DynaChannAl: Dynamic channel allocation with minimal end-to-end delay for two-tier wireless sensor networks

With recent advances in wireless networking and in low-power sensor technology, wireless sensor networks (WSNs) have taken significant roles in various applications. Whereas some WSNs only require minimal bandwidth, newer applications operate with a noticeably larger amount of data. One way to deal with these applications is to maximize the available capacity by utilizing multiple wireless channels. We propose DynaChannAl, a distributed dynamic wireless channel allocation algorithm that effectively distributes nodes to multiple wireless channels in WSNs. Specifically, DynaChannAl targets applications where mobile nodes connect to preexisting wireless backbones and takes the expected end-to-end queuing delay as its core metric. We used the link quality indicator values provided by 802.15.4 radios to whitelist high-quality links and evaluate these links with the aggregated queuing latency, making it useful for applications that require minimal end-to-end delay (i.e., health care). DynaChannAl is a lightweight and adoptable scheme that can be incorporated easily with predeveloped systems. As the first study to consider end-to-end latency as the core metric for channel allocation in WSNs, we evaluate DynaChannAl on a 45 node test bed and show that DynaChannAl successfully distributes source nodes to different channels and enables them to select channels and links that minimizes the end-to-end latency.