Random access
Random Access Transport Capacity
Abstract
This project develop a new metric for quantifying end-to end throughput in Multi hop wireless networks, which we term random access transport capacity, since the interference model presumes uncoordinated transmissions. The metric quantifies the average maximum rate of successful end-to-end transmissions, multiplied by the communication distance, and normalized by the network area. We show that a simple upper bound on this quantity is computable in closed-form in terms of key network parameters when the number of retransmissions is not restricted and the hops are assumed to be equally spaced on a line between the source and destination. We also derive the optimum number of hops and optimal per hop success probability and show that our result follows the well-known square root scaling law while providing exact expressions for the pre-constants, which contain most of the design-relevant network parameters. Numerical results demonstrate that the upper bound is accurate for the purpose of determining the optimal hop count and success (or outage) probability.
Chapter 1 - Introduction
DETERMINING the capacity of distributed wireless networks (i.e., ad hoc networks) is one of the most general and challenging open problems in information theory. Straightforward applications of known information theoretic tools and inequalities become intractable almost immediately and have hence yielded little in the way of results. This motivates the exploration of approaches to describing ad hoc network throughput that, while falling short of strict information theory upper bound standards, do provide insight into the fundamental trends on achievable throughput.
Motivation
The main line of present inquiry is to consider the transport capacity of an ad hoc network, which quantifies the bits per second that can be reliably communicated over some distance in the
Abstract
This project develop a new metric for quantifying end-to end throughput in Multi hop wireless networks, which we term random access transport capacity, since the interference model presumes uncoordinated transmissions. The metric quantifies the average maximum rate of successful end-to-end transmissions, multiplied by the communication distance, and normalized by the network area. We show that a simple upper bound on this quantity is computable in closed-form in terms of key network parameters when the number of retransmissions is not restricted and the hops are assumed to be equally spaced on a line between the source and destination. We also derive the optimum number of hops and optimal per hop success probability and show that our result follows the well-known square root scaling law while providing exact expressions for the pre-constants, which contain most of the design-relevant network parameters. Numerical results demonstrate that the upper bound is accurate for the purpose of determining the optimal hop count and success (or outage) probability.
Chapter 1 - Introduction
DETERMINING the capacity of distributed wireless networks (i.e., ad hoc networks) is one of the most general and challenging open problems in information theory. Straightforward applications of known information theoretic tools and inequalities become intractable almost immediately and have hence yielded little in the way of results. This motivates the exploration of approaches to describing ad hoc network throughput that, while falling short of strict information theory upper bound standards, do provide insight into the fundamental trends on achievable throughput.
Motivation
The main line of present inquiry is to consider the transport capacity of an ad hoc network, which quantifies the bits per second that can be reliably communicated over some distance in the
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