Abstract: A network apparatus having a chassis with an external network data port and a removable electronic module coupled to the network data port through an internal data port when the removable electronic module is present in the chassis. The chassis may also provide power, radio frequency (RF), data bus, and other types of electrical and data connections to the electronic module through the use of additional internal ports. The apparatus may additionally be connected to others via a data bus, and be included as part of a rack-mounted system. The electronic module may be inserted and removed from the chassis while electrical power is applied to the chassis.

Abstract: A system and method for equalization for forward and reverse channels of communicating highway network system having a branching tree topology. The system and method cause the forward channel to be adjusted first for equalization, then the reverse channel is adjusted for equalization. A reference node periodically transmits a frequency-rich signal on the network to the head end, which broadcasts this signal to each of a number of system nodes. Each system node compares the frequency-rich signal with an expected signal, and adjusts its receiver based on this comparison. Next, each system node transmits another frequency-rich signal to the head end, receives a return echo, compares the echo with the transmitted signal, and adjusts its transmitter based on the comparison.

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.