关键词：无线通信；频谱；无线电系统；频率分配；频谱感知
摘 要：The National Telecommunications and Information Administration (NTIA), in coordination with the Federal Communications Commission (FCC) and federal agencies, has established a Spectrum Sharing Innovation Test-Bed pilot program to examine the feasibility of increased sharing between federal and non-federal users. The pilot program is evaluating the ability of dynamic spectrum access (DSA) devices employing spectrum sensing and/or geo-location technologies to share spectrum with land mobile radio (LMR) systems operating in the 410-420 MHz Federal band and in the 470-512 MHz non-Federal band. Since NTIA published the Test-Bed Phase I test plan on its website in February 2009, it has been engaged in testing DSA devices at its laboratory, the Institute for Telecommunications Sciences (ITS), in Boulder, CO. The Phase I tests assess the performance and behavior of DSA devices in response to simulated LMR environment signals within a laboratory setting. The Phase I test plan document provided a notional definition of subsequent Phase II and III field testing. Phase II will assess the spectrum sensing capabilities of DSA devices in a live LMR environment with sufficient DSA transmitter attenuation to prevent interference to LMR systems. In Phase III, the DSA devices transmitter attenuation will be removed and the devices will be allowed to operate freely in a variety of live LMR radiofrequency signal environments.