Capacity Scaling and Optimal Operation of Wireless Networks

Scaling;Capacity;Hierarchical;Transport;Electrical and Computer Engineering

Ghaderi Dehkordi, Javad

University of Waterloo

关键词: Scaling;    Capacity;    Hierarchical;    Transport;    Electrical and Computer Engineering;   

Others  :  https://uwspace.uwaterloo.ca/bitstream/10012/3825/1/jghaderiThesis08.pdf

瑞士|英语

来源: UWSPACE Waterloo Institutional Repository

【 摘 要 】

How much information can be transferred over a wireless networkand what is the optimal strategy for the operation of suchnetwork? This thesis tries to answer some of these questions froman information theoretic approach.A model of wireless network is formulated to capture the mainfeatures of the wireless medium as well as topology of thenetwork. The performance metrics are throughput and transportcapacity. The throughput is the summation of all reliablecommunication rates for all source-destination pairs in thenetwork. The transport capacity is a sum rate where each rate isweighted by the distance over which it is transported. Based onthe network model, we study the scaling laws for the performancemeasures as the number of users in the network grows.First, we analyze the performance of multihop wireless networkunder different criteria for successful reception of packets atthe receiver. Then, we consider the problem of informationtransfer without arbitrary assumptions on the operation of thenetwork. We observe that there is a dichotomy between the cases ofrelatively high signal attenuation and low attenuation. Moreover,a fundamental relationship between the performance metrics and thetotal transmitted power of users is discovered. As a result, theoptimality of multihop is demonstrated for some scenarios in highattenuation regime, and better strategies than multihop areproposed for the operation in the low attenuation regime. Then, westudy the performance of a special class of networks, randomnetworks, where the traffic is uniformly distributed inside thenetworks. For this special class, the upperbounds on thethroughput are presented for both low and high attenuation cases.To achieve the presented upperbounds, a hierarchical cooperationscheme is analyzed and optimized by choosing the number ofhierarchical stages and the corresponding cluster sizes thatmaximize the total throughput. In addition, to apply thehierarchical cooperation scheme to random networks, a clusteringalgorithm is developed, which divides the whole network intoquadrilateral clusters, each with exactly the number of nodesrequired.