Coverage Signal Strength Indicator for Asymmetric Wireless Links

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current portable electronic devices rely on Received Signal Strength Indicator (RSSI) for wireless local area network coverage, which only represents signal strength from the device's perspective and can provide an overly optimistic view of coverage, failing to accurately indicate actual wireless coverage due to asymmetrical signal reception and transmission capabilities between the device and the access point.

Innovation Solution

The apparatus calculates a Coverage Signal Strength Indicator (CSSI) by considering both uplink and downlink parameters, including transmit power and sensitivity of the device and access point, to provide a more accurate representation of wireless coverage by determining the reception signal strength from both the device's and the access point's perspectives, allowing for a dynamic threshold-based coverage indicator to be displayed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If RSSI is used to indicate wireless coverage, then the device can provide a simple signal strength indicator, but the coverage indication becomes overly optimistic and inaccurate because it only reflects the device's reception capability, not the access point's reception capability

Engineering Contradiction:
Improvesimplicity of coverage indicationVSAvoidaccuracy of coverage indication
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies asymmetry by transitioning from a single-perspective RSSI measurement to a dual-perspective CSSI calculation that asymmetrically accounts for both the device's downlink reception and the access point's uplink reception capabilities. This asymmetric approach resolves the contradiction by incorporating the access point's reception characteristics without completely overhauling the simple indicator concept.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent introduces an intermediary calculation mechanism that bridges the gap between simple RSSI and complex bidirectional measurement. The CSSI acts as an intermediary metric that combines device-side measurements with access point parameters (transmit power, sensitivity) to produce an accurate coverage indicator without requiring direct access point measurements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If only downlink signal strength is measured, then the measurement process remains simple, but the coverage assessment fails to account for uplink transmission limitations

Engineering Contradiction:
Improvecomplexity of measurement processVSAvoidreliability of coverage assessment
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-obtaining access point parameters (transmit power, sensitivity) before performing the CSSI calculation. This allows the system to account for uplink limitations in advance without adding complex real-time measurement procedures, thus maintaining measurement simplicity while improving reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses self-service by leveraging existing device capabilities to measure downlink signal strength and combining this with stored access point parameters to self-correct for uplink limitations. This approach improves reliability without requiring additional hardware or complex external measurements.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If CSSI calculation incorporating both uplink and downlink parameters is implemented, then coverage indication accuracy improves, but the calculation complexity increases

Engineering Contradiction:
Improveaccuracy of coverage indicationVSAvoidcomplexity of calculation process
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by transforming the simple RSSI value into CSSI through mathematical operations that incorporate access point parameters. This parameter transformation approach improves accuracy while keeping the calculation process manageable by using standardized formulas rather than complex algorithms.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2991247B1Method and apparatus for calculating a coverage signal strength indicator
Publication Date: 2021.05.12 BLACKBERRY LTD
  • EP2991247B1 patent drawingFigure 1~2
  • EP2991247B1 patent drawingFigure 3
  • EP2991247B1 patent drawing

AI summary

Apparatus and method pertaining to the calculation of at least one value that represents, at least in part, wireless reception signal strength from the perspective of both a local wireless receiver and a remote receiver that receives wireless transmissions from a local wireless transmitter. By one approach the apparatus directly determines the wireless reception signal strength from the perspective of the local wireless receiver and indirectly determines the wireless reception signal strength from the perspective of the remote receiver.