Hi Bijoy,
Thanks for the information, however just wanted to point out that in Paging Scenario, “CM Serv Request” is not sent. Instead, when SDCCH is established, MS sends “Paging Response” to the network.
CM Serv Request (4 types) are only in Mobile Originated scenarios.
Moreover, RACH contains only Cause Values (for whichever service required), where CM Serv Req message is a layer 3 message which is only sent when SDCCH is established.
Regards,
Ameen