VLAN Tagged X2 Interface for CoMP Backhaul Optimization

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Solution Overview

Problem

Current mobile communication networks face challenges in reducing inter-cell interference, particularly in 3G and 4G systems, where centralized architectures for CoMP (Coordinated Multipoint) transmission are costly and complex, and distributed architectures struggle with phase noise and high backhaul traffic.

Innovation Solution

The use of Virtual Local Area Networks (VLAN) enabled Ethernet switches to organize data streams efficiently, reducing backhaul load by transmitting data bits instead of IQ samples and using VLAN tags to identify cooperation clusters, allowing for low-latency and cost-effective CoMP data exchange between base stations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If centralized architecture is used for CoMP transmission, then interference reduction performance is improved, but system cost and complexity increase

Engineering Contradiction:
Improveinterference reduction performanceVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the centralized CoMP system into distributed base stations that independently perform CoMP operations. Each base station processes local channel state information and coordinates with neighboring base stations through standardized interfaces, dividing the complex centralized function into manageable distributed units that maintain interference reduction performance while reducing overall system complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces standardized interfaces and protocols as intermediaries between distributed base stations. These intermediaries enable coordination and information exchange without requiring a complex centralized controller, thus maintaining CoMP performance while simplifying the system architecture through modular, standardized components

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If distributed architecture is used for CoMP transmission, then system cost is reduced, but phase noise and backhaul traffic increase

Engineering Contradiction:
Improvesystem complexityVSAvoidphase noise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary synchronization and channel estimation at each distributed base station before data transmission. By pre-compensating for phase noise and establishing channel conditions in advance, the system reduces the impact of phase noise without requiring complex real-time centralized coordination, thus maintaining low system complexity while mitigating harmful effects

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If IQ samples are transmitted over backhaul, then transmission precision is improved, but backhaul load increases

Engineering Contradiction:
Improvesignal transmission precisionVSAvoidbackhaul traffic
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential channel state information and coordination data from the full IQ samples for backhaul transmission. Each base station processes local IQ samples to extract relevant channel parameters, coordination messages, and interference information, transmitting only these compressed representations over the backhaul. This reduces backhaul traffic significantly while maintaining sufficient precision for CoMP operations through intelligent data selection and compression

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2434835B1Coordinated multi-point transmission COMP data and signalling on X2-interface using additional VLAN identifier
Publication Date: 2013.07.10 DEUTSCHE TELEKOM AG
  • EP2434835B1 patent drawingFigure 1
  • EP2434835B1 patent drawingFigure 2a
  • EP2434835B1 patent drawingFigure 2b

AI summary

The invention provides a mobile communication method and system in a network using coordinated multipoint, CoMP, transmission, the network comprising at least one base station serving a plurality of mobile terminals. According to the invention, the method is characterized in that each network data packet on X2-interface is tagged with an additional VLAN identifier according to IEEE 802.19 Ethernet.