Implementation of Cooperative Information Storage on Distributed Sensor Boards

Reliable data retrieval from a sensor network can require a temporal distributed data storage of the measured data among all motes. This is the case when a source of information, or a gateway, is only occasionally present in the network. We consider a network consisting of motes that in order to save energy independently of each other go into offline mode, switching their radios off. We propose a cooperative mechanism for data distribution that increases system reliability, and at the same time keeps the memory consumption for data storage low on each device. A Reed-Solomon coding scheme is applied as a solution where a certain number of unavailable devices can be tolerated without jeopardizing the system reliability. A prototype of a system is implemented to test the protocol behavior under realistic conditions. Prototyping is done on the OpenSensor platform developed at Aalborg University. To observe the system performance in different settings, additionally a simulator is developed. Performance results indicate that the proposed cooperative data distribution method outperforms the non-cooperative one. The metric used to estimate the system reliability is the probability to retrieve all sensor measurements.