PLAN: a pipeline-access local ATM network protocol for multimedia applications

This paper presents a shared media ATM LAN architecture known as pipelined-access local ATM network (PLAN) suitable for both LAN and MAN applications. It is a reservation type bi-directional broadcast bus system protocol in which stations are connected at predefined points on the bus and all transmissions are done sequentially from one end to the other in a pipelined manner. It is designed to (i) support multimedia traffic, (ii) dynamically allocate bandwidth to various types of traffic and provide fair media access to stations, (iii) provide throughput close to 100%, (iv) operate at high bit rates, and, (v) use packets of ATM cell size and format for interoperability with the wide-area ATM networks. We present the architecture, analysis and performance of the proposed PLAN protocol under various multimedia traffic conditions. The results show that its throughput approaches 100%, is independent of traffic composition, and increases slowly with bit rate. It decreases only slightly as the bus length and/or number of stations increases. For example, the throughput decreases only by 0.17% per kilometer as the bus length increases. Based on the results obtained, the proposed PLAN protocol is seen to be well suited for high speed multimedia ATM LAN and MAN applications.