# US 10,485,039 B2 · Devices and methods for D2D communication > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,485,039 B2 - Document ID: US10485039B2 - Status: Granted - Kind: B2 - Application number: 15/862,920 - Filed: 2018-01-05 - Published: 2018-07-05 - Granted: 2019-11-19 - Earliest claimed: 2015-07-06 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Liang Hu; Chan Zhou; Markus Martin Dillinger - Web page: https://patentgrep.com/patent/US10485039B2 ## CPC - H04W 76/14: Direct-mode setup - H04W 8/005: {Discovery of network devices, e.g. terminals} - H04W 76/15: Setup of multiple wireless link connections - H04W 76/23: Manipulation of direct-mode connections - H04W 88/04: adapted for relaying to or from another terminal or user - H04W 92/18: between terminal devices - H04W 72/20: Control channels or signalling for resource management - H04W 84/18: Self-organising networks, e.g. ad-hoc networks or sensor networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The application relates to a communication device configured to perform a device to device communication with a plurality of further communication devices using a second frequency band, wherein the communication device is configured to receive a control message from a further communication device of the plurality of communication devices, the control message indicating that the further communication device is within a coverage area of a cellular communication network; and wherein the communication device is further configured to, upon reception of said control message, start listening for messages from further communication devices of the plurality of communication devices using a first frequency band. ## Claims ### Claim 1 A communication device outside a coverage area of a cellular communication network, configured to perform a device to device communication with a plurality of further communication devices using a second frequency band, wherein the communication device is configured to receive a control message from a further communication device of the plurality of communication devices, the control message indicating that the further communication device is within the coverage area of the cellular communication network; wherein the communication device is further configured to, upon reception of said control message, start listening for messages from further communication devices of the plurality of communication devices using a first frequency band; wherein the communication device is configured to, as long as the communication device does not receive the control message, communicate with the further communication devices using a communication frame having a first control channel format, the first control channel format offering only communication resources for an ad-hoc communication mode; and wherein the communication device is further configured to, upon reception of the control message, communicate with the further communication devices using a communication frame having a second control channel format, the second control channel format offering communication resources for an ad-hoc communication mode and a network assisted communication mode. ### Claim 2 (depends on 1) The communication device according to claim 1, wherein the communication device is configured to stop listening for messages using the first frequency band upon not receiving said control message from any of the plurality of communication devices for a predetermined amount of time. ### Claim 3 (depends on 1) The communication device according to claim 1, wherein the communication device is configured to keep listening for messages using the first frequency band as long as it periodically receives the control message from at least one further communication device within the coverage area of the cellular communication network. ### Claim 4 (depends on 1) The communication device according to claim 1, wherein the communication device comprises a first receiver for the second frequency band and a second receiver for the first frequency band and wherein the communication device is configured to switch on the second receiver, upon reception of the control message, to start listening for messages from further communication devices of the plurality of communication devices using the first frequency band. ### Claim 5 (depends on 1) The communication device of claim 1, wherein the communication device is configured to, when it is within the coverage area of the cellular communication network, use the first frequency band for cellular communication and device to device communication and when it is within an edge region of the coverage area further use the second frequency band for device to device communication only. ### Claim 6 A method of operating a communication device outside a coverage area of a cellular communication network, configured to perform a device to device communication with a plurality of further communication devices using a second frequency band, wherein the method comprises: receiving a control message from a further communication device of the plurality of communication devices, the control message indicating that the further communication device is within the coverage area of a cellular communication network; and upon reception of the control message, starting to listen for messages from further communication devices of the plurality of communication devices using a first frequency band; wherein as long as the communication device does not receive the control message, communicating with the further communication devices using a communication frame having a first control channel format, the first control channel format offering only communication resources for an ad-hoc communication mode; and wherein upon reception of the control message, communicating with the further communication devices using a communication frame having a second control channel format, the second control channel format offering communication resources for an ad-hoc communication mode and a network assisted communication mode. ### Claim 7 (depends on 6) The method according to claim 6, further comprising stopping listening for messages using the first frequency band upon not receiving said control message from any of the plurality of communication devices for a predetermined amount of time. ### Claim 8 (depends on 6) The method according to claim 6, further comprising continuing listening for messages using the first frequency band as long as it periodically receives the control message from at least one further communication device within the coverage area of the cellular communication network. ### Claim 9 (depends on 6) The method according to claim 6, wherein the communication device comprises a first receiver for the second frequency band and a second receiver for the first frequency band, and wherein the method further comprises: switching on the second receiver, upon reception of the control message, to start listening for messages from further communication devices of the plurality of communication devices using the first frequency band. ### Claim 10 (depends on 6) The method according to claim 6, further comprising: when it is within the coverage area of the cellular communication network, using the first frequency band for cellular communication and device to device communication; and when it is within an edge region of the coverage area, using the second frequency band for device to device communication only. ### Claim 11 A non-transitory machine-readable medium having instructions stored therein, which when executed by a processor, cause a processor perform a method of operating a communication device outside a coverage area of a cellular communication network, configured to perform a device to device communication with a plurality of further communication devices using a second frequency band, the method comprising: receiving a control message from a further communication device of the plurality of communication devices, the control message indicating that the further communication device is within the coverage area of a cellular communication network; and upon reception of the control message, starting to listen for messages from further communication devices of the plurality of communication devices using a first frequency band; wherein as long as the communication device does not receive the control message, communicating with the further communication devices using a communication frame having a first control channel format, the first control channel format offering only communication resources for an ad-hoc communication mode; and wherein upon reception of the control message, communicating with the further communication devices using a communication frame having a second control channel format, the second control channel format offering communication resources for an ad-hoc communication mode and a network assisted communication mode. ### Claim 12 (depends on 11) The machine-readable medium according to claim 11, wherein the method further comprises stopping listening for messages using the first frequency band upon not receiving said control message from any of the plurality of communication devices for a predetermined amount of time. ### Claim 13 (depends on 11) The machine-readable medium according to claim 11, wherein the method further comprises continuing listening for messages using the first frequency band as long as it periodically receives the control message from at least one further communication device within the coverage area of the cellular communication network. ### Claim 14 (depends on 11) The machine-readable medium according to claim 11, wherein the communication device comprises a first receiver for the second frequency band and a second receiver for the first frequency band, and wherein the method further comprises: switching on the second receiver, upon reception of the control message, to start listening for messages from further communication devices of the plurality of communication devices using the first frequency band. ### Claim 15 (depends on 11) The machine-readable medium according to claim 11, wherein the method further comprises: when it is within the coverage area of the cellular communication network, using the first frequency band for cellular communication and device to device communication; and when it is within an edge region of the coverage area, using the second frequency band for device to device communication only.