Patent ID: 7644186
Filing Date: 2010-01-05
Classification: H04L

Abstract:
1. A header compression apparatus for compressing a header of a packet to be transmitted by referring to reference information that is also included in a receiving side, said header compression apparatus comprising: a reference information manager operable to store and manage the reference information; a packet compressor operable to compress the header of the packet in a specified operation mode by referring to the reference information, and to selectively add, to the compressed packet, update information for updating the reference information at the receiving side; a packet transmitter operable to transmit the packet compressed by said packet compressor; a packet receiver operable to receive an ACK packet indicating that the reference information at the receiving side has been correctly updated or a NACK packet for requesting transmission of the update information due to a header decompression error that occurred at the receiving side; and a mode switching unit operable to dynamically switch, based on one of a number of ACK packets received and a number of NACK packets received, the operation mode of said packet compressor between a reliable mode where, after the reference information of said header compression apparatus is updated, said packet compressor continuously adds the update information until the ACK packet is received, and an optimistic mode where said packet compressor adds the update information when the reference information of said header compression apparatus is updated and whenever receiving the NACK packet.