Ayat,
I answered you in my email, didn’t I ??
Number of MOC access attempts: MS sends a channel request (for a CALL setup), BSC answers with an IMMEDIATE ASSIGNMENT that indicates where is the SDCCH subchannel allocated. Each Imm. Asg. increments this counter
CM service request : incremented when the MS answers the IMMEDIATE ASSIGNMENT with an ESTABLIH INDICATION. It means the MS has succesfully landed onto its own new SDCCH subchannel.
Example:
900 MOC access attempts & 800 CM Service Requests
–> it means that 100 failures occured : the MS could not seize its SDCCH subchannel. Causes : radio failure (interference, coverage) / hardware failure (path balance, …)