Method and apparatus for header compression

摘要

A packet compressor 12 operates under a reliable mode or an optimistic mode. A mode determination unit 31 counts the number of ACK packets or NACK packets received by a unit time X by an ACK/NACK packet receiver 14. When the counted number of NACK packets is larger than a predetermined value Y, the mode determination unit 31 switches the operation mode of the packet compressor 12 to the reliable mode. When the counted number of ACK packets is larger than a predetermined value Z, the mode determination unit 31 switches the operation mode of the packet compressor 12 to the optimistic mode.