CHANNEL SWITCHING APPARATUS AND METHOD OF A BASE STATION AND CHANNEL SWITCHING APPARATUS AND METHOD OF A TERMINAL BASED ON THE COGNITIVE RADIO SYSTEM

摘要

In a cognitive radio system, when communication in an operational channel isdetermined to be discontinued dueto that an incumbent user (IU) entering the operational channel that iscurrently being used or due to that an excessive interferenceoccurring in the operational channel, the operational channel is switched to apre-arranged channel. However, since some parametersare different between the operational channel and the pre-arranged channel, aninitialization procedure has to be performed to allowthe cognitive radio system to be adapted to those some parameters. Since aninitialization technique aiming for this situation isnot developed yet, a conventional cognitive radio system uses a generalinitialization technique used to initially operate a system.However, the general initialization technique has to allow the system to beadapted to many parameters so that it takes a relativelylong initialization time. A channel switching apparatus and method thereof ofa base station, which allocates a slot for data exchangewith each of a plurality of terminals in a frequency channel that is not usedby the IU and thus performs communication, includetransmitting a channel switching message for requesting to switch to a backupchannel when a signal of the IU is sensed in thefrequency channel; transmitting a beacon frame via the backup channel, whereinthe beacon frame comprises allocation informationabout slots which are in the frequency channel and which are respectivelyallocated to each of the plurality of terminals; and allocatingthe slot for data exchange with each of the plurality of terminals to thebackup channel according to the allocation information, andcommunicating with each of the plurality of terminals. By doing so, frequencyresources between each of networks can be efficientlyused, and convenience and efficiency with respect to network operation can bemaximized.