Relative Capacities of Generic ADS Protocols

Abstract

A number of investigators have proposed various domestic automatic dependent surveillance (ADS) concepts based on line-of-sight (LOS) radio link networks. Each of these proposals has been based on assumptions and constraints as perceived by the individual designer or design group. This article compares the network capacity of several illustrative design alternatives on a normalized basis and parametrically examines expected capabilities. To focus on this objective, we assume the signal and message levels of the design are independent of the network protocol, and the distribution of units and link design features result in N units within reception range. Each of these N units has connectivity to other units, contends for channel access, and is a potential source of mutual interference. Results of the analysis are expressed in terms of the probability that these N units can be accommodated at some tolerable level of mutual interference by the available bandwidth and the net protocol. The alternatives considered are intended to support the use of ADS for an air-air exchange of surveillance information among network members as well as to provide cooperative surveillance information to the ground-based Air Traffic Control (ATC) system. Generic designs with common features are compared; sensitivity of described performance with variations on these normalization assumptions can be easily explored with the expressions given. © 1994 John Wiley & Sons, Inc.