Sector-Specific Random Access Time Windows for Mobile Network Cells

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Solution Overview

Problem

In heterogeneous mobile network deployments, the varying transmission delays in backhaul connections between macro and pico stations can lead to failures in the random access procedure due to mismatched time windows, and shared cell scenarios complicate resource management for random access preambles, affecting network performance and efficiency.

Innovation Solution

Determining individual time windows for each radio station based on transmission delays and providing customized system information to user equipment (UEs) through a cell controller or radio stations, allowing UEs to select optimal settings for accessing the cell, thereby optimizing random access procedures and resource allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single time window is configured for the entire cell, then resource management is simplified, but random access procedure reliability deteriorates due to varying backhaul delays across sectors

Engineering Contradiction:
Improvetime window configuration complexityVSAvoidrandom access procedure reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent divides the cell into multiple sectors, each with its own radio station, and configures separate time windows for each sector based on its specific backhaul delay characteristics. This segmentation allows each sector to be optimized independently, resolving the contradiction between simplified configuration and reliable access.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by determining time windows individually for each radio station/sector based on its specific transmission delay properties. Each sector receives customized time window parameters (Ra-responseWindowSize and mac-ContentionResolutionTimer) matched to its local backhaul conditions, rather than applying a uniform configuration across the entire cell.

Inventive Principle:
Principle #3Local quality

2Reliability

If conservative time window settings are applied to ensure reliability, then random access failure risk is reduced, but access speed deteriorates

Engineering Contradiction:
Improverandom access procedure reliabilityVSAvoidrandom access procedure speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent changes the time window parameters dynamically based on the specific backhaul delay characteristics of each sector. By adjusting Ra-responseWindowSize and mac-ContentionResolutionTimer to match actual transmission delays, the system achieves optimal balance between reliability and speed for each sector without requiring overly conservative settings across the board.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If multiple radio stations share a cell, then network capacity is increased, but processing complexity for random access preamble decoding increases

Engineering Contradiction:
Improvenetwork capacityVSAvoidpreamble decoding processing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the random access processing by assigning each radio station/sector its own time window configuration and processing domain. This allows UEs to perform random access procedures with the appropriate sector based on local conditions, reducing the processing burden on any single radio station while maintaining high network capacity through multiple concurrent access procedures across sectors.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2959738B1Sector individual control of access to a cell of a mobile network
Publication Date: 2019.04.24 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2959738B1 patent drawingFigure 1
  • EP2959738B1 patent drawingFigure 2
  • EP2959738B1 patent drawingFigure 3A

AI summary

For controlling random access individually for a given sector of a cell (10), a transmission delay of a backhaul connection (B1, B2, B3, B4) of a radio station (200-1, 200-2, 200-3, 200-4) serving the sector of the cell (10) is determined. Depending on the transmission delay, at least one time window is determined. The at least one time window defines a maximum allowed time between two messages of a random access procedure. The at least one time window is indicated via the radio station (200-1, 200-2, 200-3, 200-4) to one or more user equipments (50-1, 50-2, 50-3) in the cell (10). For this purpose, sector individual system information may be transmitted via different radio stations (200-1, 200-2, 200-3, 200-4) of the cell.