Samsung Electronics Co., Ltd.

Sungkyunkwan University

Ho-dong Kim

Hae-Young Jun

Hyuk-Choon Kwon

Soo-Yeon Jung

Sang-Bum Kim

Eun-Taek Lim

Dong-seek Park

Cheng Shan

Jung-Soo Woo

Yong-Ho Park

Ju-Yeon Song

Jae-Ik Park

Geun-Ho Lee

Jae-yong Eum

Kwang-ho No

Hae-seog Jo

Jean-Man Sur

Min-soo Lee

Hyun-seong Shin

Dong-In Kim

Kyoung-Youp Park

Woo-Jin Shin

A method and apparatus for transferring to a second communication band and returning to an original communication band according to a channel state in a multiband communication system are provided. The method includes communicating with a peer device in a first band, determining a channel state of a second band, and transferring to the second band based on a result of the determination, thereby efficiently using a plurality of bands and thus improving a data transmission speed.

Method and apparatus for band transfer in multiband communication system

A method of and apparatus for operating a Coexistence Beacon Protocol (CBP) packet transmitter in a Cognitive Radio (CR)-based wireless communication system is provided. The method includes, identifying a Self-Coexistence Window (SCW) regular pattern of neighbor Wireless Regional Area Networks (WRANs), if vacant SCW slots are not periodically occurring, selecting a WRAN as a contender among the neighbor WRANs, performing a contention for transmitting the CBP packet with the contender within SCW slots that are occupied by the WRAN, and configuring an SCW usage pattern so that an SCW usage period of the CBP packet sender is double that of an SCW usage period of the contender when winning in the contention.

Apparatus and method for transmitting coexistence beacon protocol packet in cognitive radio based wireless communication system

A method of performing hand-over in a personal basic service set (PBSS) including a plurality of stations and one coordinator is provided. An association request frame comprising PCP capability information, and requesting to associate to the PBSS, is received from each of the stations. The PCP capability information comprises information regarding at least one of whether each of the stations supports a power source capability of continuous power supply, whether each of the stations supports a channel time allocation function, and whether each of the stations supports a network clustering function. An association response frame, indicating whether the association request received from each of the stations is approved, is transmitted to each of the stations, and a priority to be a coordinator of the stations is determined based on the PCP capability information. Hand-over is performed with one of the stations according to the determined priority.

Method and apparatus for performing hand-over

A method and apparatus for switching operational modes in a Cognitive Radio (CR) system are provided. A method for switching between a normal operation mode and a coexistence operation mode in a CR system includes occupying at least one channel in the normal operation mode, when there is no channel to be occupied, selecting at least one channel for the coexistence operation mode, and occupying available frames among frames of the selected at least one channel in the coexistence operation mode.

Method and apparatus for switching operational modes in a cognitive radio system

A method and apparatus for controlling a link margin are provided. The method includes: receiving, from a second device, a link margin frame including information about the link margin related to a communication link between a first device and the second device; and performing at least one operation selected from among a change in transmission power, a change in a modulation and coding scheme (MCS), beam forming, and a change of the communication link to another frequency band, based on the received link margin frame.

Method and apparatus for controlling link margin

A method and apparatus for changing a frequency band used for communication between first and second devices supporting multiple frequency bands. The method includes transmitting a frequency band change request frame including information regarding a communication capability of the first device and a frequency band change request for requesting to change a frequency band currently being used for communication between the first and second devices, to the second device; receiving a frequency band change response frame corresponding to the frequency band change request frame, from the second device; and selectively changing the frequency band currently being used to another frequency band based on the received frequency band change response frame.

Method and apparatus for changing frequency band used for communication between devices supporting multiple frequency bands

An apparatus and operation method of a Base Station (BS) for allocating a radio resource in a Cognitive Radio (CR) wireless communication system includes, when a licensed system is activated, determining whether each of User Terminals (UTs) located in a cell satisfies Quality of Service (QoS). If all of the UTs satisfy the QoS, a binary message indicating 'on' is broadcasted to neighbor BSs. If at least one of the UTs does not satisfy the QoS, a binary message indicating 'off' is broadcasted to the neighbor BSs, and when the binary message indicating &#x2018;off&#x2019; is received from at least one of the neighbor BSs, the binary message indicating &#x2018;off&#x2019; is broadcasted to the UTs.

Apparatus and method for semi distributed resource allocation in a cognitive radio wireless communication system

A method of performing a handover between a first device and a second device is provided. The method including: transmitting a handover request frame for requesting a handover, including information about a reason for requesting the handover, to the second device; receiving a handover response frame including handover request result information indicating whether the handover request is accepted, from the second device; and selectively performing the handover with the second device based on the handover response frame.

Method and apparatus for performing handover

A base station includes an apparatus and a method for exchanging frequency channel resources between base stations in a Cognitive Radio (CR) based communication system. A requesting Base Station (BS), which requests channel exchange a neighboring BS, receives a channel advertisement message from a neighboring BS and sends a channel exchange request message to the neighboring BS. The channel exchange request message includes at least one of a neighbor BS Identifier (ID), a requesting BS ID, channel information for the channel exchange at the requesting BS, and channel information exchangeable at the neighboring BS. The requesting BS receives a channel exchange response message from the neighboring BS in response to the channel exchange request message, determines whether to execute a channel exchange process to the neighboring BS based on information in the received channel exchange response message, and sends a channel exchange reply message indicative of the determination result.

Apparatus and method for dynamic resource exchange in cognitive radio (CR) based communication system

An apparatus and a method for transmitting a Coexistence Beacon Protocol (CBP) packet in a Cognitive Radio (CR) wireless communication system are provided. In the method for transmitting CBP packet in a transmitter that operates in a scalable Orthogonal Frequency Division Multiple Access (OFDMA) mode, a priority is given to each channel of one or more channels based at least partly upon channel use statuses of two or more neighbor Wireless Regional Area Networks (WRANs). Whether a Quality of Service (QoS) for CBP packet transmission for each channel is met is sequentially determined according to the respective priority. A channel having a highest priority is selected from the one or more channels meeting the QoS as a channel for CBP packet transmission. A CBP packet is transmitted via the selected channel.

Apparatus and method for transmitting coexistence beacon protocol packet in cognitive radio wireless communication system

A transfer unit of an image forming apparatus includes a belt to receive an image developed on a photosensitive medium while rotating in a regular cycle and in contact with an outer circumference of at least one photosensitive medium. A blade arm, which is installed adjacent to the belt, moves to a first position to position a cleaning blade, which is supported by the blade arm, to be in contact with the belt. The cleaning blade is coupled to a pressure unit to bias the cleaning blade towards the belt.

Cleaning apparatus, and transfer unit and image forming apparatus including the same

An image forming process module is provided having an integrated photoreceptor unit and development unit, and an image forming apparatus having the same. The image forming process module includes a photoreceptor unit having at least one photoreceptor on which an electrostatic latent image is formed. A development unit is installed around the outer surface of the photoreceptor and having a plurality of development assemblies for developing the latent image, thereby forming a visual image. A fixing frame is detachably installed to a main body of an image forming apparatus for fixing the photoreceptor unit and the development unit to be integrated into a single module. The image forming process module has the enhanced assembly and replacement efficiencies because the photoreceptor unit and the development unit are simultaneously installed to and uninstalled from a main body of an image forming apparatus as a single module.

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Gwacheon-si, South Korea

Ho-dong Kim