Bit-coding Aggregation Tree for Global Network Link Quality Representation in WSN

Link quality monitoring in wireless sensor network has been studied in detail. There are many measurements for link quality in WSN presented by researchers. Relative to the comprehensive study for link quality monitoring, there are very little research for link quality aggregation and representation for link situation of the whole network. This paper presents a three levels framework for global network link quality aggregation and representation (LQAR) and a bit-coding aggregation tree (BAT) algorithm for link quality aggregation and routing to sink node. The LQAR framework includes three levels: storage and digest level, aggregation level and representation level. Storage and digest level defines what data should be stored in a node and how to calculate the digest value representing the link situation around the node. Aggregation level uses BAT algorithm to aggregate the digest values of nodes and transmits them to sink node. Representation level solves how to visualize these data. BAT algorithm integrates bit-coding method with aggregation tree for energy saving. The simulation results show that BAT can reduce the total number of messages and decrease energy loss greatly.