# US 12,010,763 B2 · Method for establishing relay connectivity in ETSI smartBAN > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,010,763 B2 - Document ID: US12010763B2 - Status: Granted - Kind: B2 - Application number: 17/096,037 - Filed: 2020-11-12 - Published: 2021-05-13 - Granted: 2024-06-11 - Earliest claimed: 2019-11-13 - Assignees: University of Oulu - Applicants: University of Oulu - Inventors: Berhane Gebremedhin; Tuomas Paso; Jussi Haapola - Web page: https://patentgrep.com/patent/US12010763B2 ## CPC - H04W 88/04: adapted for relaying to or from another terminal or user - H04B 7/15507: {Relay station based processing for cell extension or control of coverage area, (network planning with network coordinated processing with regard to cell extension H04W16/26; network topologies using dedicated repeater stations H04W84/047; terminal devices adapted for relaying to or from an other terminal H04W88/04)} - H04B 7/15542: {Selecting at relay station its transmit and receive resources (selection of wireless resources by user or terminal H04W72/02; arrangements affording multiple use of the transmission path by two-dimensional division of the resources H04L5/0003, or by allocating sub-channels H04L5/003)} - H04L 1/16: in which the return channel carries supervisory signals, e.g. repetition request signals - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04W 4/80: Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication - H04W 16/18: Network planning tools - H04W 84/12: WLAN [Wireless Local Area Networks] - H04W 84/18: Self-organising networks, e.g. ad-hoc networks or sensor networks - H04L 2001/0097: {Relays} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04W 76/19: Connection re-establishment - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract The present invention discloses a mechanism to initiate, establish, and maintain relay connectivity in a SmartBAN network while maintaining uninterrupted operations within the network. The present invention comprises the aspects of identifying and notifying an isolated node, initiating and establishing relay connectivity, maintaining the relay connectivity, and ending the relay connectivity when this is desired by either a hub, the isolated node or the nominated relay node. Some new frame formats comprising several new Information Units are also defined. ## Claims ### Claim 1 A method for connecting an isolated node or a node with a connection problem back to a connected state in a wireless network, wherein the method comprises the steps of: determining from lack of acknowledgement for a downlink data signal sent by a hub that a respective node is isolated or experiencing a connection problem; broadcasting an Isolated Node Notification Listen command by the hub to all connected nodes, thus triggering active listening by at least a portion of the connected nodes for a broadcast Isolated Node Notification originating from the isolated node; broadcasting Isolated Node Notifications to the wireless network by the isolated node; sending a received Isolated Node Notification by a candidate relay node to the hub; nominating a relay node by the hub based on messages received from at least one candidate relay node; sending slot allocation for a Relay Beacon, R-Beacon, from the hub to the nominated relay node; acknowledging the slot allocation for the R-Beacon by the nominated relay node to the hub; transmitting the R-Beacon by the nominated relay node to the isolated node; and acknowledging the received R-Beacon by the isolated node to the nominated relay node, resulting in a connection of the isolated node back to the wireless network. ### Claim 2 (depends on 1) The method according to claim 1, wherein the Isolated Node Notifications are broadcast in every N:th Inter-Beacon-Interval, IBI; until a response is received from a candidate relay node, wherein N is a positive integer. ### Claim 3 (depends on 2) The method according to claim 2, wherein N is equal to five. ### Claim 4 (depends on 1) The method according to claim 1, wherein after the isolated node has acknowledged the received R-Beacon, sending a Proposed Relay Link Status, R-Status, frame from the nominated relay node to the hub; and sending a Stop Isolated Node Listening, S-Listen, command by the hub to all the connected nodes. ### Claim 5 (depends on 1) The method according to claim 1, wherein after the isolated node has acknowledged the received R-Beacon, stopping broadcast of the Isolated Node Notifications by the isolated node. ### Claim 6 (depends on 4) The method according to claim 4, wherein after the last step, the hub sends slot reassignments for other nodes of the wireless network in order to enable the nominated relay node connectivity; the hub sends to the nominated relay node slot reassignments concerning the connection between the nominated relay node and the isolated node and the connection between the nominated relay node and the hub; acknowledging by the isolated node for the slot reassignments, to the nominated relay node; and sending the acknowledgement from the nominated relay node to the hub. ### Claim 7 (depends on 1) The method according to claim 1, wherein if the hub receives an Isolated Node Notification directly from the isolated node, sending a D-Beacon by the hub to the wireless network, resulting in reconnection of the isolated node into the wireless network. ### Claim 8 (depends on 1) The method according to claim 1, wherein the nomination of the relay node is made by the hub according to a first temporally received message. ### Claim 9 (depends on 1) The method according to claim 1, wherein a superframe structure of the slot reassignments comprise an R-Beacon period, isolated node time slots and relay own slots, consecutively, all locating within a scheduled period between two subsequent D-Beacons. ### Claim 10 (depends on 1) The method according to claim 1, wherein relay connectivity is maintained by performing the steps of: transmitting data, by the isolated node, to the nominated relay node in a first group of slots during a scheduled period; transmitting the received data, by the nominated relay node, to the hub in a second group of slots during the scheduled period; and transmitting own data of the nominated relay node during relay own slots within the scheduled period, or during a Control/Management period. ### Claim 11 (depends on 10) The method according to claim 10, wherein relay connectivity is further maintained by performing the step of: transmitting data, and control and management frames, by the isolated node, to the nominated relay node during the Control/Management period. ### Claim 12 (depends on 1) The method according to claim 1, wherein relay connectivity is ended by the isolated node by performing the steps of: transmitting a Disconnection Request with a null payload frame; and acknowledging, by the nominated relay node, the received Disconnection Request by transmitting a Disconnection Response. ### Claim 13 (depends on 1) The method according to claim 1, wherein relay connectivity is ended by the nominated relay node by performing the steps of: transmitting a Relay Disconnection Request, R-Dreq, to the hub; transmitting a Disconnection Request to the isolated node; and disconnecting the relay connection. ### Claim 14 (depends on 1) The method according to claim 1, wherein relay connectivity is ended by the hub by performing the steps of: transmitting a Relay Disconnection Request, R-Dreq, to the nominated relay node; and accepting, by the nominated relay node, the received Relay Disconnection Request. ### Claim 15 (depends on 1) The method according to claim 1, wherein the wireless network is a Wireless Body Area Network, WBAN. ### Claim 16 An isolated node, wherein, when the isolated node is determined to lack connection to a wireless network, the isolated node is configured to perform the steps of: broadcasting Isolated Node Notifications to the wireless network; receiving a Relay Beacon, R-Beacon, from a nominated relay node; and acknowledging the received R-Beacon by the isolated node to the nominated relay node, resulting in a connection of the isolated node back to the wireless network. ### Claim 17 A hub, wherein, when an isolated node is determined to lack connection to a wireless network, the hub is configured to perform the steps of: broadcasting an Isolated Node Notification Listen command to all connected nodes, thus triggering active listening by at least a portion of the connected nodes for a broadcast Isolated Node Notification originating from the isolated node; receiving at least one received Isolated Node Notification from at least one candidate relay node; nominating a relay node based on messages received from the at least one candidate relay node; sending slot allocation for a Relay Beacon, R-Beacon, to the nominated relay node; and receiving acknowledgement of received slot allocation for the R-Beacon from the nominated relay node. ### Claim 18 A relay node, wherein, when an isolated node is determined to lack connection to a wireless network, the relay node is configured to perform the steps of: receiving an Isolated Node Notification Listen command from the hub; listening to broadcast Isolated Node Notifications from the isolated node; sending a received Isolated Node Notification to the hub; receiving a nomination for a nominated relay node from the hub; receiving slot allocation for a Relay Beacon, R-Beacon, from the hub; acknowledging received slot allocation for the R-Beacon to the hub; transmitting the R-Beacon to the isolated node; and receiving acknowledgement of the received R-Beacon from the isolated node, resulting in a connection of the isolated node back to the wireless network. ### Claim 19 A computer program product for connecting an isolated node or a node with a connection problem back to a connected state in a wireless network, the computer program product comprising program code executable in a processor, wherein when executed, the computer program product is configured to perform the steps of: determining from lack of acknowledgement for a downlink data signal sent by a hub that a respective node is isolated or experiencing a connection problem; broadcasting an Isolated Node Notification Listen command by the hub to all connected nodes, thus triggering active listening by at least a portion of the connected nodes for a broadcast Isolated Node Notification originating from the isolated node; broadcasting Isolated Node Notifications to the wireless network by the isolated node; sending a received Isolated Node Notification by a candidate relay node to the hub; nominating a relay node by the hub based on messages received from at least one candidate relay node; sending slot allocation for a Relay Beacon, R-Beacon, from the hub to the nominated relay node; acknowledging the slot allocation for the R-Beacon by the nominated relay node to the hub; transmitting the R-Beacon by the nominated relay node to the isolated node; and acknowledging the received R-Beacon by the isolated node to the nominated relay node, resulting in a connection of the isolated node back to the wireless network.