CPRI C&M Region Allocation for Efficient NB-IoT Transmission

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Solution Overview

Problem

Existing technologies are inefficient in bandwidth utilization when transmitting Narrow Band - Internet of Things (NB-IoT) data over Common Public Radio Interface (CPRI, as NB-IoT data occupies an entire antenna-carrier (AxC) instead of utilizing the Control and Management (C&M) region, leading to underutilization of CPRI capacities.

Innovation Solution

Transmitting NB-IoT data as frequency-domain data within the C&M region of a CPRI frame, utilizing parts of the C&M region instead of an entire AxC, thereby optimizing bandwidth efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If NB-IoT data is transmitted over an entire AxC, then transmission reliability is ensured, but bandwidth efficiency deteriorates

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidbandwidth efficiency
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the CPRI frame into different regions (C&M region and IQ data region) and transmits NB-IoT data specifically in the C&M region rather than occupying the entire AxC. This segmentation allows efficient utilization of available bandwidth while maintaining transmission reliability through dedicated region allocation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different transmission characteristics to different regions of the CPRI frame. The C&M region is specifically optimized for NB-IoT data transmission with appropriate bandwidth allocation, while other regions maintain their original functions, thereby improving overall bandwidth efficiency without compromising reliability.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If NB-IoT data occupies an entire AxC, then data transmission capacity is sufficient, but CPRI capacity utilization deteriorates

Engineering Contradiction:
Improvedata transmission capacityVSAvoidCPRI capacity utilization
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent applies partial action by transmitting NB-IoT data only in the C&M region of the CPRI frame rather than utilizing the entire AxC bandwidth. Since NB-IoT data requires relatively small bandwidth, this partial utilization approach suffices for maintaining data transmission capacity while significantly improving CPRI capacity utilization efficiency.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The C&M region in the CPRI frame is designed to serve multiple functions including control messages, management information, and NB-IoT data transmission. By utilizing this multi-functional region for NB-IoT data, the patent improves overall CPRI capacity utilization without requiring dedicated resources, thereby enhancing productivity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Quantity of substance

If NB-IoT data is transmitted in frequency-domain format, then bandwidth requirements are reduced, but data transformation complexity increases

Engineering Contradiction:
Improvebandwidth requirementsVSAvoiddata transformation complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing the frequency-domain transformation of NB-IoT data before transmission over the CPRI interface. The base station converts time-domain NB-IoT data into frequency-domain representation in advance, which reduces the bandwidth requirements for transmission. Although this adds transformation complexity, the preliminary conversion simplifies the transmission process and optimizes bandwidth utilization.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3698571B1Network device and method for data transmission over common public radio interface
Publication Date: 2025.10.01 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3698571B1 patent drawingFigure 1~2
  • EP3698571B1 patent drawingFigure 3
  • EP3698571B1 patent drawingFigure 4

AI summary

The present disclosure provides a method (200) in a network device for transmission of Narrow Band -Internet of Things (NB-IoT) data between a Radio Equipment Control (REC) node and a Radio Equipment (RE) node over Common Public Radio Interface (CPRI). The method (200) comprises: transmitting (210) the NB-IoT data from the REC node to the RE node or from the RE node to the REC node in a Control and Management (C&M) region of a CPRI frame. The NB-IoT data is frequency-domain data.