SPECTRUM SHARING MAC PROTOCOL APPLICATIONS FOR THE PROPOSED 3.5 GHZ BAND

Abstract

Spectrum sharing between federal and commercial users is proposed by the FCC and NTIA to open up the 3.5 GHz band for wireless broadband use. This requires the detection and subsequent allocation of available licensed spectrum for temporary use by other users without interfering with incumbent signal transmission. The DoD has a documented requirement of 865 MHz by 2025 to support telemetry but only 445 MHz is presently available. This paper presents spectrum sharing opportunity and technology that will help reduce service interference between spectrum users. We developed protocol model for spectrum sharing and implemented cognitive radio media access sensing mechanism using cyclostationary feature detector (CFD). The paper demonstrates shared usage by secondary users with minimum interference and improvement in throughput by as 5 times compared to other protocols. This is an introductory work that shows the feasibility of the approach with the potential for many other factors to be considered. We suggest that with proper sensing mechanism and quiet period implementation by the unlicensed users, CSMA/CA RTS-CTS could be adopted for licensed user protection.