TENTATIVE REDUCTION OF ANALOG CELLULAR FACSIMILE COMMUNICATION TIME

Various studies have been done, mainly from the viewpoint of improving image deterioration on G3 facsimile transmission using analog cellula r channels. This paper discusses communication time with analog cellul ar facsimile transmission using ITU-T's error correction mode(ECM). Th e communication state graph proposed shows its transmission state. The n the protocol of standard ITU-T's ECM is studied and an effective fal l-back method is proposed. The goal is to use a 9600 bps modem rate, w hich is not used in analog cellular facsimile transmission, and then a n effective fall-back, e.g., from 9600 bps to 7200 bps, is performed i n the case of poor line conditions. This method allows the communicati on time in analog cellular facsimile transmission to be shortened. Res ults of field experiments have revealed that a shorter communication t ime can be achieved with the proposed method than with the conventiona l transmission method.