Virtual Hub Emulation for USB Connection Distance Extension

Solution Overview

Problem

The existing USB communication interface limitations, such as maximum cable length and number of hubs, restrict the distance between a host and peripheral devices, leading to operational issues with longer cables and the need for expensive additional hubs to extend distance, which are redundant if only for delay compensation.

Innovation Solution

A communication interface hub system that emulates multiple physical hubs using virtual hubs, allowing the host to allocate additional response time and extend the connection distance without the need for redundant physical components, by detecting virtual hubs and reallocating delay budget.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If additional physical hubs are connected in series to extend connection distance, then the maximum connection distance is improved, but the device complexity and cost increase due to redundant hardware components

Engineering Contradiction:

Improveconnection distanceVSAvoidnumber of physical hubs

Core Design Contradiction:

Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent creates virtual copies of physical hubs that emulate the timing characteristics and delay budget allocation of actual hubs. These virtual hubs appear to the host as real hubs would, allowing the system to extend connection distance by allocating additional response time without physically connecting more hub devices. The virtual hub emulation captures the essential functional behavior needed for distance extension while eliminating the hardware redundancy.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/physical connection of additional hubs with a software-based virtual hub emulation mechanism. Instead of physically connecting more hub devices to extend distance, the system uses virtual hub cores that simulate hub behavior and manage delay budget allocation through software control, thereby substituting physical hardware expansion with a more efficient virtual implementation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of time

If additional physical hubs are added to compensate for cable delay, then the response time budget is improved, but the hardware cost increases

Engineering Contradiction:

Improveresponse time budgetVSAvoidhardware cost

Core Design Contradiction:

Loss of timeVSEase of manufacture

Solution Approach 1:

The patent creates virtual copies of physical hubs that emulate the timing characteristics and delay budget allocation of actual hubs. These virtual hubs appear to the host as real hubs would, allowing the system to extend connection distance by allocating additional response time without physically connecting more hub devices. The virtual hub emulation captures the essential functional behavior needed for distance extension while eliminating the hardware redundancy.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces expensive physical hub components with lightweight virtual hub emulations that consume minimal hardware resources. The virtual hubs are implemented through software or firmware that requires significantly fewer components than physical hubs, making the solution cost-effective for extending connection distance without the need for multiple expensive hub devices.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Device complexity

If virtual hubs are used to extend distance, then the device complexity is reduced, but the host must allocate additional response time

Engineering Contradiction:

Improvenumber of physical componentsVSAvoidhost response time allocation

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The patent creates virtual copies of physical hubs that emulate the timing characteristics and delay budget allocation of actual hubs. These virtual hubs appear to the host as real hubs would, allowing the system to extend connection distance by allocating additional response time without physically connecting more hub devices. The virtual hub emulation captures the essential functional behavior needed for distance extension while eliminating the hardware redundancy.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS8990470B1Virtual hubs for communication interface

Publication Date: 2015.03.24 MAXIM INTEGRATED PROD INC

AI summary

A communication interface hub includes multiple ports, where one of the ports is an upstream port operative to be in direct and/or indirect communication with a host and at least one other of the ports is a downstream port operative to be in direct and/or indirect communication with at least one device. At least one hub core is coupled to the ports and implements at least one physical hub, and at least one virtual hub core is coupled to the ports and implements at least one virtual hub. The virtual hub is detectable as at least one physical hub by the host to cause the host to allocate an additional time delay in waiting for responses to signals output by the host.