| ATM/WATM as robust support of today and tommorrow communication, application and service.has been a hot topic in the field of international communication in the world wide. WATM has been proposed as a transport solution for next generation wireless and personal communication networks.However, in order to ultimately realize a ubiquitous telecommunications network which merges the concepts of wireless mobile communications and the use of ATM as a transport mechanism, the problem of high and variable bit error rate of wireless network must be resolved. Accordingly.research for wired link of ATM and error control mechanism are two emphasis(chapter3 and chapter 4) in this paper.Analytical modes based on finite state Markov chains (such as: Gilbert-Elliott channel model) have been widely used to characterize the burst error behavor of communication channels[13].In chapter 3of this paper, first a detailed research has been carried through for the performance(such as mCLR, mPER and mPBER)of Wireless link of ATM over wireless burst channels based on this model.Based on chapter3, an error control coding mechanism is presented to alleviate the problem in wireless ATM networks in chapter 4. The scheme combines BCH coding, interleaving and channel state estimation to achieve an appropriate error correction scheme. Meanwhile, simulation is operated for interleaving and uninterleaving. The result of simulation show the error correcting performance become better than that of uninterleaving two to three degrees. By changing some parameter ,we can estimate present channel noise level and correct error based on the estimation. The scheme adopts open loop control. By adopting closed loop control the scheme can be autoadapted and this work need further research.
|
PDF Full Text Request