Wireless USB
- a summary of the Wireless Universal Serial Bus ( W-USB )
The Wireless Universal Serial Bus (W-USB) is a new technology
that is starting to enter widespread use. With USB now the most successful
interface in PC history, and wireless communications becoming more widespread,
it is almost certain that W-USB will achieve similar levels of success to USB.
The interface is not only convenient to use, but it also offers high levels of
performance. The same will be true for Wireless USB
Performance
Wireless USB offers a high level of performance, and will equal that of the
current USB 2 wired connections. The initial target bandwidth is to achieve a
data rate of 480 Mbps. However the standard has built in future proofing to
allow for even high data rates to be achieved using later generations of the
specification. It is anticipated that speeds of 1 Gbps or more should be
possible.
The only transmission standard that will achieve the very
high data rates required by wireless USB (W-USB) is Ultra Wide Band (UWB). This
technology uses wideband impulse transmission techniques rather than the more
traditional carrier based transmissions that are used everywhere else. In view
of the wide bandwidths used, it is possible for these transmissions to carry
huge levels of data, supporting high data rate streaming using isochronous
transfers
It is intended that W-USB will be able to operate over
distances of up to 10 metres. Additionally they will support cluster
connectivity to the host and device-to-device connectivity.
Radio requirements
One of the major requirements placed upon the chip designers for the radio
interface is that it should not consume much power. With typical PDAs using just
250 to 400 mW without their radio connection and mobile phones using between 200
and 300 mW, adding a Wireless USB ( W-USB) connection should not significantly
increase the current consumption. Battery-powered operation requires reasonable
battery life. This is normally between two and five days for highly mobile
devices and several months for intermittently used devices like remote controls.
The power target for WUSB radio will be introduced at less than 300 mW and
reducing towards a target of 100 mW .
Device association
It is essential that any interconnection made using a Wireless USB (WUSB)
connections should be easy to make. With user expectations set by the wired USB
connections that are widely used and easy to connect, and wireless USB
connection should be just as easy.
Making wireless connections is not always as easy. The
wireless signal may establish connection paths that are not always obvious as a
result of the environment and the overall conditions. It may not always be
obvious when a device is connected. To overcome this, Wireless USB, WUSB,
devices installed for the first time should automatically install drivers and
security features to enable easy operation.
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