Handset Switch On Search mode

When a GSM handset is 1st switched on it will 1st enter search mode , scan all possible GSM carriers on which BCCH could be located, select the cell on which the strongest BCCH is detected. It will then extract the necessary information from the BCCH to access the system on the RACH and enter the dedicated mode. In the channel request sent on the RACH it will request an SDCCH to register the MS as active in the system. Once the registration is successfully completed MS will release the SDCCH and enter the Idle Mode