Feature Description
This feature is developed to provide Paging Priority support on the MME. Paging priority support is provided for Mobile Originating and Mobile Terminating CSFB calls.
Mobile Terminating CSFB calls: Mobile terminating CSFB calls are prioritized by providing paging priority information to the eNodeB during CSFB calls; the eNodeB in turn pages the UEs accordingly. If the MME is configured to send paging priority to the eNodeB, when a paging request message is received on the SGs interface with an indication of the eMLPP priority level, the MME sends the paging priority value in the S1AP paging message request to the eNodeB.
Mobile Originating CSFB calls: In Mobile originating CSFB calls if the UE is subscribed for eMLPP services, the MME uses the mps-cs-priority received in the subscription to set the priority as "CSFB High Priority" in "CS Fallback Indicator IE". This priority value is sent in the S1AP UE Context Setup/Modification message to the eNodeB, the eNodeB then initiates the CSFB procedure with priority.
Important |
This feature is license controlled. Please consult your Cisco Account Representative for information about the specific license. |
Important |
From release 20.0 onwards, Paging Priority is supported for Packet Switched traffic. The MME also supports eMPS (Enhanced Multimedia Priority Support) for both PS and CS domains. For more information see, feature chapter for Enhanced Multimedia Priority Service. |
Architecture
Paging priority IE support is implemented in a network which supports CSFB priority call handling. When a call is received with an eMLPP Priority level indication, the VLR/MSC sends this value of priority level indication in the eMLPP priority information element as a part of SGs AP PAGING-REQUEST message to the MME. MME propagates this eMLPP priority as paging priority information element in S1AP paging-request message to eNodeB.
If MPS-Priority AVP is present and the UE is subscribed to the eMLPP or 1x RTT priority service in the CS domain as indicated by the MPS-CS-Priority bit of the AVP, the MME allows the UE to initiate the RRC connection with higher priority than other normal UEs during CS Fallback procedure.
The MME uses the MPS-Priority received in subscription and sets CSFB fallback high priority in "CS Fallback Indicator IE" in the S1AP UE Context Setup/Modification in S1AP UE Context Setup/Modification messages.