Robust header compression state transition method and decompressor

Abstract

A method for the state shifting of the robust header compression and a decompression thereof are provided in the present invention. The method comprises: the decompressor receives an initialization state (IR) packet in the static context (SC) state, and calculates a cyclical redundancy code (CRC) of the static information in the IR packet; judging whether the CRC verification of the static information in the IR packet is passed, if yes, the decompressor calculates the CRC of the IR packet and verifies it, and the process ends; if not, the decompressor is shifted to the no context (NC) state and does not calculate the CRC of the IR packet again. In the solution of the present invention that: firstly, the CRC of the static information in the IR packet is verified, in the case of the CRC verification of the static information in the IR packet not being passed, the CRC of the whole IR packet need not be calculated, and the decompressor is shifted to the NC state. Thus, the CRC calculation amount of the IR packet is decreased, and the unnecessary state shifting is avoided, therefore the accurate rate of the packet decompression and the service of quality (QoS) are improved, and the bandwidth of the A-interface is saved.

Description

technical field [0001] The invention relates to robust header compression (ROHC, RObust Header Compression) technology, in particular to a robust header compression state transition method and a decompressor. Background technique [0002] For some application layer services, the overhead of huge IP header information is very large. For example, for VoIP services, the payload length is usually 15-20 bytes, while the IP header occupies 40 bytes; The header field of the packet often contains a lot of redundant information, making header compression possible. [0003] ROHC divides the message into different data streams, which are distinguished by context identifiers (CID, Context ID). Information that rarely changes or does not change during the life cycle of the data stream is sent only a limited number of times; while information that changes dynamically is sent using a corresponding compression algorithm, thereby reducing the length of the data header sent and improving ban...

AI Technical Summary

Problems solved by technology

[0011] from existing image 3 The implementation of the ROHC state transition shown in the figure increases the amount of IR packet CRC calculations, resulting in unnecessary state transitions, thereby reducing the accuracy of packet decompression and quality of service (QoS), wasting air interface bandwidth

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