# US 8,570,984 B2 · Method of channel assessment and channel searching in a wireless network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,984 B2 - Document ID: US8570984B2 - Status: Granted - Kind: B2 - Application number: 12/957,353 - Filed: 2010-11-30 - Published: 2011-03-24 - Granted: 2013-10-29 - Earliest claimed: 2006-10-26 - Assignees: LG Electronics Inc. - Applicants: Beom Jin Jeon; Taek Soo Kim; Hyeon Cheol Cho - Inventors: Beom Jin Jeon; Taek Soo Kim; Hyeon Cheol Cho - Web page: https://patentgrep.com/patent/US8570984B2 ## CPC - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - G01S 1/00: Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith (position fixing by co-ordinating a plurality of determinations of direction or position lines G01S5/00) - H04W 72/20: Control channels or signalling for resource management - H04W 72/542: using measured or perceived quality - H04W 28/04: Error control - H04W 48/08: Access restriction or access information delivery, e.g. discovery data delivery (signalling during connection H04W76/00) - H04W 74/08: Non-scheduled access, e.g. ALOHA (hybrid access H04W74/02) - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method of channel assessment and channel searching in a wireless network is disclosed. The wireless network separately performs a channel assessment procedure and a channel searching procedure for channel change or another object. The channel assessment procedure is to measure a status or quality of a channel which is currently used in the wireless network. A coordinator of the wireless network designates a time interval for the channel assessment to notify other device of it. The channel assessment procedure may be performed periodically, and is preferably scheduled to allow other devices not to use the channel for the time interval which at least one device performs channel assessment. ## Claims ### Claim 1 A coordinator for controlling channel assessment in a wireless network in which a high rate physical channel and a low rate physical channel are used for communication, the coordinator configured to: broadcast a first information element to request assessment of a channel which is currently used in the wireless network, the first information element comprising a request type field that identifies a use of the first information element; receive a response to the request of the channel assessment from at least one user device of the wireless network, the response confirming that the channel assessment will be performed by the at least one user device which has decided to perform the channel assessment; broadcast a beacon on the low rate physical channel after receiving the response confirming that the channel assessment will be performed, the beacon comprising information for allocating a channel time block which is a time interval during which the channel assessment is to be performed, wherein data transmission by all user devices in the wireless network is not allowed during the channel time block; and receive a result of the channel assessment performed during the channel time block from the at least one user device. ### Claim 2 (depends on 1) The coordinator of claim 1, wherein the first information element is included in a beacon to be transmitted. ### Claim 3 (depends on 1) The coordinator of claim 1, wherein the first information element is broadcasted periodically. ### Claim 4 (depends on 1) The coordinator of claim 1, wherein the result of the channel assessment is received by being included in a second information element. ### Claim 5 (depends on 4) The coordinator of claim 4, wherein the result of the channel assessment is represented by at least two channel status types. ### Claim 6 (depends on 4) The coordinator of claim 4, wherein the second information element comprises identification information of the high rate physical channel and low rate physical channel. ### Claim 7 (depends on 6) The coordinator of claim 6, wherein the second information element further comprises a data type indicating an index type. ### Claim 8 A user device for performing channel assessment in a wireless network in which a high rate physical channel and a low rate physical channel are used for communication, the user device configured to: receive a beacon, which comprises a first information element for requesting assessment of a channel which is currently used, the beacon broadcasted by a coordinator of the wireless network, the first information element comprising a request type field that identifies a use of the first information element; decide whether to perform the channel assessment; transmit a response to the request of the channel assessment to the coordinator, the response confirming that the channel assessment will be performed by the user device; receive a beacon broadcasted by the coordinator on the low rate physical channel after transmitting the response confirming that the channel assessment will be performed, the beacon comprising information for allocating a channel time block which is a time interval during which the channel assessment is to be performed, wherein data transmission by all user devices in the wireless network is not allowed during the channel time block; perform the channel assessment during the channel time block indicated by the information for allocating the channel time block; and transmit a result of the channel assessment to the coordinator. ### Claim 9 (depends on 8) The user device of claim 8, wherein the first information element is broadcasted periodically. ### Claim 10 (depends on 8) The user device of claim 8, wherein the result of the channel assessment is included in a second information element to be transmitted. ### Claim 11 (depends on 10) The user device of claim 10, wherein the result of the channel assessment is represented by at least two channel status types. ### Claim 12 (depends on 11) The user device of claim 11, wherein the second information element comprises identification information of the high rate physical channel and low rate physical channel. ### Claim 13 (depends on 12) The user device of claim 12, wherein the second information element further comprises a data type indicating an index type.