Understanding USB Technology

Universal Serial Bus devices have been around since 1995. In computeryears that seems like a lifetime. In that lifetime we've seen two distinct generations of USB technology – USB 1.0 and USB 2.0, and now we're entering the era of USB 3.0. This article describes thehistory of USB, technical differences between the various iterations and the future of USB technology. It will also help you update an oldcomputer for USB 2.0 support.

What is USB?

USB stands for Universal Serial Bus. USB interfaces peripheral devices, like a printer, with a host computer. USB features a standardized plug for attaching various devices. The plug and play nature of USB allows devices to be attached to a computer or notebookwithout restarting the operating system. USB has a sister technology found with many cell phones and digital cameras called Micro-USB. USB technology allows for lower power consumption and higher data transferrates between devices.

How to identify which USB technology your computer uses

When you plug in a compatible USB 2.0 device into a USB 1.x port yourcomputer will inform you that the device could perform faster if youhad a USB 2.0 port. This doesn't mean the device won't work, but due tothe technology differences between USB 2.0 and USB 1.x, the bandwidthbetween the devices would be less than adequate.

You can also figure out if your computer has USB 2.0 by opening theDevice Manager from the Control Panel, click on the Universal Serial BusControllers, and look for the word "enhanced" to describe thecontrollers installed on your system. Not all of the controllers willsay this but you should see at least one that says something like"Standard Enhanced PCI to USB Host Controller". The language may varybut if you have the word "enhanced" in there somewhere then you have USB2.0 ports on your computer. It is entirely possible for you to have USB2.0 ports in the rear of the computer, but only USB 1.x ports in thefront (or vice-versa).

Technical differences between USB technologies

The biggest difference between USB technologies exist in the datatransfer rates. The earliest USB 1.x technology had a low speed of 1.5Mb per second and a high speed of 12Mb per second. This was indeed animprovement on previous technologies for data transfer, and alloweddevices like external optical drives and external hard drives to performmuch faster.

USB 2.0 technology was unveiled in 2000 and then made standard by the USB-IF in 2001. This version upped the speed considerably to 480Mb persecond of high speed data transfer. Around the same time USB 2.0 cameonto the market, they also brought out the Mini B plugand receptacle – a connector commonly found in MP3 players and othersmall electronic devices. USB 2.0 has stood the test of time, gainingimprovements throughout the years, but staying relatively the same.


There is a technology which co-exists with USB 2.0, the certified wireless USB technology or WUSB. Imagine connecting your printer,scanner, keyboard, mouse, (etc) without any kind of cables between thedevices! WUSB is an extension of the Universal Bus Protocol And it'sjust a shame that consumers don't see it implemented more often.

As computer hard drives grow in size, processor speeds quicken, andusers move to more robust media like audio and video clips, so too doesthe data transfer technology need to advance and improve. For thisreason, USB 3.0 has been in the works for some time. It is expected tohit the shelves in late 2009 – although an exact date is not known justyet. USB 3.0 will be ten times faster than the current USB 2.0 iteration. This new version will be moving data at a rate of 4.8 Gb per second– in other words, lightning fast.

Each new USB version that comes out still works with the sameconnectors as the previous ones. The backwards compatibility of USB 2.0devices with a USB 1.0 port will remain true for USB 3.0. Many USB 3.0devices and hardware are available, although a lot of motherboards and systems are still sold with USB 2.0 at this time.

History of USB development

If we looked at USB as a family, then the grandfather would be USB1.0, which in 1998 was updated to USB 1.1. This technology slowly tookthe place of PS/2 ports on PC computers, and also made it more viable topush larger amounts of information to printers. The human interactiondevices like the keyboard and mouse soon started to ship with USBconnectors. In 1998, Apple introduced exclusive use of USB ports ontheir iMac. According to Wikipedia, this pushed the technology into themarketplace like never before.

USB devices have some unique features. Did you know one USBcontroller can have 127 devices attached to it? You could accomplishthis by daisy chaining several USB hubs to one another, until you had127 devices attached to a single port on the host computer. (Editor's note: Whether or not the motherboard would provide enough power to theUSB ports to actually have the devices operational is another story!)

USB technology relies on pipes to relay information between theperipheral device and the host computer. These pipes are one way avenuesfor information, with 16 going to the host and 16 coming from thecontroller. Without getting too technical, the pipes are constantlyasking the host controller if any information needs to be pushedthrough. Each USB device has to be installed by a driver when thecomputer is on. If the computer powers off, each of the devices usingUSB technology will reinstall the driver so they can become operable.

In the early version of USB technology, there were two competing hostcontroller device standards. One pushed by Intel called the UniversalHost Controller Interface or UHCI was done away with in USB 2.0 by the Enhanced Host Controller Interface (EHCI). The USB-IF regulates thetechnology behind USB and they demanded there not be competing hostcontroller technology in USB 2.0, as it caused problems for hardwaremanufacturers when working with USB 1.x. As of September 2008, we haveused USB 2.0 as our fully compatible standard, but that will soon changewith USB 3.0. All the old USB devices will still be backwards compatible, meaning you will still be able to attach a USB 2.0 device toa USB 3.0 port on a new computer.

The future of USB


WUSB works on the Ultra-wideband principle of radio technology. It isbased on a wireless data transmission technique to build up a secure and high-speed connection between devices.

Due to the presence of Wireless data transmission, it has low-power consumption and offers high bandwidth to provide a USB-like user experience. Theoretically, WUSB offers a maximum speed of 480 Mbps. The best possible performance is within the working range of 10 meters. But in real time working conditions, it offers around 50-100 Mbps speed at shorter range and performance decreases with increasing distance.

USB 3.0:

USB 3.0 technology incorporates a piece of fiber optic that will work with older copper connections. The move to USB 3.0 should quench the thirst of storage junkies and other savvy users. The move will likely mean very fast transfer rates from portable devices to a desktop. This could facilitate new technology for mobile users, as we can move data quicker between devices.

USB 3.0 is also known as SuperSpeed USB due to the faster datatransfer rates and an amplified maximum bus power. It also has a better power management system so that either the host computer or the USBdevice will start power saving mode when USB enabled devices are not inuse.

It also has the new and better connectors and cables to facilitate speedy data transfer and these connectors are compatible with the earlier USB 2.0 and USB 1.1 standards.

A common problem that is reported in the VIA Arena forums is that people can't have all their USB devices plugged in at the same time and this is doubtless due to the USB ports not being able to cope with thepower requirements. The greatest achievement of SuperSpeed USB is toprovide more power to power-hungry devices that are USB powered, and italso allows USB enabled battery charged devices to charge more quickly.

Although it is certain that USB 2.0 technology is here to stay for atleast the next five years, USB 3.0 has all the potential to replace USB2.0 ports in the future. The faster data transfer speed and powermanagement makes it an ideal option for smaller mobile devices. Inmobile devices, battery life is really important and having USBtechnology that is power efficient is therefore highly attractive.

The future of USB technology hinges on the success of USB 3.0. We'lllikely see this next version enjoy the long shelf life granted to its predecessors.

Author: Viaarena