Research On MAC Protocol For Fast Data Collection In Wireless Sensor Networks

As a primitive low-level protocol of wireless network, MAC protocol determinesthe allocation of radio channels and access to the medium. It plays a significant role inthe network performance, and therefore, has been got extensively concerns byresearchers. In the traditional wireless sensor network applications, energy efficiency isusually considered to be the most important concern, whereas utilizing networkbandwidth and maximizing network throughput are of secondary importance. However,network bandwidth and maximizing network throughput are becoming increasinglyimportant due to the development of wireless sensor networks, such as structural healthmonitoring, oil and gas leak monitoring, that require wireless sensor networks to collectdata in a faster rate. As we all know, the scheduling based MAC protocol is moresuitable for high-speed data collection. However, the existing MAC protocols facingbandwidth utilization low-efficiency, the channel and state transitions frequently, limitthe further improvement of the data collection rate.This paper focuses on low-latency, high-throughput MAC protocol’s research forwireless sensor network. The factors that limit the rate of data collection in wirelesssensor network are identified based on an in-depth study of the existing classic MACprotocol. Accordingly, MCF-MAC and MCC-MAC, two new multi-channel basedmedium access control (MAC) protocols are presented. The two protocols takeadvantage of multi-channel multiplexing and time division multiple access to furthereliminate interference between nodes. In this way, they provide conflict-free paralleldata transmission and hence reduce network latency and improve network throughput.At the same time, our protocols can decrease the energy consumption of nodes bymeans of minimizing the node and the state transition frequency. Node with singletransceiver could only work on half-duplex status that cannot transmit and receipt at thesame time. During the slot allocation process, half-duplex and the fairness of node arefully taken into account. In this way, scheduling delay can be further reduced. Inspiredby TreeMAC, both MCF-MAC and MCC-MAC take fixed channel allocation. ForMCF-MAC protocol, it utilizes multi-channel to eliminate interference on the verticaldirection of data collection tree, and realize the allocation process via a top-downmanner (from the sink node to the leaf nodes). In detail, the nodes of data collection treeis divided into clusters in MCC-MAC, then running channel allocation and timing scheduling to head node of the clusters in a centralized mode, the remaining nodes easyto complete the channel and the slots selection with the help of cluster’s headerinformation. This schedule is able to provide guarantee on that nodes within the networkwill not cause communication conflicts.Finally, we simulate MCF-MAC and MCC-MAC by NS2, compare theperformance of protocols under different network loading by controlling the packetgeneration rate. It is shown by our simulation results that: when the network load is high,multi-channel based MCF-MAC and MCC-MAC protocol have significantly improveon delay and throughput with respect to the SMAC and MMSN.