# US 8,787,385 B2 · Method and apparatus for determining channel bandwidth > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,385 B2 - Document ID: US8787385B2 - Status: Granted - Kind: B2 - Application number: 13/152,044 - Filed: 2011-06-02 - Published: 2011-12-15 - Granted: 2014-07-22 - Earliest claimed: 2010-06-11 - Assignees: Marvell World Trade Ltd. - Applicants: Yong Liu; Harish Ramamurthy; Raja Banerjea - Inventors: Yong Liu; Harish Ramamurthy; Raja Banerjea - Web page: https://patentgrep.com/patent/US8787385B2 ## CPC - H04L 5/001: {the frequencies being arranged in component carriers} - H04L 5/0037: {Inter-user or inter-terminal allocation} - H04L 5/0098: {Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands} - H04L 25/0204: {of multiple channels} - H04L 25/0224: {using sounding signals} - H04L 43/0888: Throughput - H04L 45/70: {Routing based on monitoring results} - H04L 47/10: Flow control; Congestion control - H04L 47/24: Traffic characterised by specific attributes, e.g. priority or QoS - H04L 47/50: Queue scheduling - H04W 8/04: Registration at HLR or HSS [Home Subscriber Server] - H04W 24/02: Arrangements for optimising operational condition - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 74/0816: with collision avoidance - H04W 84/12: WLAN [Wireless Local Area Networks] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract In a method implemented in a first communication device, a control frame having a bandwidth is generated. The control frame is transmitted via a first composite communication channel, wherein the first composite communication channel comprises a plurality of communication channels. A bandwidth of a response frame, received from a second communication device in response to transmitting the control frame, is determined. A second composite communication channel based on the bandwidth of the response frame is determined, wherein the second composite communication channel comprises at least one communication channel from the plurality of communication channels. One or more data frames are transmitted to the second communication device via the second composite communication channel. ## Claims ### Claim 1 A method implemented in a first communication device, the method comprising: generating a control frame having a bandwidth; causing the control frame to be transmitted via a first composite communication channel having the bandwidth of the control frame, wherein the first composite communication channel comprises a plurality of communication channels; determining a bandwidth of a response frame received from a second communication device in response to transmitting the control frame; and when the bandwidth of the response frame is different from the bandwidth of the control frame, determining a second composite communication channel based on the bandwidth of the response frame, wherein the second composite communication channel comprises at least one communication channel from the plurality of communication channels, and wherein the second composite communication channel has a bandwidth different than the bandwidth of the first composite communication channel, and causing one or more data frames to be transmitted to the second communication device via the second composite communication channel. ### Claim 2 (depends on 1) A method according to claim 1, wherein: the control frame is a request to send (RTS) frame; and the response frame is a clear to send (CTS) frame. ### Claim 3 (depends on 1) A method according to claim 1, wherein: the first composite communication channel comprises a plurality of bandwidth portions; and causing the control frame to be transmitted comprises causing a signal duplicated across the plurality of bandwidth portions to be transmitted. ### Claim 4 (depends on 1) A method according to claim 1, wherein: the second composite communication channel is for transmitting in a transmit opportunity period (TXOP) of the first communication device; and causing the one or more data frames to be transmitted to the second device via the second composite communication channel comprises causing the one or more data frames to be transmitted during the TXOP. ### Claim 5 (depends on 4) A method according to claim 4, further comprising: generating a subsequent control frame having a bandwidth different than the bandwidth of the second composite communication channel; causing the subsequent control frame to be transmitted during the TXOP via a third composite communication channel having the bandwidth of the subsequent control frame; determining a bandwidth of a subsequent response frame received in response to transmitting the subsequent control frame; determining a fourth composite communication channel based on the bandwidth of the subsequent response frame; and causing one or more subsequent data frames to be transmitted during the TXOP via the fourth composite communication channel. ### Claim 6 A communication device, comprising: a network interface configured to: generate a control frame having a bandwidth, cause the control frame to be transmitted via a first composite communication channel having the bandwidth of the control frame, wherein the first composite communication channel comprises a plurality of communication channels, determine a bandwidth of a response frame received from a separate communication device in response to transmitting the control frame, and when the bandwidth of the response frame is different from the bandwidth of the control frame, determine a second composite communication channel based on the bandwidth of the response frame, wherein the second composite communication channel comprises at least one communication channel from the plurality of communication channels, and wherein the second composite communication channel has a bandwidth different than the bandwidth of the first composite communication channel, and cause one or more data frames to be transmitted to the separate communication device via the second composite communication channel. ### Claim 7 (depends on 6) A communication device according to claim 6, wherein: the control frame is a request to send (RTS) frame; and the response frame is a clear to send (CTS) frame. ### Claim 8 (depends on 6) A communication device according to claim 6, wherein: the first composite communication channel comprises a plurality of bandwidth portions; and the network interface is configured to cause the control frame to be transmitted via a first composite communication channel based on duplicating a signal across the plurality of bandwidth portions to be transmitted. ### Claim 9 (depends on 6) A communication device according to claim 6, wherein: the second composite communication channel is for transmitting in a transmit opportunity period (TXOP) of the communication device; and the network interface is configured to cause the one or more data frames to be transmitted during the TXOP. ### Claim 10 (depends on 9) A communication device according to claim 9, wherein the network interface is configured to: generate a subsequent control frame having a bandwidth different than the bandwidth of the second composite communication channel, cause the subsequent control frame to be transmitted during the TXOP via a third composite communication channel having the bandwidth of the subsequent control frame, determine a bandwidth of a subsequent response frame received in response to transmitting the subsequent control frame, determine a fourth composite communication channel based on the bandwidth of the subsequent response frame, and cause one or more subsequent data frames to be transmitted during the TXOP via the fourth composite communication channel. ### Claim 11 A method implemented in a communication device, the method comprising: receiving a control frame having a bandwidth, the control frame having been transmitted via a first composite communication channel having the bandwidth of the control frame, wherein the first composite communication channel comprises a plurality of communication channels; determining a set of communication channels of the plurality of communication channels in which the control frame was received; determining a second composite communication channel based on the determination of the set of communication channels in which the control frame was received, wherein the second composite communication channel has a bandwidth different than the bandwidth of the control frame; generating a response frame that indicates the second composite communication channel; and in response to the control frame, causing the response frame to be transmitted in the second composite communication channel. ### Claim 12 (depends on 11) A method according to claim 11, wherein the control frame is a request to send (RTS) frame; wherein the response frame is a clear to send (CTS) frame. ### Claim 13 (depends on 11) A method according to claim 11, wherein the second composite communication channel comprises a plurality of bandwidth portions; wherein causing the response frame to be transmitted comprises causing a signal duplicated across the plurality of bandwidth portions to be transmitted. ### Claim 14 (depends on 11) A method according to claim 11, wherein generating the response frame comprises generating the response frame to include information that indicates the second composite communication channel. ### Claim 15 (depends on 11) A method according to claim 11, wherein determining the second composite communication channel comprises determining the second composite communication channel to include only one or more channels from the plurality of communication channels. ### Claim 16 (depends on 11) A method according to claim 11, wherein determining the second composite communication channel comprises determining the second composite communication channel to comprise only a valid combination, according to a communication protocol, of channels from the plurality of communication channels. ### Claim 17 (depends on 11) A method according to claim 11, wherein determining the second composite communication channel comprises determining whether a communication channel in which the control frame was received was idle for at least a non-zero time period prior to the start of the control frame. ### Claim 18 (depends on 17) A method according to claim 17, wherein determining whether the communication channel in which the control frame was received was idle for at least the non-zero time period prior to the start of the control frame comprises determining whether the communication channel in which the control frame was received was idle for at least a defined time period prior to the start of the control frame. ### Claim 19 A communication device, comprising: a network interface configured to receive a control frame having a bandwidth, the control frame having been transmitted via a first composite communication channel having the bandwidth of the control frame, wherein the first composite communication channel comprises a plurality of communication channels, determine a set of communication channels of the plurality of communication channels in which the control frame was received, determine a second composite communication channel based on the determination of the set of communication channels in which the control frame was received, wherein the second composite communication channel has a bandwidth different than the bandwidth of the control frame, generate a response frame that indicates the second composite communication channel, and in response to the control frame, cause the response frame to be transmitted in the second composite communication channel. ### Claim 20 (depends on 19) A communication device according to claim 19, wherein: the control frame is a request to send (RTS) frame; and the response frame is a clear to send (CTS) frame. ### Claim 21 (depends on 19) A communication device according to claim 19, wherein: the second composite communication channel comprises a plurality of bandwidth portions; and the network interface is configured to cause a signal duplicated across the plurality of bandwidth portions to be transmitted. ### Claim 22 (depends on 21) A communication device according to claim 21, wherein the network interface is configured to generate the response frame to include information that indicates the second composite communication channel. ### Claim 23 (depends on 19) A communication device according to claim 19, wherein the network interface is configured to determine the second composite communication channel to include only one or more channels from the plurality of communication channels. ### Claim 24 (depends on 19) A communication device according to claim 19, wherein the network interface is configured to determine the second composite communication channel to comprise only a valid combination, according to a communication protocol, of channels from the plurality of communication channels. ### Claim 25 (depends on 19) A communication device according to claim 19, wherein the network interface is configured to determine whether a communication channel in which the control frame was received is to be included in the second composite channel based on determining whether the communication channel was idle for at least a non-zero time period prior to the start of the control frame. ### Claim 26 (depends on 25) A communication device according to claim 25, wherein the network interface is configured to determine whether the communication channel in which the control frame was received is to be included in the second composite channel based on determining whether the communication channel in which the control frame was received was idle for at least a defined time period prior to the start of the control frame.