Active Badge

The Olivetti Research Laboratory was founded in 1986 by Hermann Hauser and Andy Hopper after Olivetti acquired Acorn Computers. The Active Badge was conceived, designed, and prototyped between 1989 and 1992.

Each badge was a small wearable device that transmitted a unique infrared signal every 10 seconds. Rooms were equipped with networked sensors that received these signals and forwarded them to a central location service. The original badge sent a 5-bit unique code; later versions expanded to 10-bit and then 48-bit addresses, with the final version adding a microprocessor and bi-directional communication. Because infrared signals do not pass through walls, the system could locate a badge at roughly room-level granularity. * Location information was exposed through a web service called the WWW Active Badge Service.

Deployments reached over 1,500 badges and 2,000 sensors across European universities and U.S. research labs. The largest single site was the Cambridge University Computer Laboratory, with more than 200 badges and 300 sensors in daily use. The system enabled early “follow-me” applications such as phone call forwarding and moving a user’s desktop session as they walked between rooms.

The Active Badge is widely cited as a foundational system for indoor localization, context-aware computing, and what later became known as sentient/ubiquitous computing. Follow-up work evolved into the Active Bat ultrasonic system and the broader Sentient Computing project.

The Active Badge was once the subject of a cartoon in a British national newspaper. The system raised early privacy questions: wearing a badge that broadcasts your location every few seconds was a novel social concern in the early 1990s. * ORL later became AT&T Laboratories Cambridge and is also famous for developing VNC.