# US 9,521,536 B2 · Device discovery of second user equipments in a second network 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 9,521,536 B2 - Document ID: US9521536B2 - Status: Granted - Kind: B2 - Application number: 14/400,975 - Filed: 2012-09-28 - Published: 2015-06-04 - Granted: 2016-12-13 - Earliest claimed: 2012-05-15 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget L M Ericsson (publ) - Inventors: Gabor Fodor; Marco Belleschi; Bengt Lindoff; Leif Wilhelmsson - Web page: https://patentgrep.com/patent/US9521536B2 ## CPC - H04W 8/005: {Discovery of network devices, e.g. terminals} - H04W 72/04: Wireless resource allocation - H04W 92/20: between access points - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract According to a first aspect of embodiments herein, a method in a first network node for handling device discovery of second user equipments in a second network for Device-to-Device (D2D) communication is provided. The network node is comprised in a first network. The first network node obtains information from a second network node within the second network. The information relates to resources for sending device discovery beacon signals in a second network. The first network node sends the obtained information to a first user equipment served by the first network node. The obtained information relates to said resources for sending device discovery beacon signals in the second network. The information enables the first user equipment to discover beacon signals from the second user equipments in the second network and/or to send beacon signals to be discovered by the second user equipments in the second network. ## Claims ### Claim 1 A method in a first network node for handling device discovery of second user equipments in a second network for Device to Device, D2D, communication, wherein the first network node is comprised in a first network, the method comprising: obtaining by the first network node within the first network from a second network node within the second network, information about resources for sending device discovery beacon signals in the second network, and sending by the first network node to a first user equipment within the first network and served by the first network node, the obtained information about resources for sending device discovery beacon signals in the second network, which information enables the first user equipment to discover beacon signals from the second user equipments in the second network, and/or to send beacon signals to be discovered by the second user equipments in the second network, wherein a first operator operates the first network and a second operator, different from the first operator, operates the second network. ### Claim 2 (depends on 1) The method according to claim 1, wherein the information comprises resource description of any of time, frequency and code resources that the second user equipments in the second network use to transmit beacon signals. ### Claim 3 (depends on 1) The method according to claim 1, wherein the information comprises resource description of system frame numbers of frames in which the second user equipments of the second network send beacon signals and specific physical resource blocks of a spectrum of the second network that the second user equipments of the second network use to transmit beacon signals. ### Claim 4 (depends on 1) The method according to claim 1, further comprising: receiving at the first network node from the first user equipment a request for discovering second user equipments in the second network. ### Claim 5 (depends on 4) The method according to claim 4, further comprising: forwarding to the second network node the request for discovering second user equipments in the second network which request indicates a device identity of the first user equipment. ### Claim 6 (depends on 4) The method according to claim 4, wherein the request specifies the second operator, and wherein the information sent to the first user equipment comprises the second operator's identity and a description of its resources for sending device discovery beacon signals. ### Claim 7 (depends on 1) The method according to claim 1, further comprising: sending to the second network node a request for information about resources for sending device discovery beacon signals in the second network. ### Claim 8 (depends on 7) The method according to claim 7, wherein the request for information to the second network node further indicates the number of registered user equipments in the first network that have registered a request for discovering second user equipments in the second network. ### Claim 9 (depends on 1) The method according to claim 1, further comprising: sending to the second network node, information about the first user equipment listening to discover beacon signals, including the user equipment capabilities of the first user equipment. ### Claim 10 (depends on 1) The method according to claim 1, further comprising: receiving from the second network node periodic information about the registered second user equipments that are broadcasting beacon signals in the second network, and based on the received periodic information, sending to the first user equipment, information about the probability that the first user equipment finds a beacon signalling user equipment if the first user equipment decides to listen to beacon signals in the second network. ### Claim 11 (depends on 1) The method according to claim 1, wherein the information about resources for sending device discovery beacon signals in the second network relates to second user equipments that that are in radio range of the first user equipment. ### Claim 12 A method in a first user equipment for handling device discovery of second user equipments in a second network for Device to Device, D2D, communication, wherein the first user equipment is within a first network and served by a first network node comprised in the first network, the method comprising: receiving from the first network node, information received by the first network node from a second network node in the second network about resources for sending device discovery beacon signals in the second network, and listening to beacon signals according to the received information to discover beacon signals from the second user equipments in the second network, or sending beacon signals according to the received information to be discovered by the second user equipments in the second network, wherein a first operator operates the first network and a second operator, different from the first operator, operates the second network. ### Claim 13 (depends on 12) The method according to claim 12, wherein the information comprises resource description of any of time, frequency and code resources that the second user equipments in the second network use to transmit beacon signals. ### Claim 14 (depends on 13) The method according to claim 13, wherein the information comprises resource description of system frame numbers of frames in which the second user equipments of the second network send beacon signals and specific physical resource blocks of a spectrum of the second network that the second user equipments of the second network use to transmit beacon signals. ### Claim 15 (depends on 12) The method according to claim 12, further comprising: sending to the first network node a request for discovering second user equipments in the second network. ### Claim 16 (depends on 15) The method according to claim 15, wherein the request specifies the second operator. ### Claim 17 (depends on 16) The method according to claim 16, wherein the information received from the first network node comprises the second operator's identity and a description of its resources for sending device discovery beacon signals, and wherein sending the beacon signals are performed by repeatedly transmitting the beacon signals according to a pattern. ### Claim 18 (depends on 12) The method according to claim 12, further comprising: receiving from the first network node, information about the probability that the first user equipment finds a beacon signalling user equipment if the first user equipment decides to listen to beacon signals in the second network. ### Claim 19 (depends on 12) The method according to claim 12, wherein the information about resources for sending device discovery beacon signals in the second network relates to second user equipments that are in radio range of the first user equipment. ### Claim 20 (depends on 12) The method according to claim 12, further comprising: listening to a second beacon signal from the second network, and which second beacon signal identifies the presence or absence of second user equipments, and when presence of second user equipments has been identified, performing the sending of the request for discovering second user equipments in the second network. ### Claim 21 (depends on 20) The method according to claim 20, wherein the second beacon signal is sent by the second network node, or by the second user equipments in the second network. ### Claim 22 A first network node for handling device discovery of second user equipments in a second network for Device to Device, D2D, communication, wherein the first network node is comprised in a first network, the first network node comprising a processing circuit configured to: obtain from a second network node within the second network, information about resources for sending device discovery beacon signals in a second network, and send to a first user equipment within the first network and served by the first network node, the obtained information about resources for sending device discovery beacon signals in the second network, which information enables the first user equipment to discover beacon signals from the second user equipments in the second network, and/or to send beacon signals to be discovered by the second user equipments in the second network, wherein a first operator operates the first network and a second operator, different from the first operator, operates the second network. ### Claim 23 (depends on 22) The first network node according to claim 22, wherein the information comprises resource description of any of time, frequency and code resources that the second user equipments in the second network use to transmit beacon signals. ### Claim 24 (depends on 22) The first network node according to claim 22, wherein the information comprises resource description of system frame numbers of frames in which the second user equipments of the second network send beacon signals and specific physical resource blocks of a spectrum of the second network that the second user equipments of the second network use to transmit beacon signals. ### Claim 25 (depends on 22) The first network node according to claim 22, wherein the processing circuit further is configured to receive from the first user equipment a request for discovering second user equipments in the second network. ### Claim 26 (depends on 25) The first network node according to claim 25, wherein the processing circuit further is configured to forward to the second network node the request for discovering second user equipments in the second network which request indicates a device identity of the first user equipment. ### Claim 27 (depends on 25) The first network node according to claim 25, wherein the request specifies the second operator, and wherein the information to be sent to the first user equipment comprises the second operator's identity and a description of its resources for sending device discovery beacon signals. ### Claim 28 (depends on 22) The first network node according to claim 22, wherein the processing circuit further is configured to send to the second network node a request for information about resources for sending device discovery beacon signals in the second network. ### Claim 29 (depends on 22) The first network node according to claim 22, wherein the request for information to be sent to the second network node further indicates the number of registered user equipments in the first network that have registered a request for discovering second user equipments in the second network. ### Claim 30 (depends on 22) The first network node according to claim 22, wherein the processing circuit further is configured to send to the second network node, information about the first user equipment listening to discover beacon signals including the user equipment capabilities of the first user equipment. ### Claim 31 (depends on 22) The first network node according to claim 22, wherein the processing circuit further is configured to receive from the second network node periodic information about the registered second user equipments that are broadcasting beacon signals in the second network, and based on the received periodic information, send to the first user equipment, information about the probability that the first user equipment finds a beacon signalling user equipment. ### Claim 32 (depends on 22) The first network node according to claim 22, wherein the information about resources for sending device discovery beacon signals in the second network relates to second user equipments that are in radio range of the first user equipment. ### Claim 33 A first user equipment for handling device discovery of second user equipments in a second network for Device to Device, D2D, communication, wherein the first user equipment is within a first network and served by a first network node comprised in the first network, the first user equipment comprising a processing circuit configured to: receive from the first network node, information received by the first network node from a second network node in the second network about resources for sending device discovery beacon signals in the second network, and listen to beacon signals according to the received information to discover beacon signals from the second user equipments in the second network, or send beacon signals according to the received information to be discovered by the second user equipments in the second network, wherein a first operator operates the first network and a second operator, different from the first operator, operates the second network. ### Claim 34 (depends on 33) The first user equipment according to claim 33, wherein the information comprises resource description of any of time, frequency and code resources that the second user equipments in the second network use to transmit beacon signals. ### Claim 35 (depends on 33) The first user equipment according to claim 33, wherein the information comprises resource description of system frame numbers of frames in which the second user equipments of the second network send beacon signals and specific physical resource blocks of a spectrum of the second network that the second user equipments of the second network use to transmit beacon signals. ### Claim 36 (depends on 33) The first user equipment according to claim 33, wherein the processing circuit further is configured to send to the first network node a request for discovering second user equipments in the second network. ### Claim 37 (depends on 36) The first user equipment according to claim 36, wherein the request specifies the second operator. ### Claim 38 (depends on 37) The first user equipment according to claim 37, wherein the information received from the first network node comprises the second operator's identity and a description of its resources for sending device discovery beacon signals, and wherein the processing circuit further is configured to send the beacon signals by repeatedly transmitting the beacon signals according to a pattern. ### Claim 39 (depends on 33) The first user equipment according to claim 33, wherein the processing circuit further is configured to receive from the first network node, information about the probability that the first user equipment finds a beacon signalling user equipment. ### Claim 40 (depends on 33) The first user equipment according to claim 33, wherein the information about resources for sending device discovery beacon signals in the second network relates to second user equipments that that are in radio range of the first user equipment. ### Claim 41 (depends on 33) The first user equipment according to claim 33, wherein the processing circuit further is configured to listen to a second beacon signal from the second network, which second beacon signal identifies the presence or absence of second user equipments, and when presence of second user equipments has been identified, send the request for discovering second user equipments in the second network. ### Claim 42 (depends on 40) The first user equipment according to claim 40, wherein the second beacon signal is to be sent by the second network node, or by the second user equipments in the second network. ### Claim 43 (depends on 1) The method according to claim 1, wherein the first network is configured to operate in different spectrum bands and/or use different radio access technologies than the second network. ### Claim 44 (depends on 5) The method according to claim 5, wherein the device identity of the first user equipment forwarded to the second network node comprises a portion with a value that is specific to the first network. ### Claim 45 (depends on 22) The first network node according to claim 22, wherein the first network is configured to operate in different spectrum bands and/or use different radio access technologies than the second network. ### Claim 46 (depends on 26) The first network node according to claim 26, wherein the device identity of the first user equipment forwarded to the second network node comprises a portion with a value that is specific to the first network.