# US 2022/0286995 A1 · Method and apparatus for core network registration and radio access network notification update > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0286995 A1 - Document ID: US20220286995A1 - Status: Published application - Kind: A1 - Application number: 17/637,300 - Filed: 2019-08-23 - Published: 2022-09-08 - Earliest claimed: 2019-08-23 - Assignees: Lenovo (Beijing) Limited - Applicants: Lenovo (Beijing) Limited - Inventors: Lianhai Wu; Haiming Wang; Jing Han; Zhi Yan; Jie Shi - Web page: https://patentgrep.com/patent/US20220286995A1 ## CPC - H04W 52/028: {switching on or off only a part of the equipment circuit blocks} - H04W 60/04: using triggered events - H04L 1/0025: {Transmission of mode-switching indication} - H04W 48/18: Selecting a network or a communication service - H04W 52/0229: {where the received signal is a wanted signal} - H04W 76/19: Connection re-establishment - H04W 76/20: Manipulation of established connections - H04W 76/14: Direct-mode setup - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract The present disclosure relates to methods and apparatuses. According to some embodiments of the disclosure, a method includes: receiving, at a first communication device from a second communication device, first registration information of a last serving cell, the first registration information at least including a first tracking area code and the identity of the second communication device; and determining whether to perform a registration procedure for the second communication device based on the first registration information. ## Claims ### Claim 1 A method comprising: receiving, at a first communication device from a second communication device, first registration information of a last serving cell, the first registration information at least including a first tracking area code and an identity of the second communication device; and determining whether to perform a registration procedure for the second communication device based on the first registration information. ### Claim 2 (depends on 1) The method of claim 1, further comprising: transmitting a message to a base station when the first tracking area code is different from a second tracking area code of a serving cell of the first communication device, wherein the message comprises the identity of at least one child communication device of the first communication device, and the at least one child communication device is in an idle mode. ### Claim 3 (depends on 1) The method of claim 1, further comprising: in response to the first tracking area code being different from a second tracking area code of a serving cell of the first communication device, transmitting the second tracking area code to the second communication device. ### Claim 4 (depends on 2) The method of claim 2, wherein the at least one child communication device comprises the second communication device, and the message comprises the identity of the second communication device. ### Claim 5 (canceled) ### Claim 6 (canceled) ### Claim 7 (canceled) ### Claim 8 (canceled) ### Claim 9 (canceled) ### Claim 10 (canceled) ### Claim 11 (canceled) ### Claim 12 (depends on 1) The method of claim 1, further comprising: transmitting a message to a base station in response to a trigger condition being met, wherein the trigger condition is a change in a number of child communication devices of a first communication device. ### Claim 13 (depends on 12) The method of claim 12, wherein: the trigger condition is a change in the number of idle child communication devices of the first communication device; and the message comprises registration information, the registration information at least including the identity of at least one idle child communication device of the first communication device. ### Claim 14 (canceled) ### Claim 15 A method comprising: receiving timer information from a child communication device at a first communication device, wherein the timer information comprises a time interval of a first periodic timer and an amount of elapsed time of the first periodic timer; starting a second timer at the first communication device according to the timer information; and transmitting a message at the first communication device in response to an expiry of the second timer. ### Claim 16 (depends on 15) The method of claim 15, wherein the child communication device is in an idle mode, and the message comprises registration information, the registration information at least including an identity of at least one idle child communication device of the first communication device. ### Claim 17 (depends on 15) The method of claim 15, wherein the child communication device is in an inactive mode, and the message comprises radio access network (RAN) notification information, the RAN notification information at least including an identity of at least one inactive child communication device of the first communication device. ### Claim 18 (depends on 15) The method of claim 15, wherein the second timer has a time duration equal to the time interval of the first periodic timer minus the amount of elapsed time of the first periodic timer. ### Claim 19 (depends on 15) The method of claim 15, further comprising: starting a third periodic timer in response to the expiry of the second timer, wherein the third periodic timer has a time interval equal to the time interval of the first periodic timer. ### Claim 20 (depends on 16) The method of claim 16, wherein the first periodic timer corresponds to a periodic registration timer. ### Claim 21 (depends on 17) The method of claim 17, wherein the first periodic timer corresponds to a periodic RAN notification area update timer. ### Claim 22 (canceled) ### Claim 23 (canceled) ### Claim 24 (canceled) ### Claim 25 (canceled) ### Claim 26 (depends on 15) The method of claim 15, further comprising: receiving a configuration message from a base station at the first communication device, wherein the configuration message indicates a timer interval of a period timer for at least one child communication device of the first communication device. ### Claim 27 (depends on 26) The method of claim 26, wherein the periodic timer corresponds to a periodic registration timer, and the method further comprises: transmitting a message to the base station, wherein the message comprises an identity of the at least one child communication device of the first communication device, and the at least one child communication device is in an idle mode. ### Claim 28 (depends on 26) The method of claim 26, wherein the periodic timer corresponds to a periodic radio access network (RAN) notification area update timer, and the method further comprises: transmitting a message to a base station, wherein the message comprises an identity of the at least one child communication device of the first communication device, and the at least one child communication device is in an inactive mode. ### Claim 29 A method comprising: storing first registration information of a last serving cell; receiving, from a first communication device, a message comprising second registration information of a serving cell of the first communication device; and determining whether to perform a registration procedure based on the first registration information and the second registration information. ### Claim 30 (depends on 29) The method of claim 29, further comprising: performing a registration procedure when the second registration information does not match the first registration information. ### Claim 31 (depends on 29) The method of claim 29, wherein the first registration information indicates a first tracking area code of the last serving cell, and the second registration information indicates a second tracking area code of the serving cell of the first communication device. ### Claim 32 (canceled) ### Claim 33 (canceled) ### Claim 34 (canceled) ### Claim 35 (canceled)