在WiFi干扰下的ZigBee网络可靠性研究

Study on the Reliability of ZigBee Network under Interference of WiFi

WiFi系统和ZigBee无线传感器网络系统均主要工作在2.4GHz的ISM频段.同一区域同时部署两种网络的场景越来越多,如何有效地避免干扰,是目前亟待解决的问题.从理论上讲,当两者共存时,都会对彼此产生一定程度的干扰.主要研究WiFi网络对ZigBee网络的干扰.通过对两者共存时的同频干扰问题进行详细地分析,搭建反映ZigBee和WiFi共存的网络仿真模型,提出了一种在强干扰下的基于改进的频率捷变的干扰避免方法,该方法检测到干扰之后,自适应地将节点切换到安全信道上来避免WiFi干扰.ZigBee网络在WiFi干扰下的网络性能根据误比特率BER和误包率PER来进行评估.仿真结果表明所设计的方案能够有效地减轻WiFi干扰的影响,进而能够提高ZigBee网络的性能.

The systems of WiFi and WSN mainly work in the 2.4 GHz Industrial,Scientific,and Medical（ ISM） band.How to effectively avoid the interference is the problem to be solved.In theory,when coexistence happens,it will have a certain degree of interference on each other.In this paper,we mainly research on reliabilities of ZigBee network under WiFi interference.By analyzing the problem of same frequency interference between WiFi and ZigBee in detail,a simulation model which reflects the ZigBee and WiFi coexistence has been introduced.And we have proposed an interference avoidance algorithm under strong interference based on modified frequency agility.The algorithm detects interference and adaptively switches nodes to safe channel to avoid WiFi interference. The performance of ZigBee under WiFi is evaluated in terms of the packet error rate（ PER） and bit error rate（ BER）. The simulation results demonstrate that the design guideline can efficiently mitigate the effect of WiFi interference and enhance the performance of ZigBee networks.