TeamWorkStation was designed to provide seamless realtime shared drawing space for geographically distributed group. The key design idea of TeamWorkStation is a "translucent overlay" of individual workspace video images.
TeamWorkStation-1 (TWS-1) combines two or more translucent live-video images of computer screens or physical desktop surfaces using a video synthesis technique. Translucent overlay allows users to combine individual workspaces and to point to and draw on the overlaid images simultaneously. We chose video as the basic medium of TWS because it is the most powerful for fusing presentations of a variety of traditionally incompatible visual media such as papers and digital documents.
TeamWorkStation-2 (TWS-2) was designed to provide a shared workspace over narrowband ISDN (N-ISDN) Basic Rate Interface (2B+D) and the Primary Rate Interface (H1/D) using the CCITT H.261 standard of moving picture transmission.
This project was conducted when Ishii was working for NTT Human Interface Laboratories, Japan.
(Source: http://tangible.media.mit.edu/projects/TeamWorkStation/)