Network Access Device Backpowering via Subscriber Line

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Solution Overview

Problem

The high costs of supplying and maintaining power for components at intermediate points in fiber-to-the-cabinet (FTTC) and fiber-to-the-distribution point (FTTDP) architectures, particularly in rural areas where fewer customers are served, limit the deployment of these telecommunication network architectures.

Innovation Solution

A communication system that uses customer premises equipment (CPE) to backpower network access devices, such as DSLAM, via the subscriber line, converting POTS control signaling to digital data and utilizing the vacated band for power transmission, allowing the system to bypass components during power failures and prevent power signal leakage through the network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate power sources are installed at intermediate points in FTTC/FTTDP architectures, then network components can be powered reliably, but deployment costs and maintenance complexity increase significantly

Engineering Contradiction:

Improvepower supply reliabilityVSAvoidpower infrastructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The CPE at customer premises provides power to the network access device at the intermediate point through the existing subscriber line, eliminating the need for separate power sources at the intermediate point. The system serves itself by using customer equipment to power network equipment.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The subscriber line serves multiple functions: data transmission, voice communication, and power delivery. By making the subscriber line multi-functional, the patent eliminates the need for dedicated power infrastructure at intermediate points.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If FTTC/FTTDP architectures are deployed in rural areas with fewer customers, then network coverage is expanded, but the cost per customer for power supply and maintenance becomes prohibitively high

Engineering Contradiction:

Improvenetwork coverage capabilityVSAvoiddeployment cost effectiveness

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Each CPE unit independently powers its associated network access device, eliminating the need for centralized power infrastructure. This distributes the power supply responsibility to individual customers, making rural deployment economically viable.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The power supply function is extracted from the network operator's infrastructure and transferred to customer premises equipment. This removes the burden of maintaining power infrastructure at intermediate points, especially beneficial for low-density rural areas.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If the subscriber line is used for power transmission, then separate power infrastructure is eliminated, but power signal leakage through the network must be prevented

Engineering Contradiction:

Improvepower infrastructure complexityVSAvoidpower signal leakage

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

A coupling device acts as an intermediary between the subscriber line and the network access device. This coupling device allows power signals to be transmitted while preventing them from leaking into the network, serving as a protective barrier.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The potential harmful effect of power signal leakage is converted into a controlled power transmission mechanism. The coupling device ensures that what could be harmful (power signals on the subscriber line) becomes beneficial by preventing leakage while enabling power delivery.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces the need for separate power sources at intermediate points, lowers deployment costs, and ensures continuous POTS service during power failures while enabling simultaneous high-speed data transmission, making FTTC and FTTDP architectures more cost-effective and deployable in rural areas.

Implementation Method 1

converting POTS control signaling to digital data and utilizing the vacated band for power transmission

Methodology Applied

Scientific EffectFrequency band conversion and power signal transmission:

Data Source

PatentUS10298778B1Systems and methods for powering network access devices from customer premises equipment

Publication Date: 2019.05.21 ADTRAN INC

AI summary

A communication system has a network access device (NAD) that is designed to deliver Plain Old Telephone Service (POTS) along with high-speed data to Customer Premises Equipment (CPE). The NAD is backpowered by the CPE across a subscriber line. When backpower is provided from the CPE, circuitry (referred to as a “POTS signaling element”) within the network access device converts POTS control signaling to digital data for transmission to the CPE. The band vacated by the POTS control signaling is used for the power signal on the subscriber line. In the absence of backpower, components of the network access device are bypassed, thereby providing POTS in the event of a power failure. The NAD receives advance warning of the backpowering so that it can disable the bypassing in order to prevent the power signal from leaking through the NAD to the network.