Abstract: A communications highway network system for the interactive communication of digital and analog information that incorporates LAN, MAN, and CATV technology to provide an information pathway of metropolitan size that has a spanning tree topology. The system is multiple drop that operates according a network protocol. The network protocol is based on modified TDM techniques, compensation for round trip loop delay, dynamic allocation of time slots on the network bus, and global synchronization. The protocol also permits concatenation of data packets to reduce overhead. Access to the network bus is controlled by a system allocator operating according to the network protocol. The allocator may allocate network bus bandwidth to simultaneously provide three levels of service for the system nodes to access the network bus, namely, isochronous, demand-based dedicated, and contention bandwidth allocation. This allocation method incorporates fairness to give all nodes sufficient bus access opportunities.