Dual-RAT Core Network Paging to Cut Border Update Overhead

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Solution Overview

Problem

Existing wireless communication networks face inefficiencies in inter-RAT paging, particularly at the border of two radio access technologies (RATs), leading to increased power consumption and network signaling overhead due to frequent tracking area updates and ping-pong effects.

Innovation Solution

A first core network node detects dual registration of a user equipment (UE) in multiple RATs and transmits a paging notification to a second core network node, enabling simultaneous paging in both RATs, thereby reducing unnecessary updates and optimizing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the network performs paging in only one RAT when UE is at the border of two RATs, then the paging process is simple, but the UE may be missed and frequent tracking area updates occur

Engineering Contradiction:

Improvepaging success rateVSAvoidpaging process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The paging process is segmented into two independent parts: one for the first RAT and one for the second RAT. The core network node sends separate paging messages to radio network nodes in each RAT, allowing parallel execution of paging in both networks without interfering with each other, thus improving reliability while maintaining manageable complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The core network merges the paging operations for multiple RATs by coordinating the paging messages sent to different radio network nodes simultaneously. This combining approach ensures the UE is reached regardless of which RAT it is currently using, improving paging success rate at borders

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If the network pages the UE in both RATs simultaneously, then the paging reliability is improved, but the network signaling overhead increases

Engineering Contradiction:

Improveinter-RAT paging success rateVSAvoidnetwork signaling overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The core network performs preliminary actions by determining UE location and registration status before initiating paging. By checking which RATs the UE is registered in and where it is currently located, the network can optimize paging message distribution, sending pages to the most likely RAT first or simultaneously based on location information, thus improving reliability while controlling signaling overhead

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The network applies partial paging action by sending paging messages to radio network nodes based on UE location and registration status. Instead of always paging in both RATs, the system pages in the RAT where the UE is currently located or most likely to be found, using excessive action (paging in both RATs) only when necessary at border locations

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If the UE performs frequent tracking area updates at the border of two RATs, then the UE remains registered in the network, but power consumption increases

Engineering Contradiction:

Improveregistration statusVSAvoidUE power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system implements feedback by monitoring UE location and registration status across multiple RATs. When the UE is at a border location, the core network receives feedback about the UE's presence in both RATs and adjusts paging behavior accordingly, which reduces the need for frequent tracking area updates and thereby reduces UE power consumption while maintaining reliable registration

Inventive Principle:

Principle #23Feedback

4Device complexity

If the network uses crude update information about UE location, then the paging search is simple, but the paging efficiency decreases

Engineering Contradiction:

Improvepaging search complexityVSAvoidpaging efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes parameters dynamically by adjusting paging behavior based on UE location and registration status. When the UE is at a border location, the network changes the paging approach to include both RATs; when the UE is clearly in one RAT, only that RAT is paged. This parameter-based adaptation improves paging efficiency while keeping the system manageable

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4173387B1First core network node and method performed therein for paging in a wireless communication network

Publication Date: 2026.03.18 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

A method performed by a first core network node (16) serving a first RAT, for enabling paging of a UE (10) in a wireless communication network. The first core network node receives (401) an incoming communication addressed to the UE. The first core network node further detects (402) that the UE has a dual registration in the first RAT and in a second RAT. The first core network node then further transmits (405) a paging notification to a second core network node (18) serving the second RAT as an instruction to page the UE in the second RAT, thereby enabling paging of the UE in both the first RAT and the second RAT of the wireless communication network.