Heterogeneous Network Control Channel Configuration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In heterogeneous networks, high-density small cells exacerbate mobility issues and interference, leading to increased handover failure rates and suboptimal performance, especially for users with medium to high mobility, due to frequent handovers and interference between high power and low power cells operating on different frequency bands.

Innovation Solution

The implementation of a method where a user equipment (UE) can have multiple serving cells, with the macro serving cell operating on a low frequency band and small serving cells on a higher frequency band, enhancing camping procedures, discontinuous reception, and hybrid automatic repeat request (HARQ) processes to mitigate mobility and interference issues, while coordinating Almost Blank Subframes and uplink timing alignments across cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-density small cells are deployed to improve network capacity, then network capacity and cell edge performance are improved, but mobility overhead increases and handover failure rates increase

Engineering Contradiction:
Improvenetwork capacityVSAvoidhandover success rate
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the network into macro cells and small cells with distinct functional roles. Macro cells provide control plane functions and mobility management, while small cells provide user plane data transmission. This segmentation allows high-density small cell deployment for capacity improvement without requiring frequent handovers, as the control plane remains anchored to the macro cell, thereby resolving the contradiction between network capacity and handover reliability.

Inventive Principle:
Principle #1Segmentation

2Productivity

If small cells are deployed within macro cell coverage to improve capacity, then network capacity is improved, but interference between high power and low power cells increases

Engineering Contradiction:
Improvenetwork capacityVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the network into macro cells and small cells with distinct functional roles. Macro cells provide control plane functions and mobility management, while small cells provide user plane data transmission. This segmentation allows high-density small cell deployment for capacity improvement without requiring frequent handovers, as the control plane remains anchored to the macro cell, thereby resolving the contradiction between network capacity and handover reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces the macro cell as an intermediary that handles control plane functions for UEs connected to small cells. The macro cell acts as a mediator that manages mobility, authentication, and control signaling, while small cells focus on data transmission. This intermediary approach allows small cells to operate at high density without causing excessive interference, as the control plane is protected by the macro cell's stronger signal.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If small cells use different frequency bands from macro cells to remove interference, then interference is reduced, but device complexity and resource management complexity increase

Engineering Contradiction:
ImproveinterferenceVSAvoidfrequency management complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies local quality by assigning different functional characteristics to different parts of the network. Macro cells operate with full functionality (control plane and user plane), while small cells operate with specialized functionality (user plane only). This local differentiation allows interference management without requiring complex frequency coordination, as the functional segmentation naturally reduces interference scenarios.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2936841B1Method and apparatus for control channel configuration in a heterogeneous network architecture
Publication Date: 2020.11.11 BLACKBERRY LTD
  • EP2936841B1 patent drawingFigure 1
  • EP2936841B1 patent drawingFigure 2
  • EP2936841B1 patent drawingFigure 3

AI summary

Methods, systems and apparatus are provided for camping, assisted serving cell addition or removal, and discontinuous reception (DRX) in networks having a macro cell and at least one assisted serving cell. In other aspects, enhancements to Layer 1 channels and uplink timing alignments are provided in networks having a macro cell and at least one assisted serving cell. In further aspects, assisted serving cell Layer 2 architecture and transport channels are provided in networks having a macro cell and at least one assisted serving cell. In further aspects, collaborated HARQ solutions are provided in networks having a macro cell and at least one assisted serving cell.