Terminal Code Word Conflict Resolution in Optical Networks

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Solution Overview

Problem

In high-speed optical networks using coherent CDMA, the limited availability of spreading codes leads to code word conflicts when multiple service stations access the network simultaneously, preventing normal access and efficient data transmission.

Innovation Solution

A data transmission method where a terminal device selects a code word, encodes an identifier using it, and sends it to a network side device, which broadcasts the identifier to determine if it matches a received identifier, allowing the terminal to encode and transmit data without conflicts by using the selected code word, and optionally compensates for dispersion and frequency offset information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple service stations simultaneously access the network using available spreading codes, then network access capability is improved, but code word conflicts occur because limited spreading codes are allocated to multiple stations

Engineering Contradiction:
Improvenetwork access capabilityVSAvoidcode word conflict
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The terminal device performs preliminary actions by selecting a code word from available code words before actual data transmission, encodes an identifier using the selected code word, and sends it to the network side device for confirmation. This preliminary code word selection and verification process prevents conflicts during simultaneous network access by ensuring code word availability before use.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network side device provides feedback by broadcasting the received identifier back to the terminal device. The terminal device decodes this broadcast identifier and compares it with the originally sent identifier to determine whether the code word is uniquely selected. This feedback mechanism enables conflict detection and resolution, ensuring reliable code word allocation among multiple accessing stations.

Inventive Principle:
Principle #23Feedback

2Productivity

If a terminal device selects and uses a code word for data transmission, then data transmission efficiency is improved, but code word conflicts prevent normal access when multiple stations use the same code word

Engineering Contradiction:
Improvedata transmission efficiencyVSAvoidnormal network access
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The terminal device performs preliminary code word selection and identifier encoding before actual data transmission. By confirming code word availability through the identifier verification process with the network side device, the system ensures that data transmission proceeds only with valid, conflict-free code words, thereby maintaining both efficiency and reliable access.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The feedback mechanism where the network side device broadcasts the received identifier enables the terminal device to verify whether its selected code word is uniquely allocated. This verification ensures that data transmission using the code word will be successful without conflicts, maintaining both transmission efficiency and reliable network access.

Inventive Principle:
Principle #23Feedback

3Quantity of substance

If spreading codes are allocated to multiple service stations to enable simultaneous access, then network capacity is improved, but the limited number of available spreading codes causes conflicts

Engineering Contradiction:
Improvenetwork capacityVSAvoidcode word availability
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The terminal device performs preliminary code word selection from the limited pool of available spreading codes before data transmission. By encoding and sending an identifier using the selected code word for network verification, the system enables multiple stations to efficiently share limited codes without conflicts, effectively increasing network capacity while maintaining code word availability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network side device's feedback through broadcasting the received identifier allows terminal devices to verify code word uniqueness. This feedback mechanism enables the system to maximize the utilization of limited spreading codes by ensuring each allocated code is uniquely assigned, thereby increasing network capacity without causing conflicts.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3540983B1Method for data transmission, terminal device and network side device
Publication Date: 2022.05.04 HUAWEI TECH CO LTD
  • EP3540983B1 patent drawingFigure 1
  • EP3540983B1 patent drawingFigure 2
  • EP3540983B1 patent drawingFigure 3A

AI summary

Embodiments of this application provide a data transmission method, a terminal device, and a network side device. The method includes: selecting, by a terminal device, a first code word from at least one code word; encoding, by the terminal device, a first identifier by using the first code word; sending, by the terminal device, the encoded first identifier to the network side device; receiving, by the terminal device, a second identifier sent by the network side device; decoding, by the terminal device, the second identifier by using the first code word; when the decoded second identifier is the same as the first identifier, encoding, by the terminal device, subsequent data by using the first code word; and sending, by the terminal device, the encoded subsequent data to the network side device. In the embodiments of this application, the terminal device can normally access a network without a code word conflict, and effectively transmit data to the network side device.