# US 8,542,678 B2 · System and method for managing call continuity in IMS network environment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,678 B2 - Document ID: US8542678B2 - Status: Granted - Kind: B2 - Application number: 12/830,650 - Filed: 2010-07-06 - Published: 2010-10-28 - Granted: 2013-09-24 - Earliest claimed: 2006-08-11 - Assignees: BlackBerry Limited - Applicants: Adrian Buckley - Inventors: Adrian Buckley - Web page: https://patentgrep.com/patent/US8542678B2 ## CPC - H04M 7/123: {where the packet-switched network is an Internet Protocol Multimedia System-type network} - H04L 65/1083: In-session procedures - H04L 65/1094: Inter-user-equipment sessions transfer or sharing - H04L 65/1095: Inter-network session transfer or sharing - H04M 7/1235: {where one of the core networks is a wireless network} - H04W 8/26: Network addressing or numbering for mobility support - H04W 36/00226: {wherein the core network technologies comprise IP multimedia system [IMS], e.g. single radio voice call continuity [SRVCC]} - H04L 65/1016: IP multimedia subsystem [IMS] - H04W 80/10: adapted for {application} session management, e.g. SIP [Session Initiation Protocol] {(connection management H04W76/00; arrangements for session management H04L67/14)} - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) - 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 In one embodiment, a scheme is disclosed for managing call continuity in a network environment including a circuit-switched (CS) network and an IP multimedia subsystem (IMS) network wherein unique identity (ID) information supplied by a user equipment (UE) device is utilized. A pool of dynamically allocable IP multimedia routing numbers (IMRNs) maintained at an IMS network node are used for associating an IMRN with call information received from the UE device, which can include at least one of a GRUU, Instance ID, and the called party number relating to a call. When the dynamically allocated IMRN is returned by the UE device, the network node utilizes the IMRN mapping to effectuate call continuity with respect to the called party. ## Claims ### Claim 1 A method for a user equipment (UE) device, the method comprising: providing call information associated with a call having bearer traffic in one domain to a network node disposed in an Internet Protocol (IP) multimedia subsystem (IMS) network, the call information including a call reference associated with the call; receiving an IP multimedia routing number (IMRN) and the call reference from the network node; verifying that the call reference received back from the network node remains valid; and sending a message containing the IMRN to the network node to transfer the call having bearer traffic to another domain. ### Claim 2 (depends on 1) The method as recited in claim 1, wherein the call information further includes an Instance identifier comprising a unique ID parameter. ### Claim 3 (depends on 2) The method as recited in claim 2, wherein the unique ID parameter comprises at least one of a Globally Routable User Agent (UA) Uniform Resource Identifier (URI) (GRUU), International Mobile station Equipment Identity (IMEI), an IMEI Software Version (IMEISV), an Electronic Serial Number (ESN), a Mobile Identification Number (MIN), and a unique Layer-2 address associated with the UE device. ### Claim 4 (depends on 1) The method as recited in claim 1, wherein the call information is provided to the network node using a Session Initiation Protocol (SIP) message. ### Claim 5 (depends on 1) The method as recited in claim 1, wherein the call information is provided to the network node using an Unstructured Supplementary Service Data (USSD) message. ### Claim 6 (depends on 1) The method as recited in claim 1, wherein the IMRN is received via a SIP message. ### Claim 7 A user equipment (UE) device comprising: a processor configured to control at least one of a plurality of sub-systems to provide call information associated with a call having bearer traffic in one domain to a network node disposed in an Internet Protocol (IP) multimedia subsystem (IMS) network, the call information including a call reference associated with the call; the processor further configured to control at least one of the plurality of sub-systems to process an IP multimedia routing number (IMRN) received from the network node; the processor further configured to control at least one of the plurality of sub-systems to verify that the call reference received from the network node is valid; and the processor further configured to control at least one of the plurality of sub-systems to send a message containing the IMRN to the network node to transfer the call having bearer traffic to another domain. ### Claim 8 (depends on 7) The UE device as recited in claim 7, wherein the call information includes an Instance identifier comprising a unique ID parameter. ### Claim 9 (depends on 8) The UE device as recited in claim 8, wherein the unique ID parameter comprises at least one of a Globally Routable User Agent (UA) Uniform Resource Identifier (URI) (GRUU), International Mobile station Equipment Identity (IMEI), an IMEI Software Version (IMEISV), an Electronic Serial Number (ESN), a Mobile Identification Number (MIN), and a unique Layer-2 address associated with the UE device. ### Claim 10 (depends on 7) The UE device as recited in claim 7, wherein the call information is provided to the network node using a Session Initiation Protocol (SIP) message. ### Claim 11 (depends on 7) The UE device as recited in claim 7, wherein the call information is provided to the network node using an Unstructured Supplementary Service Data (USSD) message. ### Claim 12 (depends on 7) The UE device as recited in claim 7, wherein the IMRN is received via a SIP message.