US11522923B2

5G,4G,3G,2G

Title

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

Application Number:

US201817277357

Publication Date:

05-12-2022

Current Assignee:

Family ID:

Application Date:

12-11-2018

Publication Country:

US

Priority Date:

19-09-2018

Declaring Company:

Abstract  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.

Note:

The information in blue was extracted from the third parties (Standard Setting Organisation, Espacenet)

The information in grey was provided by the patent holder

The information in purple was extracted from the FrandAvenue

Explicitly disclosed patent:openly and comprehensibly describes all details of the invention in the patent document.

Implicitly disclosed patent:does not explicitly state certain aspects of the invention, but still allows for these to be inferred from the information provided.

Basis patent:The core patent in a family, outlining the fundamental invention from which related patents or applications originate.

Family member:related patents or applications that share a common priority or original filing.