Cesar Santivanez

Study of Various TDMA Schemes for Wireless Networks in the Presence of Deadlines and Overhead

Tuesday, August 25, 1998
3:00 PM
422 Snell Building

Abstract

Wireless networks designed to support real time (and other time constrained) applications need to implement mechanisms which attempt to minimize the cell dropping rate due to deadline expiration. In addition, wireless networks need to employ some of their resources for coordinating the distributed users' access to the shared medium (air interface); such resources are regarded as overhead. The objective of this work is to determine the minimum system dropping rate induced by TDMA schemes supporting time-constrained applications with common maximum cell delay tolerance. Expressions are derived for the induced system dropping rate for various TDMA schemes with different overhead and the maximum number of users than can be admitted in the network without violating the maximum dropping rate constrain is determined. Based on these derivations, the optimal (or of largest ``capacity'') TDMA scheme - in the class considered - is determined. The performance limiting factors associated with the suboptimal schemes are identified, and the magnitude of their (negative) impact is evaluated. Based on this information it is possible to point to performance improving modifications which should be pursued to the extent permitted by technological constraints.

Thesis Committee:
Prof. I. Stavrakakis (advisor)
Prof. M. Stojanovic
Prof. J.G. Proakis
Prof. I. Matta (CCS)