Securement of optical fibers against eavesdropping using a patch panel
A method is provided for securement of a network of optical fibers against attempts to detect sounds such as private conversations emitted in the vicinity of the fiber network such as in a secure room. The cable entering the room contains a plurality of fibers some of which have data and some are unused. It has been found that the sensitivity of systems such as DAS monitoring systems can detect such conversations from the vibration of the fibers in the vicinity. The method includes monitoring at least some of the fibers for detecting transmission therealong of light signals used for monitoring of fiber vibration which provide information on the sounds. An indication alert is emitted when detected of an intrusion attempt. A jamming signal can be transmitted along the detected fiber to prevent the monitoring. The monitoring and jamming can take place at a patch panel where the fibers are connected.
1 . A patch panel for an optical fiber network comprising:
a plurality of first terminals for receiving and connecting to one end of each of a plurality of optical fibers of a fiber cable;
a plurality of second terminals each for connecting to a respective one of a plurality of outputs;
a plurality of connections arranged such that light signals on at least some of the plurality of optical fibers are communicated between a respective one of the optical fibers and a respective one of the outputs;
a light signal monitoring system arranged for monitoring signals on at least some of the optical fibers;
the light signal monitoring system including a receiver for receiving the light signals and a light signal analysis system for detecting transmission along said at least some of the optical fibers to the receiver of light signals used for monitoring of fiber vibration and/or movement which light signals provide information on sounds;
and an indicator system on the patch panel responsive to the light signal analysis system and providing an indication of an intrusion attempt to detect said sounds.
2 . The patch panel according to claim 1 wherein said light signals are narrow wavelength, low duty cycle, and high powered laser pulses.
3 . The patch panel according to claim 1 wherein said light signals are generated by a Distributed Acoustic Sensing system.
4 . The patch panel according to claim 1 wherein said at least some of the optical fibers which are monitored are data fibers which contain transmitted data and wherein the transmitted data is separated from other light signals on the optical fiber to allow the other light signals to be monitored to detect said light signals used for said monitoring of said fiber vibration and/or movement.
5 . The patch panel according to claim 1 wherein said at least some of the optical fibers which are monitored are unused or dark optical fibers which therefore do not contain transmitted data and all light signals on the unused or dark optical fiber are monitored to detect said light signals used for said monitoring of said fiber vibration and/or movement.
6 . The patch panel according to claim 1 wherein the patch panel includes a control system for controlling the light signal monitoring system and the indicator system.
7 . The patch panel according to claim 6 wherein the control system for receives information about which optical fibers are data fibers and which fibers are unused or dark optical fibers and uses this information to monitor the optical fibers.
8 . The patch panel according to claim 1 wherein the optical fibers are monitored by detecting an amplitude of a total light signal in the optical fiber excluding any transmitted data.
9 . The patch panel according to claim 8 wherein the optical fibers are monitored by detecting the amplitude with added level monitoring as a fail safe, that is an indication alert is emitted when a light signal appears and remains present.
10 . The patch panel according to claim 1 wherein the optical fibers are monitored by a use of slope vs time algorithm to detect intermittent access to the optical fibers.
11 . The patch panel according to claim 1 wherein the patch panel includes a housing with the plurality of first and second terminals provided thereon.
12 . The patch panel according to claim 11 wherein the indicator system includes a plurality of individual indicators each associated with a respective one of said plurality of first terminals monitoring signals on at least some of the optical fibers.
13 . The patch panel according to claim 1 wherein each of said at least some of the optical fibers which are monitored includes a tap coupler where data on the optical fiber passes through and a smaller proportion is tapped for monitoring.
14 . The patch panel according to claim 1 wherein there is provided a central monitoring system which provides information for selecting which optical fibers expect activity and which optical fibers are unused or dark.
15 . The patch panel according to claim 1 wherein at least two of the optical fibers which are monitored are connected to a coupler for common monitoring of said at least two fibers.
16 . The patch panel according to claim 15 including optical switches for selecting one or more of the optical fibers which are monitored which are commonly monitored for detecting which of the optical fibers which are monitored contains said light signals.
17 . The patch panel according to claim 15 including a Fiber Optic Multicast Switch to allow individual optical fibers to be commonly monitored.
18 . The patch panel according to claim 1 wherein there is provided a jamming system which includes a wavelength analysis system to determine a wavelength of the said light signals and to create a jamming light signal selected to interfere with said monitoring of said fiber vibration and/or movement which is transmitted into the optical fiber which is monitored.
19 . The patch panel according to claim 18 wherein the jamming system includes a tunable CW laser which is used to generate the jamming light signal matching the wavelength of said light signals.
20 . The patch panel according to claim 19 wherein the laser comprises a high-power non-CW Fabry-Perot laser for wavelength chirping.
21 . The patch panel according to claim 18 wherein the jamming system includes a laser signal which is used to transmit the jamming light signal as jamming disinformation.
22 . The patch panel according to claim 18 wherein the jamming system includes a laser signal that is used to transmit the jamming light signal as a jamming overwhelming signal.
23 . The patch panel according to claim 18 wherein the jamming system includes a laser signal that is used to transmit the jamming light signal and wherein the analysis and transmission of the jamming light signal are repeatedly and periodically cycled to compensate for changing wavelength of the transmitter.
24 . The patch panel according to claim 18 wherein the jamming light signal is transmitted into the optical fiber while continuing to monitor other optical fibers.
25 . The patch panel according to claim 18 wherein the jamming system includes a 1×N splitter which is used to transmit the jamming light signal to a plurality of the optical fibers.
26 . The patch panel according to claim 18 wherein the jamming light signal is pulsed in time randomly, and/or pulsed with randomize pulse widths and/or random pulsed occurrence.
27 . The patch panel according to claim 18 wherein the jamming system includes an out of band OTDR signal which is multiplexed in to the optical fiber, and is used to measure a distance travelled by the light signals.
28 . The patch panel according to claim 18 wherein the jamming system includes an out of band DAS signal is multiplexed in to the optical fiber, which allows monitoring of sounds.
29 . The patch panel according to claim 18 wherein the jamming system includes out of band OTDR or DAS systems which are multiple wavelength capable in order to compensate for attempts to interfere with the DAS or OTDR signal by changing wavelengths or injecting jamming wavelengths.
30 . A secure room in which sounds are created which may contain sensitive data comprising:
at least one cable containing optical fibers with at least a part of at least one of the optical fibers is located in the secure room so that said at least one of the optical fibers vibrates in response to the sounds in the room;
and a patch panel in the secure room, the patch panel comprising:
a plurality of first terminals for receiving and connecting to one end of each at least some of said optical fibers of the fiber cable;
a plurality of second terminals each for connecting to a respective one of a plurality of outputs;
a plurality of connections arranged such that light signals on at least some of the plurality of optical fibers are communicated between a respective one of the optical fibers and a respective one of the outputs;
a light signal monitoring system arranged for monitoring light signals on at least some of the optical fibers;
the light signal monitoring system including a receiver for receiving the light signals and a signal analysis system for detecting transmission along said at least some of the optical fibers to the receiver of light signals where the light signals are used for monitoring fiber vibration and/or movement which light signals provide information on said sounds in the secure room;
and an indicator system on the patch panel responsive to the signal analysis system and providing an indication of an intrusion attempt to detect said sounds in the secure room.