Multi-Tier Spectrum Sharing via Beacon Synchronization

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Solution Overview

Problem

Wireless communication networks face interference and congestion due to increased demand for mobile broadband access, which degrades performance and requires efficient management of shared spectrum among multiple tiers of users.

Innovation Solution

The method involves a second tier transmitter sending beacons to identify itself and transmit data after an idle period, while a third tier transmitter synchronizes with the second tier infrastructure, switches to silence mode during beacon slots, and conducts clear channel assessments to determine when to transmit data on shared spectrum, ensuring minimal interference with higher-priority users.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If more UEs access the long-range wireless communication networks and more short-range wireless systems are deployed, then mobile broadband access demand is met, but interference and network congestion increase

Engineering Contradiction:
Improvemobile broadband access capacityVSAvoidinterference and congestion
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the wireless network into multiple tiers (first tier long-range networks, second tier mid-range networks, third tier short-range networks) that operate simultaneously on the same spectrum. Each tier is further segmented into beacon periods and data periods, allowing organized coexistence and reducing interference while meeting diverse broadband demands.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a temporal dimension to spectrum sharing by dividing time into beacon periods and data periods. Different tiers transmit in different time windows, transforming the frequency-domain resource allocation into time-frequency domain allocation, thereby reducing interference while increasing overall capacity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If second tier transmitters continuously transmit data on shared spectrum, then data transmission efficiency is improved, but interference to first tier and third tier users increases

Engineering Contradiction:
Improvedata transmission efficiencyVSAvoidinterference to other tiers
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent implements periodic action by requiring second tier transmitters to send beacons at regular intervals and to transmit data only during designated data periods. This periodic structure allows other tiers to predict and avoid interference, maintaining data transmission efficiency while protecting other users.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The beacon signal acts as an intermediary that announces the presence and timing of second tier transmissions. Other tiers can detect these beacons and adjust their transmissions accordingly, using the beacon as a mediator to coordinate spectrum sharing and minimize interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If third tier transmitters transmit during beacon slots, then spectrum utilization is improved, but detection of higher priority users becomes unreliable

Engineering Contradiction:
Improvespectrum utilizationVSAvoidbeacon detection reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by requiring third tier transmitters to first detect and synchronize to second tier beacons before initiating data transmissions. This preliminary detection ensures that third tier users do not interfere with higher priority transmissions and maintains reliable beacon detection for proper tiered operation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3198975B1Shared spectrum operation
Publication Date: 2019.07.10 QUALCOMM INC
  • EP3198975B1 patent drawingFigure 1
  • EP3198975B1 patent drawingFigure 2
  • EP3198975B1 patent drawingFigure 3

AI summary

Shared spectrum operation is disclosed for sharing spectrum among multiple wireless deployments. Coordination procedures between and among 2nd and 3rd Tier deployments include the use of beacons transmitted by the 2nd Tier for clearing access to spectrum occupied by 3rd Tier users and multiple 3rd Tier deployments sharing resources using a group-listen before talk (LBT) protocol, rather than a per-node LBT protocol. The 2nd Tier beacon signals are transmitted to alert 3rd Tier users of their presence, which, upon detection, will leave the particular spectrum within a predetermined time. For the shared LBT protocol, the 3rd Tier deployments share the channel with each other through an LBT with random backoff, in which the start time of clear channel assessment (CCA) procedure and the random backoff values are synchronized among nodes of the same deployment.