Design of a Real-Time Wireless Network for the Northern Pierre Auger Observatory

The Pierre Auger Cosmic Ray Observatory employs a large array of Surface Detector (SD) stations to detect the secondary particle showers generated by Ultra High Energy Cosmic Rays. The operational Auger South site uses a tower-based wireless network for communication between SD stations and the observatory campus. Plans for a larger Auger North array call for a similar system. However, a variety of factors render direct station-to-tower routing infeasible in Auger North. Thus, we have adopted a new peer-to-peer paradigm, the Wireless Architecture for Hard Real-Time Embedded Networks (WAHREN), designed specifically for highly reliable message delivery over fixed networks, under hard real-time deadlines. This paper introduces the topologies, protocols, performance, formal verification, and reliability modeling of WAHREN. It also presents the adaptation of WAHREN to Auger North, including its embedding in the SD array, hardware development, and plans for an in-situ Research and Development Array.