Investigation Of The Robust Header Compression In Wireless IP Networks

The interactive service based on IP over radio link is tending to be a new focus as the lasting development of radio communication technology and the worldwide availability of Internet application. Header compression technology, which can reduce the overload generated by protocol headers, must be adopted to resolve one single important issue that this overload seems too fat for IP phone services over radio link, which makes effective use of the bandwidth resource and provides economic feasibility and practicability for realtime services. However, some of the currently available compression schemes do not work well in that the code error rate is unbearable large or the RTT is longer than expected.This paper concentrates on designing an effective and robust header compression scheme compared against the shortcoming of current schemes. This scheme has both realizing significance and practising value for it balances the the relationship between compression rate, error-tolerance and robustness and can be adapted to the changing feature of radio links, when the rapid development of the multimedia business of 3G is linked to.In this paper, the task mainly includes the following issues:1. Render, design and implement an effective compression method.It is detailed how the compressor compresses the data packets through the most limited size within the strictly short time interval according to the information of current working mode, state and the context, in order to make a fast, correct and effective process.2. Design and implement a feedback mechanism. It is also specified how a reasonable synchronization mechanism is selected to recover the consistence of the contexts between the compressor and its decompressor peer over the radio link with long RTT.3. Render, design and implement the scenarios for performance benchmark to evalue the performance of ROHC when it is applied in radio IP network for facilitating the realtime audio and video businesses. The test result is also available in the paper.