# US 2019/0174565 A1 · Communications device and methods of communicating via a wireless access interface to perform device-to-device communications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174565 A1 - Document ID: US20190174565A1 - Status: Published application - Kind: A1 - Application number: 16/272,155 - Filed: 2019-02-11 - Published: 2019-06-06 - Earliest claimed: 2014-03-21 - Assignees: Sony Corporation - Applicants: Sony Corporation - Inventors: Brian Alexander MARTIN - Web page: https://patentgrep.com/patent/US20190174565A1 ## CPC - H04W 76/14: Direct-mode setup - H04W 72/04: Wireless resource allocation - H04W 76/18: Management of setup rejection or failure - H04W 76/45: for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A communications device and method of communicating using a communications device is disclosed for performing device-to-device communications. The communications device is configured to determine in accordance with predetermined conditions whether the communications device is within a coverage area of a mobile communications network, and if the communications device is determined to be within the coverage area of the mobile communications network, to transmit or to receive signals via the wireless access interface to one or more other communications devices in accordance with device to device communications using communications resources of the wireless access interface allocated according to a first mode in which the mobile communications network performs resource allocation. ## Claims ### Claim 1 A communications device comprising for performing device-to-device (D2D) communications with one or more other communications devices via a wireless access interface, the communications device comprising: circuitry configured to receive signals from the one or more other communications devices via the wireless access interface; determine in accordance with predetermined conditions whether the communications device is within a coverage area for transmitting or receiving radio signals using a wireless access interface provided by a mobile communications network; and if the communications device is determined to be within the coverage area of the mobile communications network, transmit or to receive signals via the wireless access interface to one or more other communications devices in accordance with the D2D communications using communications resources of the wireless access interface allocated according to a first mode in which the mobile communications network performed resource allocation, or if the communications device is determined not to be within the coverage area of the mobile communications network, then transmit or receive the signals via the wireless access interface to one or more other communications devices in accordance with the D2D communications using communications resources of the wireless access interface allocated according to a second mode in which the communications device allocates resources from a predetermined set of resources, wherein if the communications device is determined to be within the coverage area of the mobile communications network, the transmitting or the receiving the signals via the wireless access interface using the first mode of resource allocation, includes accessing the mobile communications network to receive an allocation of the communications resources of the wireless access interface, detecting a failure condition in accessing the communications resources of the wireless access interface, and if the failure condition is detected then transmitting or receiving the signals via the wireless access interface by accessing the communications resources of the wireless access interface using the second mode. ### Claim 2 (depends on 1) The communications device of claim 1, wherein the circuitry is configured to: access the mobile communications network to receive an allocation of the communications resources of the wireless access interface by performing a radio resource control establishment procedure; and detect the failure condition in accessing the communications resources by determining that the radio resource control establishment procedure has failed. ### Claim 3 (depends on 2) The communications device of claim 2, wherein the circuitry is configured to determine that the radio resources connection establishment procedure fails by detecting that a time after sending a radio resource control request message has exceeded a predetermined time. ### Claim 4 (depends on 3) The communications device of claim 3, wherein the predetermined time is less than a time associated with a radio resource establishment procedure failure within which more than one response to a message can be received which transmitted as part of the radio resource control establishment procedure. ### Claim 5 (depends on 1) The communications device of claim 1, wherein the circuitry is configured to: receive an allocation of the communications resources of the wireless access interface by requesting an allocation of the communications resources of the wireless access interface from the mobile communications network for performing D2D communications in a radio resource connected state; and detect the failure condition by determining that the requested access to the communications resources of the wireless access interface are not allocated by the mobile communications network. ### Claim 6 (depends on 5) The communications device of claim 5, wherein the circuitry is configured to determine that the requested access to the communications resources of the wireless access interface are not allocated by the mobile communications network by detecting that a time after sending a random access request message has exceeded a predetermined time without being allocated the communications resources of the wireless access interface. ### Claim 7 (depends on 6) The communications device of claim 6, wherein the predetermined time is less than a time associated with a failure to receive more than one response message after transmitting the random access message. ### Claim 8 A communications device comprising: transmitter circuitry configured to transmit signals to one or more other communications devices via a wireless access interface to perform device-to-device communications, receiver circuitry configured to receive signals from the one or more other communications devices via the wireless access interface, and controller circuitry for controlling the transmitter circuitry and the receiver circuitry to transmit or to receive the signals via the wireless access interface to transmit or to receive data represented by the signals in accordance with a device to device communication, and the controller circuitry is configured in combination with the transmitter circuitry and the receiver circuitry to determine in accordance with predetermined conditions whether the communications device is within a coverage area for transmitting or receiving radio signals using a wireless access interface provided by a mobile communications network, and if the communications device is determined to be within the coverage area of the mobile communications network, to transmit or to receive signals via the wireless access interface to one or more other communications devices in accordance with the device to device communications using communications resources of the wireless access interface allocated by the mobile communications network, or if the communications device is determined not to be within the coverage area of the mobile communications network, then to transmit or to receive the signals via the wireless access interface to one or more other communications devices in accordance with the device to device communications by accessing the communications resources of the wireless access in accordance with a device to device communications protocol, wherein if the communications device is determined to be within the coverage area of the mobile communications network, the controller circuitry is configured in combination with the transmitter circuitry and the receiver circuitry to transmit or to receive the signals via the wireless access interface using communications resources of the wireless access interface allocated by the mobile communications network by accessing the mobile communications network to receive an allocation of the communications resources of the wireless access interface, detecting a failure condition in accessing the communications resources of the wireless access interface, and if the failure condition is detected then transmitting or receiving the signals via the wireless access interface by accessing the communications resources of the wireless access in accordance with the device to device communications protocol.