Time Division Multiple Access Without a Bus Master

Philip J. Koopman, Jr
Bhargav P. Upender

June 30, 1995

UTRC Technical Report RR-9500470

Abstract

Time Division Multiple Access (TDMA) protocols have the potential to provide simple but effective broadcast bus communications for embedded systems. However, bus-master based protocols such as TDMA can be undesirable in practice because the bus master node constitutes a single-point failure vulnerability and adds to system expense. We present the Jam-TDMA (J-TDMA) protocol, which eliminates the need for having a bus master through the use of a nondestructive jamming signal for frame synchronization. We give a detailed description of the J-TDMA protocol and show how to minimize the effects of speed differences among nodes on TDMA systems, which can be critical for low-cost implementations. We believe that J-TDMA reaps the benefits of TDMA protocols without suffering the reliability and system complexity drawbacks of other TDMA methods.

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Phil Koopman -- koopman@cmu.edu