Introduction to CDMA and load balancing in wireless networks

Dr. Parthasarathy Guturu

University of North Texas, Denton

Tuesday, April 11th, 2006, 3:30-4:30pm

113 Jerry Junkins Building

Abstract

In this talk, Dr. Partha Guturu will first provide a brief introduction to CDMA/WCDMA wireless networks and then present methods for load balancing on the CDMA carrier frequencies in multiple bands. For better capacity and higher availability, present day third generation (3G) wireless systems based on the Code Division Multiple Access(CDMA) technology are evolving to operate on multiple carriers (frequencies) spread over multiple bands. In order to provide better quality of service, the 3GB (3rd Generation and Beyond) systems need to distribute calls equitably to different carriers on different base-stations accessible to the mobiles irrespective of the bands or carriers on which those mobiles initiated their calls. However, there is a risk of call failure when a call originated on a carrier in a band is migrated to another carrier in a different band, particularly because of the differences in the radio coverage of the base-stations operating in different bands. To address this problem, the speaker, as part of his work earlier in Nortel, developed a class of methods that offer equal robustness against call failures and varying degrees of call distribution effectiveness. For call distribution, these methods employ an enhanced carrier capacity measure (ECM) which augments the gross capacities of the carriers (to house calls) with preconfigured biases specific to the mobile users. An intuitively appealing measure based on the ECM has also been developed for comparing the methods for distribution-effectiveness. Relative performances of the proposed methods with respect to call failure rate and distribution effectiveness are established by means of simulation results for calls originating anywhere in the cell coverage area as well as calls originating exclusively near the cell boundaries. The latter results help to study the effect of mobility on the performances of the algorithms.

 

 

Biography:  Dr. Parthasarathy (Partha) Guturu is currently an Assistant Professor in the Electrical Engineering Depart of North Texas (UNT), Denton. Prior to his recent return to academia, Dr. Guturu has had more than seven years experience in Nortel Networks’ corporate R&D and over ten years in teaching and academic research abroad. His achievements in the Telecom industry include three innovations (two patents awarded, one pending) and successful architectures and designs for complex real-time systems. While at Nortel, he taught graduate level Software Engineering courses to UNT CSE student as an adjunct professor. In his earlier stints in academia, Dr. Guturu was a visiting professor at the University of Quebec at Montreal, Canada, and an Associate Professor at Indian Institute of Technology (IIT), Kharagpur, wherefrom he got all his degrees from B. Tech (Honors) through PhD. While at IIT, he supervised 4 PhD theses and a large number of graduate and undergraduate theses, directed funded research, and published over 35 papers in international journals and conferences in areas such as pattern recognition, computer vision, neural networks and genetic algorithms. Dr. Guturu, a Senior Member of IEEE, plans to integrate his past experience in Computational Intelligence and the latest experience in Wireless Networks to embark upon an ambitious multi-disciplinary research program crosscutting the areas of Networking, Imaging, Sensors and Data Fusion.

 

 

 

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