Relay Node Coverage Enhancement for Random Access
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Solution Overview
Problem
In 5G and LTE networks, initial access failures occur due to UEs being too far from access points or experiencing coverage outages, leading to unsuccessful random access procedures, particularly on the physical random-access channel, which limits connectivity and increases resource wastage.
Innovation Solution
Implementing a coverage enhancement procedure using a relay node that assists in the random access procedure by triggering a coverage-enhanced mode, allowing the UE to transmit random access messages over multiple radio resources and increasing beam gain, without tunneling data through the relay node, to improve link budget and success rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a UE transmits random access messages using conventional procedures, then the procedure is simple and quick, but the success rate is low when the UE is far from the access point or in outage
Solution Approach 1:
A relay node is introduced as an intermediary between the UE and the access point. The relay node receives random access messages from the UE, processes them, and forwards them to the access point, enabling successful communication when direct transmission fails due to distance or outage conditions.
Solution Approach 2:
The random access procedure is segmented into multiple stages: initial transmission by UE, reception and processing by relay node, and forward transmission to access point. This segmentation allows the complex procedure to be managed in discrete, controllable steps that can be independently optimized.
2Area of stationary object
If radio resource aggregation is increased to extend coverage, then the coverage area expands, but the resource consumption and power usage increase
Solution Approach 1:
Radio resource aggregation is applied partially - only when and where needed for coverage extension. The relay node selectively aggregates radio resources based on signal quality metrics and coverage requirements, rather than continuously maximizing resource usage, thereby extending coverage while controlling power consumption.
Solution Approach 2:
The system dynamically adjusts the level of radio resource aggregation based on real-time conditions such as signal strength, coverage requirements, and power availability. This dynamic adaptation allows the system to optimize between coverage extension and energy consumption rather than using a fixed aggressive aggregation strategy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the likelihood of successful random access procedures, extends coverage, and reduces resource wastage by autonomously adjusting radio resource aggregation and beam gain, while maintaining legacy transparency and minimizing relay node power consumption.
Implementation Method 1
increasing beam gain
Data Source
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AI summary
There is provided a method at a first radio device, comprising: determining that a random access -procedure between a second radio device and a third radio device is not successful; and informing at least one of the third radio device and the second radio device to trigger a coverage enhancement -procedure for performing the random access -procedure.