Data link considerations for GPS based airport surface traffic management systems

The author discusses the communications capability for airport surface traffic management systems, and, more specifically, the communications capability for those systems that derive at least a portion of their position and velocity information by processing transmissions from the Global Positioning Satellite (GPS) system. Both communications requirements and communications subsystem design are considered. Attention is given to top level communication requirements including such issues as the types of communication that are necessary, the value and benefits to be derived from communications, and the key design drivers. Communication requirements are then discussed in somewhat more detail, and an attempt is made to quantify requirements wherever possible. In addition, the key system design issues and alternatives are briefly explained. Alternative communication system implementations that appear to have promise with respect to meeting the stated requirements are listed. A spread spectrum data link alternative for the data link implementation is highlighted