Reply To: nokia flexi ,ultra bts reading material 5th November 2009 at 12:22 #58628 M. Asif ShabbirGuest Q. what is flexi& ultra bts & there diff. Q. processes of make a call with gsm & bts? Q.processes of bss? Q.difference between fipa & fifa? Q.when to use RRI & E1T1? Q.working of bio card?