Hi everybody, I looked a bit more at the code and output of the mobile application, and it seems the problem is that the connection is always dropped because of channel sync failure. Sylvain suggested (to someone having a similar problem) to use the stick option, and actually after trying this, I observed a different behavior it seems the phone performed the identification and the authentication procedures and during a different trial the location update was performed. Can someone explain the stick option? Anyway, I still can't receive or make calls this is what usally happens when trying to make a call <0007> mnccms.c:534 Make call to 150 <0007> mnccms.c:150 support TCH/H also <0007> mnccms.c:174 support full rate v2 <0007> mnccms.c:178 support full rate v1 <0007> mnccms.c:187 support half rate v1 <0005> gsm48_cc.c:496 Sending MMCC_EST_REQ <0004> gsm48_mm.c:3568 (ms 1) Received 'MMCC_EST_REQ' event in state MM idle <0004> gsm48_mm.c:3571 -> substate normal service <0004> gsm48_mm.c:3573 -> callref 8, transaction_id 255 <0004> gsm48_mm.c:2873 Init MM Connection. <0004> gsm48_mm.c:1332 New MM Connection (proto 0x03 trans_id 255 ref 8) <0004> gsm48_mm.c:1291 (ref 8) new state IDLE -> CONN_PEND <0004> gsm48_mm.c:2650 CM SERVICE REQUEST (cause 9) <0004> gsm48_mm.c:2685 -> Using IMSI 234------------- <0001> gsm48_rr.c:4911 (ms 1) Message 'RR_EST_REQ' received in state idle <0001> gsm48_rr.c:4271 Not camping normally, rejecting! (cs->state = 7) <000d> gsm48_rr.c:4241 Establishing radio link not possible <0004> gsm48_mm.c:887 new state MM IDLE, normal service -> wait for RR connection (MM connection) <0004> gsm48_mm.c:3695 (ms 1) Received 'RR_REL_IND' from RR in state wait for RR connection (MM connection) <0004> gsm48_mm.c:1367 Release any MM Connection <0004> gsm48_mm.c:1348 Freeing MM Connection <0004> gsm48_mm.c:1291 (ref 8) new state CONN_PEND -> IDLE <0004> gsm48_mm.c:1055 We are in registered LAI as returning to MM IDLE <0004> gsm48_mm.c:892 new state wait for RR connection (MM connection) -> MM IDLE, normal service <0005> gsm48_cc.c:2122 (ms 1) Received 'MMCC_ERR_IND' in CC state MM_CONNECTION_PEND <0005> gsm48_cc.c:189 (ms 1 ti ff) Sending 'MNCC_REL_IND' to MNCC. <0007> mnccms.c:336 Call has been released (cause 21) Can someone help me with this? I do not understand why is not possible to establish the radio link, and does anyone know where I can find out what 'cause 21' means? Thanks, loretta