An Industrial Communication Platform designed for Multimedia Traffic
Franck Vamparys · 1996
In this paper, we present our experiences and observations related to the design and the im- plementation of an industrial communication platform that can can accept hard real-time, soft real-time and non real-time traffic. There is always a trade-off be- tween QoS and performance in a platform that must support different protocols. We demonstrate the abil- ity of our platform to deal flexibly and efficiently with this trade-off. We insist on the buffer management and the data flow management with its scheduling al- gorithms. I. INTRODUCTION The realization of communication systems has become very complex because of the inherent complexity of the protocols and the existence of different requirements of Quality of Service (QoS). A platform of communication can be viewed as a set of functions that offers common services for the support of different network protocols. A platform can be integrated in an operating system (OS) or can be built independently. In the latter case, the plat- form can be ported on several operating systems. A large research effort has been invested into realizing network protocol stacks with good performance, as in the case of the Internet protocols in a Unix environment (l). How- ever, comparatively little work has been done to develop a portable environment that can support various stacks with various QoS at the same time. Such a characteristic is often needed in an industrial context when video, au- dio, download (ftp) and system control traffic are merged in one system. First, we in- troduce our new platform called ACME (Architecture de Communication Multimedia EfJcace) . This platform is derived from our portable communication platform called LitCommEngine (2), which supports different protocol stacks, such as the OS1 MMS stack (3,4) and the TCP/IP stack both running either on high-level operating systems (Unix) or in embedded systems (e.g. VME board). We introduce the ACME architecture, and we show that our ACME platform has strong advantages. Thanks to our im- plementation choice of memory management and schedul- The article is divided into two parts.