# US 2014/0153505 A1 · Methods and Apparatus for Generating a Control Message Frame > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153505 A1 - Document ID: US20140153505A1 - Status: Published application - Kind: A1 - Application number: 14/060,178 - Filed: 2013-10-22 - Published: 2014-06-05 - Earliest claimed: 2012-10-23 - Assignees: Renesas Mobile Corporation - Applicants: Renesas Mobile Corporation - Inventors: Anna PANTELIDOU; Timo Kafevi Koskela; Juho Mikko Osakari Pirskanen - Web page: https://patentgrep.com/patent/US20140153505A1 ## CPC - H04W 74/04: Scheduled access (hybrid access H04W74/02) - H04W 28/065: {using assembly or disassembly of packets} - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A wireless network communication device comprises a host processor, a network interface coupled to the host processor and comprising a transceiver operable to generate and transmit a control message frame. The control message frame includes: a short training field, a long training field, and a signal field including modulation and coding scheme subfield to hold message type information, transmitter address information, receiver address information, and frame check sequence information. ## Claims ### Claim 1 A method comprising: generating a control message frame comprising a signal field (SIG) to instruct the end a contention-free period; and wirelessly transmitting the control message frame. ### Claim 2 (depends on 1) A method according to claim 1, wherein the said signal field is generated in response to an instruction to acknowledge a prior message and to end a contention-free period. ### Claim 3 (depends on 1) A method according to claim 1, wherein the said signal field is used to instruct the end restricted access window (RAW) period. ### Claim 4 (depends on 1) A method according to claim 1, wherein the said signal field comprises message type, transmitter and receiver address information, and frame check sequence information. ### Claim 5 (depends on 1) A method according to claim 1, wherein generating a control message frame comprises at least one of: generating a short training field and a long training field; generating a signal field without the transmitter address information; generating a signal field without the receiver address information; generating a signal field that includes a MCS subfield, optional BSSID/TA subfield, optional RA subfield, Tail subfield, CRC subfield, Reserved subfield, and FCS subfield; generating the control message frame in response to an instruction to end an HCF (hybrid coordination function) controlled channel access period; generating the control message frame in response to an instruction to end an enhanced distributed channel access period; generating the control message frame in response to no more data to send at a client station; generating the contention-free control message frame to include a group receiver address. ### Claim 6 (depends on 1) A method according to claim 1, wherein generating the control message frame comprises generating the control message frame at an access point of a wireless network. ### Claim 7 (depends on 1) A method according to claim 1, wherein generating the control message frame comprises generating the control message frame at a client station in a wireless network. ### Claim 8 (depends on 1) A method according to claim 1, wherein generating and wirelessly transmitting a control message frame comprises generating and transmitting the control message frame to trigger uplink or downlink transmission for one or more client stations in a current restricted access window time slot. ### Claim 9 (depends on 1) A method according to claim 1, wherein generating and wirelessly transmitting a control message frame comprises generating and transmitting the control message frame to trigger an uplink or downlink transmission in a next restricted access window time slot. ### Claim 10 A wireless network communication device comprising: a host processor; a network interface coupled to the host processor and comprising a transceiver operable to generate and transmit a control message frame to end a contention-free period including: a short training field; a long training field; and a signal field including modulation and coding scheme subfield to hold message type information, transmitter address information, receiver address information, and frame check sequence information. ### Claim 11 (depends on 10) A wireless network communication device according to claim 10, wherein the transceiver is operable to at least one of: generate a signal field that includes a signal field without the transmitter address information; generate a signal field that includes a signal field without the receiver address information; generate a signal field that includes a signal field that includes a MCS subfield, optional BSSID/TA subfield, optional RA subfield, Tail subfield, CRC subfield, Reserved subfield, and FCS subfield; generate the control message frame in response to an instruction to end restricted access window operation; generate the control message frame in response to an instruction HCF (hybrid coordination function) controlled channel access period; generate the control message frame in response to an instruction to end an enhanced distributed channel access period; and generate the control message frame in response to no more data to send at a client station. ### Claim 12 (depends on 10) A wireless network communication device according to claim 10, wherein the transceiver is operable to generate the control message at an access point of a wireless network or at a client station in a wireless network. ### Claim 13 (depends on 10) A wireless network communication device according to claim 10, wherein the transceiver is operable to generate and wirelessly transmit the control message frame to trigger uplink or downlink transmission in a current restricted access window time slot. ### Claim 14 (depends on 10) A wireless network communication device according to claim 10, wherein the transceiver is operable to generate and wirelessly transmit the control message frame to trigger an uplink or downlink transmission in a next restricted access window time slot. ### Claim 15 (depends on 10) A wireless network communication device according to claim 10, wherein the transceiver is operable to generate and wirelessly transmit the control message frame to contain a group receiver address. ### Claim 16 (depends on 10) A wireless network communication device according to claim 10, wherein the transceiver is operable to generate and wirelessly transmit the control message frame to contain a broadcast address. ### Claim 17 A method of restricted access window operation in a wireless network, the method comprising: initiating a restricted access window channel access operation; and generating and transmitting a CF-End message frame at an access point to one or more client stations in response to an instruction to end restricted access window channel access operation. ### Claim 18 A method of restricted access window operation in a wireless network, the method comprising: initiating a restricted access window channel access operation; and generating and transmitting a CF-End+CF-Ack message frame at an access point to one or more client stations in response to an instruction to acknowledge a prior message and end restricted access window channel access operation. ### Claim 19 A method of restricted access window operation in a wireless network, the method comprising: initiating a restricted access window channel access operation; and generating and transmitting a CF-End message frame at a client station in response to no more data to send and to trigger downstream transmission from an access point. ### Claim 20 A method of restricted access window operation in a wireless network, the method comprising: initiating a restricted access window channel access operation; and generating and transmitting a CF-End+CF-Ack message frame at a client station in response to acknowledging a prior message and no more data to send, and to further trigger downstream transmission from an access point.