plz clearyfy ur question?
anyhow for conecting to BTS of Particular network, there is signal present(GSM). accourding to ur sim which is registered to a paricular network scans the all signals and only respond to the registered network.
ok clearify ur question and type of network.....
Added after 3 minutes:
any one of you having the helpping material regarding RF Plaining in mobile Communication.
First... authentication is done by the BTS by sending a Random sequence to the MS & the MS replies with a Signed response using the cipher key in the SIM. The BTS tallies this with the expected signed response.
If the 2 are the same... the handset is authenticated and readied for communication.