eNB D2D Resource Pool Exchange via X2 Interface

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Solution Overview

Problem

Current LTE systems lack the ability to effectively indicate device-to-device (D2D) resources to neighboring eNBs, leading to issues with D2D discovery and communication, especially in scenarios where UEs are in proximity but under different eNB coverage areas, resulting in failed discovery signals due to non-overlapping resource pools.

Innovation Solution

A method for indicating D2D resources by using the X2 setup procedure and eNB configuration update procedures to exchange information on resource pools through specific information elements (IEs) such as Served Cell Information IE, D2D Resource Area IE, and Discovery Resource Area IE, ensuring neighboring eNBs allocate compatible resource pools for D2D communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If each eNB independently allocates D2D resource pools without information exchange, then resource allocation is simple and fast, but D2D discovery fails when UEs are under different eNB coverage due to non-overlapping resource pools

Engineering Contradiction:
ImproveD2D discovery success rateVSAvoideNB configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having eNBs exchange D2D resource pool information in advance through X2 setup and configuration update procedures. This allows neighboring eNBs to pre-configure compatible resource pools before D2D communication occurs, ensuring that UEs under different eNBs can still discover each other. The information exchange happens beforehand through standardized interfaces, preventing discovery failures without adding complex real-time coordination mechanisms.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If eNBs exchange detailed D2D resource pool information through X2 interface, then resource alignment between neighboring eNBs is achieved, but signaling overhead and processing load increase

Engineering Contradiction:
ImproveD2D communication reliabilityVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent extracts only the essential D2D resource pool information parameters needed for compatibility (such as resource pool identifiers, frequency resources, and time resources) and exchanges them through the X2 interface. By taking out only the necessary information elements rather than complete configuration details, the patent achieves reliable D2D communication between neighboring eNBs while minimizing signaling overhead and processing requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If D2D resource pools are made overlapping across neighboring eNBs, then D2D discovery works across cell boundaries, but interference between D2D transmissions from different cells increases

Engineering Contradiction:
ImproveD2D coverage areaVSAvoidinter-cell interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by allowing D2D resource pools to overlap in the frequency-time resource grid across neighboring eNBs, but enabling each eNB to independently configure specific resource allocations within their local coverage areas. This localized resource management approach ensures that UEs can discover each other across cell boundaries while each eNB maintains control over its local resource distribution, thereby managing inter-cell interference through local optimization rather than global coordination.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3097650B1Method and apparatus for exchanging between ENB information on device-to-device resources in wireless communication system
Publication Date: 2019.08.28 LG ELECTRONICS INC
  • EP3097650B1 patent drawingFigure 1
  • EP3097650B1 patent drawingFigure 2
  • EP3097650B1 patent drawingFigure 3(a)~3(b)

AI summary

A method and apparatus for indicating a resource pool for device-to-device (D2D) transmission in a wireless communication system is provided. A first evolved NodeB (eNB) transmits information on a resource pool of the first eNB for D2D transmission to a second eNB. The second eNB also transmit information on a resource pool of the second eNB for D2D transmission.