Reliable routing for low-power smart space communications

Smart space (SS) communication has rapidly emerged as an exciting new paradigm that includes ubiquitous, grid and pervasive computing to provide intelligence, insight and vision for the emerging world of intelligent environments, products, services and human interaction. Dependable networking of a SS environment can be ensured through reliable routing, efficient selection of error-free links, rapid recovery from broken links and the avoidance of congested gateways. Since link failure and packet loss are inevitable in SS wireless sensor networks (WSNs), the authors have developed an efficient scheme to achieve a reliable data collection for SSs composed of low capacity wireless sensor nodes. WSNs must tolerate a certain lack of reliability without a significant effect on packet delivery performance, data aggregation accuracy or energy consumption. An effective hybrid scheme is presented that adaptively reduces control traffic with a metric that measures the reception success ratio of representative data packets. Based on this approach, the proposed routing scheme can achieve reduced energy consumption while ensuring minimal packet loss in environments featuring high link failure rates. The performance of the proposed routing scheme is experimentally investigated using both simulations and a test bed of TelosB motes. It is shown to be more robust and energy efficient than the network layer provided by TinyOS2.x. The results show that the scheme is able to maintain better than 95% connectivity in an interference-prone medium while achieving a 35% energy saving.