Design, implementation and testing of communication protocols in wireless sensor networks with a single relay node

Wireless sensor network (WSN) consists of a group of sensors or nodes, linked by a wireless medium to perform distributed sensing tasks. The highly variable nature of wireless communication poses major challenges for implementing a reliable WSN. WSNs are gaining in popularity to collect data in the physical world for different purposes such as military surveillance, habitat monitoring and medical applications.;The objective of our work is to design and implement a collaborative and distributed networking protocol for data dissemination in WSNs with relay nodes and network coding. In particular, software components are being implemented within the TinyOS operating system to provide a flexible software platform and scalable performance using Crossbow off-the shelf WSN nodes. The challenge in our protocol implementation is the fact that wireless sensors are resource constrained, where the usage of energy and memory must be done wisely to increase the lifetime of nodes. In addition, in order to implement network coding, it is expected that non-conventional requirements in the network protocol will be accommodated such as synchronization of nodes, transmission rate control and procedures for termination of data exchanges.;Recently, an innovative way of using network resources has been discovered by introducing network coding. In a traditional WSN, relay nodes receive packets from incoming links and forward them to outgoing links. In network coding, a relay node can modify data and redistribute the results of coding received packets to its outgoing links with the purpose of reducing network energy consumption or improving the packet delivery reliability.