Zigbee Channel Selection Algorithm Research Based On Markov Chain

A lot of wireless communicational technology got rapidly development on recentyears. It is mainly due to the rapidly development of smart home and the Internet ofthings. Especially some low energy consumption, low cost of wireless communicationtechnology is obtainning the unprecedented development. Like ZigBee technologybased on the IEEE802.15.4standard, it is its low power consumption and thecharacteristics of low cost makes it a dominant position in the wireless sensor networkapplications. In order to maximize the promotion of ZigBee technology, ZigBeealliance adopted international free ISM (Industrial Scientific Medical) spectrum whenthey formulated the ZigBee protocol wireless communication standard. Due to thenature of the ISM band’s free, there are already kinds of radio technology exitscommunicatting with the spectrum. Such as WiFi, bluetooth, wireless USB, includingmicrowave ovens and cordless phones also work in the spectrum. So the Numbers ofwireless technology which is on this spectrum is more and more bigger. With more andmore new wireless technology’s research and development and the addition of newwireless technologies, the2.4Ghz ISM band inevitably becoming more and morecrowder, which leads to the interference between each2.4Ghz equipment.But like smart home, wearable wireless equipment and Internet of things ofagriculture is in a stage of rapid development in wireless sensor network application,there will be more and more2.4Ghz equipment to join in, which let people to begin topay closely attention to the2.4Ghz equipment under the interference. Especially in thescenes like some high-risk operations in smart home environment; the importantindicators for health monitoring nodes in wearable devices; or the control nodes whichcontrol some key cultivation in agricultural indicators (such as PH value, etc.), etc.Therefore, to explore and research on ZigBee node to make it perform more well underthe disturbance of other2.4Ghz equipment has important significance. There have some solutions to decrease to interferenc from other2.4Ghzequipment, like Clear Channel Assessment (CCA) algorithm, dynamic Channelselection, Channel direct sequence spread spectrum technology and the response frameretransmission and cache technology to improve the anti-interference ability of ZigBeenode. However, these traditional methods still exist many deficiencies. For example,the traditional channel selection algorithm by polling the scanning ZigBee protocol isthe16channel (2.4Ghz frequency band), choosing a free channel as ZigBee nodecommunication channel. There may exist15times redundancy detectio action in theprocess. And also the frequency to detect the clear channel will increase in the case ofstrong interference. It will greatly increase the power consumption of the node if everytime for more than half of the redundant query action, which lead to the shorten life ofthe node and seriously affect the real-time performance of the node.This article put the ZigBee channel selection algorithm as the breakthrough point,and ZigBee channel prediction model based on Markov chain is put forward in thechannel selection algorithm. Compared with the traditional channel selection method,this method can be estimated according to the markov chain model of science topredict the future moment idle channel, with the highest probability increased the idlechannel choice of shooting, thereby reducing the ZigBee nodes constantly polling scanall channels of redundant operations. Reflect on the practical effect is to ensure that thereal-time and saved the nodes of the node energy consumption. According to specificexperimental environment, the transmission under the condition of the same file, thechannel selection algorithm based on markov chain can save2.2%energy consumptionand shorten the transmission time of7.1%.On the structure of the article, this artical firstly introduce the basic knowledge ofZigBee protocol, which emphasis on the classification of the ZigBee protocol onchannel. And we also make a brief introduction of ZigBee networking process.Secondly, this article give a brief introduction to the basic knowledge of Markov chain,and the common three kind of prediction method based on markov chain and also theconcrete prediction steps has carried on the detailed discussion and comparison.Finally in this artical, we evaluate and verify the Markov chain’s parameter through theactual sample data. And It is verified that ZigBee channel selection algorithm based onMarkov chain does improve the transmission of real-time and ZigBee node have certain effect on reducing power consumption.