Inter-Frequency Neighbor Cell Filtering for Network Sharing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In network sharing scenarios, User Equipment (UE) faces challenges with inter-frequency handover due to limited measurement capabilities, leading to increased call drop rates and reduced success rates of inter-frequency handovers, especially in complex network environments where multiple operators share frequencies, resulting in UE measuring invalid neighbor cells and exceeding measurement capacity.

Innovation Solution

A method and device for determining inter-frequency neighbor cells by acquiring the Public Land Mobile Network Identity Document (PLMN ID) of UE accessing a border region, processing configuration information for inter-frequency handover, and filtering neighbor cells to retain only valid frequencies, allowing UE to perform handovers efficiently, thereby reducing measurement gaps and improving handover success rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE measures all configured inter-frequency neighbor cells in the border region, then the handover coverage is improved, but the UE measurement capability is exceeded and invalid measurements are performed

Engineering Contradiction:
Improvehandover success rateVSAvoidmeasurement capability
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The network side performs preliminary filtering of neighbor cells before configuring them to the UE. The filtering is based on PLMN identity matching and frequency configuration, so that only valid neighbor cells relevant to the UE's home network are included in the measurement configuration. This preliminary action prevents the UE from wasting measurement resources on invalid cells.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The neighbor cell list is segmented into valid and invalid cells based on PLMN identity and frequency configuration. The network filters the complete neighbor cell list to create a reduced valid list that is tailored to each UE's specific home network and service context. This segmentation allows the UE to focus measurements only on relevant cells.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If multiple operators share the network with different frequencies, then network sharing capability is improved, but the number of frequencies for handover increases beyond UE support capacity

Engineering Contradiction:
Improvenetwork sharing capabilityVSAvoidnumber of frequencies
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The measurement configuration is customized for each UE based on its home network's specific frequency requirements. Instead of providing a universal list of all frequencies used by all sharing operators, the network provides a tailored list containing only the frequencies relevant to that specific UE's home network. This local quality approach ensures each UE receives appropriate frequency information without overwhelming it.

Inventive Principle:
Principle #3Local quality

3Reliability

If the UE performs measurements on all neighbor cells including invalid ones, then measurement coverage is improved, but measurement gaps are wasted and UE performance is consumed

Engineering Contradiction:
Improvemeasurement coverageVSAvoidmeasurement gaps
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Invalid neighbor cells are extracted and removed from the measurement configuration before being provided to the UE. The filtering process identifies and eliminates cells that do not match the UE's home network PLMN or are not configured for inter-frequency handover. This extraction ensures the UE only measures valid cells, eliminating wasted measurement opportunities.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3979688B1Method and apparatus for determining inter-frequency adjacent area
Publication Date: 2025.01.08 ZTE CORP
  • EP3979688B1 patent drawingFigure 1~2
  • EP3979688B1 patent drawingFigure 3~4
  • EP3979688B1 patent drawingFigure 5(a)~5(b)

AI summary

Disclosed in the present disclosure are a method and apparatus for determining an inter-frequency adjacent area. The method comprises: a user terminal enters a shared network boundary area, obtains a network identifier of a network to which the user terminal belongs, and according to configuration information of an inter-frequency point which is capable of executing inter-frequency switching corresponding to the network identifier, processes information of an adjacent area to which the user terminal can be switched, so as to obtain inter-frequency adjacent area information comprising the adjacent area belonging to the inter-frequency point.