FACSIMILE DATA TRANSMISSION SYSTEM

PURPOSE:To easily deal with plural data compression systems, by providing a promise for transmission procedure, and informing in advance a central computer of the compression system and the data quantity, when transmitting a facsimile data. CONSTITUTION:2 facsimile terminal equipments 1A, and 1B have each different data compression system, and a central computer 3 is capable of dealing with each data compression system. Also, the switching network is constituted of a telephone/data switchboard 2, a terminal subscriber line 4, a switching network junction circuit 5 and a computer subscriber line 6. Moreover, the data transmission procedure is constituted of a discriminating data of the data compression system, the quantity of a data before compression and the quantity of a data after compression. In this regard, the upper stage of the data transmission procedure uses a procedure stated in the advice of the International Telegraph and Telephone Consultative Committee.