Adaptive Cell Measurement Cycle for Mobile Terminal Mobility

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Solution Overview

Problem

Existing mobile telecommunications networks face inefficiencies in mobility management, particularly in setting optimal cell measurement cycle lengths, which are often fixed relative to DRX cycle lengths, leading to suboptimal performance in both high and low mobility states, and difficulty in transitioning between active and inactive states to build accurate histories of mobility state measurements.

Innovation Solution

The solution involves varying the cell measurement cycle length based on the calculated mobility state of the mobile terminal, allowing for adaptive adjustment of DRX and cell measurement intervals to optimize cell reselection and handover parameters, enabling better performance in varying mobility conditions and facilitating the use of mobility state measurements from both active and inactive states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the cell measurement cycle length is set to be long to reduce battery consumption, then energy efficiency is improved, but mobility state detection accuracy deteriorates

Engineering Contradiction:
Improvebattery consumptionVSAvoidmobility state detection accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent makes the cell measurement cycle length dynamic by adjusting it according to the detected mobility state. When high mobility is detected, the cycle length is shortened to improve measurement accuracy; when low mobility is detected, the cycle length is extended to save battery power. This resolves the contradiction by making the measurement frequency adaptive rather than fixed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of cell measurement cycle length based on mobility state detection. The system transitions from a static parameter setting to a dynamic one where the measurement cycle length is modified according to the terminal's movement characteristics, thereby optimizing both energy consumption and measurement accuracy under different operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the cell measurement cycle length is set to be short to improve mobility state detection accuracy, then measurement precision is improved, but battery consumption increases

Engineering Contradiction:
Improvemobility state detection accuracyVSAvoidbattery consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the measurement cycle length based on mobility state, shortening it only when high mobility is detected and requiring accurate measurements, rather than maintaining a consistently short cycle length. This dynamic adaptation reduces overall battery consumption while preserving measurement accuracy when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The measurement cycle length parameter is changed adaptively based on mobility conditions. The system uses mobility state detection to determine appropriate parameter values, transitioning from a fixed short cycle length to a variable one that balances measurement accuracy requirements with battery conservation.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a fixed DRX cycle length is used for all mobile terminals, then network simplicity is maintained, but adaptability to different mobility states deteriorates

Engineering Contradiction:
Improvenetwork configuration simplicityVSAvoidadaptability to mobility states
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic adjustment of the cell measurement cycle length based on detected mobility states, allowing the system to adapt to different terminal movement patterns. This maintains network simplicity by using a single DRX cycle length configuration while achieving adaptability through dynamic measurement cycle adjustment.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If the mobile terminal frequently moves between active and inactive states, then communication flexibility is improved, but difficulty in building mobility state measurement history increases

Engineering Contradiction:
Improvecommunication state transition flexibilityVSAvoidmobility state measurement history maintenance
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary mobility state detection and measurement during the inactive state, before the terminal transitions to the active state. This preliminary action allows the network to have mobility state information ready when the terminal becomes active, eliminating the need to build measurement history after frequent state transitions and simplifying the overall process.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1985137B1Network and method for optimizing an estimation of mobility of a mobile terminal
Publication Date: 2018.05.09 VODAFONE GRP PLC
  • EP1985137B1 patent drawingFigure 1
  • EP1985137B1 patent drawingFigure 2
  • EP1985137B1 patent drawingFigure 3

AI summary

The mobile telecommunications network (n) has at least one mobile terminal (1) registered therewith. The network (n) has an active communication state with the mobile terminal (1) and an inactive communication state with the mobile terminal (1) . Means Q; V for calculating an indication of the movement of the mobile terminal (1) within the network (n) in each of the states is provided. One embodiment is characterised in that, when the communication changes from a first of the states to a second of the states, the mobility indication calculated in the first of the states is used in the second of the states. In another embodiment, the indication of movement of the mobile terminal is calculated periodically at a time interval (CMCL) . A value (DRX Cycle Length) which determines this time interval (CMCL) is transmitted by the network (n) to the mobile terminal (1) . This second embodiment is characterised by including means for varying the time interval (CMCL) in dependence upon an indication of movement of the terminal (1) .