IP Library Granted Patent US 12676900
Granted Patent B2
US 12676900 · App. 18/658,261 · Granted Jul 7, 2026

IMS routing based on subscriber type

Inventors: Mohammed Al-Mehdar (Bellevue, WA); Shujaur Mufti (Snoqualmie, WA); Khurram Ahmad Mirza (Bellevue, WA); Saqib Badar (Bellevue, WA); Kalyan Kalepu (Sammamish, WA)
Assignee: T-Mobile USA, Inc.
H04L65/1069H04L61/503H04L65/00H04L65/1016H04L65/1073H04L65/1104H04M15/66H04W8/04
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12676900
App. No.
18/658,261
Granted
Jul 7, 2026
Kind
B2
Abstract

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.

Claims (33)

1 . A method comprising:

receiving, by a Proxy Call Session Control Functions (P-CSCF) of an internet protocol (IP) Multimedia Subsystem (IMS), a Session Initiation Protocol (SIP) registration message associated with a user equipment (UE);

forwarding, by the P-CSCF, the SIP registration message to an Interrogating Call Session Control Function (I-CSCF), wherein the I-CSCF assigns the UE to a Serving Call Session Control Function (S-CSCF) based at least in part on a subscriber type associated with the UE;

receiving, by the P-CSCF, a SIP response message from the S-CSCF indicating the subscriber type associated with the UE, wherein the subscriber type is included in a private header field and includes a predefined value of multiple predefined values that is associated with a classification of a subscriber distinct from other classes of subscriber, the classification of the subscriber indicating at least one of a class of service, a service level, or a service plan; and

sending, by the P-CSCF, a Policy and Charging Rules Functions (PCRF) request message to a PCRF selected from a subset of PCRFs that have been carved out for the subscriber type, wherein the PCRF request message is sent via a Diameter protocol Rx interface.

2 . The method of claim 1 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to services of a mobile network operator (MNO) and a second value indicating that the user of the UE subscribes to services of a mobile virtual network operator (MVNO).

3 . The method of claim 1 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to a first type of subscription plan for Long-Term Evolution (LTE) services and a second value indicating that the user of the UE subscribes to a second type of subscription plan for fifth generation (5G) services.

4 . The method of claim 1 , wherein the SIP registration message includes at least one of an IP Multimedia Private Identity (IMPI), an IMS Public User Identity (IMPU), or an IP address.

5 . The method of claim 1 , wherein the P-CSCF is configured to select the PCRF that is associated with the subscriber type associated with the UE and to send information about the UE to the PCRF.

6 . The method of claim 1 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to a priority tier subscription plan and a second value indicating that the user of the UE subscribes to a standard tier subscription plan.

7 . An IP Multimedia Subsystem (IMS) comprising:

a Proxy Call Session Control Functions (P-CSCF) associated with a user equipment (UE), the P-CSCF configured to:

receive, by the P-CSCF, a Session Initiation Protocol (SIP) registration message associated with a user equipment (UE);

forward, by the P-CSCF, the SIP registration message to an Interrogating Call Session Control Function (I-CSCF), wherein the I-CSCF assigns the UE to a Serving Call Session Control Function (S-CSCF) based at least in part on the subscriber type associated with the UE;

receive, by the P-CSCF, a SIP response message from the S-CSCF indicating a subscriber type associated with the UE, wherein the subscriber type is included in in a private header field and includes a predefined value of multiple predefined values that is associated with a classification of a subscriber distinct from other classes of subscriber, the classification of the subscriber indicating at least one of a class of service, a service level, or a service plan; and

send, by the P-CSCF, a Policy and Charging Rules Functions (PCRF) request message to a PCRF selected from a subset of PCRFs that have been carved out for the subscriber type, wherein the PCRF request message is sent via a Diameter protocol Rx interface.

8 . The IMS of claim 7 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to services of a mobile network operator (MNO) and a second value indicating that the user of the UE subscribes to services of a mobile virtual network operator (MVNO).

9 . The IMS of claim 7 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to a first type of subscription plan for Long-Term Evolution (LTE) services and a second value indicating that the user of the UE subscribes to a second type of subscription plan for fifth generation (5G) services.

10 . The IMS of claim 7 , wherein the SIP registration message includes at least one of an IP Multimedia Private Identity (IMPI), an IMS Public User Identity (IMPU), or an IP address.

11 . The IMS of claim 7 , wherein the P-CSCF is configured to select the PCRF that is associated with the subscriber type associated with the UE and to send information about the UE to the PCRF.

12 . The IMS of claim 7 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to a priority tier subscription plan and a second value indicating that the user of the UE subscribes to a standard tier subscription plan.

13 . A computing device comprising:

one or more processors; and

non-transitory computer-readable media storing computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to perform actions comprising:

receiving, by a Proxy Call Session Control Functions (P-CSCF) of an IP Multimedia Subsystem (IMS), a Session Initiation Protocol (SIP) registration message associated with a user equipment (UE);

forwarding, by the P-CSCF, the SIP registration message to an Interrogating Call Session Control Function (I-CSCF), wherein the I-CSCF assigns the UE to a Serving Call Session Control Function (S-CSCF) based at least in part on the subscriber type associated with the UE;

receiving, by the P-CSCF, a SIP response message from the S-CSCF indicating a subscriber type associated with the UE, wherein the subscriber type is included in in a private header field and includes a predefined value of multiple predefined values that is associated with a classification of a subscriber distinct from other classes of subscriber, the classification of the subscriber indicating at least one of a class of service, a service level, or a service plan; and

sending, by the P-CSCF, a Policy and Charging Rules Functions (PCRF) request message to a PCRF selected from a subset of PCRFs that have been carved out for the subscriber type, wherein the PCRF request message is sent via a Diameter protocol Rx interface.

14 . The computing device of claim 13 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to services of a mobile network operator (MNO) and a second value indicating that the user of the UE subscribes to services of a mobile virtual network operator (MVNO).

15 . The computing device of claim 13 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to a first type of subscription plan for Long-Term Evolution (LTE) services and a second value indicating that the user of the UE subscribes to a second type of subscription plan for fifth generation (5G) services.

16 . The computing device of claim 13 , wherein the SIP registration message includes at least one of an IP Multimedia Private Identity (IMPI), an IMS Public User Identity (IMPU), or an IP address.

17 . The computing device of claim 13 , wherein the P-CSCF is configured to select the PCRF that is associated with the subscriber type associated with the UE and to send information about the UE to the PCRF.

18 . The computing device of claim 13 , wherein the subscriber type is selected from at least a first value indicating that a user of the UE subscribes to a priority tier subscription plan and a second value indicating that the user of the UE subscribes to a standard tier subscription plan.