HEADER COMPRESSOR AND HEADER COMPRESSION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a header transmission system employing header compression that reduces a header decoding error caused by dissidence of reference information between a transmitter side and a receiver side and enhance the transmission efficiency. SOLUTION: A packet compression section 12 is operated by a reliability warrant method or a compression efficiency priority method. A mode discrimination section 31 obtains number of ACK or NACK packets per unit time X by an ACK/NACK packet reception section 14. A mode discrimination section 31 selects the reliability warrant method for the operation mode of the packet compression section 12 when obtained number of NACK packets exceeds a prescribed value Y. The mode discrimination section 31 selects the compression efficiency priority method for the operation mode of the packet compensation section 12 when obtained number of ACK packets exceeds a prescribed value Z.