A method for encoding ATS-QSIG standard-based content for transmission over a 56 kb/s clear channel. The method encodes each of the three 16 kb/s ATS-QSIG voice sub-channels on to corresponding 16 kb/s voice sub-channels in the 56 kb/s clear channel. The method encodes the 16 kb/s ATS-QSIG data sub-channel on to a 8 kb/s data sub-channel in the 56 kb/s clear channel. Using the method, the ATS-QSIG standard can be used in a network such as, for example, the North American PSTN that utilizes 56 kb/s clear channels. In addition, a system for adapting ATS-QSIG standard-based content transmitted on a 64 kb/s clear channel for transmission on a 56 kb/s clear channel and a system for adapting ATS-QSIG standard-based content transmitted on a 56 kb/s clear channel for transmission on a 64 kb/s clear channel. The systems can be used, for example, as gateways to permit ATS-QSIG standard-based communications between 56 kb/s and 64 kb/s based networks.