Link scheduling and Data Forwarding in Wireless Sensor Networks of long chains tree topology

Wireless sensor network (WSN) is characterized by the information transmission from multiple sensor nodes observing an environment. WSN based monitoring system with its nodes of low cost can be deployed in strict environment. According to the structure and the layout of the Monitoring objects, the long chain tree-like topology of wireless sensor network is often used. Such monitoring systems include power transmission line, oil transportation, gas transportation and road traffic monitoring. This paper firstly reviews the basic WSN theory and protocols concentrating basically on the MAC layer, try to identify the maximum throughput achievable in multi-hop long chain tree structure WSNs. A second objective of this paper is to propose a multimode hierarchical network based multi-channel assignment algorithm for data collection applications. The proposed algorithm has three components, Multimode Hierarchical Network Establishment (MHN), Channel Assignment (CA), and Data Forwarding (DF). The MHN module partitions the whole network into NL subnetworks, and each subnetwork represents a data dissemination mode. CA module assigns one unique channel to each mode. And then DF forwards each data flow only along its corresponding level. Evaluation results show that the algorithm proposed in this paper can significantly reduce data collection time, improve the network throughput.