GAO's V.22 & V.22bis software modules implement the ITU-T standards for 1200 bps and 2400 bps full-duplex data communication on the GSTN and on point-to-point 2 wire leased line circuits. In these modems, channels are separated by frequency division and each channel is phase shift modulated. A symbol rate of 600 carries 2-bits per symbol for a rate of 1200 bps for V.22. For V.22bis, each channel is quadrature amplitude modulated (QAM) to carry 4-bits per symbol at 600 symbols per second for a rate of 2400 bps. Carrier frequencies are 1200 Hz and 2400 Hz for the low and high channels respectively.
For examples of GAO's Modem Software Architecture, click GAO's Modem Software Architecture.
For a complete list of GAO's Modem Software products, please see GAO's Softmodem List.