SR-Code: Smart Relay Network Coding for Data Collection for Wireless Sensor Networks

Reliability in data collection for wireless sensor networks is one of the major problems in IoT applications. Sensor nodes are usually placed in harsh conditions where data communication is at risk of losing packets. Retransmissions are considered costly in terms of delay and power consumptions, especially that wireless sensor nodes are battery operated. In this context we introduce SR-Code, a novel network coding algorithm that achieves reliability in harsh conditions. SR-Code utilizes the XOR operator to code overheard packets. The targeted network topology is a 2-tier network where data loss can occur in all tiers. SR-Code utilizes bit addresses where each node is identified by a single bit in an address bit vector. Identifying packets and computing the cardinality of coded messages can be easily done using address bit vectors. SR-Code realizes redundancy as a function of overheard packet. SR-Code achieved a reliability factor of 75% when the number of packets lost was 100% of the original (un-coded) packet sent.