Universal
Serial Bus, also known as USB, has become the interface of choice for
computer enthusiasts for a variety of reasons including speed, ease of
use and availability. When using USB, however, you are limited to a 16
foot maximum distance before encountering signal loss and degradation.
You have a variety of options available to increase this distance,
however, depending on how far you need to go and what price you are
willing to spend to extend the distance to your USB device.
For the past ten years USB and FireWire have struggled to dominate the
desktop interface market. Until five years ago, because of the
relatively fast 400 Mbps offered by FireWire, USB, jokingly referred to
as Ultra Slow Bandwidth, was relegated to low-bandwidth applications
such as keyboards and mice. At the end of 2001, however, USB dealt a
fatal blow to FireWire with the release of the new USB 2.0 standard
offering a maximum speed of 480 Mbps, faster than the theoretical limit
of FireWire (though, in practice, usually slower).
It seems that USB has essentially won the standards battle with
FireWire because of its relative low-cost and high availability. The
limitation of USB (both the 1.1 and 2.0 standards popular today) is the
16 foot limit. When you have more than 16 feet between your computer
and your USB device you will see significant degradation in the signal
that can cause problems ranging from slower transmission speeds to an
entirely dropped connection. This causes problems for people who want
to run a USB cable to a printer located in another room, to a
presentation keyboard/mouse combo or any other USB device that may be
in a remote location.
The cheapest (and arguably easiest) way to extend the distance to your
USB device is by using a USB Active Extension Cable. These cables have
built-in USB repeaters that actually boost the USB signal, allowing you
to go further than the 16 foot maximum distance. The most common length
for these cables is 16 feet and you can chain up to four of these
together with no loss in signal. Assuming you are using the longest USB
device cable available (also 16 feet), USB Active Extension Cables
allow for a maximum distance of 80 feet between your computer and USB
device. They are available in USB 1.1 (12 Mbps) and USB 2.0 (480 Mbps).
For most USB extensions 80 feet is long enough, but what if you need to
go further? Super USB Extenders allow you to extend the distance to
your USB devices up to 150 feet with no loss in signal. The Super USB
Extender uses similar technology for the male and female interfaces,
but rather than have a regular USB cable in the middle, it uses a Cat 5
cable (also known as a networking cable). The advantage of Super USB
Extenders, other than the increased maximum distance, is the ability to
create a custom length. If you need to go 63 feet, for example, you can
simply use a Super USB Extender with a 63 foot Cat 5 Cable between the
booster and receiver. Super USB Extenders are also available in USB 1.1
and 2.0 interfaces.
If you are looking for a connection beyond 150 feet, many manufacturers
offer a special Super USB Extender capable of USB transfer with no
signal loss at 330 feet, though this is limited to USB 1.1. Black Box
has created a USB 1.1 extender capable of transmission up to 1000 feet
without signal loss, perfect for connecting your computer to a security
camera or webcam hundreds of feet away from your computer.
Another exciting innovation for USB extension technology is the pending
release of Wireless USB. Wireless USB hubs and devices are anticipated
to show up in early 2006 with maximum distances over 100 feet. Keep in
mind that this is the first release and as the technology matures this
distance limitation will inevitably be lifted in favor of much further
distances.
