Page Size Optimization for Code Dissemination in Wireless Sensor Networks

Wireless sensor networks (WSNs) have recently gained a great deal of research attention, with a wide range of applications being explored. In most applications, WSNs are deployed in inaccessible areas for a long lifetime. Software maintenance and update in WSNs are challenging. Network reprogramming is an important way to address this challenge. Code dissemination is a critical service to enable network reprogramming. Most code dissemination protocols employ segmentation and pipelining to improve the reprogramming efficiency. As we show in this paper, the choice of the page size in these segmented and pipelined dissemination protocols is of vital importance to the overall dissemination time. Hence, we explore the tradeoff in determining the optimal page size in terms of the overall dissemination time. We investigate the impact of page size for two typical code dissemination protocols in WSNs. Results show that the optimal page size decreases when the maximum hop count from the source node increases; and the optimal page size increases when the program size increases. The absolute value of the optimal page size is determined by the network scale, program image size, and protocol details.