Dynamic Fronthaul Load Reduction in Centralized Radio Access Networks
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Solution Overview
Problem
Conventional Centralized Radio Access Network (CRAN) architectures face flexibility and scalability issues due to the burden of signal processing operations at central units, particularly with algorithms like adaptive beamforming and network coordination, which require significant modifications and limit the number of remote units that can be connected, and existing frequency-domain transmission methods do not adequately reduce data rates over fiber links to meet modern requirements.
Innovation Solution
The system dynamically reduces fronthaul load by transmitting only part of the control data from the central unit, with the remaining control data generated and processed within the remote units, using techniques such as pseudo-random sequences, synchronization data, and multiplexing to combine control and information data for transmission in the frequency domain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If signal processing operations are performed at central units in conventional CRAN architectures, then coordination algorithms can be implemented, but the system complexity and processing burden at central units increases
Solution Approach 1:
The patent segments the control data into two parts: time-varying control data transmitted from central units, and time-invariant control data generated locally at remote units. This segmentation reduces the processing burden at central units while maintaining coordination capabilities, as time-invariant data no longer needs to be processed and transmitted centrally.
Solution Approach 2:
The patent extracts the time-invariant control data from the central unit processing function and relocates its generation to remote units. This extraction removes the redundant transmission and processing of static control data at central units, reducing system complexity while preserving the necessary coordination functionality.
2Adaptability or versatility
If more remote units are connected to a central unit, then network coverage increases, but the transmission capacity bottleneck on fiber links worsens
Solution Approach 1:
The patent extracts and removes the time-invariant control data from the transmission stream between central units and remote units. By eliminating this redundant static data transmission, the overall data rate on fiber links is reduced, allowing more remote units to be connected without saturating the transmission capacity.
Solution Approach 2:
The patent changes the parameter of control data transmission by separating time-varying and time-invariant components. This parameter change transforms the transmission requirement from sending complete control data sets to only transmitting the necessary time-varying portions, effectively reducing the data rate and increasing fiber link capacity for supporting more remote units.
3Loss of information
If control data is fully transmitted from central units to remote units, then all control information is available, but the data rate over fiber links increases
Solution Approach 1:
The patent extracts the time-invariant control data from the transmission stream and generates it locally at remote units. This extraction ensures that no control information is lost (as it is generated locally with the same values) while significantly reducing the data rate over fiber links by eliminating redundant transmission of static control data.
Solution Approach 2:
The patent implements a copying mechanism where remote units locally generate copies of time-invariant control data instead of receiving them through transmission. This copying approach ensures data availability identical to full transmission while reducing fiber link data rate by eliminating the transmission path for these static values.
Data Source
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AI summary
A method is proposed of arranging, in a mobile communication network (100), transmission of data (S*INFOi,n,S*CTRLn) between user equipments (UEi) and a base station (BS) comprising a central unit (CU) and at least one remote unit (RUj) associated therewith. Said data (S*INFOi,n,S*CTRLn) comprise information data (S*INFOi,n) and, associated with the information data (S*INFOi,n), first control data (S*CTRL,1n) substantially time-varying over a scheduling time period, and second control data (S*CTRL,2n) substantially time-unvarying over said scheduling time period. The method comprises: at the central unit (CU) side, transmitting said information data (S*INFOi,n) and said first control data (S*CTRL,1n) to the at least one remote unit (RUj), and at the at least one selected remote unit (RUj) side, receiving said information data (S*INFOi,n) and said first control data (S*CTRL,1n) from the central unit (CU), generating the second control data (S*CTRL,2n), combining the generated second control data (S*CTRL,2n) with said received information (S*INFOi,n) and first control (S*CTRL,1n) data into said data (S*INFOi,n,S*CTRLn), and transmitting said data (S*INFOi,n,S*CTRLn) to a selected user equipment (UEi).