Development of digital mobile radio facsimile

Fast and accurate image transmission methods are needed for transmitting non-voice information such as maps and handwritten information to officers in patrol cars. The National Police Agency of Japan has developed a digital mobile radio facsimile machine capable of transmitting image information using digital radio. Starting in 1986, the facsimile machines have beer) installed in several Prefectural Police Headquarters. The facsimile machine is characterized by adopting the developed picture signal transmission method called pseudo random block interleave as countermeasures for the burst errors which occur during mobile radio communications due to fading. The facsimile machine can send the picture elements at random and diffuse burst errors by using the pseudo-random block interleave method. This is also good for data security. Application of this method enables transmission and reception of good image information using a mobile radio with a bit error rate of about 10/sup -2/. This outlines the transmission method of the facsimile machine and its evaluation test results.