# US 12,003,271 B2 · Sleepy device operation in asynchronous channel hopping networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,271 B2 - Document ID: US12003271B2 - Status: Granted - Kind: B2 - Application number: 18/185,609 - Filed: 2023-03-17 - Published: 2023-07-13 - Granted: 2024-06-04 - Earliest claimed: 2016-04-26 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Kumaran Vijayasankar; Robert Liang; Jyothsna Kunduru; Kwang Seop Eom - Web page: https://patentgrep.com/patent/US12003271B2 ## CPC - H04B 1/7156: Arrangements for sequence synchronisation - H04W 4/80: Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication - H04W 52/0235: {where the received signal is a power saving command} - H04W 52/0274: {by switching on or off the equipment or parts thereof} - H04B 2001/71563: {Acquisition} - H04B 2201/71338: Asynchronous systems - Y02D 30/70: in wireless communication networks - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A radio communications device includes a RTC configured to run even during sleep for receiving from a coordinator node (CN) in an asynchronous channel hopping WPAN an asynchronous hopping sequence (AHS) frame that includes the CN's hopping sequence. A processor implements a stored sleepy device operation in asynchronous channel hopping networks algorithm. The algorithm is for determining a time stamp for the AHS frame and the CN's initial timing position within the hopping sequence, storing the time stamp, going to sleep and upon waking up changing a frequency band of its receive (Rx) channel to an updated fixed channel. A data request command frame is transmitted by the device on the CN's listening channel that is calculated from the CN's hopping sequence, time stamp, CN's initial timing position and current time, and the device receives an ACK frame transmitted by the CN at the updated fixed channel of Rx operation. ## Claims ### Claim 1 A method comprising: determining, by a first node, a reception time stamp for an asynchronous hopping sequence frame, wherein the asynchronous hopping sequence frame comprises a hoping sequence; determining, by the first node, an initial timing position of a coordinator node within the hopping sequence; causing the first node to transition into sleep mode; waking up the first node from the sleep mode at a first time; changing a frequency band of a receive channel of the first node to an updated channel; determining a first listening channel of the coordinator node based on the hopping sequence, the reception time stamp, the initial timing position, and the first time; and transmitting a data request command frame from the first node at the first listening channel, the data request command frame including the updated channel. ### Claim 2 (depends on 1) The method of claim 1, wherein determining the reception time stamp comprises determining, by the first node, the reception time stamp based on a last received data from the coordinator node. ### Claim 3 (depends on 1) The method of claim 1, wherein the initial timing position within the hopping sequence is based on timing information included in the asynchronous hopping sequence frame. ### Claim 4 (depends on 1) The method of claim 1, wherein the first node operates in a wireless personal area network (WPAN) that includes the coordinator node. ### Claim 5 (depends on 4) The method of claim 4, wherein the first node includes a sensor or actuator. ### Claim 6 (depends on 4) The method of claim 4, wherein the WPAN is part of a smart grid that comprises an electricity supply network which uses digital communications to detect and react to local changes in electrical usage. ### Claim 7 (depends on 1) The method of claim 1, wherein the first node comprises a real-time clock (RTC). ### Claim 8 (depends on 7) The method of claim 7, wherein the first node remains in sleep mode for shorter time than a wraparound time of the RTC. ### Claim 9 (depends on 7) The method of claim 7, wherein determining the first listening channel comprises determining the first listening channel based on the RTC. ### Claim 10 (depends on 7) The method of claim 7, wherein determining the reception time stamp comprises determining the reception time stamp based on the RTC. ### Claim 11 (depends on 8) The method of claim 8, wherein the wraparound time of the RTC is based on 4 bytes of data. ### Claim 12 (depends on 1) The method of claim 1, further comprising storing, by the first node, the initial timing position before the first node transitions into sleep mode. ### Claim 13 (depends on 1) The method of claim 1, further comprising receiving, by the first node, an acknowledgement frame at the updated channel after transmitting the data request command frame. ### Claim 14 (depends on 1) The method of claim 1, wherein the first node and the coordinator node are part of a tree-based or star-based network. ### Claim 15 (depends on 1) The method of claim 1, wherein the first node does not have any child nodes. ### Claim 16 (depends on 1) The method of claim 1, wherein the first node remains in sleep mode during a sleep time that spans more than one sequential frame. ### Claim 17 (depends on 1) The method of claim 1, wherein the first node comprises a battery. ### Claim 18 (depends on 1) The method of claim 1, wherein the updated channel in within a frequency band between 902 MHz and 928 MHz. ### Claim 19 (depends on 1) The method of claim 1, wherein the updated channel is the same channel as the first listening channel. ### Claim 20 (depends on 1) The method of claim 1, further comprising, after transmitting the data request command frame, receiving, by the first node, a response from the coordinator node at the first listening channel.