Multi-Channel Real-Time Communication in Wireless Sensor Network

Many radio chips used in today's sensor mote hardware can work at different frequencies. Recently, several multi-channel communication protocols have been proposed to improve network throughput and reduce packet loss for wireless sensor networks. However, existing work does not provide explicit guarantees for application-specified end-to-end communication delays, which are critical to many real-time applications such as surveillance and disaster response. On the other hand, those radio chips also have adaptable transmission power which allows a trade-off between communication delays and energy efficiency.

This work proposes two multi-channel real-time communication protocols. One of the protocols features a node-based channel assignment policy while the other allocates channels to network partitions organized based on data flows. Both protocols are designed based on the multi-channel realities of existing mote hardware. The two proposed protocols are compared with other real-time protocols for wireless sensor networks to evaluate their performance using simulations based on a realistic radio model. The simulations are supplemented with results from hardware experiment done using Sentilla Tmote Invent motes [35]. The results demonstrate that the two protocols can effectively utilize multiple channels to reduce the number of deadlines missed in end-to-end communications.