On the Delay-Throughput Tradeoff in Distributed Wireless Networks
This paper deals with the delay-throughput analysis of a single-hop wireless network with n transmitter/receiver pairs. All channels are assumed to be block Rayleigh fading with shadowing, described by parameters (alpha, (omega) over bar), where alpha denotes the probability of shadowing and (omega) over bar represents the average cross-link gains. The analysis relies on the distributed on-off power allocation strategy (i.e., links with a direct channel gain above a certain threshold transmit at full power and the rest remain silent) for the deterministic and stochastic packet arrival processes. It is also assumed that each transmitter has a buffer size of one packet and dropping occurs once a packet arrives in the buffer while the previous packet has not been served. In the first part of the paper, we define a new notion of performance in the network, called effective throughput, which captures the effect of arrival process in the network throughput, and maximize it for different cases of packet arrival process. It is proved that the effective throughput of the network asymptotically scales as (log n)/(alpha) over cap, with (alpha) over cap, (alpha) over cap Delta = alpha(omega) over bar regardless of the packet arrival process. In the second part of the paper, we present the delay characteristics of the underlying network in terms of the packet dropping probability. We derive the sufficient conditions in the asymptotic case of n --> infinity such that the packet dropping probability tend to zero, while achieving the maximum effective throughput of the network. Finally, we study the trade-off between the effective throughput, delay, and packet dropping probability of the network for different packet arrival processes. In particular, we determine how much degradation will be enforced in the throughput by introducing the aforementioned constraints.
delay-throughput tradeoff on-off power allocation dropping probability poisson arrival process throughput maximization