This project is funded under the National Science Foundation's (NSF) Small Business Innovation Research (SBIR) program, which is designed to provide an opportunity for small business, particularly the small high technology firm, to participate in NSF research. Phase I of the SBIR program serves as a filter to select promising proposals and determine if the firm can do high quality research. Phase II is the principal research project. Phase III is the conversion of the NSF-funded research into commercial applications and technological innovation supported by follow-on private venture capital or other non-federal financing.  This is a Phase I project. The PI is developing a video protocol for ISDN, to provide the foundation for all the real-time video teleconferencing implementations likely to derive from the ISDN and image compression technologies in the near future. The protocol is directed toward personal computers, converting them to video telephones for the application. The open architecture of personal computers will most likely be the platform of choice for personal video telephones, which should be the boom market that will cause the general public to finally embrace the ISDN standard. The principal objective of this protocol is to provide support for personal video teleconferencing over basic access ISDN, and corporate video teleconferencing, with larger and higher resolution images, over primary access ISDN. Thus, one protocol could support video teleconferencing in a variety of ISDN configurations.