Toshiba is putting considerable resources into developing new applications and devices that will elevate Bluetooth to its full potential. Today, Bluetooth is seen as a widely supported short-range wireless interface for cellular phones. For the future, we see it as one of several potential interfaces for home networking and more. Toshiba, together with other Bluetooth promoter companies, has been working hard to realize this pervasive wireless technology since 1998.

This year Toshiba established an internal Bluetooth business development division whose mission is to promulgate the open standard throughout our product line-including notebook computers and semiconductors-as well as work with outside vendors to find new uses for the wireless interface.

Bluetooth was first conceived a wireless interface linking cellular phones to notebook PCs, replacing cables, which required each phone vendor to provide unique drivers for each manufacturer. Clearly, a standard wireless interface such as Bluetooth is the superior solution.

Recent advancements in semiconductor process technology are leading to small, low-power RF and control devices that will make such a wireless interface possible. While cellular phones will be the first application in which Bluetooth will shine, people are starting to realize that Bluetooth can be used to transmit multimedia data among many applications. That will happen once sales of cellular phones using Bluetooth achieve critical mass, enabling module costs to come down significantly. Prices will continue to slide as semiconductor makers switch to standard CMOS process technology for both the baseband and RF portions of the Bluetooth module, a trend that is already taking root.

At the same time, cellular phones and personal digital assistants (PDAs) are getting smarter as they are become more popular. In Japan, for example, the number of cellular phone users surpassed the number of fixed-line users earlier this year, and the i-Mode Internet service from NTT DoCoMo has reached nearly 7 million users after little more than a year. Users will inevitably expect better connectivity to other digital appliances, whether a PC, a set-top box or a PDA.

At Toshiba, we've shown how Bluetooth can play a role in the home or office networking sphere. Earlier this year, we showed how MPEG-4 data from a VCR transmitted in real-time over a 340-kbit/second Bluetooth connection can be displayed on a PC in 320 x 240 format at 15 frames/second. The VCR was linked to a home network server via an IEEE 1394 connection. The home server is responsible for converting the VCR's video signal into the MPEG-4 format, which has better compression and error tolerance suitable for wireless transmission.

That is just a taste of what can be done with Bluetooth. A user, for example, can quickly zap digital still images from a digital camera onto a set-top box so that the image can be viewed on a TV. A still camera can be mounted on a user's front porch, turning it into an observational camera as it sends a live video transmission to a PC or TV. And when digital television gains popularity, Bluetooth can download compressed music files from a digital set-top box directly to a stereo. That last example is only one of many possible uses for Bluetooth as an access point for making online purchases through digital TV.

As a wireless interface, Bluetooth is robust and flexible. It occupies the 2.4-GHz ISM band and transfers data at 1 Mbits/s. Voice data can be sent synchronously at 64 kbits/s, while data can be transferred at 432.6 kbits/s (full-duplex) or at 712 kbits/s (asymmetric). Within a network, the interface can be used either as a point-to-point or point-to-multipoint wireless connection.

Using a fast frequency-hopping scheme, the Bluetooth connection switches frequencies every 625 microseconds. So while performance may drop slightly, there's little chance data communication will be lost if the devices encounter significant interference.

There's also room in the specification to extend the range of Bluetooth. Currently, a Bluetooth module dissipating 1 milliwatt of active power can support a 10-meter range. Increasing the power consumption to 10 mW, however, provides a proportional increase in range of 100 meters.

We're also looking at ways to assure that Bluetooth won't interfere with wireless LANs, paving the way to a true heterogeneous home network. One way is to configure Bluetooth to frequency-hop outside the wireless LAN's frequency band. Another option is to employ a time-sharing scheme that would allow, for example, a PC connected to a wireless LAN to use a Bluetooth-enabled keyboard.

Such a keyboard would be superior to one using an infrared connection because it would not have any line-of-sight restrictions.

But let's be clear about one thing: at this time we don't see Bluetooth as a catch-all networking interface for the home. Bluetooth, for example, doesn't have the bandwidth to carry high-definition video. Even with today's highest speed radio technology, it is still not possible. That function is better left to wired networks like cable or 1394, which can serve as the backbone for home networks.