Small Cell Timing via Uplink Signal Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Accurate timing acquisition for small cell base stations in 5G heterogeneous wireless networks is challenging due to limitations in the Precision Time Protocol (PTP) method, which requires substantial network upgrades and a dense deployment of grand masters, making it costly and inefficient.

Innovation Solution

A method for determining the timing of small cell base stations by detecting and adjusting their system timing using uplink signals from mobile devices to nearby base stations, employing self-learning algorithms and calibration techniques to account for timing offsets and accuracy ratings based on hop distances from GNSS reference points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If PTP (1588 Precision Time Protocol) is used for timing acquisition, then timing accuracy can be achieved, but network upgrades and device complexity increase substantially

Engineering Contradiction:
Improvetiming accuracyVSAvoidnetwork upgrades
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses macro base stations as intermediary timing reference points for small cells. Instead of requiring direct PTP synchronization to grand master clocks, small cells obtain timing references from nearby macro cells, which act as mediators. This eliminates the need for substantial network upgrades while maintaining timing accuracy through the hierarchical timing distribution architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The timing synchronization system is segmented into hierarchical levels: grand master clocks at the network level, macro base stations as intermediate timing references, and small cells as edge nodes. This segmentation allows timing accuracy to be achieved at each level without requiring all network devices to support full PTP functionality, thereby reducing overall device complexity and upgrade requirements.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If PTP is used for timing acquisition, then timing accuracy can be achieved, but dense deployment of grand masters is required which increases cost

Engineering Contradiction:
Improvetiming accuracyVSAvoidnumber of grand masters
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent combines timing reference functionality with existing macro base station infrastructure. Instead of deploying separate grand master clocks densely throughout the network, the timing reference function is merged into macro cells that already provide coverage. This eliminates the need for dense grand master deployment while maintaining timing accuracy through the macro-small cell hierarchical relationship.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Macro base stations serve multiple functions: providing wireless coverage, backhaul connectivity, and acting as timing reference points for small cells. This multi-functionality eliminates the need for dedicated grand master clock deployments, reducing the quantity of timing reference devices required while maintaining timing accuracy across the heterogeneous network.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If limited hops between GM and small cell are enforced for 200ns accuracy, then timing accuracy is maintained, but deployment becomes costly and complex

Engineering Contradiction:
Improvetiming accuracyVSAvoiddeployment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic timing reference selection where small cells can adaptively choose their timing reference based on proximity and signal quality. Instead of enforcing a fixed hop limit that requires dense GM deployment, the system dynamically adjusts timing references using macro cells at varying distances, maintaining 200ns accuracy through adaptive calibration and timing offset compensation mechanisms.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3841801B1Reverse timing for small cells
Publication Date: 2024.07.17 CISCO TECHNOLOGY INC
  • EP3841801B1 patent drawingFigure 1
  • EP3841801B1 patent drawingFigure 2
  • EP3841801B1 patent drawingFigure 3A

AI summary

Systems, methods, and computer-readable media are provided for determining/adjusting a timing of small cell base stations deployed in 5th generation (5G) heterogeneous wireless networks through timing detected on uplink signals from mobile devices to nearby base stations. In one aspect of the present disclosure, a method includes detecting, by a target network component, at least one uplink signal between a mobile device and a neighboring network component; determining, by the target network component, a timing of the at least one uplink signal; determining, by the target network component, a current system timing of the target network component; and adjusting, by the target network component, the current system timing of the target network component using the timing of the at least one uplink signal.