  In cognitive radio networks (CRN), Out-of-Band (OoB) spectrum sensing
provides seamless communication. Cognitive radio (CR) users, so called
secondary users (SUs), should avoid interference with primary users (PUs), the
owner of the licensed band, while trying to access the unused licensed or
unlicensed band, for spectrum utilization. When PUs request to access their
band, SUs need to vacate the band, thus it is inconvenient to provide seamless
communication without OoB sensing. In this paper, we suggest an OoB sensing
algorithm to guarantee seamless communication and also minimize the
interference of SUs on PUs. Also we obtain analysis-based achievable throughput
by considering the OoB sensing duration. To verify our algorithm, we perform
simulation and find that the effect due to OoB sensing on the aggregate
throughput is insignificant.
