Universal Serial Bus (USB)

USB - Universal Serial Bus - is a standard for connecting additional equipment to your computer, like printers, scanners, webcam's, digital camera's, keyboards, mouse, harddisks, etc.

It was supposed to solve all the confusion and issues on PC ports. Well it didn't ... as with all standards: confusion became even worse.

Apple introduced a similar product years ago called FireWire, the direct competition of USB 2.0. That's not all, within the USB standard we also have USB 1.1, USB 2.0, HiSpeed, FullSpeed, and LowSpeed.

So what now?

Tip: not all Windows versions can deal with USB ports, for example Windows 95 and Windows NT 4.0.

Tip: Keep in mind that your BIOS, by default, does not support a USB keyboard. Menaing: that if you boot your PC while having a USB keyboard, you will NOT be able to modify anything! As a matter of fact: you won't even be able to get in to the BIOS! So first sue your old PS/2 keyboard to go into the BIOS and set "USB Keyboard Support" to enabled!

Today just about every PC comes with Universal SerialBus, or USB ports. In fact, many computers will even have additional USB ports located on the front of the tower, in additional to two standard USB ports at the back. In the late 1990s, a few computer manufacturers started including USB support in their new systems, but today USB has become a standard connection port for many devices such as keyboards, mice, joysticks and digital cameras to name but a few USB-enabled devices. USB is able to support and is supported by a large range of products. Adding to the appeal of USB is that it is supported at the operating system level, and compared to alternative ports such aspraallel orserial ports, USB is very user-friendly. When USB first started appearing in the marketplace, it was (and still is) referred to as a plug-and-play port because of its ease of use. Consumers without a lot of technical or hardware knowledge were able to easily connect USB devices to their computer. You no longer needed to turn the computer off to install the devices either. You simply plug them in and go. USB devices can also be used across multiple platforms. USB works on Windows andMac, plus can be used with other operating systems, such as Linux, for example, with a reliable degree of success. Before USB, connecting devices to your system was often a hassle. Modems and digital cameras were connected via the serial porlwhich was quite slow, as only 1 bit is transmitted at a time through a serial port. While printers generally required a parallel printer port, which is able to receive more than one bit at a time — that is, it receives several bits in parallel. Most systems provided two serial ports and a parallel printer port. If you had several devices, unhooking one device and setting up the software and drives to use another device could often be problematic for the user. The introduction of USB ended many of the headaches associated with needing to use serial ports and parallel printer ports. USB offered consumers the option to connect up to 127 devices, either directly or through the use of a USBhub. It was much faster since USB supports data transfer rates of 12 Mbps for disk drives and other high-speed throughput and 1.5Mbps for devices that need less bandwidth. Additionally, consumers can literally plug almost any USB device into their computer, and Windows will detect it and automatically set-up the hardware settings for the device. Once that device has been installed you can remove it from your system and the next time you plug it in, Windows will automatically detect it.

USB 1x

First released in 1996, the original USB 1.0standard offered data rates of 1.5 Mbps. The USB 1.1 standard followed with two data rates: 12 Mbps for devices such as disk drives that need high-speed throughput and 1.5 Mbps for devices such as joysticks that need much less bandwidth.

USB 2x

In 2002 a newer specification USB 2.0 also called Hi-Speed USB 2.0, was introduced. It increased the data transfer rate for PC to USB device to 480 Mbps, which is 40 times faster than the USB 1.1 specification. With the increased bandwidth, high throughput peripherals such as digital cameras, CD burners and video equipment could now be connected with USB. It also allowed for multiple high-speed devices to run simultaneously. Another important feature of USB 2.0 is that it supports Windows XP through Windows update.

USB OTG

USB On-the-Go (OTG) addresses the need for devices to communicate directly for mobile connectivity. USB OTG allows consumers to connect mobile devices without a PC. For example, USB OTG lets consumers plug their digital camera directly into a compliant printer and print directly from the camera, removing the need to go through the computer. Similarly, a PDA keyboard with a USB OTG interface can communicatea with any brand PDA that has a USB OTG interface.

USB-OTG also provides limited host capability to communicate with selected other USB peripherals, a small USB connector to fit the mobile form factor and low power features to preserve battery life. USB OTG is a supplement to the USB 2.0 specification.

Types of USB Connectors

Currently, there are four types of USB connectors: Type A, Type B, mini-A and mini-B and are supported by the different USB specifications (USB 1, USB 2 and USB-OTG).

USB A (Host)

Often referred to as the downstream connector, the Type A USB connector is rectangular in shape and is the one you use to plug into the CPU or USB hub.

USB B (Device)

Also called the upstream connector, the Type B USB connector is more box-shaped and is the end that attaches directly to the device (such as a printer or digital camera).

USB 1.1 specifies the Type A and Type B.

Mini-B

The USB 2.0 connector was too large for many of the new handheld devices, such as PDAs and cell phones. The mini-B was introduced to enable consumers to take advantage of USB PC connectivity for these smaller devices.

USB 2.0 specifies the Type A, Type B and mini-B.

Mini-A

With the need to connect mobile devices without the aid of a computer, the mini-A port was designed to connect the new generation of smaller mobile devices.

USB OTG specifies the mini-A.

Certified Wireless USB

With an estimated 2 billion plus USB connected devices in the world and a growing interest in wireless computing, it's no surprise that development has turned to wireless USB. The USB Implementers Forum has introduced Certified Wireless USB the newest extension to the USB technology. Wireless USB applies wireless technology to existing USB standards to enable wireless consumers to still use USB devices without the mess of wires and worry of cords. Still in its infancy, the Wireless USB specifications were made available to the public only in May 2005.

Wireless USB is based on the WiMedia MAConvergence Architecture, using the WiMedia Alliance's MB-OFDM ultra wideband MAC and PHY. It delivers speeds equivalent to wired Hi-Speed USB, with bandwidths of 480Mbs at 3 meters and 110 Mbs at 10 meters.