) and ignore any BCM parameter, if included in the Request Secondary PDP Context Activation message.
The SGSN validates the Activate Secondary PDP Context Request using the TI indicated by Linked TI. The same S-GW and P-GW addresses are used by the SGSN as for the already-activated PDP context(s) for that TI and PDP address.
In A/Gb mode, security functions may be executed. These procedures are defined in clause "Security Function".
In Iu mode, RAB setup is done by the RAB Assignment procedure.
In A/Gb mode, BSS packet flow context procedures may be executed. These procedures are defined in clause "BSS Context".
The SGSN acknowledges the bearer activation to the Serving GW by sending a Create Bearer Response (EPS Bearer Identity, UL TEID, DL TEID, User Location Information) message. The SGSN sets the EPS Bearer Identity to an equivalent value as the NSAPI for the Bearer associated with the MS. The DL TEID value can be either the SGSN user plane TEID (2G or non-DT 3G) or the RNC user plane TEID.
The Serving GW acknowledges the bearer activation to the PDN-GW by sending a Create Bearer Response (EPS Bearer Identity, S5/S8-TEID, User Location Information) message. The PDN-GW may interact with PCRF (refer to TS 23.203
, e.g. to to deliver User Location Information and/or UE Time Zone Information if it was requested by the PRCF.
If the dedicated bearer activation is rejected with a cause indicating that the MS is temporarily not reachable due to power saving, then the PDN-GW re-attempts the same procedure after it receives the indication that the is MS available for end to end signalling in the subsequent Modify Bearer Request message.