ECPC: Toward preserving downtime data persistence in disruptive wireless sensor networks

Sensor networks have particularly important applications in challenging environments. However, those challenging environments also pose significant challenges to network sustainability and reliability. In such environments, the network often becomes disruptive and even unavailable during downtime. This results in undesired loss of valuable spatial-temporal sensor data. Data persistence can be achieved by using insitu encoding and caching of data through distributed mechanisms. However, the existing methods in the literature are mainly based on network random walks, which not only incur significant communication overhead, but also are prone to network or node failures. In this article, we present ECPC, a distributed Erasure Coding with randomized Power Control protocol for preserving data in disruptive sensor networks. ECPC only requires each sensor node to perform several rounds of broadcast in its neighborhood at some randomly chosen radio transmission power levels, and thus it incurs low communication overhead. We proved that ECPC achieves the expected code degree distribution and pseudo-global randomness of erasure coding principles. We have also evaluated the performance of ECPC by comparing it with several key related approaches in the literature (such as EDFC and RCDS). The performance comparisons validate that our proposed ECPC protocol can reach higher data reliability under varying node failure probabilities. In addition, ECPC protocol is also shown to be scalable with different network sizes.