Expanding and Extending USB
With the number of connections in the world today estimated to be over 6 billion, USB is by far the most common computer interface with many devices such as keyboards, printers and digital cameras using it as standard.
As the number of USB devices has grown the need to easily access them has also increased. This has meant many users now need to expand and extend the USB connectivity of their laptop or desktop computer.
Expanding allows devices to be shared, split and accessed by more than one computer or enables a computer to connect to multiple USB devices at the same time. Expanding overcomes the problems of the limited number of USB ports often supplied with modern computers, especially smaller laptops and netbooks.
Extending increases the distance USB signals can be sent so a computer doesn't have to be closely situated to the peripheral. This combats one of USB's major limitations in that the standard maximum recommend length for USB cables is 5m due to performance restrictions. However, for some applications for example interactive whiteboard installations, 5m is not always enough so the signals need to be extended.
USB Hubs and Switches
USB switches expand peripheral connectivity by allowing them to be shared with multiple computers. They are a cost effective solution especially useful for devices which need to be accessed by more than one computer, such as printers. They eliminate the need for duplicate devices and multiple cables. Switches alternate between computers as the users decide who has access to the equipment at that particular time.
USB sharing hubs combine the functionality of both a hub and a switch and can serve multiple USB devices between a number of computers at the same time. Just like switches, sharing hubs are ideal for larger, more expensive equipment that needs to be accessed by more than one person at a time, but with the capability that allows users to do this simultaneously.
USB Extension Cables
An alternative to standard 'passive' USB extension cables is a USB Active Extension cable. This cable features built-in electronics which regenerate the USB signal to support distances of 5m. Indeed, you can even daisy-chain several active extension cables together to achieve maximum distances of up to 25m.
The 'plug and play' capability of all extension cables makes them a simple and easy to use solution. They work with both smaller and larger devices such as card readers and printers. USB extension cables are ideal for use with wireless dongles or with products that have built-in USB cables.
USB over CAT5/6 Cable
Commonly used with devices such as interactive whiteboards, extenders are a great solution for connecting devices further away from a host computer than an extension cable would allow. Distances of up to 50m can be achieved; however, USB 2.0 is not usually supported so devices are limited to USB 1.1 performance of up to 11Mbps. Cat.5 USB Extenders are probably the cheapest and easiest solution for connecting a USB device and host computer over great distances.