# US 2018/0324754 A1 · Method and apparatus for monitoring user equipment reachability in wireless communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0324754 A1 - Document ID: US20180324754A1 - Status: Published application - Kind: A1 - Application number: 16/033,140 - Filed: 2018-07-11 - Published: 2018-11-08 - Earliest claimed: 2015-03-25 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Jinsook RYU; Hyunsook KIM; Laeyoung KIM; Jaehyun KIM; Taehun KIM - Web page: https://patentgrep.com/patent/US20180324754A1 ## CPC - H04W 68/02: Arrangements for increasing efficiency of notification or paging channel - H04W 68/00: User notification, e.g. alerting and paging, for incoming communication, change of service or the like - H04W 76/28: Discontinuous transmission [DTX]; Discontinuous reception [DRX] - H04W 8/04: Registration at HLR or HSS [Home Subscriber Server] - H04W 8/06: Registration at serving network Location Register, VLR or user mobility server - H04W 8/18: Processing of user or subscriber data, e.g. subscribed services, user preferences or user profiles; Transfer of user or subscriber data - H04W 60/00: Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration - H04W 60/06: De-registration or detaching - H04W 68/005: {Transmission of information for alerting of incoming communication} - Y02D 30/70: in wireless communication networks - 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 Disclosed herein are a method and apparatus for monitoring UE reachability in a wireless communication system. A method for monitoring UE reachability may include receiving, by a Mobility Management Entity, a monitoring request message for UE reachability including a maximum response time from a Home Subscriber Server, detecting, by the MME, the UE reachability if it is expected that paging is able to be transmitted to UE when extended Discontinuous Reception is applied to the UE, and sending, by the MME, a UE reachability notification to a Service Capability Exposure Function before a next paging occasion of the UE, wherein the maximum response time may indicate a time during which the UE maintains a reachable state so that downlink data is reliably delivered to the UE, and wherein an occasion when the UE reachability notification is transmitted may be determined by taking into consideration the maximum response time. ## Claims ### Claim 1 A method for monitoring a user equipment (UE) in a wireless communication system, the method performed by a first network node device, the first network node device including a transceiver, a processor and a memory, the method comprising: receiving a first message from a second network node; after receiving the first message, monitoring the UE for when the UE will become reachable; and based on the monitoring, sending a second message to a third network node regarding UE reachability. ### Claim 2 (depends on 1) The method of claim 1, wherein the first message includes a time duration, wherein the time duration indicates a time during which the UE stays reachable in order to allow a server to deliver downlink data. ### Claim 3 (depends on 1) The method of claim 1, wherein the second message is transmitted in consideration of the time duration. ### Claim 4 (depends on 1) The method of claim 1, wherein the UE is in an extended Discontinuous Reception (DRX) mode, wherein the extended DRX mode is a function for reducing the UE's power consumption by monitoring a physical channel to receive a paging message at specific period dependent on an extended DRX cycle value, wherein the extended DRX cycle value is configured to a maximum of several tens of minutes greater than a legacy DRX cycle value. ### Claim 5 (depends on 1) The method of claim 1, wherein the third network node is an entity in the wireless communication system to provide an Application Program Interface (API) for the server. ### Claim 6 (depends on 1) The method of claim 1, wherein the time duration is used to determine how early the second message should be transmitted before a paging occasion of the UE. ### Claim 7 (depends on 1) The method of claim 1, wherein the second message is sent to the third network node based on when the UE enters a connected mode. ### Claim 8 (depends on 1) The method of claim 1, wherein the time duration is configured so that downlink data can be transmitted from a server to the UE based on when the UE will become reachable. ### Claim 9 A first network node device for monitoring a user equipment (UE) reachability in a wireless communication system, the first network node comprising: a memory; a transceiver configured to send and receive signals; and a processor configured to control the communication module, wherein the processor is configured to: receive a first message from a second network node; after receiving the first message, monitor the UE for when the UE will become reachable; and based on the monitoring, send a second message to a third network node regarding UE reachability. ### Claim 10 (depends on 9) The first network node device of claim 9, wherein the first message includes a time duration, wherein the time duration indicates a time during which the UE stays reachable in order to allow a server to deliver downlink data. ### Claim 11 (depends on 9) The first network node device of claim 9, wherein the second message is transmitted in consideration of the time duration. ### Claim 12 (depends on 9) The first network node device of claim 9, wherein the UE is in an extended Discontinuous Reception (DRX) mode, wherein the extended DRX mode is a function for reducing the UE's power consumption by monitoring a physical channel to receive a paging message at specific period dependent on an extended DRX cycle value, wherein the extended DRX cycle value is configured to a maximum of several tens of minutes greater than a legacy DRX cycle value. ### Claim 13 (depends on 9) The first network node device of claim 9, wherein the third network node is an entity in the wireless communication system to provide an Application Program Interface (API) for the server. ### Claim 14 (depends on 9) The first network node device of claim 9, wherein the time duration is used to determine how early the second message should be transmitted before a paging occasion of the UE. ### Claim 15 (depends on 9) The first network node device of claim 9, wherein the second message is sent to the third network node based on when the UE enters a connected mode. ### Claim 16 (depends on 9) The first network node device of claim 9, wherein the time duration is configured so that downlink data can be transmitted from a server to the UE based on when the UE will become reachable.