CPRI and Ethernet Signal Delivery Over Optical Networks

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Solution Overview

Problem

Current communication networks face challenges in efficiently delivering high-rate Common Public Radio Interface (CPRI) and Ethernet signals over optical networks, particularly due to limitations in data rate and compatibility with existing CPRI specifications, leading to increased costs and potential errors in synchronization and clocking.

Innovation Solution

The method involves receiving input frames with data and synchronization symbols, mapping characters into communication frames at a lower data rate, and reconstructing the frames by discarding synchronization symbols, allowing for efficient transmission and synchronization of CPRI and Ethernet signals over optical networks using OTN structures, including OPUflex and OPU2r, and employing clock recovery techniques to maintain signal integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If CPRI signals are transmitted over optical networks using traditional mapping schemes, then data rate compatibility is maintained, but network cost increases and synchronization errors occur

Engineering Contradiction:
Improvesynchronization accuracyVSAvoidnetwork cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the data rate parameter of CPRI signals to match OTN network capabilities. By converting high-rate CPRI signals to lower data rates compatible with OTN networks, the system achieves reliable transmission over optical infrastructure without requiring expensive high-speed optical equipment, thus reducing network cost while maintaining synchronization accuracy through rate-matched mapping

Inventive Principle:
Principle #35Parameter changes

2Productivity

If high-rate CPRI signals are delivered over optical networks, then data transmission capacity increases, but synchronization stability deteriorates

Engineering Contradiction:
Improvedata transmission capacityVSAvoidsynchronization stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent introduces an intermediary conversion process that translates high-rate CPRI signals into OTN-compatible lower-rate signals for transmission, then reconstructs them at the destination. This intermediary rate conversion acts as a buffer that maintains synchronization stability by using OTN's robust clock recovery mechanisms, while still enabling high data transmission capacity through efficient bandwidth utilization

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If CPRI synchronization symbols are transmitted over OTN, then clock recovery is maintained, but overhead increases and efficiency decreases

Engineering Contradiction:
Improveclock recovery accuracyVSAvoidsignal overhead
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent extracts and removes CPRI-specific synchronization symbols before mapping signals to OTN frames, as these symbols are incompatible with OTN's framing structure. Instead, the system leverages OTN's native overhead fields and pointer mechanisms for synchronization, thereby eliminating redundant overhead while maintaining clock recovery accuracy through OTN's established synchronization protocols

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If traditional CPRI mapping schemes are used over OTN, then protocol compatibility is maintained, but transmission efficiency decreases

Engineering Contradiction:
Improveprotocol compatibilityVSAvoidtransmission efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent changes the mapping parameters to optimize for OTN's frame structure and transmission characteristics. By adapting the mapping scheme to align with OTN's synchronous transfer mode and overhead structure, the system achieves improved transmission efficiency through better bandwidth utilization and reduced overhead, while maintaining protocol compatibility through standardized interface mappings

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10044471B2Delivering CPRI and ethernet signals over optical networks
Publication Date: 2018.08.07 TERA PASS LTD

AI summary

A method for passing communications over an Optical Transport Network (OTN) from a first communication interface to a second communication interface. The first interface extracts characters from received data symbols, maps the characters into OTN communication frames and discards the synchronization symbols. The mapping is performed using a Bit-synchronous Mapping Procedure (BMP), while filling some locations in the OTN frames with stuffing characters, so that the rate of the characters matches a desired rate of the OTN communication frames. The characters are extracted from the communication frames in the second communication interface by synchronizing to the mapped input frames independently of the synchronization symbols. The input frames are reconstructed to produce reconstructed input frames including the data symbols and the synchronization symbols, by re-encoding the extracted characters. In some embodiments, data from Ethernet frames is passed along with the extracted characters in the OTN frames.