Simulation Study of Local Multipoint Distribution Service

by Khobare, Abhijit

This thesis describes simulation models for Local Multipoint Distribution Service (LMDS) systems, and uses simulation to examine the performance of two different multiple access schemes and two different duplexing schemes. LMDS is a broadband wireless point-to-multipoint access network that aims to improve network access capacity for end-users by solving the "last mile" problem. This study involves building a parameterized simulation model for symmetric LMDS systems and comparing performance of the systems for different multiple access and duplexing schemes.

The report describes the LMDS system and briefly discusses other broadband access networks. Objectives of this study are discussed and methodology is chosen. The simulation model design is explained. Further, the experimental design is discussed. The simulation results are presented and discussed, and conclusions are drawn.

The multiple access schemes under study are Time Division Multiple Access (TDMA), and Frequency Division Multiple Access (FDMA). The duplexing schemes under study are Time Division Duplexing (TDD), and Frequency Division Duplexing (FDD).

For the system under study, it was observed that TDMA results in lower end-to-end (ETE) delay per packet, but higher jitter, than FDMA. In addition, TDD results in lower ETE delay per packet than FDD. Specifically, TDMA in conjunction with TDD was found to result in lowest ETE delay per packet among the configurations under study. In addition, FDMA in conjunction with FDD was found to result in lowest jitter among the configurations under study.