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


Unknown 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?


Anonymous said...

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.