【作者】 陈伟；

【导师】 周正； 邹卫霞；

【作者基本信息】 北京邮电大学 ， 电路与系统， 2010， 硕士

【摘要】 信标期的应用对于分布式网络中节点的加入具有至关重要的作用。而信标期只能进行信标帧发送的特点,使得信标期成为无线个域网(Wireless Personal Area Network, WPAN)媒体接入子层的主要开销,因此如何在保证节点无冲突接入网络的同时尽量减小信标期的长度,是WPAN网络的重要研究内容。本文选题来源于华为基金,具有重要的理论意义和应用前景。本文通过对IEEE802.15.3a的介绍和分析,指出集中式网络在无线个域网中的局限性,接下来分析了采用分布式结构的ECMA标准良好的鲁棒性和可扩展性,同时分析了无线个域网存在的挑战和研究热点。接下来,通过对信标期融合算法的研究发现,现有的方案由于不合理的信标时隙重定位,造成了在信标期融合期间信标期长度明显增长,影响网络的稳定时间。本文利用信标时隙的空间复用的特性提出了一种新的信标时隙重定位方法,优化信标期融合方案。经过分析和仿真验证,改进方案在信标期融合可以有效降低信标期的长度,同时网络稳定时间也显著降低。本文对单信道无线网络中普遍存在的隐藏终端和暴露终端问题进行了研究,并指出该问题行之有效的解决方法是采用多信道设计。针对ECMA标准物理层特点,提出了WPAN网络中基于跳频序列实现正交多信道的方法,并主要对多信道信标期的设计进行了研究,综合各种因素,提出一种采用分布式信标期的多信道方案。经过仿真验证,该方案可以有效减少信标期的长度,同时提高了吞吐量。论文最后对全文进行了总结,并对与论文研究方向相关的领域进行了展望。更多还原

【Abstract】 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.更多还原