T-mobile Usa, Inc.

Khurram Ahmad Mirza

Shujaur Rehman Mufti

Saqib Badar

Kalyan Kalepu

Mohammed Al-Mehdar

Muhammad Waqar Afzal

Boris Antsev

Madhuri Kotta

Anas Said M Jabeiti

Nassereddine Sabeur

Joel Arends

Zeeshan Jahangir

Muhammad Ejaz Sial

Sasikala Mannepally

Marc A Proctor

Umair Rehmat

Aziz Motiwala

Jhon Nelson Sihotang

Anselmo Myungsup Shim

Solutions for service aware proxy-call session control function (P-CSCF) traffic routing include: receiving, at a master P-CSCF in a pool of a plurality of P-CSCFs, internet protocol (IP) multimedia subsystem (IMS) traffic from a device; determining, by the master P-CSCF, a traffic type (e.g., 5G, 4G, SMS, WiFi, etc.) of the IMS traffic from the device; based on at least the traffic type of the IMS traffic from the device, selecting, by the master P-CSCF, a serving P-CSCF from the pool for the device; and forwarding, by the serving P-CSCF for the device, the IMS traffic from the device to an IMS. In some examples, the serving P-CSCF selection also includes loading considerations. In some examples, an alternate P-CSCF is available for failover as the new master P-CSCF. In some examples, a network includes multiple pools of P-CSCFs, with each pool having its own master P-CSCF and alternate P-CSCF.

Service aware proxy-call session control function (P-CSCF) traffic routing

A system includes a session border controller (SBC) coupled to an internet protocol (IP) multimedia core subsystem (IMS) of a telecommunications network. The SBC obtains information indicative of a roaming profile of a particular subscriber associated with the telecommunications network. The roaming profile indicates geographic areas in which the particular subscriber is authorized to access a communications service. The SBC receives a request to connect a particular voice call over a Wi-Fi network from a wireless device on the telecommunications network. The wireless device is associated with the particular subscriber to the telecommunications network. The SBC identifies a current location of the wireless device and compares the current location of the wireless device with geographic areas in which the particular subscriber is authorized to access the communications service. The SBC can then enable or deny the IMS to establish a session for the particular voice call over the Wi-Fi network.

Selectively restricting Wi-Fi calls supported by telecommunications network

Solutions are disclosed that provide for proxy-call session control function (P-CSCF) awareness of access point name (APN) or data network name (DNN). This permits the P-CSCF to enforce policies regarding use of internet protocol (IP) multimedia subsystem (IMS) resources, such as certain voice codecs (e.g., enhanced voice services, EVS) that use larger amounts of bandwidth, based on the APN/DNN assigned to a user equipment (UE). For example, certain IMS resources may be prioritized for home UEs over mobile virtual network operator (MVNO) UEs, or outbound roamers over inbound roamers, leveraging the P-CSCF's awareness of APN/DNN. In some examples, a packet gateway (PGW) or session management function (SMF) inserts APN/DNN information into a session initiation protocol (SIP) message going to the P-CSCF. In some examples, the P-CSCF retrieves APN/DNN information from a policy and charging rules function (PCRF) or a policy control function (PCF).

Proxy node awareness of access point name (APN) or data network name (DNN)

Solutions for providing proxy node (e.g., proxy-call session control function (P-CSCF)) selection by traffic type include: receiving, by a network node (e.g., a packet gateway (PGW)), from a network device (e.g., a user equipment (UE) or internet of things (IoT) device), a first message indicating a request for identification of a proxy node; receiving, by the network node, from the network device, an indication of a first data traffic type; based on at least the indication of the first data traffic type, selecting, by the network node, a first proxy node over a second proxy node to identify to the network device; and transmitting an identification of the first proxy node to the network device. Examples support network slicing and improve wireless priority service (WPS) and enhanced 911 (SECOND DATA TRAFFICE911).

Proxy-call session control function (P-CSCF) selection by traffic type

A network operator can partition network elements, including elements of an IP Multimedia Subsystem (IMS) or Policy and Charging Rules Functions (PCRFs) into groups reserved for specific types of subscribers. When a user equipment (UE) registers with an IMS, elements of the IMS can contact a Home Subscriber Server (HSS) to determine a subscriber type associated with the UE. Based on the UE's subscriber type, an IMS element can determine an application server or other IMS element to contact about the UE based on identifying application servers or IMS elements that are also associated with the same subscriber type as the UE. Similarly, an IMS element can determine a PCRF to contact about the UE based on identifying a PCRF that is associated with the same subscriber type as the UE.

IMS routing based on subscriber type

When operational, a first node of an IMS network handles a registration of a UE on the IMS network, and receives a first request to reregister the UE with the IMS network. The first node creates a registration confirmation, and sends the registration confirmation to the UE. The second node of the IMS network receives a second request to reregister the UE with the IMS network and an indication that the first node has failed. The second node reduces IMS network congestion by avoiding reporting to the UE that the first node has failed, and by sending a message confirming reregistration. Upon receiving the message, the UE considers the registration valid for a predetermined period. Upon expiration of the predetermined period the UE sends a request to reregister. The message prevents the UE from congesting the IMS network.

Reducing IMS network congestion when a node in the IMS network becomes unavailable

Techniques and systems for recovering a communication session from a dedicated bearer failure are disclosed. For example, a P-CSCF node can determine that a dedicated bearer associated with a communication session has failed, and, in response, send a SIP message to a UE associated with the communication session, the SIP message causing the UE to refrain from sending SIP requests using a SIP INVITE method. The process may further include identifying a first network node associated with an identifier of the UE, the first network node comprising one of a PGW or a SMF, and sending an instruction to the first network node to dissociate the dedicated bearer from the communication session. This causes a new attach procedure to be performed by the UE to recover the session without session failure.

Session recovery from dedicated bearer failure

A system uses deep packet inspection and a services policy database to select policy control functions based on services associated with a packet data session rather than an access point name or data network name. As a packet data session is initiated, a system management function (SMF) determines a service associated with the session and routes a policy request to one of several policy control functions (PCF or PCRF) depending on the service. Policies specific to the service may be chosen and enforced at the selected PCF/PCRF.

Service-based policy for cellular communications

Improved systems and method are described for addressing issues when an S-CSCF goes appears non-responsive or an application server appears non responsive. Profile recovery is executed through application servers which may allow additional options in efficiencies in maintain applications while recovering from the non-responsive devices.

IMS recovery

A solution for establishing a data traffic session (e.g., a voice call or a video call) for a user equipment (UE) on a network (e.g., a 5G cellular network) comprises: receiving, by a session management node, from a network repository, identification of a first session control node and a second session control node; receiving, by the session management node, from the UE, a request for identifying a session control node for supporting the data traffic session; determining whether the first session control node is available; and based on at least determining that the first session control node is available and not determining that the second session control node is available, sending, by the session management node, to the UE, identification of the first session control node and not sending identification of the second session control node.

P-CSCF discovery through NRF

Policy node grouping provides efficient network operation by improving the speed and reliability of policy node traffic. Disclosed solutions include: receiving, at a proxy-call session control function (P-CSCF), from a user equipment (UE), a data traffic session request; based on at least the data traffic session request and group policy criteria, selecting a policy node group from among a plurality of policy node groups, the plurality of policy node groups each comprising policy node peers grouped by a service type; based on at least the selected policy node group, determining a selected policy node; based on at least the selected policy node and the data traffic session request, establishing a data traffic session for the UE; and based on at least meeting policy node failover criteria and a failover latency timer, performing an inter-group or intra-group failover according to the group policy criteria.

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Bellevue, WA, United States of America

Khurram Ahmad Mirza