What is USB 2.0?
USB specification version 2.0 is the next-generation peripheral connection for personal computers. It is intended as an upgrade for USB 1.1. Not only the new standard provides additional bandwidth for multimedia and storage applications but also offers Plug-and-Play capability and full backward compatibility for legacy USB devices.

What is USB Hi-Speed?
USB Hi-Speed is another name for USB 2.0. The official USB Promoter Group didn’t want the new USB 2.0 specification to be seen as a completely new standard, which may confuse consumers. Therefore, USB 2.0 becomes USB Hi-Speed, and USB 1.1 gets a new title as USB Basic Speed.

Who are the participants in the development of USB 2.0?
Intel, Microsoft, Compaq, Hewlett-Packard, Lucent, Philips, NEC. NEC and Philips are two new members that are added to the development of USB 2.0 and to the USB Promoter Group.

How fast is USB 2.0?
USB 2.0 has a raw data rate at 480Mbps, and it is rated 40 times faster than its predecessor interface, USB 1.1, which tops at 12Mbps. Originally, USB 2.0 was intended to go only as fast as 240Mbps, but then, USB 2.0 Promoter Group increased the speed to 480Mbps in October 1999.

How will consumers benefit from USB 2.0?
With speed 40 times more than that of USB 1.1, USB 2.0 broaden the range of external peripherals that can be used on a computer. Even with multiple high-speed peripherals connected to a USB 2.0 bus, the system will less likely to hit the bandwidth bottleneck. The new specification also inherits the current USB’s Plug and Play and hot-swapping capability as well as providing backward compatibility for USB 1.1 hardware, allowing existing user base to upgrade seamlessly.

What are the differences between USB 2.0 and USB 1.1?
Basically, USB 2.0 includes everything that USB 1.1 offers and adds a high-speed mode, which runs at 480Mbps. USB 1.1 supports two speed modes: 1.5 and 12Mbps whereas USB 2.0 has three of them: 1.5, 12 and 480Mbps. USB 2.0 also uses the same USB 1.1 compliant cables to connect high-speed devices. However, classic USB hubs will slow down USB 2.0 devices. In addition, a USB 2.0 host controller is required to enable the high-speed connection with a USB 2.0 device.

USB 2.0 hubs are now given a lot more work to do than USB 1.1 as they need to handle all the traffic from three different speed mode devices. Plugging a USB 1.1 device to a USB 2.0 hub is okay, but connecting a USB 2.0 device to a USB 1.1 hub is prohibited.

Will USB 2.0 replace USB 1.1?
Not entirely, because many products such as generic keyboards, mice, joysticks and audio speakers do not require the faster speed of the new USB 2.0 technology. Only bandwidth-hungry devices, such as webcams and high-capacity storage systems, will need all the speed. However, next-generation systems will come with USB 2 ports rather than USB 1.1.

Will USB 1.1 devices run any faster on a USB 2.0 bus?
No. However, the new USB 2.0 architecture allows more high-speed USB 1.1 devices, such as webcams, audio devices, to share the bandwidth. Developers need to follow USB 2.0 spec in order to design higher speed peripherals that can take advantage of the extra bandwidth. USB 1.1 devices still operate at 12Mbps at full-speed and 1.5Mbps at low-speed on a USB 2.0 bus. Even though USB 1.1 devices won’t run any faster, they can work alongside of USB 2.0 devices on the same bus.

What happen if a USB 2.0 device is plugged into a USB 1.1 system?
The entire bus under the USB 1.1 root hub will slow to 12Mbps. The operating system will probably notify the user about the sub-optimal configuration and recommend for a better course of action.

If several USB 1.1 hubs are connected to a USB 2.0 bus, then each of the USB 1.1 hub will get a full 12Mbps bandwidth.

What is the max. length of a USB 2.0 cable?
5m. However, if you cascade 5 hubs with 5m USB cables, this will allow you to connect a device 30m away.

What do I need to use a USB 2.0 device?
The requirement is similar to that of USB 1.1, but all components will have to be USB 2.0 compliant. A successful USB 2.0 connection requires a USB 2.0 host controller card, a USB 2.0 driver and a USB 2.0 peripheral.

Will USB 2.0 arrive on mobile computers?
Yes, but not in integrated solution on laptops. You will need a USB 2.0 CardBus card. Orange Micro. is shipping USB 2.0 compliant 4-port CardBus card. Eventually, notebook vendors will adapt to USB 2.0 technology, and we will see USB 2.0 ports on laptops. This transition won't happen until 2002 at the earliest.

Which operating systems support USB 2.0? 
Microsoft has released the official USB 2.0 driver for Windows XP and Windows 2000. The version is 5.1.2600. The software is available on-line at Windows Update website. (If you don't have a USB 2.0 card installed in your system, Windows Update won't list the USB 2.0 driver as an update.)

The software company is still considering USB 2.0 support for Windows ME, but it already has decided not to bring USB 2.0 to Windows 98 and Windows 98 SE. If you have Windows 98, you will have to rely on 3rd party USB 2.0 support from USB card manufacturer.

As for Mac users, Orange Micro. and KeySpan are providing USB 2.0 for MacOS X exclusively.

Do USB 1.1 cables work with USB 2.0 devices?
Ideally, yes. USB 2.0 architecture uses the same cables and connectors as USB 1.1 compliant products. Unfortunately, only 3 out of 11 cables on the market are certified as USB 1.1 compliant. You may run into the cables that cause problems connecting high-speed peripherals. To avoid negative user experience, most vendors include USB 2.0 compliant cables with their USB 2 PCI cards and peripherals.

What kind of USB 2.0 devices are available now?
Right now, USB 2.0 has held strong in external storage devices like CD-RW drives and hard drives. Beside applications in storage category, USB 2.0 compliant webcams have yet to arrive in the digital video market. We will also see digital still cameras to equip with the new USB 2.0 interface to speed up the image download process.