Beacon Period Improvement And Multi-Channel Implement In Wireless Personal Area Network

Beacon period is critical to access network for nodes in distributed network. However, only beacons frame can be transmitted in beacon period, which is evidently main overhead in media access layer of Wireless Personal Network (WPAN) Therefore it is very important to decline the beacon period length as shortly as possible while nodes can access network without collisions. This thesis has important values on theory and practice, which is supported by Huawei science and technology foundation.IEEE802.15.3a standard is studied in the paper, which presents that centralized network structure is not fit for WPAN, and whereas ECMA standard with totally distributed network structure demonstrates excellent robust and scalability. And then challenges and directions are analyzed in WPAN with ECMA standard.While beacon period merging algorithm is studied in ECMA, current beacon period function may cause too long beacon period length and network stable time according to improper beacon slot redirection during beacon period merging. And an improved beacon redirection method is proposed based on spatial reuse of beacon slot to optimize beacon period merging, which decreases significantly beacon period length and network stable time demonstrated in simulations.Multi-channel is proved to be one of most effective solutions to the hidden station and exposed terminal which are universal problems in wireless single channel. Considering physical layer in ECMA, a method based on frequency-hopping sequence is proposed to implement multi-channel in WPAN. And then we focus on beacon period proposal in multi-channel to apply to requirements in WPAN, which decreases beacon period length and improves throughout illustrated in simulations.Finally, the content of the whole dissertation is summarized and many valuable research directions are also discussed.