Fault-Tolerant Cognitive Diversity Scheme for Topology Information-Based Hybrid Ubiquitous Sensor Networks

In this paper, a special scenario of the topology in the hybrid ubiquitous sensor networks is studied and a new cross layer fault-tolerant cognitive scheme based on topology information is proposed to exploit both the channel diversity and the spatial reusability. The proposed Cross Layer Fault-tolerant Topology Information-based Cognitive Diversity Scheme (CL-FTICDS) integrated the attributes both of the new performance evaluation of the cooperative diversity and the attributes of the topology space. It resides between MAC and network layer and aims to improve the network throughput by coordinating the transmission power, channel assignment and route selection among multiple nodes in a distributed way. The CL-FTICDS jointly coordinates the transmission power at each node, the channel selection on each wireless interface, and route selection among interfaces based on the traffic information measured and exchanged among the multi-hop neighbor nodes. The Cognitive Diversity Time Topology Metric (CDTTM) is presented to quantify the difference of various adjustment candidates. It achieves efficient utilization of available channels by selecting feasible adjustment candidate with the smallest CDTTM value and coordinating affected nodes to realize the adjustment. The average achievable sum rates and the outage probability of the networks are all examined with the cross layer constraints.