Tuesday, 28 April 2009

Simplified RRC in LTE as compared to UMTS

RRC states in LTE have been simplified. In case of UMTS there was a possibility of four states with complicated movements between them but in case of LTE, there is 'RRC Idle' and 'RRC Connected'.


Figure Source: Freescale White Paper

As in case of UMTS, in 'RRC_Idle' the main task of the RRC would be monitoring and cell/plmn selection. Everything else falls in 'RRC_Connected' state. The figure above shows RRC functions in both these states.

RRC Specs for LTE is 3GPP TS 36.331

3 comments:

Jean Pierre said...

Thanks for this memo. In case you need to decode some RRC messages, this tool is very usefull: 3GPP message decoder

Anonymous said...

Hi Jean Pierre

I am trying to use this 3GPP message decoder in the Wireshark mode. When I press the decode button wireshark opens but gives an error stating that the file "decode_temp.pcap" doesn't exist. Any ideas what is wrong?

Thanks
Eddie

Anonymous said...

JP,
I have read that with the always-on Smart phones, Cell_PCH and URA_PCH are really required, since they reduce latency (from 2.5 to 1 sec, and reduce signalling overhead
Asghar - JWT Inc.