Everything you need in the palm of your hand

We’ve already got the mobile phone, the all digital camera, and the personal organiser. What more could we want? The whole thing rolled up in one? Dave Wilson went to Cambridge Consultants and found out that they had already thought of that one.

In 1994, designers at Cambridge Consultants (CCL) developed a concept for a `Personal Communicator’ that anticipated the convergence of the telecomms, broadcast and computing industries. The product itself looked very much like a small mobile phone, but the functionality was far greater. It was obvious in 1994 that high bandwidth communications standards would soon emerge. For that reason, CCL designers assumed that future personal communications devices would not only be able to receive and transmit speech, but also moving pictures as well. So, in addition to the two way videophone capability provided courtesy of the device’s large touch screen and built in CCD camera, the Personal Communicator could also act as a still camera as well.

Although it was developed before the World Wide Web emerged as an information source, the Personal Communicator could allow the user to access many sources of information remotely – a weather forecast or a TV listing were seen as typical candidates. At the touch of a button, the data could be presented to the user on the high definition screen contained within the unit. Finally, the Communicator contained a built in personal organiser with such features as an electronic diary and a telephone book.

At the time, it was envisaged that input to the unit would be achieved by a writing stylus. The user would simply unclip the stylus, place it onto the finger, and write on a piece of paper. The stylus would transmit data back to the Communicator via a low-power wireless link.

The device was to be powered by a small thin battery.

Many of the ideas have already become a reality: digital cameras, Internet access, mobile phones, all provide some of the functionality that the designers at CCL embraced in their concept.

How close are we to producing such a highly integrated product? And what technological barriers still need to be crossed before a product can become a reality?

In terms of bandwidth requirements, the DECT digital phone system is already capable of handling the needs of a mobile videophone in use today, offering 1.15MBit/s raw data rate and 700kBit/s useable data rate. This is adequate for still photograph and videophone applications within local area mobility.

In fact Siemens demonstrated a videophone over DECT at this year’s CeBit show in Germany. DECT, however, cannot manage wide area mobility and high speed mobile telephony, because the system is not immune to large multipath effects.

On the hardware front, there are various techniques for recognising significant content in videophone pictures and compressing them. A number of manufacturers now offer single chip coders and decoders for the MPEG standard. One of the latest is MPEG 4, which is a content sensitive coding standard that will allow certain elements in a scene to be updated quickly (such as a face), while other parts (like the background) can be updated slowly.

For the future, the Universal Mobile Telephone System (UMTS), a code division multiplexed system looks set to take centre stage. This system is specified up to 2MBit/s for local mobility and supports a 400kBit/s wide area capability. The launch of the UMTS system, however, is not scheduled until the year 2002.

In 1994, designers were faced with limited options when it came to display technology. Expensive liquid crystal technologies were virtually the only type available, and its cost and power would have made the Communicator highly impractical. Today inexpensive full-colour LCDs are available as are newer technologies such as plastic polymer displays that have been developed at Cambridge Display Technology.

As far as the personal organiser function on the Communicator is concerned, it is already a reality. One need look no further than the Palm Pilot and the Psion handheld computers.

On the handheld computer front, many designers have opted for the Microsoft CE operating system for their designs. On the personal organiser front, it is more common to see proprietary standard operating systems.

Both provide the same sort of user interface, identical, in fact, to that envisaged by the Communicator design team: on screen icons that allow the user to access programs. One potential problem is that neither format is particularly good for viewing data downloaded from the Web – the source for many information needs originally conceived for the Communicator.

For the future, the man machine interface may look entirely different. Voice command, for example, is an obvious alternative to the keyboard or the pen. Unfortunately, to provide a reasonable speed and error rate, today’s voice recognition systems occupy most of the attention of an Intel Pentium II. By the year 2000, however, such capability on a system the size of a mobile phone may be commonplace. And, even if traditional voice recognition is never perfected, future voice recognisers that lip read may provide close to 100% accuracy. Other techniques that might be used for input include eyeball tracking. In the future, an on-screen cursor on a personal communicator could be moved just by looking at the icon. Speech recognition would then be used to open the program behind the icon.

For the communicator vision subsystem, inexpensive colour cameras developed on standard CMOS IC processes would suffice. Although they do not yet provide broadcast quality, the quality gets better each year. Better still, because the cameras are now built on CMOS processes, they can be integrated with a microprocessor and digital signal processor chips – making them very affordable.

Originally, the Communicator sported a remote earpiece. This required a very small radio transmitter which would work at high frequencies to ensure that the antenna would be reasonably small. The designers decided they would need a radio specification for remote access that was very similar to today’s Blue Tooth Specification – a standard for short range radio communication that has been developed by a consortium of Ericcson, Nokia, IBM Intel and Toshiba.

Blue Tooth is analogous to an infra-red link, but without the geometric limitations. It uses the 2.4GHz license exempt band which can be used internationally. It is short range: the transmit power is specified at 1mW which will provide a range up to about 10m. It is also aimed at medium speed data communications applications.

In terms of the stylus technology, the concept of using a remote pen input device, has failed to emerge as a widely embraced concept. Perhaps this is because styli that work direct on the touch screen have emerged in its place as the standard way of inputting data. In the past, handwriting recognition using a stylus on a touch screen was unsuccessful due to its inaccuracy and slow speed. Today systems such as Graffiti have been more effective.

Finally, there is the battery technology. When the CCL designers presented their original concept the idea of a wafer thin battery with a useful lifetime was greeted with a certain amount of ridicule. Then, rechargeable batteries were based on NiCad technology, with NiMH batteries just entering the marketplace. A GSM phone had barely an hour of talk time and tens of hours of standby time.

Today, almost all mobile phones can use a lithium ion battery, sporting a talk time of 10h and a standby time of 600h. Ultimately, talk time is limited by the power consumption of the RF circuitry required to put the signal into the air. Nevertheless, it is possible to increase the amount of standby time in such a system, because this is only limited by the amount of power consumption in the electronic devices. Indeed, CCL developers believe that another order of magnitude increase in the standby time may be achievable in the next few years.

By the year 2000, one thing is clear to the CCL developers. The entire electronics functions including the camera and display will all be integrated onto a single chip. What comes after that is anyone’s guess.

The Personal Communicator concept developed by CCL was designed to provide the user with a versatile portable unit that could perform a number of functions. One of these was to allow the user access to remote data such as the weather forecast shown here.