Communication Protocols for Embedded Systems
Date of Original Version
Abstract or Description
In this article, we will first discuss the special considerations for networking real-time embedded systems. Then, we describe several media access protocols that demonstrate fundamentally different ways of accessing the shared medium. The protocols we discuss are: Connection Oriented Protocols, Polling, Time Division Multiple Access (TDMA), Token Ring, Token Bus, Binary Countdown, Carrier Sense Multiple Access with Collision Detection (CSMA/CD), and Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). For each of these protocols, we will evaluate the strengths and weaknesses against the special considerations. We conclude the article by presenting a protocol tradeoff chart which will enable you the select a protocol to fit your needs. While no protocol is perfect for all purposes, we think that a variation of CSMA/CA offers the most versatility for many embedded systems.