Traffic-Aware Low Duty Cycle MAC Protocols Based On6LoWPAN For WSN

As a key branch and important technology of the underlying network in the field of IoT, wireless sensor network (WSN) causes highly attention of the industry and academia. In recent years, applications of IPv6protocol in IoT cause more and more focus, which can provide larger address space and can facilitate seamless connectivity to a variety of IP networks have been widely deployed to achieve true end-to-end control and communication.6LoWPAN is a solution of combination of WSN and IPv6proposed by IETF working group. Compared to traditional mode of WSN,6LoWPAN constituted of CoAP/IPv6/6LoWPAN/IEEE802.15.4has big distinctions in the aspects of communication mode, delay requirement and topology. Communication is often many to many, burst and nonperiodic. In entire life cycle, the load of node is changing dynamically, and the node is more sensitive to latency.In most cases, the communication of WSNs is one-way, cyclical, and topology is relatively stable. Sender and receiver can select the appropriate scheduling cycle to achieve synchronization. Most of the existing WSN MAC protocol used periodical dormancy technology based on duty cycle to reduce energy cost.For burst and nonperiodic communication, fixed RDC is of very low efficiency, mainly because a reasonable scheduling interval can’t be found to satisfy not only the periodic data communication, but also the nonperiodic data communication and burst data request of communication on the basis of low power consumption.Based on the in-depth study on the existing MAC protocols, we mainly conduct a research on the scheduling mechanism for wireless sensor networks based on duty cycle.In the paper, the main innovations and contributions are as follows:1. For the decreasing of network throughput and the increasing of communication delay for asynchronous sleep scheduling mechanism, we proposed an adaptive protocol TA-ContikiMAC by ameliorating ContikiMAC protocol. The nodes timely wakeup to adapt to dynamic traffic load conditions and reduce communication delays2. For situations with high traffic load and burst/nonperiodic data, adopting the advantages of sender-initiated MAC protocol ContikiMAC and receiver-initiated protocol RI-MAC, we propose SRI-MAC protocol which can adaptive adjust RDC by estimating traffic online to meet low power consumption and other performance requirements.