Invention Grant
- Patent Title: Method for enabling a calling User Equipment, UE, to retry a Session Initiation Protocol, SIP, call attempt to a called UE, over a Circuit Switched domain
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Application No.: US17277357Application Date: 2018-11-13
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Publication No.: US11522923B2Publication Date: 2022-12-06
- Inventor: Beatriz Maroto Gil , Juan De Dios Del Moral Moya , Margarita Gayo Arnaldo , Ignacio Saez Matallana , Emiliano Merino Vazquez
- Applicant: Telefonaktiebolaget LM Ericsson (PUBL)
- Applicant Address: SE Stockholm
- Assignee: Telefonaktiebolaget LM Ericsson (PUBL)
- Current Assignee: Telefonaktiebolaget LM Ericsson (PUBL)
- Current Assignee Address: SE Stockholm
- Agency: Baker Botts, LLP
- Priority: EP18382677 20180920
- International Application: PCT/EP2018/081074 WO 20181113
- International Announcement: WO2020/057764 WO 20200326
- Main IPC: H04L65/1073
- IPC: H04L65/1073 ; H04L65/1069 ; H04L65/1045 ; H04L65/1104 ; H04L65/1016 ; H04W76/16

Abstract:
A method for enabling a calling User Equipment, UE, to retry a Session Initiation Protocol, SIP, call attempt to a called UE, over a Circuit Switched domain, in a telecommunication network, wherein said called UE has a SIP session established towards said telecommunication network, wherein said method comprises the steps of receiving, by a Proxy Call Session Control Function, P-CSCF, node, an indication that a signalling bearer between said called UE and said telecommunication network is released, wherein said signalling bearer is associated with said SIP session, transmitting, by said P-CSCF node, to a Serving Call Session Control Function, S-CSCF, node triggered by said received indication, a subscribe message for informing said S-CSCF node that said P-CSCF unsubscribes to registration events pertaining to said called UE due to the released signalling bearer such that said S-CSCF node is able to initiate a CS retry when said telecommunication network receives a SIP call attempt from said calling UE to said called UE.
Public/Granted literature
Information query