Optical fiber data transmission system
First Claim
1. An optical fiber data transmission system in which the individual subscriber stations are connected by means of T-couplers arranged at discrete positions along a main lead and the coupling out and in of the light is effected directionally, so that two T-couplers are necessary for the connection of one subscriber'"'"'s station, which effect directional coupling and collectively form a unit termed a TT-coupler, the incoming light being divided into two components in the first T-divider of the TT-coupler, of which one of said components passes to the receiver of the subscriber station and the second of said components passes directly through the TT-coupler, and wherein for the purpose of ensuring continued data transfer between the remaining subscriber stations connected along the main lead in the event of failure of one or more subscriber'"'"'s stations, each subscriber station further possesses intermediate amplifier means for demodulating a signal arriving at a subscriber station said demodulating means including means for regenerating a signal not addressed to that station transmitter means responsive to the regenerated signal for passing the signal into the main lead by way of the second T-coupler, and wherein the attenuation of the individual transmission sections of the TT-coupler is so chosen, having regard to the limiting sensitivity of the receivers and the instantaneous light output of the transmitter means, that in the event of failure of one or more stations, the drop in signal level thus resulting can be compensated for by the next following operative station so as to be returned to a signal level within the normal operating range.
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Accused Products
Abstract
A TT coupler for use in fiber optics data transmission systems wherein the incoming light to the coupler passes to both the receiver of the subscriber station and through the coupler lead toward the next subscriber station in succession in a ratio controlled by the design and geometry of the coupler. Signals not addressed to that station are identified as such by the receiver for that station and are regenerated and/or amplified and then passed to the transmitter for that station to be returned into the appropriate portion of the aforesaid coupler. The failure of one or even several receiver-transmitter facilities in succession will not degrade the system to the level of becoming inoperative due to the coupler design and its interaction with the receiver-transmitter facility at each subscriber station.
Means are provided for monitoring signal strength at each station and for providing necessary amplification in cases where it is so required.
39 Citations
11 Claims
- 1. An optical fiber data transmission system in which the individual subscriber stations are connected by means of T-couplers arranged at discrete positions along a main lead and the coupling out and in of the light is effected directionally, so that two T-couplers are necessary for the connection of one subscriber'"'"'s station, which effect directional coupling and collectively form a unit termed a TT-coupler, the incoming light being divided into two components in the first T-divider of the TT-coupler, of which one of said components passes to the receiver of the subscriber station and the second of said components passes directly through the TT-coupler, and wherein for the purpose of ensuring continued data transfer between the remaining subscriber stations connected along the main lead in the event of failure of one or more subscriber'"'"'s stations, each subscriber station further possesses intermediate amplifier means for demodulating a signal arriving at a subscriber station said demodulating means including means for regenerating a signal not addressed to that station transmitter means responsive to the regenerated signal for passing the signal into the main lead by way of the second T-coupler, and wherein the attenuation of the individual transmission sections of the TT-coupler is so chosen, having regard to the limiting sensitivity of the receivers and the instantaneous light output of the transmitter means, that in the event of failure of one or more stations, the drop in signal level thus resulting can be compensated for by the next following operative station so as to be returned to a signal level within the normal operating range.
Specification