A multipoint teleconference system dispensing with an MCU, in which terminals are connected into a loop configuration through an ISDN in such a way that each terminal is coupled with each of the adjacent terminals by a single B channel. Thus, a communication frame is revolved through a looped communication...http://www.google.com.au/patents/US5970054?utm_source=gb-gplus-sharePatent US5970054 - Multipoint teleconference system employing H. 221 frames
