# US 2024/0205758 A1 · Method and Apparatus for Handover Management > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0205758 A1 - Document ID: US20240205758A1 - Status: Published application - Kind: A1 - Application number: 18/555,590 - Filed: 2022-05-09 - Published: 2024-06-20 - Earliest claimed: 2021-05-11 - Applicants: Telefonaktiebolaget LM Ericsson (pub) - Inventors: Wenming Chen; Juying Gan; Yong Yang; Qiong Song; Lei Xia; Xuemei Zhang; Yunjie Lu; Xiaoming Li; Ce Zhang - Web page: https://patentgrep.com/patent/US20240205758A1 ## CPC - H04W 36/0033: {with transfer of context information} - H04W 36/00226: {wherein the core network technologies comprise IP multimedia system [IMS], e.g. single radio voice call continuity [SRVCC]} - H04W 36/0066: {of control information between different types of networks in order to establish a new radio link in the target network} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Embodiments of the present disclosure provide method and apparatus for handover management. A method performed by a first mobility management function in a first system comprises obtaining mobility management context for single radio voice call continuity (SRVCC). The method further comprises sending a forward relocation request to a second mobility management function in a second system during a handover from the first system to the second system. The forward relocation request comprises mobility management context for the SRVCC. ## Claims ### Claim at position 1 -29. (canceled) ### Claim 30 A method performed by a first mobility management function in a first system, comprising: obtaining mobility management context for single radio voice call continuity (SRVCC); and sending a forward relocation request to a second mobility management function in a second system during a handover from the first system to the second system, wherein the forward relocation request comprises mobility management context for the SRVCC. ### Claim 31 (depends on 30) The method according to claim 30, wherein the first system is a fifth generation system (5GS), and the second system is an evolved packet system (EPS). ### Claim 32 (depends on 30) The method according to claim 30, wherein the handover from the first system to the second system is 5GS to EPS handover using N26 interface. ### Claim 33 (depends on 30) The method according to claim 30, wherein the forward relocation request further comprises at least one of session transfer number for SRVCC (STN-SR) or correlation mobile subscriber integrated services digital network number (C-MSISDN). ### Claim 34 (depends on 30) The method according claim 30, wherein the forward relocation request further comprises at least one of session transfer number for SRVCC (STN-SR) or correlation mobile subscriber integrated services digital network number (C-MSISDN), when a user equipment related to the handover is subscribed to second system SRVCC. ### Claim 35 (depends on 30) The method according to claim 30, wherein the mobility management context for the SRVCC comprises information necessary for the second mobility management function to perform SRVCC. ### Claim 36 (depends on 35) The method according to claim 35, wherein the information comprises at least one mobile station classmark and/or supported codec list of a user equipment related to the handover. ### Claim 37 (depends on 30) The method according to claim 30, wherein the first mobility management function comprises an access and mobility function (AMF), and the second mobility management function comprises a mobility management entity (MME). ### Claim 38 A method performed by a second mobility management function in a second system, comprising: receiving a forward relocation request from a first mobility management function in a first system during a handover from the first system to the second system, wherein the forward relocation request comprises mobility management context for single radio voice call continuity (SRVCC); determining a SRVCC operation possible indication indicating whether both a user equipment and the second mobility management function are SRVCC-capable based at least partly on the mobility management context for SRVCC; and sending a handover request message comprising the SRVCC operation possible indication to an access network node in the second system. ### Claim 39 (depends on 38) The method according to claim 38, wherein the first system is a fifth generation system (5GS), and the second system is an evolved packet system (EPS). ### Claim 40 (depends on 38) The method according to claim 38, wherein the handover from the first system to the second system is 5GS to EPS handover using N26 interface. ### Claim 41 (depends on 38) The method according to claim 38, wherein the forward relocation request further comprises at least one of session transfer number for SRVCC (STN-SR) or correlation mobile subscriber integrated services digital network number (C-MSISDN). ### Claim 42 (depends on 38) The method according to claim 38, wherein the forward relocation request further comprises at least one of session transfer number for SRVCC (STN-SR) or correlation mobile subscriber integrated services digital network number (C-MSISDN), when a user equipment related to the handover is subscribed to second system SRVCC. ### Claim 43 (depends on 38) The method according to claim 38, wherein the mobility management context for the SRVCC comprises information necessary for the second mobility management function to perform SRVCC. ### Claim 44 (depends on 43) The method according to claim 43, wherein the information comprises at least one mobile station classmark and/or supported codec list of a user equipment related to the handover. ### Claim 45 (depends on 38) The method according to claim 38, wherein the first mobility management function comprises an access and mobility function (AMF), and the second mobility management function comprises a mobility management entity (MME). ### Claim 46 A method performed by an access network node in a second system, comprising: receiving a handover request message from a second mobility management function in the second system during a handover from a first system to the second system, wherein the handover request message comprises a single radio voice call continuity (SRVCC) operation possible indication indicating whether both a user equipment and the second mobility management function are SRVCC-capable; and based on the SRVCC operation possible indication, triggering SRVCC from the second system to a third system after the handover from the first system to the second system. ### Claim 47 (depends on 46) The method according to claim 46, wherein triggering SRVCC from the second system to a third system after the handover from the first system to the second system comprises: based on the SRVCC operation possible indication, immediately triggering SRVCC from the second system to the third system after the handover from the first system to the second system. ### Claim 48 (depends on 46) The method according to claim 46, wherein the first system is a fifth generation system (5GS), the second system is an evolved packet system (EPS), and the third system is a second generation system or a third generation system. ### Claim 49 (depends on 46) The method according to claim 46, wherein the handover from the first system to the second system is 5GS to EPS handover using N26 interface. ### Claim 50 (depends on 46) The method according to claim 46, wherein the second mobility management function comprises a mobility management entity (MME). ### Claim 51 An apparatus configured to implement a first mobility management function in a first system, the apparatus comprising: a processor; and a memory coupled to the processor, said memory containing instructions executable by said processor, whereby said processor is operative to: obtain mobility management context for single radio voice call continuity (SRVCC); and send a forward relocation request from the first mobility management function to a second mobility management function in a second system during a handover from the first system to the second system, wherein the forward relocation request comprises mobility management context for the SRVCC. ### Claim 52 An apparatus configured to implement a second mobility management function in a second system, the apparatus comprising: a processor; and a memory coupled to the processor, said memory containing instructions executable by said processor, whereby said processor is operative to: receive a forward relocation request from a first mobility management function in a first system during a handover from the first system to the second system, wherein the forward relocation request comprises mobility management context for single radio voice call continuity (SRVCC); based at least partly on the mobility management context for SRVCC, determine a SRVCC operation possible indication indicating whether both a user equipment and the second mobility management function are SRVCC-capable; and send a handover request message comprising the SRVCC operation possible indication to an access network node in the second system. ### Claim 53 An access network node in a second system, comprising: a processor; and a memory coupled to the processor, said memory containing instructions executable by said processor, whereby said access network node is operative to: receive a handover request message from a second mobility management function in the second system during a handover from a first system to the second system, wherein the handover request message comprises a single radio voice call continuity (SRVCC) operation possible indication indicating whether both a user equipment and the second mobility management function are SRVCC-capable; and based on the SRVCC operation possible indication, trigger SRVCC from the second system to a third system after the handover from the first system to the second system.