On the same day that PictureTel Inc was demonstrating its video telephone in the UK (CI No 1,231), British Telecommunications Plc was also demonstrating a videophone primarily developed for use by the deaf. The equipment used in the trial comprised a miniature video camera and 2.5 square TV screen. Like PictureTel’s V-3100 it has been designed for use over a digital network, but for the purposes of the demonstration, image coding algorithms developed by Professor Don Pearson at Essex University were used to reduce the picture to a level suitable for British Telecom’s analogue network at 14,400 bits per second. The resulting image (picture may be pushing the experience too far) is described as a moving black and white outline that is sufficient to enable the hand movements of sign language to be reliably identified. But according to British Telecom a commercial product is still many years away, which prompts the question – does the company know that it can already buy in the requisite technology from PictureTel?
