Design and Implementation of an End-to-End Architecture for 3.5 GHz Shared Spectrum

Regulatory bodies world-wide are facing increased demand for sub-6 GHz spectrum needed to build future ultrabroadband wireless networks that must keep up with anticipated exponential growth in wireless data traffic. To that end, they are increasingly pursuing policy innovations based on the paradigm of shared spectrum that allows spectrum bands that are underutilized by primary owners to be exploited opportunistically by secondary devices. The 2008 FCC rule-making allowing unlicensed use of underutilized DTV white space represented the first step in that direction and elicited similar efforts in other countries. The 2012 PCAST report [4] in the U.S. pushed this new trend further by announcing the government's intentions to explore shared use of 1000 MHz of federal government spectrum with commercial systems and set the goal to release 500 MHz of spectrum by 2022. As a first step towards this goal, the FCC targeted 3550-3700 MHz band used primarily by naval radars and fixed satellite station for release. As of writing of this paper, the FCC has announced the first set of rules for this band to enable deployment of relatively low-powered network technologies like small cells. The proposed rules require a Spectrum Access System (SAS), akin to a TV Database (TVDB) to implement an innovative three-tiered spectrum management system ­ dynamic incumbents in the top tier, Priority Access License (PAL) users in the second tier and Generalized Authorized Access (GAA) users in the third tier.