and baseband LAN US 4885747 A
Original IBM F-Coupler
connector US 5293298 A
Improved IBM F-Coupler
F-Coupler Planning Guide (GA27-3949)
F-Coupler Assembly and Installation Instructions (GA27-3950)
Baseband signals may be identified as
the cable ICS (IBM Cabling System) or the actual
network, such as "Token Ring" or "PC Network".
Broadband is VHF
F-Coupler and Faceplate
F-Coupler Figure 1
FIG. 1 shows a schematic of the improved communications system
according to the teachings of the present invention.
FIG. 2 shows a distribution link in the communications system and
an electrical schematic of one embodiment of the F-coupler.
FIG. 3 shows a schematic of the signaling spectrum for different
types of signals that are transmitted on the improved
communications system of FIG. 1.
FIG. 3 shows a graphic representation of the signal spectrum and
the allocation for data signals which are transmitted in the
baseband frequency range and VHF signals which are transmitted in
the broadband frequency range. The graph is helpful in
understanding the relationship between signals that are
simultaneously on the common lobe assembly means which
interconnects the wiring closet to the office (FIG. 1). In FIG. 3,
frequency is plotted on the horizontal axis and amplitude is
plotted on the ordinate or vertical axis. The frequency range
which transmits data for baseband machines is identified on the
graph as ICS data. Information for the PC Network stations and
other machines is transmitted at a transmit frequency identified
in FIG. 3 as PC Network Data Transmit and is received at a higher
frequency identified as PC Network Data Receive. The frequency
range used by the high frequency devices is identified as VHF TV
(Very High Frequency Television) and VHF, respectively. These may
be typical CATV (Cable Television) signals following the NCTA
(National Cable Television Association) standards for bandwidth,
frequency allocation and signal amplitudes.