Relay Node Handover in LTE-Advanced Networks
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Solution Overview
Problem
In LTE-Advanced wireless communication systems, the introduction of relay nodes complicates handover processes due to uncertainties in interface operations, particularly with the X2 interface, leading to challenges in delivering messages to the correct relay node and determining appropriate handover types for user equipment.
Innovation Solution
A method and apparatus that receive information from a relay node about new neighboring nodes, determine parameter information, establish connections if necessary, and manage access to these connections to facilitate handover processes, ensuring correct routing of messages and handover decisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If relay nodes are introduced to extend coverage and enhance capacity, then coverage area and cell capacity are improved, but interface operation complexity and message delivery reliability deteriorate
Solution Approach 1:
The patent introduces a proxy mechanism where the donor eNodeB acts as an intermediary for relay nodes. When a relay node needs to communicate with neighboring nodes, the donor eNodeB proxies these communications by sending messages to the correct relay node based on relay node identification information embedded in the messages. This resolves the reliability issue by ensuring messages are delivered to the correct relay node despite the complex multi-node interface operations.
2Area of stationary object
If relay nodes are introduced to extend coverage and enhance capacity, then coverage area and cell capacity are improved, but device complexity and operation difficulty worsen
Solution Approach 1:
The donor eNodeB serves as a mediator that simplifies interface operations for relay nodes. Instead of requiring each relay node to directly manage complex point-to-point X2 interfaces with multiple neighboring nodes, the donor eNodeB centralizes this functionality by proxying communications and making handover decisions based on relay node identification information.
Solution Approach 2:
The patent enables the X2 interface to function in multiple modes: direct point-to-point communication between eNodeBs and proxied communication through donor eNodeBs for relay nodes. This multi-functionality allows the same interface infrastructure to support both traditional and relay-based architectures without requiring separate complex management systems.
3Ease of operation
If relay nodes share eNB identification with donor base station, then neighbor node identification and communication are simplified, but handover type determination and message routing become uncertain
Solution Approach 1:
The patent applies different identification rules at different levels: relay nodes share the donor eNodeB's eNB ID for neighbor discovery and initial communication (simplifying operations), but include specific relay node identification information in messages for precise routing and handover decisions (ensuring reliability). This local differentiation resolves the contradiction between ease of operation and decision reliability.
4Device complexity
If X2 interface operates as point-to-point as originally designed, then interface simplicity is maintained, but relay node message delivery and handover initiation become problematic
Solution Approach 1:
The X2 interface is designed to support both traditional point-to-point eNodeB communications and proxied relay node communications through the donor eNodeB. This multi-functionality allows the interface to maintain its original simple point-to-point design while accommodating relay nodes by having the donor eNodeB act as an intermediary that forwards messages to the appropriate relay nodes.
Data Source
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AI summary
There is a method comprising receiving information from a relay node associated with a first node. The information comprises an indication of at least one second node. The method also comprises determining parameter information of the at least one second node on the basis of the indication.