to a frame the header of the received frame is analyzed for each information bit by determining the kind or class of the received frame in the batch processing of the frame header according to the present invention on the contrary when the receive or transmit processing of one frame is ended a reference header for the next received frame is anticipated and prepared to predict the class of a next received frame the header of the actually received frame and the reference header are then compared and checked as a whole i e for a plurality of bits in fig7 a received frame 700 composed of a data field 701 and headers h1 h2 and h2 39 702 to 704 is transmitted on the line 103 according to the shown format the header h1 702 and the data 701 are processed by the upper rank protocol i e the processor 201 whereas the headers h2 and h2 39 703 and 704 i e a preamble a starting delimiter sd a destination address da a source address sa a data length l a frame check sequence fcs and an ending delimiter ed are processed by an mac lsi 207 included in the communication control equipment 102 here will be described the processing of the header h1 702 to be processed by the.