Capacity and Protocols for Integrated Voice/Data CDMA Systems

Project Details


The aim of this project is to develop an analytical framework that provides new understanding of the interaction of voice and data in an integrated voice/data CDMA system. The insights obtained from this study will be further used to develop new algorithms. The effect of the variability of data and its impact on the capacity and performance of the voice service in such a multimedia wireless system will be analyzed. New easily implemented real-time strategies for call admission, and control after call setup will be derived for the data service with delay sensitive voice being given priority. The effect of variable quality of service (QoS) the different classes of service may require will be included in the analysis framework and methodology. Further, the interaction between protocol layers will be included in the study and design of access control schemes for data. Specifically, we will analyze the interactions of end-to-end protocols like TCP (Transmission Control Protocol) with data access control schemes on the radio link. Analytical Methodology: Analysis of these problems encounters two serious difficulties. Even if all the information (e.g., distributions of relevant random variables) was available, exact analysis appears to be beyond current theory leading to computationally tractable solutions. Secondly, the needed distributions are often not available. We develop instead simple, reasonably accurate, analytic methodology which uses only means and variances, when appropriate, and distributional assumptions when necessary. Data Control Strategies: Recognizing that voice is delay sensitive, we develop data access control strategies. One type of real-time control is based on readily measurable quantities related to voice quality and uses broadcasted permission probabilities to the data users. The proposal will investigate the varied questions associated with the optimization of the data control algorithms. We will develop and analyze such control strategies for both conve ntional and multiuser receivers. Interaction between Protocol Layers : Serious problems can arise when protocol layers are designed independently but end up with unexpected interactions. We address this in the context of a data access control strategy operating under TCP. We investigate the problems due to such interactions and appropriate modifications in the light of the interactions. Significance of this Project: This project will provide a more complete understanding of the complex issues of voice/data integration. This will include development of analytical methodology which is convenient to use and consistent with the limited information expected to be available. New effective real-time algorithms will be developed for both conventional and multiuser receivers. Further, the study of the interactions between data link retransmission schemes and higher layer reliability protocols (like TCP) should provide valuable insights into system design for optimum coexistence of diverse traffic. The work will thus provide a better understanding of the complex interactions both between service types with different traffic characteristics and different QoS requirements, and between different protocol layers. This will lead to improved design of real-time algorithms for data.

Effective start/end date9/1/978/31/01


  • National Science Foundation: $328,057.00


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