Preventing mobile communications in a quiet zone using artificially imposed signal time delay
View Patent ↗Terminating or otherwise preventing communications in a predefined quiet zone by imposing a time delay. In one embodiment an existing call is terminated during a transition between two wireless access points by imposing a time delay on communications through one of the access points. The time delayed signal is interpreted as noise and causes a base station to drop the call if the noise causes the signal strength from the other access point to fall below a threshold. Within a quiet zone, a signal time delay prevents a client device from responding to a base station connection instruction, which causes the base station to believe that the client device is out of range of a quiet zone access point. The time delay may be imposed by an optical fiber spool between the quiet zone access point and the base station, or other delay mechanism. One embodiment is aboard a vessel.
1. A system for controlling communications, comprising:
a base station with a predefined signal parameter threshold, which when crossed, prevents communication with the base station; and
a delay control component coupled to the base station and coupled to a client device, wherein the delay control component selectively imposes a time delay on a signal between the client device and the base station to selectively control a signal parameter of the signal, thereby controlling whether the signal parameter crosses the signal parameter threshold.
2. The system of claim 1 wherein the signal parameter threshold comprises an acknowledgement period within which a connection request must be acknowledged to establish communication between the base station and the client device, and wherein the delay component selectively causes a connection request acknowledgement to be delayed beyond the acknowledgement period.
3. The system of claim 1 wherein the signal parameter threshold comprises a signal to noise ratio threshold, below which communication is prevented between the base station and the client device, wherein the base station compares the signal to noise ratio threshold to a signal to noise value that is based on:
an open zone signal received by the base station through an open zone access point coupled between the base station and the client device; and
a quiet zone signal received by the base station through the delay control component that is coupled to an open zone access point, which is coupled to the client device.
4. The system of claim 1 further comprising:
a quiet zone wireless access point coupled between the delay control component and the client device, the quiet zone wireless access point providing a quiet zone area, within which wireless communication between the client device and the base station is selectively controlled by the delay control component; and
an open zone wireless access point coupled between the base station and the client device, the open zone wireless access point providing an open zone area in which wireless communication between the client device and the base station is not controlled by the delay control component; and wherein the open zone area partially overlaps with the quiet zone area in an overlap area in which wireless communication between the client device and the base station is controlled by the delay control component if a quiet zone signal strength exceeds an open zone signal strength.
5. The system of claim 1 wherein the delay control component comprises an optical fiber that causes a signal to propagate along the optical fiber for a period that causes the predefined signal parameter threshold to be crossed.
6. The system of claim 1 , wherein the delay control component comprises:
a first optical fiber coupled between a transmitter of the base station and the client device; and
a second optical fiber coupled between a receiver of the base station and the client device.
7. The system of claim 1 , further comprising an optical converter coupled between the base station and the delay control component, wherein the optical converter converts between radio frequency signals and optical signals.
8. The system of claim 1 , further comprising a gateway coupled to the base station, the gateway enabling communication between the base station and a remote network.
9. The system of claim 1 , further comprising a vessel carrying the base station and the delay control component.
10. A delay device for controlling communications, comprising:
a base station interface for communication with a base station;
an access point interface for communication with a client access point; and
an optical fiber coupled between the base station interface and the access point interface, wherein the optical fiber has a length that causes a time delay in a signal propagating between the base station interface and the access point interface, wherein the time delay exceeds a predefined threshold period for enabling communication between a base station and a client device.
11. The delay device of claim 10 , further comprising a switch coupled to coupled to the optical fiber for selectively coupling the optical fiber to a different optical fiber having a length that does not causes a time delay in the signal propagating to exceed the predefined threshold period.
12. A base station for controlling communication, comprising:
a processor,
an open zone communication interface coupled to the processor;
a quiet zone communication interface coupled to the processor; and
a memory coupled to the processor and storing processor readable instructions that cause the processor to perform a plurality of operations, including:
receiving a first communication at a first signal strength through the open zone communication interface;
receiving a second communication at a second signal strength through the quiet zone communication interface;
determining that the first communication and the second communication indicate that they are both from the same client device;
determining whether the first signal strength is below a predefined signal strength threshold, and whether the second signal strength exceeds the first signal strength;
sending a connection request through the quiet zone communication interface to the client device, if the first signal strength is below the predefined signal strength threshold, and the second signal strength exceeds the first signal strength; and
terminating communication with the client device through the quiet zone communication interface, if a connection acknowledgement is not received from the client device within a predefined delay limit.
13. The base station of claim 12 , wherein the processor readable instructions further cause the process to perform the operations of:
receiving through the quiet zone communication interface, a communication connection request identifying the client device;
transmitting a client acknowledgement request to the client device through the quiet zone communication interface;
receiving from the quiet zone communication interface, a client acknowledgement from the client device; and
determining that the client acknowledgement was received after a predefined delay period, such that a communication connection is not established with the client device.
14. The base station of claim 13 , further comprising a delay device coupled to the quiet zone communication interface, causing a delay in at least one of the following:
receipt of the second communication;
the connection acknowledgement;
the communication connection request;
the client acknowledgement request; and
the client acknowledgement.
15. The base station of claim 12 , wherein the delay limit is less than a delay induced by signal transmission through a length of optical fiber.
16. The base station of claim 12 , wherein the processor readable instructions further cause the process to perform the operation of establishing a communication session with the client device through the quiet zone communication interface if the first signal strength is below the predefined signal strength threshold, the second signal strength exceeds the first signal strength, and a connection acknowledgement is received from the client device within a predefined delay limit.
17. A communication controller, comprising:
a processor,
a quiet zone communication interface coupled to the processor;
a delay control component coupled to the quiet zone communication interface; and
a memory coupled to the processor and storing processor readable instructions that cause the processor to perform a plurality of operations, including:
receiving a communication connection request from a client device through the quiet zone communication interface;
transmitting through the quiet zone communication interface, an acknowledgement request to the client device in response to the communication connection request;
receiving through the quiet zone communication interface and through the delay control component, an acknowledgement from the client device;
determining whether the acknowledgement was received after a predefined delay period; and
selecting not to establish a communication session with the client device if the acknowledgement was received after the predefined delay period.
18. The communication controller of claim 17 , further comprising a switch coupled to the delay control component, wherein the processor readable instructions further cause the processor to perform the operations of:
activating the switch to switch off the delay control component; and
selecting to establish a communication session with the client device if the acknowledgement was received within the predefined delay period.
19. The communication controller of claim 17 , wherein the delay component comprises one of the following; a length of optical fiber, a buffer, and a timer.
20. The communication controller of claim 17 , wherein the predefined delay period is less than a delay induced by signal transmission through a length of optical fiber.
21. A method of producing a storage device with stored data, comprising:
receiving a first communication at a first signal strength from an open zone access point;
receiving a second communication at a second signal strength from a quiet zone access point;
determining that the first communication and the second communication indicate that they are both from the same client device;
determining whether the first signal strength is below a predefined signal strength threshold, and whether the second signal strength exceeds the first signal strength;
sending a connection request through the quiet zone access point to the client device, if the first signal strength is below the predefined signal strength threshold, and the second signal strength exceeds the first signal strength;
terminating communication with the client device, if a connection acknowledgement is not received from the client device within a predefined delay limit; and
storing on a storage device, an indication that the communication with the client device was terminated, if the communication was terminated.
22. The method of claim 21 , further comprising:
receiving from the quiet zone access point a communication connection request identifying the client device;
transmitting a client acknowledgement request to the quiet zone access point for transmission to the client device;
receiving from the quiet zone access point a client acknowledgement from the client device;
determining that the client acknowledgement was received after a predefined delay period, such that a communication connection is not established with the client device; and
storing on the storage device, an non-connection indication that the communication connection was not established with the client device.
23. A method for controlling communication, comprising:
receiving a first communication at a first signal strength from an open zone access point;
receiving a second communication at a second signal strength from a quiet zone access point;
determining that the first communication and the second communication indicate that they are both from the same client device;
determining whether the first signal strength is below a predefined signal strength threshold, and whether the second signal strength exceeds the first signal strength;
sending a connection request through the quiet zone access point to the client device, if the first signal strength is below the predefined signal strength threshold, and the second signal strength exceeds the first signal strength; and
terminating communication with the client device, if a connection acknowledgement is not received from the client device within a predefined delay limit.
24. A machine readable medium storing machine readable instructions that cause a processor to perform the operations of claim 23 .
25. A machine readable medium storing machine readable instructions that cause a processor to perform the operations of:
receiving a communication connection request from a client device;
transmitting an acknowledgement request to the client device in response to the communication connection request;
receiving an acknowledgement from the client device through a delay control component;
determining whether the acknowledgement was received after a predefined delay period; and
selecting not to establish a communication session with the client device if the acknowledgement was received after the predefined delay period.