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    METHOD AND APPARATUS FOR ALLOCATING HYBRID BURSTS IN OFDMA SYSTEM
    22.
    发明专利
    METHOD AND APPARATUS FOR ALLOCATING HYBRID BURSTS IN OFDMA SYSTEM 未知

    公开(公告)号：CA2689496C

    公开(公告)日：2015-08-18

    申请号：CA2689496

    申请日：2008-06-11

    Applicant: KOREA ELECTRONICS TELECOMM

    Inventor： HWANG SUNG-HYUN ,  UM JUNG-SUN ,  SONG MYUNG-SUN ,  KIM CHANG-JOO ,  KO GWANGZEEN

    IPC: H04L27/26

    Abstract: Provided are a method of adaptively allocating appropriate hybrid bursts according to terminal attributes including terminal position, channel state, and service type in an orthogonal frequency-division multiple access (OFDMA) system, and an upstream-MAP information element (US-MAP IE) structure supporting the method. The method includes dividing an upstream subframe into a plurality of zones depending on the number of OFDMA symbols and allocating bursts of a zone to a terminal according to the terminal attributes. Bursts are formed by allocating slots along a time axis in the upstream subframe, and are formed by allocating slots along a frequency axis in a downstream subframe.

    CHANNEL SWITCHING APPARATUS AND METHOD OF A BASE STATION AND CHANNEL SWITCHING APPARATUS AND METHOD OF A TERMINAL BASED ON THE COGNITIVE RADIO SYSTEM
    24.
    发明专利
    CHANNEL SWITCHING APPARATUS AND METHOD OF A BASE STATION AND CHANNEL SWITCHING APPARATUS AND METHOD OF A TERMINAL BASED ON THE COGNITIVE RADIO SYSTEM 未知

    公开(公告)号：CA2708838A1

    公开(公告)日：2009-06-25

    申请号：CA2708838

    申请日：2008-12-05

    Applicant: KOREA ELECTRONICS TELECOMM

    Inventor： KO GWANGZEEN ,  YOU SUNG-JIN ,  SONG MYUNG-SUN ,  HWANG SUNG-HYUN ,  UM JUNG-SUN ,  KIM CHANG-JOO

    IPC: H04B7/155

    Abstract: In a cognitive radio system, when communication in an operational channel is determined to be discontinued due to that an incumbent user (IU) entering the operational channel that is currently being used or due to that an excessive interference occurring in the operational channel, the operational channel is switched to a pre-arranged channel. However, since some parameters are different between the operational channel and the pre-arranged channel, an initialization procedure has to be performed to allow the cognitive radio system to be adapted to those some parameters. Since an initialization technique aiming for this situation is not developed yet, a conventional cognitive radio system uses a general initialization technique used to initially operate a system. However, the general initialization technique has to allow the system to be adapted to many parameters so that it takes a relatively long initialization time. A channel switching apparatus and method thereof of a base station, which allocates a slot for data exchange with each of a plurality of terminals in a frequency channel that is not used by the IU and thus performs communication, include transmitting a channel switching message for requesting to switch to a backup channel when a signal of the IU is sensed in the frequency channel; transmitting a beacon frame via the backup channel, wherein the beacon frame comprises allocation information about slots which are in the frequency channel and which are respectively allocated to each of the plurality of terminals; and allocating the slot for data exchange with each of the plurality of terminals to the backup channel according to the allocation information, and communicating with each of the plurality of terminals. By doing so, frequency resources between each of networks can be efficiently used, and convenience and efficiency with respect to network operation can be maximized.

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