Abstract: Methods, media, and systems are provided for continuity of a telecommunications network service in an IP Multimedia Subsystem (IMS) layer providing telecommunications network services to devices located on an island. The IMS layer may comprise a Call Session Control Function (CSCF) or an application server. A diameter routing agent (DRA) or other diameter traffic controller associated with the CSCF transmits a request to a Home Subscriber Server (HSS) (e.g., that is located on a mainland). The CSCF, application server, or both have a skip HSS flag comprising instructions for connectivity loss with the HSS. Based on determining a loss of connectivity with the HSS, a Serving CSCF associated with the island is automatically selected or the Serving CSCF automatically transmits a response indicating the request was successful registering a user device, such that the user device continues working remotely on the island.

Abstract: A network may include an International Serials Data System (ISDS) that is configured to register and determine an identity of a receiving or originating user equipment (UE) that has a home network that operates using a different format or standard than the current network. The ISDS may be configured to generate transmissions on behalf of the UE for registration and identification for outgoing and incoming voice or text messages using the format of both networks.

Abstract: A server of a fifth generation (5G) network can provide substantially real-time charges for a UE during fallback to another network. A Telephony Application Server (TAS) in an IP Multimedia Subsystem (IMS) can identify Evolved Packet System Fallback (EPSFB) and report the EPSFB to a charging system to cause the charging system to generate accurate charges for user equipment communicating over the 5G network and the other network. The TAS can comprise logic to identify a change in P-Access-Network-Information associated with each network, and generate a call detail records for billing, or real-time communication via an online charging and/or offline charging for the served UE. Information (a user profile, call detail records, instance of EPSFB, etc.) associated with the TAS can be used to make network improvements that decrease instances of EPSFB and increase an amount of new radio services available to UEs.

Abstract: Described herein are techniques, devices, and systems for using an application server (AS) to trigger home subscriber server (HSS)-based proxy call session control function (P-CSCF) restoration for a user equipment (UE) in order to restore service to the UE via an in-service P-CSCF node. For example, an AS is configured to receive, from a serving CSCF (S-CSCF) node, an indication that a P-CSCF node assigned to a UE is unavailable, and, in response, the AS is configured to send, to a HSS, a request to initiate P-CSCF restoration for the UE. In turn, the HSS or a Unified Data Management (UDM) node is configured to send, to a control node, an indication to perform the P-CSCF restoration for the UE. The disclosed AS-triggered, HSS-based P-CSCF restoration procedure restores service to the UE.

Abstract: A network may include an International Serials Data System (ISDS) that is configured to register and determine an identity of a receiving or originating user equipment (UE) that has a home network that operates using a different format or standard than the current network. The ISDS may be configured to generate transmissions on behalf of the UE for registration and identification for outgoing and incoming voice or text messages using the format of both networks.

Abstract: A server of a fifth generation (5G) network can provide substantially real-time charges for a UE during fallback to another network. A Telephony Application Server (TAS) in an IP Multimedia Subsystem (IMS) can identify Evolved Packet System Fallback (EPSFB) and report the EPSFB to a charging system to cause the charging system to generate accurate charges for user equipment communicating over the 5G network and the other network. The TAS can comprise logic to identify a change in P-Access-Network-Information associated with each network, and generate a call detail records for billing, or real-time communication via an online charging and/or offline charging for the served UE. Information (a user profile, call detail records, instance of EPSFB, etc.) associated with the TAS can be used to make network improvements that decrease instances of EPSFB and increase an amount of new radio services available to UEs.

Abstract: A first carrier may support inbound roaming requests for subscribers of a trusted second carrier. For example, the first carrier may receive an inbound roaming request from a UE. The first carrier may determine a second carrier that is a home carrier of the UE is a trusted carrier associated with the first carrier. In response, an IMS procedure associated with the UE may be performed including communicating, by a first CSCF node of the first carrier, with a first HSS of the second carrier, using a same protocol as used by the first CSCF node to communicate with a second HSS of the first carrier and communicating, by the first CSCF node, with a first AS of the second carrier, using a same protocol as used by the first CSCF node to communicate with a second AS of the first carrier.

Abstract: In a telecommunication network, network slices can be identified by slice identifiers used within a core network. The same slice identifiers can also be used by elements of an IP Multimedia Subsystem (IMS) to identify the network slices. For example, a Home Subscriber Server (HSS) can be provisioned with user data associated with a user equipment (UE), including a slice identifier of a network slice that the UE is assigned to use. The HSS can provide the slice identifier to an S-CSCF in the IMS when the UE registers with the IMS. The S-CSCF can share the slice identifier with other IMS elements, such as a P-CSCF and/or one or more application servers. Accordingly, the IMS elements can determine key performance indicators (KPIs) and perform other operations in association with usage of network slices by UEs, based on the same slice identifiers used within the core network.

Abstract: An Internet Protocol Multimedia Subsystem (IMS) application server can initially attempt to route a terminating call invite to a user equipment (UE) via a packet-switched (PS) domain radio access network (RAN). However, if that initial attempt fails, the application server can follow either a PS retry option to reattempt routing the terminating call invite via a PS-domain RAN, or a circuit-switched (CS) retry option to instead reattempt routing the terminating call invite via a CS-domain RAN. In some examples, if Home Subscriber Server (HSS) data indicates that the UE is connected to a Long-Term Evolution (LTE) RAN and that CS-domain location information for the UE is older than a threshold, the application server can enable the PS retry option. However, if the UE is connected to an LTE RAN but the CS-domain location information is more recent than the threshold, the application server can instead enable the CS retry option.

Abstract: In some examples, an authentication node of a telecommunications network can receive an authentication request from a terminal, and an authentication-control message. The authentication node can skip an authentication operation with respect to the authentication request in response to the authentication-control message. In some examples, a relay node of the telecommunications network can detect an overload or service-interruption condition and determine, in response, the authentication-control message. The relay node can send the authentication-control message to the authentication node. In some examples, an authentication node can detect that its load level satisfies a predetermined criterion and, in response, skip an authentication operation and send a first message. Another authentication node can receive an indication of the first message and, in response, perform a second authentication operation.

Abstract: Systems and methods for selectively routing a connect to a network through a control function associated with the network. The system can distinguish between control functions based on functionalities associated with the control function itself or capabilities associated with a user device. The system can select between the control functions based at least in part on an identifier associated with the user device, a subscriber account associated with the user device, or another trait of the connection. The system can select the control function based on a determination made by a control node associated with the network and may be further based on a Network Resource Function, a Domain Name System server, internal static listings of the control functions, or other resource that associates one or more identifiers with the control function. The system can obtain the identifier once the user device requests a connection with the network and provide the identifier to the control node.

Abstract: A first carrier may support inbound roaming requests for subscribers of a trusted second carrier. For example, the first carrier may receive an inbound roaming request from a UE. The first carrier may determine a second carrier that is a home carrier of the UE is a trusted carrier associated with the first carrier. In response, an IMS procedure associated with the UE may be performed including communicating, by a first CSCF node of the first carrier, with a first HSS of the second carrier, using a same protocol as used by the first CSCF node to communicate with a second HSS of the first carrier and communicating, by the first CSCF node, with a first AS of the second carrier, using a same protocol as used by the first CSCF node to communicate with a second AS of the first carrier.

Abstract: Systems and methods for selectively routing a connect to a network through a control function associated with the network. The system can distinguish between control functions based on functionalities associated with the control function itself or capabilities associated with a user device. The system can select between the control functions based at least in part on an identifier associated with the user device, a subscriber account associated with the user device, or another trait of the connection. The system can select the control function based on a determination made by a control node associated with the network and may be further based on a Network Resource Function, a Domain Name System server, internal static listings of the control functions, or other resource that associates one or more identifiers with the control function. The system can obtain the identifier once the user device requests a connection with the network and provide the identifier to the control node.

Abstract: In some examples, an authentication node of a telecommunications network can receive an authentication request from a terminal, and an authentication-control message. The authentication node can skip an authentication operation with respect to the authentication request in response to the authentication-control message. In some examples, a relay node of the telecommunications network can detect an overload or service-interruption condition and determine, in response, the authentication-control message. The relay node can send the authentication-control message to the authentication node. In some examples, an authentication node can detect that its load level satisfies a predetermined criterion and, in response, skip an authentication operation and send a first message. Another authentication node can receive an indication of the first message and, in response, perform a second authentication operation.

Abstract: Systems and methods for modifying a challenge requirement for user equipment registrations are described herein. The systems and methods enable a registrar of a network to modify a user equipment to reconfigure the user equipment to perform an initial registration, whereby the user equipment waits for a challenge from the network, rather than a refresh registration.

Abstract: A system and method for performing an emergency call route failover between an Emergency Call Session Control Function (E-CSCF) and multi-homed remote end-point functions such as Border Gateway Control Function (BGCF)/Media Gateway Control Function (MGCF) or Interconnection Border Control Function (IBCF) in an Internet Protocol Multimedia Subsystem (IMS) uses Session Initiation Protocol (SIP) and/or Domain Name System (DNS) methods. The E-CSCF and/or a DNS server monitors the availability of the remote end-points to create a peer list of route options. The E-CSCF or the DNS server selects a route option from the peer list to route an emergency call to an appropriate Public Safety Answering Point (PSAP). In the event that the route option fails, the E-CSCF fails over to the next available route option to route the emergency call.

Abstract: Systems and methods are described herein for handling E911 communications within IMS networks, such as Voice over LTE (VoLTE) networks. In some embodiments, the systems and methods, via various communication nodes, handle or otherwise govern emergency calls within the VoLTE network, by sending an INVITE message from a sender node of the VoLTE network to a recipient node of the VoLTE network, and starting a retry timer at the sender node that is specific to handling E911 calls by the VoLTE network.

Abstract: A system and method for performing an emergency call route failover between an Emergency Call Session Control Function (E-CSCF) and multi-homed remote end-point functions such as Border Gateway Control Function (BGCF)/Media Gateway Control Function (MGCF) or Interconnection Border Control Function (IBCF) in an Internet Protocol Multimedia Subsystem (IMS) uses Session Initiation Protocol (SIP) and/or Domain Name System (DNS) methods. The E-CSCF and/or a DNS server monitors the availability of the remote end-points to create a peer list of route options. The E-CSCF or the DNS server selects a route option from the peer list to route an emergency call to an appropriate Public Safety Answering Point (PSAP). In the event that the route option fails, the E-CSCF fails over to the next available route option to route the emergency call.

Abstract: A system and method for performing an emergency call route failover between an Emergency Call Session Control Function (E-CSCF) and multi-homed remote end-point functions such as Border Gateway Control Function (BGCF)/Media Gateway Control Function (MGCF) or Interconnection Border Control Function (IBCF) in an Internet Protocol Multimedia Subsystem (IMS) uses Session Initiation Protocol (SIP) and/or Domain Name System (DNS) methods. The E-CSCF and/or a DNS server monitors the availability of the remote end-points to create a peer list of route options. The E-CSCF or the DNS server selects a route option from the peer list to route an emergency call to an appropriate Public Safety Answering Point (PSAP). In the event that the route option fails, the E-CSCF fails over to the next available route option to route the emergency call.

Abstract: Systems and methods are described herein for handling E911 communications within IMS networks, such as Voice over LTE (VoLTE) networks. In some embodiments, the systems and methods, via various communication nodes, handle or otherwise govern emergency calls within the VoLTE network, by sending an INVITE message from a sender node of the VoLTE network to a recipient node of the VoLTE network, and starting a retry timer at the sender node that is specific to handling E911 calls by the VoLTE network.