Real-time centralized spectrum monitoring: Feasibility, architecture, and latency

Abstract

This paper describes the implementation and evaluation of a real-time, centralized spectrum monitoring and alert system. Such a system can be used to support emerging spectrum sharing solutions that use a centralized controller to mediate tiered access to spectrum. These controllers rely on realtime awareness of spectrum activity. In addition to describing the architecture and prototype implementation of this real-time monitoring system, we propose a test method to measure the latency of detecting a spectrum occupancy event. This latency is measured as the time from when the event (e.g., a signal transmission) begins to when an alert of that event is delivered to a subscribed client. We used this test method to measure the latency of two different sensor implementations in conjunction with our spectrum occupancy server and found the 95th percentile of latency to be under 80 ms in both cases, plus the network transmission delays of any wide area network involved.