Tracking Area Identity List Configuration for Fast-Moving User Equipment

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Solution Overview

Problem

In wireless communication networks, particularly in LTE, fast-moving user equipment (UE) experiences high paging failure rates and prolonged response times due to inefficient paging processes, leading to wastage of radio resources, especially for time-critical services where the entire tracking area list is used, which is ineffective for quickly reaching the UE.

Innovation Solution

The solution involves determining the fast-moving state of a UE by analyzing timestamp durations within tracking areas and configuring the tracking area identity (TAI) list to include only the current TAI for paging, thereby minimizing the paging area and conserving radio resources, especially for fast-moving UEs in time-critical services.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the MME pages the UE using the entire TAI list for time-critical services, then the UE can be reached more quickly, but radio resources are wasted significantly

Engineering Contradiction:
Improvepaging response timeVSAvoidradio resources consumption
Core Design Contradiction:
Loss of timeVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the paging area adaptive based on UE mobility state. The MME determines whether the UE is fast-moving by analyzing tracking area residence times and adjusts the paging area accordingly - using only the current TAI for fast-moving UEs and the full TAI list for stationary UEs, thus optimizing both response time and resource consumption dynamically

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of paging area size based on UE mobility characteristics. By monitoring residence time in tracking areas and comparing it against thresholds, the system adjusts the paging scope from minimal (current TAI only) to extensive (full TAI list) based on the detected mobility state, resolving the contradiction between speed and resource efficiency

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the MME expands the paging area gradually in adaptive paging, then radio resources are saved, but the UE cannot be reached quickly

Engineering Contradiction:
Improveradio resources consumptionVSAvoidpaging response time
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-determining the UE's mobility state and selecting the appropriate paging area before the actual paging process begins. The MME analyzes residence time data and configures the paging area in advance, so that when paging is needed, the system already knows whether to use minimal or full coverage, eliminating the need for gradual expansion and its associated time delays

Inventive Principle:
Principle #10Preliminary action

3Loss of energy

If the MME uses the last visited eNB or eNB list for paging fast-moving UEs, then the paging process can start with a small area, but the UE will probably not return to these areas

Engineering Contradiction:
Improveradio resources consumptionVSAvoidpaging success rate
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent uses feedback from UE mobility behavior (residence time measurements) to adjust the paging strategy. The MME monitors how long UEs stay in tracking areas and uses this feedback to identify fast-moving UEs, then switches to a different paging approach (current TAI only) that accounts for their continued movement, thereby maintaining both efficiency and success rate

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3707941B1Methods and devices for mobility management
Publication Date: 2023.01.04 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3707941B1 patent drawingFigure 1~2
  • EP3707941B1 patent drawingFigure 3
  • EP3707941B1 patent drawingFigure 4~5

AI summary

A method implemented by a network device for mobility management in a wireless communication network is provided. The network device is communicatively connected to at least a user equipment in the wireless communication network. The method comprises determining whether the user equipment is in a fast-moving state upon receipt of a tracking area update request from the user equipment. The method further comprises: in response to the user equipment being in the fast-moving state, configuring a tracking area identity list associated with the user equipment to include only a current tracking area identity associated with the user equipment, and paging the user equipment using the tracking area identity list. Accordingly, a network device for mobility management in a wireless communication network is also provided.