PoE Switch Power Allocation Without Hardware Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In power over Ethernet (PoE) systems, some Ethernet switches lack hardware support to detect powered devices without enabling power, leading to inefficient power allocation and potential overload, especially in switches with a large number of ports, which can result in failure to meet IEEE 802.3af standards and unfair allocation of power.

Innovation Solution

A method that initializes power allocation by setting each port's configuration power to 0 Watts, enabling power in a single step, and reallocating power based on device detection, priority, and available capacity, ensuring fair distribution and preventing overload by disabling lower priority ports if necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If power is pre-allocated to all ports before detection in switches without separate detection capability, then power allocation can be performed, but power capacity is quickly reduced to zero and ports cannot be enabled even when capacity exists

Engineering Contradiction:

Improvepower allocation efficiencyVSAvoidpower capacity utilization

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary power allocation to ports based on detected powered devices before actually enabling power delivery. The system identifies which ports have powered devices connected and pre-allocates power reserves to those specific ports, rather than allocating to all ports. This preliminary action ensures that when power is enabled, the allocation is already optimized and won't immediately deplete capacity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies different power allocation strategies to different ports based on local conditions. Instead of uniform allocation across all ports, the system detects which specific ports have powered devices and applies power pre-allocation only to those local locations. This localized approach prevents unnecessary power reservation at ports without devices while ensuring adequate capacity at active ports.

Inventive Principle:

Principle #3Local quality

2Device complexity

If power is enabled in a single indivisible step without separate detection, then hardware operation is simplified, but fair and efficient power allocation becomes difficult

Engineering Contradiction:

Improvehardware control mechanismVSAvoidpower allocation fairness

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The patent segments the power allocation process into distinct phases: detection phase, pre-allocation phase, and enablement phase. Even though hardware enables power in a single step, the software performs sequential operations - first detecting powered devices on each port, then pre-allocating power reserves to identified ports, and finally enabling power. This segmentation allows fair allocation logic to be applied before the indivisible enablement occurs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system performs preliminary detection and power reserve allocation before the indivisible enablement step. By detecting powered devices and allocating power reserves in advance, the system ensures that when the single-step enablement occurs, the allocation is already fair and efficient. The preliminary actions prepare the system state so that the simplified hardware operation doesn't compromise allocation fairness.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If power is pre-allocated assuming each enabled port has a powered device, then allocation can proceed, but remaining power capacity quickly reduces to zero

Engineering Contradiction:

Improvepower allocation speedVSAvoidavailable power capacity

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies power pre-allocation selectively to specific ports where powered devices are detected, rather than allocating to all enabled ports. The system checks each port locally to determine if a powered device is present, and only then pre-allocates power reserves to that port. This prevents unnecessary power reservation at ports without devices, preserving overall power capacity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system performs preliminary detection of powered devices before pre-allocation. By detecting which ports actually have powered devices connected, the system can pre-allocate power reserves only to those specific ports. This preliminary detection prevents over-allocation to ports without devices, ensuring that remaining power capacity is preserved for actual needs.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8683239B2Managing power allocation to Ethernet ports in the absence of mutually exclusive detection and powering cycles in hardware

Publication Date: 2014.03.25 ARRIS ENTERPRISES LLC

AI summary

A method of allocating power to ports in an Ethernet switch, including: (1) assigning a configuration power to a selected port, wherein the assigned configuration power is less than a power supplied by the selected port to a powered, (2) enabling and powering the selected port in a single indivisible step, (3) determining the power limit of a device coupled to the selected port, (4) comparing the power supplied by the selected port to the device with the configuration power assigned to the selected port, and (5) if the power supplied by the selected port to the device is greater than the configuration power assigned to the selected port, then increasing the configuration power of the selected port to correspond with the power limit of the device.