companies around the world have been vying with each other to come up with the lightest and easiest to carry mobile phone. Thanks to Japan's penchant for miniaturisation, now you can carry a phone around your wrist. The Japanese telecommunications giant, nit , has developed a wristwatch-telephone that could be on sale by the end of 1997.

To shrink a mobile phone to the size of a watch, the company overcame the problem of fitting a power supply and receiver that are powerful and small enough to be wearable. nit has done this by removing most of the hardware associated with a mobile phone and putting it into a base station that is connected to the national phone network. The watch-phone sends all its communications via radio link to the base station.

The watch itself has only four buttons for the primary functions such as switching on and off and checking battery levels. Everything else is done at the base station. For dialling a number, the owner speaks it into the microphone or repeats the name of someone whose number has been recorded.

The request is sent by the radio link to the nearest base station where speech-recognition software converts it into the correct dialling pulses which are sent down the national phone network. When the call is connected, the base station immediately relays the answer to a small loudspeaker on the watch-phone or to an earphone if preferred. Including battery, the watch-phone weighs 70 grams. nit is working at reducing the weight.