Flexicom | Das Systemhaus für Identifikationstechnik

USB 2.0 extends the speed of the connection from 12 Mbps on USB 1.1 up to 480 Mbps on USB 2.0, providing an attachment point for next-generation peripherals which complement higher performance PCs and user applications. USB 2.0 is both forward and backward compatible with USB 1.1, resulting in a seamless transition process for the end user. In fact, USB 2.0 uses the same cables and connectors as USB 1.1. USB 2.0 offers a compelling opportunity for peripherals vendors to migrate their USB peripherals to higher performance, while still being able to sell the same peripherals into the huge installed base of USB-capable PCs. USB 2.0 is also expected to lead to the development of higher performance peripherals that will bring new applications to the PC.

USB 1.1's data rate of 12 Mbps is sufficient for many PC peripherals such as telephones, keyboards, mice, digital joysticks, floppy drives, digital speakers, and low-end printers. These peripherals will continue to operate with no change in USB 2.0 systems. The higher bandwidth of USB 2.0 will permit PC peripherals with more functionality, including higher resolution video conferencing cameras, next generation scanners and printers, fast storage units, and faster broadband Internet connections. It will make today's user applications more productive, such as taking the time to download a "roll" of digital photos from a few minutes on USB 1.1 down to a few seconds on USB 2.0. In addition, the higher bandwidth will support the most demanding PC user applications, such as digital image creation and interactive gaming, where multiple high-speed peripherals will be running simultaneously. The higher data rate of USB 2.0 will also open up the possibilities of new and exciting peripherals.

As with USB 1.1, USB 2.0 is expected to eventually be in industry chipsets. Once these chipsets reach high volume, it is expected that USB 2.0 will be about the same cost as USB is today. Because of this, USB 2.0 is expected to supercede USB 1.1, which is already a ubiquitous connector on PC systems today. Also like USB 1.1, USB 2.0 will satisfy the peripheral-interface needs of desktops, mobile systems and other classes of host platforms. To satisfy the needs of power-sensitive applications such as notebook computers, USB 2.0 will provide the same power-management mechanisms as USB 1.1 to allow aggressive management of I/O power consumption. This is expected to allow USB 2.0 to find use even in demanding low-power systems.

USB 2.0 and 1394

I/O connectivity is being further advanced with the IEEE 1394 standard. USB 2.0 and 1394 primarily differ in terms of application focus. The USB 2.0 Promoter group expects USB 2.0 to be the preferred connection for most PC peripherals, whereas IEEE 1394's primary target is audio/visual consumer electronic devices such as digital camcorders, digital VCRs, DVDs, and digital televisions. Both USB 2.0 and 1394 are expected to co-exist on many consumer systems in the future.

USB 2.0 and 1394 differ in application focus because of continuous evolution of the current environment. Today, there is a large and rapidly increasing installed base of USB-capable PCs, and hundreds of USB peripherals in the marketplace that connect to the PC. It is a natural evolution to increase the speed of USB and provide an easy migration path for existing USB peripherals. In the A/V consumer electronics equipment industry, IEEE 1394 is on its way to becoming the dominant connector. Therefore, if a PC wants to connect to one of these devices, it needs an IEEE 1394 connection.

They also support different connection models. USB 2.0 continues to use a low cost host-centric connection model, which is the best solution for a PC connection to PC peripherals. The added capability of a peer-to-peer connection enabled by IEEE 1394, however, allows a PC to connect to a cluster of consumer electronics devices, such as one that might exist in the family room.