IMS Exposure Subscription Routing via Distributor and Locator Functions

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current IMS architectures lack standard mechanisms to dynamically locate serving Network Functions (NFs) that provide specific RESTful based events/data related to subscribers, complicating the handling of short-lived Session Initiation Protocol (SIP) sessions served by different NFs.

Innovation Solution

Introduce a distributor function and a locator function to handle subscriptions for IMS exposure data, enabling the locator function to identify the correct IMS node serving a UE and the distributor function to distribute subscription requests and notifications to the correct IMS node, using Service Based Architecture (SBA) principles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional IMS architecture is used without standardized mechanisms, then network simplicity is maintained, but the ability to dynamically locate serving Network Functions and handle subscriptions for IMS exposure data is compromised

Engineering Contradiction:

Improveability to dynamically locate serving NFs and handle subscriptionsVSAvoidnetwork architecture complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the IMS architecture by introducing separate functional components: a distributor function for handling subscriptions and a locator function for identifying serving NFs. This segmentation allows each component to specialize in specific tasks, improving adaptability while managing complexity through functional decomposition.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediary functions (distributor and locator) that mediate between application functions and serving Network Functions. These intermediaries simplify the overall system by providing standardized interfaces and abstraction layers, allowing application functions to be IMS-agnostic without requiring detailed knowledge of IMS topology.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If application functions have detailed knowledge of IMS NF topology, then direct communication efficiency is improved, but adaptability and ease of operation are worsened

Engineering Contradiction:

Improvecommunication efficiencyVSAvoidIMS agnosticism and operational simplicity

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The distributor and locator functions serve as intermediaries that enable application functions to communicate with serving NFs without requiring detailed topology knowledge. The locator function resolves NF identifiers to actual network addresses, while the distributor manages subscription routing, thereby maintaining both efficiency and operational simplicity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates universal interfaces through standardized protocols (such as SIP and RESTful APIs) that allow application functions to interact with the network in a generic manner. This universality enables IMS-agnostic operation while maintaining communication efficiency through standardized data formats and message routing mechanisms.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If standardized mechanisms are introduced for locating serving NFs, then adaptability and subscription handling are improved, but device complexity increases

Engineering Contradiction:

Improvestandardized mechanisms for locating NFsVSAvoidnumber of network functions

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent designs the distributor and locator functions with multi-functional capabilities that can serve multiple purposes within the IMS architecture. These functions handle various subscription types, support different NF types, and provide standardized interfaces for diverse application scenarios, thereby reducing the need for multiple specialized components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20260019447A1Distributor function, locator function and methods in a communications network

Publication Date: 2026.01.15 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method performed by a distributor function for handling a subscription to expose Internet protocol Multimedia Subsystem (IMS) exposure data in a communications network is provided. The exposure data is related to a User Equipment (UE) connected to an IMS network comprised in the wireless communications network. The distributor function is comprised in any one out of a first network node or a first IMS node. The distributor function receives (1001) a request requesting a subscription to expose IMS exposure data related to the UE. The request is originating from a second network node operating outside of the IMS network. The distributor function obtains (1002), from a locator function, data identifying a second IMS node supporting exposure capabilities and serving the UE. The locator function is comprised in any one out of the first IMS node or a third network node. The distributor function sends (1003) to the identified second IMS node, a subscription request to expose data related to the UE. The subscription request instructs the second IMS node to notify a network exposure function of a triggering occurrence fulfilling a triggering condition, to expose exposure data, when detected by the second IMS node. The network exposure function is located in the first network node. The notification enables the network exposure function to notify the second network node of the detected triggering occurrence.