I was also wondering about if is is possible to use network-frm-scratch setup (calypso-transceiver) with more phones to get more TCH channels as well as gprs? Regards erich Hello, list! I am trying to make working two and more TCH channels in OpenBSC (NiTB mode) with calypso based phones. How to understand timeslots allocation in this strings of transceiver app? as->l1l[0].tx_mask = 0xe3; /* TS 5,6,7,0,1 */ as->l1l[0].rx_mask = 0x01; /* TS 0 */ Why 2, 3, 4 timeslots is not used? And how to connect more than two phones to the transceiver? Should I add a new TRX in OpenBSC config and/or modify source code of the transceiver app? With best regards, fixeria.