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A guide to understanding USB technology

A guide to understanding USB technology

 

A guide to understanding USB technology

Universal Serial Bus devices have been around since 1995. In computer years 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 the history of USB, technical differences between the various iterations and the future of USB technology. It will also help you update an old computer 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 notebook without 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 transfer rates 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 your computer will inform you that the device could perform faster if you had a USB 2.0 port. This doesn't mean the device won't work, but due to the technology differences between USB 2.0 and USB 1.x, the bandwidth between the devices would be less than adequate.

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

Technical differences between USB technologies

The biggest difference between USB technologies exist in the data transfer 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 an improvement on previous technologies for data transfer, and allowed devices like external optical drives and external hard drives to perform much 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 per second of high speed data transfer. Around the same time USB 2.0 came onto the market, they also brought out the Mini B plug and receptacle – a connector commonly found in MP3 players and other small electronic devices. USB 2.0 has stood the test of time, gaining improvements 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 the devices! WUSB is an extension of the Universal Bus Protocol And it's just a shame that consumers don't see it implemented more often.

As computer hard drives grow in size, processor speeds quicken, and users move to more robust media like audio and video clips, so too does the data transfer technology need to advance and improve. For this reason, USB 3.0 has been in the works for some time. It is expected to hit the shelves in late 2009 – although an exact date is not known just yet. 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 same connectors as the previous ones. The backwards compatibility of USB 2.0 devices with a USB 1.0 port will remain true for USB 3.0. Many USB 3.0 devices 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 USB 1.0, which in 1998 was updated to USB 1.1. This technology slowly took the place of PS/2 ports on PC computers, and also made it more viable to push larger amounts of information to printers. The human interaction devices like the keyboard and mouse soon started to ship with USB connectors. In 1998, Apple introduced exclusive use of USB ports on their iMac. According to Wikipedia, this pushed the technology into the marketplace like never before.

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

USB technology relies on pipes to relay information between the peripheral device and the host computer. These pipes are one way avenues for information, with 16 going to the host and 16 coming from the controller. Without getting too technical, the pipes are constantly asking the host controller if any information needs to be pushed through. Each USB device has to be installed by a driver when the computer is on. If the computer powers off, each of the devices using USB technology will reinstall the driver so they can become operable.

In the early version of USB technology, there were two competing host controller device standards. One pushed by Intel called the Universal Host Controller Interface or UHCI was done away with in USB 2.0 by the Enhanced Host Controller Interface (EHCI). The USB-IF regulates the technology behind USB and they demanded there not be competing host controller technology in USB 2.0, as it caused problems for hardware manufacturers when working with USB 1.x. As of September 2008, we have used USB 2.0 as our fully compatible standard, but that will soon change with 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 to a USB 3.0 port on a new computer.

The future of USB

WUSB:

WUSB works on the Ultra-wideband principle of radio technology. It is based 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 data transfer rates and an amplified maximum bus power. It also has a better power management system so that either the host computer or the USB device will start power saving mode when USB enabled devices are not in use.

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 the power requirements. The greatest achievement of SuperSpeed USB is to provide more power to power-hungry devices that are USB powered, and it also allows USB enabled battery charged devices to charge more quickly.

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

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

 

 

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