Department of Electrical and Computer Engineering
M.S. Thesis Abstract
Dual Rate Multiple Access: A Radio link Protocol
In the recent past, there has been an increased demand for Cellular/Personal Communication Services. However, the increase in demand has not been matched by an increase in the available spectrum. This has resulted in an urgent need for the development of efficient techniques for spectral utilization. Efficient utilization of the spectrum could be achieved through improvements in various modules of a cellular system. This thesis suggests a method for improving spectral efficiency through the design of an efficient Media Access Control (MAC) Protocol.
In this thesis, we propose and analyze the Dual Rate Multiple Access (DRMA) protocol. The DRMA system supports high and low packet rates for voice users. High rate service is offered to active users with talkspurts, while the low rate service is used to poll inactive users. The polling strategy for inactive voice users enables statistical multiplexing of voice talkspurts. The low rate service is also used to generate a low bit rate representation of the background noise and could also be used as an embedded full time control channel for the voice users.
We also examine the integration of data and voice in the DRMA system. The residual bandwidth that goes unused by voice is assigned to the data users. Note that explicit priority is given to the voice users. An appropriate media access strategy for data users is dependent on the type of data messages. In this work, we integrate a random access protocol for an email messaging data service. We and through simulation and analysis that DRMA affords a considerable increase over TDMA in spectral utilization in terms of the number of simultaneous calls that can be carried, and also in terms of the bandwidth available for data messaging.
Thesis Director: Professor Roy Yates