An MS requests resources from a cell by transmitting an “access burst(RACH) containing the
channel request message. The access burst has to be scheduled so that it is
transmitted during a frame that has been configured as a RACH. This scheduling Channel requests will only be repeated upto M+1 times where M is equal to max_retran,
broadcast on BCCH system information. After the last channel request T3126 is started
in the MS, on expiry the channel request procedure will be aborted.