Passive Proximity Detection for Cellular Base Station Energy Optimization

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Solution Overview

Problem

Current systems for activating or waking base stations in a supporting layer of a cellular network are inefficient, particularly in dynamically adapting to short-term load fluctuations and require accurate position information or active signal transmission, leading to high energy consumption and limited dynamic response.

Innovation Solution

Implementing a passive proximity detection method where supporting radio access nodes listen for ranging signals from wireless devices, determine range estimates using assistance information from anchor nodes, and autonomously decide to enter an active state based on these estimates, reducing the need for continuous active listening and enhancing energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If supporting base stations continuously transmit signals to detect wireless devices, then detection accuracy is improved, but energy consumption increases

Engineering Contradiction:

Improvedetection accuracyVSAvoidenergy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Instead of having supporting base stations actively transmit signals to detect wireless devices, the patent inverts the approach by having supporting base stations passively listen for ranging signals transmitted by wireless devices to anchor base stations. This allows detection accuracy to be maintained while dramatically reducing energy consumption at supporting base stations.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The wireless device performs the ranging signal transmission to the anchor base station, which inadvertently provides detection information to supporting base stations that are passively listening. The system utilizes the wireless device's own transmission for the detection purpose, eliminating the need for separate active detection transmissions from supporting base stations.

Inventive Principle:

Principle #25Self-service

2Speed

If supporting base stations use active listening to detect wireless devices, then responsiveness to load changes is improved, but energy consumption increases

Engineering Contradiction:

Improveresponsiveness to load changesVSAvoidenergy consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

Supporting base stations perform passive listening at periodic intervals rather than continuously transmitting. This allows them to detect wireless devices and respond to load changes while consuming significantly less energy compared to continuous active transmission.

Inventive Principle:

Principle #19Periodic action

3Measurement precision

If accurate position information is used to activate supporting base stations, then activation precision is improved, but system complexity increases

Engineering Contradiction:

Improveactivation precisionVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces ranging assistance information from anchor base stations as an intermediary element. This assistance information enables supporting base stations to calculate accurate range estimates to wireless devices without requiring complex position information systems, thereby maintaining activation precision while reducing system complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for dynamic and efficient activation of base stations, reducing energy consumption by minimizing unnecessary active states and improving responsiveness to changing load conditions, thereby optimizing energy usage in cellular networks.

Implementation Method 1

determine a range estimate for a range between the wireless device and the supporting radio access node based on the ranging signal transmitted by the wireless device and detected by the supporting radio access node while passively listening for a ranging signal and ranging assistance information

Methodology Applied

Scientific EffectTime of Flight: Time of Flight

Data Source

PatentUS10225797B2Passive proximity detection of wireless devices in a synchronous, cooperative network

Publication Date: 2019.03.05 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Systems and methods for passive proximity detection of wireless devices in a cellular communications network are disclosed. In one embodiment, a supporting radio access node in a cellular communications network including one or more coverage radio access nodes in a coverage layer and one or more supporting radio access nodes in a supporting layer is disclosed. In this embodiment, the supporting radio access node detects a ranging signal transmitted by a wireless device while passively listening for a ranging signal. The supporting radio access node receives ranging assistance information from an anchor radio access node of the wireless device in the coverage layer and determines a range estimate for a range between the wireless device and the supporting radio access node based on the ranging signal transmitted by the wireless device and detected by the supporting radio access node and the ranging assistance information.