# US 2016/0262124 A1 · Method and apparatus for device-to-device communication in partial network environment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0262124 A1 - Document ID: US20160262124A1 - Status: Published application - Kind: A1 - Application number: 15/032,480 - Filed: 2014-11-10 - Published: 2016-09-08 - Earliest claimed: 2013-11-15 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Chiwoo LIM; Hyunseok RYU; Seunghoon PARK - Web page: https://patentgrep.com/patent/US20160262124A1 ## CPC - H04W 56/0015: {one node acting as a reference for the others} - H04J 11/00: Orthogonal multiplex systems, {e.g. using WALSH codes}(H04J13/00 takes precedence) - H04L 5/14: Two-way operation using the same type of signal, i.e. duplex - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04W 12/06: Authentication - H04W 56/0025: {synchronizing potentially movable access points} - H04W 72/04: Wireless resource allocation - H04W 88/06: adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract According to an embodiment of this disclosure, a method for transmitting and receiving a signal in a device of a mobile communication system includes steps of receiving, from a base station, a first message containing one or more of synchronization information and resource allocation information; transmitting, to other device, a second message containing the received synchronization information and resource allocation information; and receiving, from the other device, a third message for a random access based on the synchronization information and the resource allocation information. According to an embodiment of the present disclosure, even a device failing to obtain synchronization can obtain synchronization from a base station through other device, receive authentication and security related information, and thereby perform reliable D2D communication. Also, a communication efficiency can be improved by transmitting and receiving D2D related information between devices through limited resources. ## Claims ### Claim 1 A method for transmitting and receiving a signal in a device of a mobile communication system, the method comprising steps of: receiving, from a base station, a first message containing one or more of synchronization information and resource allocation information; transmitting, to other device, a second message containing the received synchronization information and resource allocation information; and receiving, from the other device, a third message for a random access based on the synchronization information and the resource allocation information. ### Claim 2 (depends on 1) The method of claim 1, further comprising step of: transmitting, to the other device, a fourth message containing timing advance (TA) information of the other device determined based on the third message. ### Claim 3 (depends on 2) The method of claim 2, further comprising step of: receiving, from the other device, a fifth message containing authentication related information created based on the fourth message. ### Claim 4 (depends on 1) The method of claim 1, further comprising steps of: receiving, from the base station, resource allocation information for device-to-device signal transmission and reception; and transmitting, to the other device, the received resource allocation information for device-to-device signal transmission and reception. ### Claim 5 A device for transmitting and receiving a signal in a mobile communication system, the device comprising: a transceiver configured to transmit and receive a signal; and a control unit configured to receive, from a base station, a first message containing one or more of synchronization information and resource allocation information, to transmit, to other device, a second message containing the received synchronization information and resource allocation information, and to receive, from the other device, a third message for a random access based on the synchronization information and the resource allocation information. ### Claim 6 (depends on 5) The device of claim 5, wherein the control unit is further configured to transmit, to the other device, a fourth message containing timing advance (TA) information of the other device determined based on the third message. ### Claim 7 (depends on 6) The device of claim 6, wherein the control unit is further configured to receive, from the other device, a fifth message containing authentication related information created based on the fourth message. ### Claim 8 (depends on 5) The device of claim 5, wherein the control unit is further configured to receive, from the base station, resource allocation information for device-to-device signal transmission and reception, and to transmit, to the other device, the received resource allocation information for device-to-device signal transmission and reception. ### Claim 9 A base station for transmitting and receiving a signal in a mobile communication system, the device comprising: a transceiver configured to transmit and receive a signal; and a control unit configured to create a first message containing one or more of synchronization information and resource allocation information for a random access of a device, and to transmit the created message to a first device, wherein a second message created based on information contained in the first message is transmitted to a second device by the first device, and wherein a third message for a random access based on the synchronization information and the resource allocation information is transmitted to the first device from the second device. ### Claim 10 (depends on 9) The base station of claim 9, wherein a fourth message containing timing advance (TA) information of the second device determined based on the third message is transmitted to the second device from the first device. ### Claim 11 (depends on 10) The base station of claim 10, wherein a fifth message containing authentication related information created based on the fourth message is transmitted to the first device from the second device. ### Claim 12 (depends on 9) The base station of claim 9, wherein the control unit is further configured to transmit, to the first device, resource allocation information for device-to-device signal transmission and reception, and wherein the resource allocation information for device-to-device signal transmission and reception is transmitted to the second device from the first device. ### Claim 13 A device for transmitting and receiving a signal in a mobile communication system, the device comprising: a transceiver configured to transmit and receive a signal; and a control unit configured to receive, from other device, a first message containing synchronization information and resource allocation information for a random access, and to transmit, to the other device, a second message for a random access based on the synchronization information and the resource allocation information. ### Claim 14 (depends on 13) The device of claim 13, wherein the control unit is further configured to receive, from the other device, a third message containing timing advance (TA) information of the device determined based on the second message. ### Claim 15 (depends on 14) The device of claim 14, wherein the control unit is further configured to transmit, to the other device, a fourth message containing authentication related information created based on the third message. ### Claim 16 (depends on 13) The device of claim 13, wherein the control unit is further configured to receive, from the other device, resource allocation information for device-to-device signal transmission and reception.