A multi-channel MAC protocol design based on IEEE 802.15.4 standard in industry

With the development of wireless sensor networks in industry, it is difficult for MAC protocol with single channel to meet the demands of combating interference, high reliability and low delay. The multichannel MAC protocol is a promising approach to meet these challenges. IEEE 802.15.4 standard is the foundation of ZigBee, WirelessHART and ISA100. This article proposes a multi-channel MAC protocol based on 802.15.4 standard for industrial wireless sensor networks. First we monitor the wireless signal in industry environment - The Institute of Electronics Chinese Academy of Sciences, and establish signal interference model for wireless sensor networks. Then a maximum discrete channel allocation algorithm is designed. Last, in order to realize multichannel, we extend 802.15.4 MAC protocol by adding RTS(Request To Send) and CTS(Clear To Send) in CAP(Contention Access Period) and modifying the GTS(Guaranteed Time Slot) list structure in CFP(Contention Free Period). Theoretical analysis shows that this multi-channel MAC protocol can reduce interference and increase capacity of system communication effectively. This protocol is suitable for large scale network.