A Distributed Binary Tree Protocol with Advanced Reservation (DBTP/AR) for Local Area Networks

Abstract

When several different types of services such as data, speech, video, facsirmile, etc., are integrated into a local area network (LAN) and/or when traffic is quite high, a multipacket-user environment is created. In this paper, we propose and evaluate a new protocol called Distributed Binary Tree Protocol with Advanced Reservation (DBTP/AR) where a terminal with multiple packets is allowed to make advanced reservation in the next transmission cycle thereby reducing the number of collisions. The performance of DBTP/AR has been compared with that of the conventional Distributed Binary Tree Protocol (DBTP). Mean throughput and mean packet delay performances of both DBTP/AR and DBTP protocols have been determined by computer simulation with channel bit rate, packet length, and packet arrival rate as parameters. From the results it is seen that the throughput under moderate to high traffic conditions approaches to 1 packet/slot in the case of DBTP/AR compared to 0.5 packet/slot for DBTP, depending upon the above parameters. For example at a bit rate of 3 Mbps and a packet size of 24 bits the maximum throughput for DBTP/AR protocol was found to be about 49% with a mean packet delay of 42 ms while those for DBTP protocol were found to be 25% and 120 ms, respectively. Based on the results it is seen that the DBTP/AR protocol is well suited for designing a high throughput and low mean packet delay local area network for operation in a normal as well as integrated services environments.