ABSTRACTRadio Technical Commission for Aeronautics Special Committee‐159 (RTCA SC‐159) recently established a working group to address the design of a wide‐area broadcast service for providing rapid and frequent indications of the health of the GPS satellites. The GPS Integrity Channel Working Group has met over the last year to recommend a system architecture that would provide 10 s warning of any deterioration of service causing the navigation guidance accuracy to be outside the limits for nonprecision approach. The architecture to be selected was also to permit international implementation of the service. These requirements can be satisfied by a sparse ground‐monitoring network sending integrity messages through a satellite communications link. The working group considered the tradeoffs between placing the decision burden on the ground subsystem and placing it on the avionics processor. Their recommendations call for the broadcast of a coarse range measurement for each satellite; this will enable the on‐board GPS receiver to determine positively whether the GPS navigation accuracy is within prescribed limits. This paper addresses the tradeoffs, message content, data throughput requirements, and data link considerations involved in this