Ali, Omar Ahmed (2008-05). Delay-sensitive communication over wireless multihop channels. Master's Thesis.
Wireless systems of today face the dual challenge of both supporting large traffic flows
and providing reliable quality of service to different delay-sensitive applications. For
such applications, it is essential to derive meaningful performance measures such as
queue-length distribution and packet loss probability, while providing service guarantees.
The concepts of effective bandwidth and effective capacity offer a powerful
cross-layer approach that provides suitable performance metrics for the bandwidth
and capacity of wireless channels supporting delay-sensitive traffic. Many wireless
systems rely on multihop forwarding to reach destinations outside the direct range
of the source. This work extends part of the methodology available for the design of
wireless systems to the multihop paradigm. It describes the analysis of a communication
system with two hops using this cross-layer approach. A framework is developed
to study the interplay between the allocation of physical resources across the wireless
hops and overall service quality as defined by a queueing criterion based on large
deviations. Decoupling techniques introduce simple ways of analyzing the queues independently.
Numerical analysis helps identify fundamental performance limits for
Rayleigh block fading wireless channel models with independent and identically distributed
blocks. Simulation studies present comparable results akin to that obtained
using the analytical framework. These results suggest that it is imperative to account
for queueing aspects while analyzing delay-sensitive wireless communication systems.