Distributed Random Access Control for C-RAN Front Haul Bandwidth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In current LTE communication systems, the bandwidth required for the front haul (FH) between the DU and RU increases significantly with the improvement in peak rate, especially in 5G, due to the centralized configuration of Layer 1 to Layer 3 functions on the DU side, leading to inefficiencies in random access (RA) procedures when DU and RU cooperate.
Innovation Solution
A method and device configuration that allows the DU and RU to cooperate during the RA procedure by sharing functions, with the DU acquiring and notifying RACH parameters to the RU, enabling the RU to determine the appropriateness of received RA preambles and transmit RA preamble reception notifications, thereby reducing the processing load on the DU and optimizing bandwidth usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If all Layer 1 to Layer 3 functions are implemented on the DU side, then centralized control and management are improved, but the bandwidth required for front haul connection between DU and RU increases dramatically
Solution Approach 1:
The patent segments the base station functions by implementing Layer 1 (physical layer) functions on the RU side and Layer 2/3 functions on the DU side. This functional segmentation allows the RU to perform local signal processing including random access preamble detection, reducing the amount of data that needs to be transmitted over the front haul connection while maintaining centralized control for higher-layer protocols.
Solution Approach 2:
The patent introduces a new dimension of distributed processing by allowing the RU to independently detect and process random access preambles locally. This creates a multi-dimensional architecture where certain functions are distributed to the edge (RU) while others remain centralized (DU), optimizing the balance between centralized control and bandwidth efficiency.
2Quantity of substance
If Layer 1 functions are implemented on the RU side, then front haul bandwidth is reduced, but the coordination and cooperation between DU and RU during RA procedure becomes more complex
Solution Approach 1:
The patent establishes a feedback mechanism where the RU detects random access preambles and sends detection results to the DU, which then provides random access responses. This feedback loop enables coordinated operation between DU and RU, with each entity performing its designated functions while maintaining synchronization through structured information exchange.
Solution Approach 2:
The patent uses standardized interface protocols as intermediaries between the DU and RU. These interfaces define clear message formats and procedures for random access detection and response, simplifying the coordination complexity by providing a well-defined communication framework that masks the underlying complexity of distributed processing.
3Productivity
If the RU detects RA preambles independently, then processing load on the DU is reduced, but standardization and regulation of the procedure becomes more difficult
Solution Approach 1:
The patent creates a universal standardized procedure for random access that can be applied across different C-RAN deployments. By defining a generic interface and message format that works for various configurations of DU and RU capabilities, the solution achieves both processing efficiency through distributed detection and adaptability through standardized procedures that can be universally implemented.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A communication device used as a first communication device in a wireless communication system including the first communication device, a second communication device communicating with the first communication device, and a user equipment communicating with the first communication device, includes an acquisition unit configured to acquire a parameter used for performing a random access procedure from the second communication device; and a control unit configured to transmit, in the case of receiving a random access preamble from the user equipment in a random access channel indicated by the parameter, information indicating that the random access preamble indicated by the parameter is received from the user equipment to the second communication device.