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USB Goes Wireless 

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PCQ Bureau
New Update

Wireless USB is exactly what it sounds-a logical extension of the popular interface standard from the wired world to the wireless. It would be unnecessary to explain the motivation behind such a change-everything else being the same, what would you rather have: A wireless device and the freedom that comes with it or a wired one that limits you to a certain area? Well, if you want wires, then you are in minority!

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Intel is at the forefront of the group that is working on the WUSB (Wireless USB) specification. The group also includes Agere Systems, Hewlett-Packard, Microsoft, NEC, Philips Semiconductors and Samsung Electronics. Intel (along with the other members of the WUSB group) has decided to break away from the work being done under the IEEE umbrella because of little progress on the specification since last year. 

WUSB is based on the UWB (Ultra WideBand) efforts of MBOA (MultiBand OFDM Alliance) of which Intel is an integral part. It is designed to function similar to (wired) USB. A typical WUSB setup (called a WUSB cluster) would consist of a host (for example, a computer) with one or more devices attached to it. The host is responsible for controlling communication with the devices attached to it, and allotting them timeslots for data transfer. A host can have a maximum of 127 devices attached to it. Also, supported is limited host capabilities for devices, such as USB On-The-Go that enables devices to act as hosts for other devices under certain conditions. Essentially, this eliminates the need of a central authority (host) to mediate between your devices and allows, say, your digital camera (device) to bypass your computer (host) and print directly to your printer (device). It also means that devices within a cluster can access data outside the cluster by acting as limited hosts for devices they wish to connect to. The exact details of the number of clusters that can co-exist in an area are yet to be worked out.

The initial goal is to provide WUSB devices throughput that's as fast as the (wired) USB 2.0 specification, ie, devices capable of speeds up to 480 Mbps, up to a distance of 10 meters. This top speed would go down as the distance increases. This makes WUSB ideal for applications that require transfer of huge amounts of data without the wire. WUSB hosts streaming HDTV to multiple devices within a small area is not ruled out either, especially , with the aim to improve the top speeds to 1 Gbps. This sort of application could result in most PC connected devices to switch to WUSB from whatever their current interfaces are. 

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WUSB is designed to be backward compatible with (wired) USB 2.0. Many are seeing WUSB as a rival to Bluetooth. But, it remains to be seen how valid that comparison is. There's definitely no comparing their speed-to say that USB is way ahead would be an understatement. But, for WUSB to find its way into devices such as mobile phones and remote controls, aka Bluetooth, it would need to be cost effective as well as light on power consumption. The targeted power consumption of initial WUSB devices is around 300 mW, with a goal to push it down to 100 mW, which is nowhere near as efficient as the Bluetooth devices available, even with the lower of the two targets. 

Direct Hit!
Applies to: Desktop PC users
USP: Extension of the most popular standard

In the wired world, ownership of devices is hardly an issue-a mouse belongs to the computer it is connected to. But, what happens when a WUSB mouse has 25 computers within its range? Special provisions have been made to ensure that the device is connected to only the computer (host) you want it to. Efforts are underway to ensure that this process is as easy for the user as possible-plug and play without the plug!

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Work on the first WUSB specification is expected to complete by the end of this year with WUSB-based products coming out sometime next year. Initial products may include add-on cards that could be plugged into existing computers to make them WUSB enabled, with the future clearly being motherboards with embedded WUSB support.

One for the future it seems, but again, a year is a long time as far as technology is concerned.

Kunal Dua

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