Thursday, November 5, 2009

The MME Function

  • NAS signalling;
  • NAS signalling security;
  • AS Security control;
  • Inter CN node signalling for mobility between 3GPP access networks;
  • Idle mode UE Reachability (including control and execution of paging retransmission);
  • Tracking Area list management (for UE in idle and active mode);
  • PDN GW and Serving GW selection;
  • MME selection for handovers with MME change;
  • SGSN selection for handovers to 2G or 3G 3GPP access networks;
  • Roaming;
  • Authentication;
  • Bearer management functions including dedicated bearer establishment;
  • Support for PWS (which includes ETWS and CMAS) message transmission.



Rauf said...

Hi Vikram,

I was wondering what will be the status of ongoing data call (through S-GW) of a UE if MME fails in the middle of data call.

Vikram said...

Hi Rauf,

MME & SGW will have exhange of echo request/response using GTP protocol. So SGW may detect MME unreachable when it doesnt receive echo request.