# US 2021/0243579 A1 · Method and network node for handling a service setup for a user equipment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243579 A1 - Document ID: US20210243579A1 - Status: Published application - Kind: A1 - Application number: 17/051,773 - Filed: 2018-04-30 - Published: 2021-08-05 - Earliest claimed: 2018-04-30 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Raimundo GARCIA FERNANDEZ - Web page: https://patentgrep.com/patent/US20210243579A1 ## CPC - H04L 65/1069: Session establishment or de-establishment - H04W 4/50: Service provisioning or reconfiguring - H04L 65/1016: IP multimedia subsystem [IMS] - H04L 65/65: Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP] - H04W 8/245: {from a network towards a terminal} - H04W 76/10: Connection setup - H04W 80/10: adapted for {application} session management, e.g. SIP [Session Initiation Protocol] {(connection management H04W76/00; arrangements for session management H04L67/14)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method performed by a serving core network node in a communications network, for handling a service setup for a target User Equipment (UE) located in the communications network. The serving core network node receives a service setup request directed towards the target UE. The serving core network node sends a ping message to the target UE in response to the service setup request prior to a completion of a terminating service handling procedure of the serving network, wherein the terminating service handling procedure is completed when the service setup request is forwarded from a serving core network towards the target UE. ## Claims ### Claim 1 A method performed by a serving core network node in a communications network, for handling a service setup for a target User Equipment (UE) located in the communications network, the method comprising: receiving a service setup request directed towards the target UE; and sending a ping message to the target UE in response to the service setup request prior to a completion of a terminating service handling procedure of the serving core network, wherein the terminating service handling procedure is completed when the service setup request is forwarded from a serving core network towards the target UE. ### Claim 2 (depends on 1) The method according to claim 1, wherein the serving core network node is an IP Multimedia Subsystem (IMS) node of an IP Multimedia Subsystem (IMS) in a communications network, and wherein the sending further comprises sending the ping message to the target UE in response to the service setup request prior to a completion of a terminating service handling procedure of the IMS, wherein the terminating service handling procedure is completed when the service setup request is forwarded from the IMS to an Evolved Packet Core (EPC) associated with the target UE. ### Claim 3 (depends on 1) The method according to claim 1, wherein the ping message to the target UE is sent in response to the service setup request within a time frame of 0-30 ms from receiving the service setup request. ### Claim 4 (depends on 2) The method according to claim 2, wherein the ping message is sent in response to the service setup request prior to performing any further actions of the terminating call handling procedure in the IMS. ### Claim 5 (depends on 2) The method according to claim 2, wherein the ping message is sent in response to the service setup request prior to performing a Terminating Access Domain Selection procedure (T-ADS) in the IMS. ### Claim 6 (depends on 2) The method according to claim 2, wherein the ping message is sent in response to the service setup request prior to performing a service invocation with a Multimedia Telephony Application Server (MMTel-AS) node in the IMS. ### Claim 7 (depends on 2) The method according to claim 2, wherein the ping message is sent in response to the service setup request prior to performing a Location Information Request (LAR) in the IMS. ### Claim 8 (depends on 1) The method according to claim 1, wherein the service setup request received by the serving core network node is received from a remote network. ### Claim 9 (depends on 2) The method according to claim 2, wherein the IMS node is a Call Session Control Function CSCF node. ### Claim 10 (depends on 9) The method according to claim 9, wherein the CSCF node comprises a Serving CSCF (S-CSCF) node and wherein the S-CSCF sends the ping message in response to the received service setup request. ### Claim 11 (depends on 10) The method according to claim 10, wherein the service setup request received by the S-CSCF node is forwarded from an Interrogating CSCF (I-CSCF) node comprised in the CSCF node. ### Claim 12 (depends on 1) The method according to claim 1, wherein the service setup request is a Session Initiation Protocol (SIP) invite, a H.323 protocol invite or a Web Real-Time Communication (WebRTC) invite. ### Claim 13 (depends on 1) The method according to claim 1, wherein the ping message is a Session Initiation Protocol (SIP) OPTION message sent to the UE. ### Claim 14 A serving core network node in a communications network, for handling a service setup for a target User Equipment (UE) located in the communications network, the serving core network node comprising: at least one processor; and a memory containing instructions which, when executed by the at least one processor, cause the serving core network node to: receive a service setup request directed towards the target UE; and send a ping message to the target UE in response to the service setup request prior to a completion of a terminating service handling procedure of the serving network, wherein the terminating service handling procedure is completed when the service setup request is forwarded from a serving core network towards the target UE. ### Claim 15 (depends on 14) The serving core network node according to claim 14, wherein the serving core network node is a IP Multimedia Subsystem (IMS) node of an IP Multimedia Subsystem (IMS) in a communications network, and wherein the IMS node is further to: send the ping message to the target UE in response to the service setup request prior to a completion of a terminating service handling procedure of the IMS, wherein the terminating service handling procedure is completed when the service setup request is forwarded from the IMS to an Evolved Packet Core (EPC) associated with the target UE. ### Claim 16 (depends on 14) The serving core network node according to claim 14, wherein the serving core network node is to send the ping message to the target UE in response to the service setup request within a time frame of 0-30 ms from receiving the service setup request. ### Claim 17 (depends on 15) The serving core network node according to claim 15, wherein the serving core network node is to send the ping message in response to the service setup request prior to performing any further actions of the terminating service handling procedure in the IMS. ### Claim 18 (depends on 15) The serving core network node according to claim 15, wherein the serving core network node is to send the ping message in response to the service setup request prior to performing a Terminating Access Domain Selection procedure (T-ADS) in the IMS. ### Claim 19 (depends on 15) The serving core network node according to claim 15, wherein the serving core network node is to send the ping message in response to the service setup request prior to performing a service invocation with a Multimedia Telephony Application Server (MMTel-AS) node in the IMS. ### Claim 20 (depends on 15) The serving core network node according to claim 15, wherein the serving core network node is to send the ping message in response to the service setup request prior to performing a Location Information Request (LAR) in the IMS. ### Claim 21 (depends on 14) The serving core network node according to claim 14, wherein the serving core network node is to receive the service setup request from a remote network. ### Claim 22 (depends on 15) The serving core network node according claim 15, wherein the serving core network node is a Call Session Control Function (CSCF) node. ### Claim 23 (depends on 22) The serving core network node according to claim 22, wherein the CSCF node comprises a Serving CSCF (S-CSCF) node and wherein the S-CSCF node is to send the ping message in response to the received service setup request. ### Claim 24 (depends on 23) The serving core network node according to claim 23, wherein the service setup request received by the S-CSCF node is forwarded from an Interrogating CSCF (I-CSCF) node comprised in the CSCF node. ### Claim 25 (depends on 14) The serving core network node according to claim 14, wherein the service setup request is a Session Initiation Protocol (SIP) invite, a H.323 protocol invite or a Web Real-Time Communication (WebRTC) invite. ### Claim 26 (depends on 14) The serving core network node according to claim 14, wherein the ping message is a Session Initiation Protocol (SIP) OPTION message to the target UE. ### Claim at position 27 27-28. (canceled)