Reverse link rate control based on traffic load and terminal characteristics for CDMA packet system

Abstract

cdma2000 1xEV-DO technology, also known as, High Data Rate (HDR) or IS-856 standard, provides a cost-effective packet data service solution for consumers and business professionals. It offers high speed, high capacity wireless Internet technology, which is compatible with CDMA networks and optimized for packet data services. On the reverse link of 1xEV-DO system, a Reverse Traffic Channel is assigned to each mobile, and the data rate is autonomously controlled based on a probabilistic rate control model. In the literature, the capacity of the reverse link in the 1xEV-DO has been analyzed by a computer simulation and an analytic model using Markov model. In addition, several schemes to enhance the performance of the reverse link rate control have been introduced. However, in spite of the importance for controlling the maximum possible data rate, there has not been research on the means to control the maximum possible data rate, called RateLimit. Therefore, this dissertation proposes several schemes to control the value of RateLimit. First, we propose a new adaptive rate control scheme based on the reverse link traffic load. Since the Data Channel gain is not entirely proportional to the data rate and increases rapidly in a high data rate, the interference level may increase significantly in Data Channels with high data rates for a large number of mobiles. Therefore, it is desirable to restrict the available maximum data rate by controlling the RateLimit. Numerical and simulation results show that our proposed scheme outperforms 1xEV-DO rate control, in view of overload probability, reverse link throughput and reverse link capacity, both in single-cell and multi-cell environments. Moreover, since the proposed scheme provides a tighter control on the noise rise, it reduces an overload probability and allows stable operation at high traffic loads. Second, we propose a new reverse-link rate control scheme that controls the maximum possible data rate by co...