Apparatus and method for interfering with wireless communications devices in response to transmission power detection

An apparatus operable to disable operation of wireless communications devices, for use within a vehicle, includes a drive circuit coupled to at least one active antenna element to produce interference within at least one wireless communications band of frequencies in response to the wireless communications device transmitting at a transmission power above a defined power threshold for a defined amount of time. The interference may take the form of a bare carrier wave, or may take the form of noise, and is transmitted at sufficient power to interfere with communication between the wireless communications device and a destination device.

BACKGROUND

This disclosure generally relates to the field of wireless communications, and more particularly to wireless communications devices used within vehicles.

2. Description of the Related Art

Wireless communications devices, for example cellular phones, satellite phones, pagers, text messaging devices, personal digital assistants (e.g., BLACKBERRY® and TREO®) and the like are becoming ubiquitous.

Such devices, and in particular cellular phones are currently being used by an increasing number of people while driving. Research studies have shown that cellular phone usage diverts the concentration or attention of the motorist from the road and significantly increases the likelihood of an accident. Some countries as well as several states in the Unites States have banned the usage of hand-held cell phone devices during driving. However, studies indicate that usage of hands-free cellular phones are almost as distracting as hand-held cellular phones. At least one study suggests that hands-free cellular phone usage is almost the equivalent of driving while intoxicated.

Compliance with laws banning cellular phone usage appears to be low, and enforcement requires the diversion of police resources, which may otherwise be used to address other issues. Consequently, a new approach to addressing cellular phone usage in vehicles is therefore desirable.

BRIEF SUMMARY OF THE INVENTION

According to one aspect, an apparatus operable to disable operation of wireless communications devices prior to use within a vehicle includes at least one active antenna element, and a drive circuit coupled to drive the at least one active antenna element to produce interference within at least one wireless communications band of frequencies in response to the wireless communications device transmitting at a transmission power above a defined power threshold for a defined amount of time, wherein the interference is at sufficient power to interfere with communication between the wireless communications device and a destination device. The interference may take the form of a bare carrier wave (i.e., a carrier wave with no signal or noise imposed thereon), or may take the form of noise or a carrier wave imposed with noise.

According to another aspect, an apparatus operable to disable operation of wireless communications devices prior to use within a vehicle includes at least one active antenna element, and a drive circuit coupled to drive the at least one active antenna element to produce interference within at least one wireless communications band of frequencies in response to the wireless communications device transmitting at a transmission power above a defined power threshold for a defined amount of time while the vehicle is moving above a defined movement threshold, wherein the interference is at sufficient power to interfere with communication between the wireless communications device and a destination device.

According to another aspect, a method to disable operation of wireless communications devices prior to use within vehicles includes determining whether a transmission power of the wireless communications device is above a defined power threshold, determining a duration of time the transmission power of the wireless communications device is above the defined power threshold, and driving at least one active antenna element to produce interference within at least one wireless communications band of frequencies in response to a determination that the transmission power of the wireless communications device is above the defined power threshold for a duration of time that exceeds a defined time limit.

According to yet another aspect, a method to disable operation of wireless communications devices prior to use within vehicles includes determining whether the vehicle is moving above a defined movement threshold, determining whether the wireless communications device is transmitting at a transmission power above a defined power threshold for a defined amount of time, and driving at least one active antenna element to produce interference within at least one wireless communications band of frequencies in response to a determination that the transmission power of the wireless communications device is above the defined power threshold for the defined amount of time and in response to a determination that the vehicle is moving above the defined movement threshold.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. However, one skilled in the art will understand that the embodiments may be practiced without these details. In other instances, well-known structures, equipment and processes associated with interfering with or jamming wireless communications, including voltage controlled oscillators, tuned circuits (e.g., LC circuits, RLC circuits), noise generators, RF (Radio Frequency) power amplification, antenna transmission and resulting structures have not been shown or described in detail to avoid unnecessarily obscuring the description.

The headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed invention.

FIG. 1Ais a schematic illustration of a communications system2as used with a vehicle8, according to an illustrated embodiment.

The communications system2comprises a destination device4communicatively coupled to a wireless communications device6carried by the vehicle8via a base station9or some other communications switch. An interference device10is installed in or otherwise carried by the vehicle8or occupant thereof. The interference device10is operable to substantially interfere with communication between the destination device4and the wireless communications device6to a degree sufficient to effectively render the wireless communications device6inoperable.

The interference device10comprises a drive circuit12(FIGS. 2A-3B) electrically coupled to drive at least one active antenna element14to produce interference within at least one wireless communications band of frequencies. In some embodiments, the drive circuit12drives the active antenna element14to produce communications disabling interference in response to the wireless communications device6transmitting at a transmission power above a defined power threshold (e.g., 0.4 Watt, 0.3 Watt, 0.1 Watt, etc.) for a defined amount of time (e.g., 100 milliseconds, 50 milliseconds, 25 milliseconds, etc.). The defined power threshold and the defined amount of time may be defined via a power threshold input16and a timing input18, respectively. In other embodiments, the drive circuit12drives the active antenna element14to produce communications disabling interference in response to the wireless communications device6transmitting at a transmission power above the defined power threshold for the defined amount of time while the vehicle8is moving above a defined movement threshold (e.g., 5 miles per hour, 2.5 miles per hour, etc.). The defined movement threshold may be defined via a movement threshold input20. The interference device10may transmit a bare carrier wave or noise or undesired signal imposed on a carrier wave within one frequency band or automatically switch between transmission within two or more frequency bands that are likely to be used by the wireless communications device6, as discussed below. Additionally or alternatively, the interference device10may periodically detect the frequency band used by the wireless communications device6and adjust itself accordingly.

The destination device4may, for example, be a further wireless communications device communicatively coupled to the wireless communications device6positioned within the vehicle8. The interference may with wireless communications between the wireless communications device6and the base station9responsible for receiving and transmitting electromagnetic signals (e.g., radio frequency signals), for example, within a cellular region in which the wireless communications device6is located. The base station9may include a combination of antennas and electronic equipment used to receive and transmit the electromagnetic signals.

The wireless communications device6may take a variety of forms, for example, cellular phones, satellite phones, pagers, text messaging devices, personal digital assistants (e.g., BLACKBERRY® and TREO®). The wireless communications device6may transmit and receive electromagnetic signals within multiple bands of frequencies such as, for example, a 800 MHZ band, 900 MHz band, an 1800 MHz band, or a 1900 MHz band.

The vehicle8may be any suitable structure for transport on land, sea or in air, such as, for example, an automobile, truck, boat, submarine, plane, or helicopter. The vehicle8may include an RF (Radio Frequency) power sensor22to provide a signal indicative of the transmission power of the wireless communications device6. Additionally, the vehicle8may also include a sensor24such as, for example, a speedometer, tachometer, acceleration sensor or a rotational encoder, to provide a signal indicative of movement of the vehicle8. The signal may, for example, be indicative of change in position, rate of change in positions and/or rate of change in speed.

FIG. 1Bshows a detailed isometric bottom view of the active antenna element14and a passive antenna element25, according to one illustrated embodiment.

The active antenna element14may be a directional antenna element mounted proximate a dashboard26of the vehicle8(e.g., automobile) with a primary axis28of radiation directed into a passenger compartment30of the vehicle8. In another embodiment, the passive antenna element25may be positioned with respect to the active antenna element14to produce a directional radiation pattern with the primary axis28of the directional radiation pattern directed into the passenger compartment30of the vehicle8. The active antenna element14and the passive antenna element25are mounted proximate the dashboard26of the vehicle8. As illustrated inFIG. 1B, the passive antenna element25may be formed as a portion of a cylinder, with a longitudinally extending slot extending a length thereof. The passive antenna element25may be inexpensively manufactured by a stamping and rolling process.

FIG. 1Cshows a schematic illustration of the active antenna element14printed on a printed circuit board31, according to one illustrated embodiment.

The active antenna element14may comprise conductive traces printed on a non-conductive substrate such as the printed circuit board31. The active antenna element14may be designed as a dual-response Planar Inverted F-Antenna (PIFA) having a circular antenna design that is omni-directional with a reduced dB gain of approximately a few dB off the active antenna element14edges. The printed circuit board31with the active antenna element14printed thereon may be advantageously mounted perpendicular to the dashboard26or similar mountable surface so that the primary axis28of radiation may be directed into a driver side of the vehicle8.

FIGS. 2A-2Bare schematic illustrations of the interference device10positioned within the vehicle8, according to some illustrated embodiments.

The drive circuit12comprises at least one interference generation circuit32configured to cause the at least one active antenna element14to transmit interference (e.g., bare carrier wave, noise or undesired signal imposed on carrier wave) within the wireless communications band of frequencies. The frequency of operation of the interference generation circuit32may be implemented at manufacture, installation in the vehicle, on startup of the vehicle8and/or during use of the interference device10. More specifically, the interference generation circuit32may include at least one variable circuit element34(e.g., inductor, capacitor, resistor, etc.) that may be varied according to input signals received via a reconfiguration port36. The reconfiguration port36may receive a user defined input or a generated input based upon an anticipated or a detected frequency of operation of the wireless communications device6. The reconfiguration port36may, for example, receive the user defined input during installation indicative of one or more frequency bands allocated to wireless communications in the geographic region in which the vehicle8or interference device10will be distributed, sold, operated and/or used. Alternatively, or additionally, the reconfiguration port36may for example receive the input generated in response to frequency detection. Such can accommodate new wireless communications devices and/or changes to existing wireless communications devices6.

The interference generation circuit32may be electrically coupled to receive power via an electrical system of the vehicle8. Alternatively, or additionally the interference generation circuit32may receive power via a power supply (e.g., a battery) or plugged into a standard electrical outlet.

The drive circuit12comprises a first input port38coupled to the RF power sensor22to receive the signal indicative of the transmission power of the wireless communications device6. A first comparator40may be configured to compare the signal indicative of the transmission power of the wireless communications device6with the defined power threshold. A timer42coupled to the first comparator40is operable to determine an amount of time the transmission power is above the defined power threshold. A third comparator44is operable to compare the amount of time the transmission power is above the defined power threshold with the defined amount of time. In response to the transmission power of the wireless communications device6being above the defined power threshold for the defined amount of time, the drive circuit12drives the active antenna element14to produce interference. The interference device10transmits interference via the active antenna element14within the wireless communications band of frequencies, which approximately matches the frequency band used by the wireless communications device6. The interference is transmitted at sufficient power to substantially interfere with communications between the wireless communications device6and the base station9, and hence with the destination device4. The base station9may, for example, be located less than approximately 22 meters from the wireless communications device6. The defined power threshold may indicate a user set power threshold value while the defined amount of time may indicate a user set amount of time. For example, the user set power threshold value may be 0.1 Watts and the user set amount of time may be 100 milliseconds.

In some embodiments, as illustrated inFIG. 2B, the drive circuit12may further comprise a second input port46coupled to the sensor24to receive the signal indicative of movement of the vehicle8. A second comparator48configured to compare the movement of the vehicle8with the defined movement threshold may be included in the drive circuit12. Thus, according to such embodiments the drive circuit12drives the active antenna element14to produce interference in response to the wireless communications device6transmitting at a transmission power above the defined power threshold for the defined amount of time while the vehicle is moving above the defined movement threshold. The interference device10transmits interference via the active antenna element14within the wireless communications band of frequencies, which approximately matches the frequency band used by the wireless communications device6. The interference is transmitted at sufficient power to substantially interfere with communication between the wireless communications device6and the base station9, and hence with the destination device4. The destination device4may, for example, be located less than approximately 22 meters from the base station9. The defined movement threshold may indicate a user-defined movement threshold such as, for example, a speed threshold and/or an acceleration threshold and/or a change in position threshold. For example, the speed threshold may be a value indicative of a speed of approximately 5 miles per hour.

During manufacture, the interference generation circuit32may, for example, be configured to produce interference within the following frequency bands: 800 MHz band, 900 MHz band, 1800 MHz band, or 1900 MHz band. Prior to installation, the interference generation circuit32may be manually reconfigured based on the geographic location (e.g., Unites States, Europe, Japan, etc.) in which the vehicle8is sold, leased or operated, to interfere with one or more frequencies licensed for wireless communications in that area. Reducing the number of bands to only the bands that are licensed in the geographic location may advantageously reduce possible unintended interference with other devices, reduce power consumption, and/or comply with applicable laws or regulations.

As mentioned above, the reconfiguration port36may receive the generated input based upon the detected frequency of operation of the wireless communications device6. For example, the drive circuit12may include an optional frequency detector50(e.g., RF signal analyzer) to detect the wireless communications band of frequencies used by the wireless communications device6. The variable circuit element34of the interference generation circuit32is adjusted according to the input received via the reconfiguration port36. The frequency detector50may be enabled at start-up of the vehicle8and/or periodically thereafter or at movement of the vehicle8above the defined threshold and/or periodically thereafter. The frequency detector50may be in constant detection mode irrespective of the movement of the vehicle8. During enablement of the frequency detector50(e.g., at vehicle8start up and periodically thereafter), the reconfiguration port36receives the generated inputs from the frequency detector50indicating the current frequency band being used by the wireless communications device6. The reconfiguration port36adjusts the variable circuit element34accordingly, so as to ensure that the generated interference interferes with the operation of the wireless communications device6.

In another embodiment, the reconfiguration port36is programmed to automatically switch the adjustment of the variable circuit element34and cause the interference generation circuit32to cycle between several frequency bands to render the wireless communications device6ineffective without regard to the particular one of the licensed band or bands of frequency in which the particular wireless communications device6is operating. The possible frequency bands may be bands licensed for wireless communications in the geographic location in which the vehicle8is operated.

The interference generation circuit32may include a tuned circuit (e.g., RLC circuit, LC circuit, etc.) with an interference generator coupled thereto. The interference generator provides interference within one or more wireless communications bands of frequencies. The tuned circuit passes interference within the wireless communications band of frequencies that approximately matches the band of frequencies used during operation of the wireless communications device6. The tuned circuit may include the variable circuit element34to allow for the selection of the new band of frequencies that approximately matches the wireless communications band of frequencies used during operation of the wireless communications device6. The variable circuit component may be, for example, a varicap diode, integrated within the tuned circuit to form a voltage controlled oscillator (VCO). The varicap diode is a diode having a large depletion region that may be varied by an applied voltage, thereby functioning as a variable capacitor. The interference generation circuit32may further comprise an amplification circuit to increase the power of the transmitted interference. The amplification circuit provides sufficient power such that the transmitted interference interferes with the communication between the wireless communications device6and the destination device4.

FIGS. 3A and 3Bshow schematic illustrations of the interference device10positioned within the vehicle8and including at least two interference generation circuits32a,32b(collectively referenced as32) and a multiplexer52, according to an illustrated embodiment.

The drive circuit12ofFIGS. 3A and 3Bis similar in some respects to the drive circuit12ofFIGS. 2A and 2B, respectively. Hence, identical or similar elements or components will be identified by the same reference numbers. Only significant differences in structure and operation are discussed below.

The multiplexer52is operable to selectively couple a respective one of the at least two interference generation circuits32to the active antenna element14at a time. Each of the at least two interference generation circuits32is operable to cause the active antenna element14to produce interference within a respective wireless communications band of frequencies. For example, the drive circuit12may include three interference generation circuits32, wherein each is operable to cause the active antenna element14to produce interference within a respective one of three wireless communications bands of frequencies. The three bands of frequencies may include, for example, the 800 MHz band, 900 MHz band, 1800 MHz band and the 1900 MHz band, as configured during manufacture or installation of the interference device10.

The third comparator44may trigger one or more of the interference generation circuits to generate interference when the transmission power of the wireless communications device is above the defined power threshold for the defined amount of time. In other embodiments, as shown inFIG. 3B, one or more of the interference generation circuits32are triggered based on both the second and the third comparators48,44such that the interference generation circuits32generate interference in response to the transmission power of the wireless communications device6being above the defined power threshold for the defined amount of time while the vehicle8is moving above the defined movement threshold.

The interference signal is supplied to a respective input of the multiplexer52. The multiplexer52selects the respective input corresponding to the interference generation circuit32to cause the active antenna element14to produce interference within the wireless communications band of frequencies that approximately matches the frequency band used by the wireless communications device6.

In some embodiments, the drive circuit12may include the frequency detector50that detects the frequency band or bands in which the wireless communications device6is operating and supplies an appropriate signal to the multiplexer52to cause the multiplexer52to select the respective input. The respective input corresponds to the interference generation circuit32designed to produce interference within the wireless communications band of frequencies that approximately matches the frequency band used by the wireless communications device6. Similarly to the interference device10ofFIGS. 2A-2B, the frequency detector50may be enabled at start-up of the vehicle8and/or periodically thereafter or at transmission of the wireless communications device6above the defined power threshold for the defined amount of time and/or periodically thereafter or at transmission of the wireless communications device6above the defined power threshold for the defined amount of time while the vehicle8is moving above the defined movement threshold and/or periodically thereafter. The frequency detector50may be in constant detection mode irrespective of the power transmission of the wireless communications device6or the movement of the vehicle8. During enablement of the frequency detector50(e.g., at vehicle8start up and/or periodically thereafter), the multiplexer52receives the signals from the frequency detector50to cause the multiplexer52to select the respective input. The respective input corresponding to the interference generation circuit32designed to produce interference to interfere with the current frequency band being used by the wireless communications device6.

During manufacture, each of the interference generation circuits32may, for example, be configured to produce interference within the 800 MHz, 900 MHz, 1800 MHz or 1900 MHz bands, respectively. However, prior to installation, the multiplexer52may be manually set based on the geographic location (e.g., United States, Europe, Japan, etc.) in which the vehicle is sold, leased or operated, to select the input corresponding to the interference signal that can interfere with one or more frequencies licensed for wireless communications in that area.

Alternatively, the multiplexer52may be preprogrammed to automatically cycle selection between two or more inputs, effectively rendering the wireless communications device6ineffective without regard to the particular one of the licensed band or bands of frequency in which the particular wireless communications device6is operating. The two or more inputs may correspond to interference signals within respective frequency bands licensed for wireless communications in the geographic location in which the vehicle8is operated.

Similarly to the drive circuit12ofFIGS. 2A and 2B, if neither of the interference generation circuits32produce interference within the frequency band used by the wireless communications device6, the variable circuit element34of one of the interference generation circuits may be adjusted. The reconfiguration port36may receive the user defined input (e.g., during installation) or the generated input based upon the detected frequency of operation of the wireless communications device6. The reconfiguration port36may, for example, receive the user defined input during installation or the generated input during frequency detection.

FIG. 4shows a flowchart of a method400of disabling operation of the wireless communications device6within the vehicle8, according to one illustrated embodiment.

The method400starts at402, for example in response to the start of manufacture of the interference device10. At404, the interference device10is configured to produce interference within at least one of the frequency bands licensed for wireless communications in the geographic region in which the interference device10will be distributed, sold and/or used.

Optionally at406, prior to installation of the interference device10, the interference generation circuit32is manually configured based on the geographic location (e.g., Unites States, Europe, Japan, etc.) in which the vehicle8is sold, leased or operated, to interfere with one or more frequencies licensed for wireless communications in that area.

Optionally at408, in response to the starting up or movement of the vehicle8, the sensor24sends the signal indicative of the movement of the vehicle8to the drive circuit12. The signal may be indicative of position, speed and/or acceleration of the vehicle8or a component thereof, for example, a drive shaft or axle.

Optionally at410, the comparator48determines whether the movement of the vehicle8exceeds the defined movement threshold. As discussed above, the movement threshold may be defined via the movement threshold input20. The signal indicative of the movement of the vehicle8is compared to the defined movement threshold. If it is determined that the vehicle8is moving below the defined movement threshold, control passes back to408.

At412, the RF power sensor22detects the transmission power of the wireless communications device6and provides the drive circuit12with the signal indicative of the transmission power of the wireless communications device6. At414, the comparator40determines whether the transmission power is above the defined power threshold (e.g., 0.1 Watt, 0.2 Watt, 0.3 Watt, etc.). The signal indicative of the transmission power is compared to the defined power threshold. If it is determined that the transmission power is below the defined power threshold, control passes back to408.

At416, the timer42is enabled and sends a signal indicative of the duration of time the transmission power is above the defined power threshold to the third comparator44. The timer42remains enabled for the duration of time the transmission power remains above the defined power threshold. Optionally, the timer42remains enabled for the duration of time the transmission power remains above the defined power threshold while the vehicle8is moving above the defined movement threshold. If the transmission power subsequently drops below the defined power threshold or optionally if the vehicle8is moving below the movement threshold, the timer42is reset and disabled. The timer42is re-enabled when the transmission power subsequently rises back above the defined power threshold or optionally for the duration of time the transmission power remains above the defined power threshold while the vehicle8is moving above the defined movement threshold.

At418, the third comparator44determines whether the signal indicative of the duration of time the transmission power is above the defined power threshold exceeds the defined time limit (e.g., 100 milliseconds). If the duration of time does not exceed the defined time limit, control passes back to408.

At420, the drive circuit12drives the active antenna element12to produce interference within at least one wireless communications band of frequencies in response to the determination that the transmission power of the wireless communications device6is greater than or equal to the defined power threshold for a duration of time that exceeds the defined time limit, which may optionally occur while the vehicle8is moving above the movement threshold. The at least one wireless communications band of frequencies approximately matches a frequency band used by the wireless communications device6. The method400passes control back to408.

It will be apparent to those of skill in the art, that the acts of the method400may be performed in a different order. It will also be apparent to those with skill in the art, that the method400omits some acts and/or may include additional acts.

FIGS. 5A and 5Bshow a flowchart of a method500of disabling operation of the wireless communications devices6within the vehicle8, according to one illustrated embodiment.

The method500starts at502, for example in response to starting up or movement of the vehicle8.

Optionally at504, the sensor24sends the signal indicative of the movement of the vehicle8to the drive circuit12. The signal may be indicative of position, speed and/or acceleration of the vehicle8or a component thereof, for example, a drive shaft or axle.

Optionally at506, the comparator24determines whether the movement of the vehicle8exceeds the defined movement threshold. As discussed above, the movement threshold may be defined via the movement threshold input20. As described above, the signal indicative of the movement of the vehicle8is compared to the defined movement threshold. If it is determined that the vehicle8is moving below the defined movement threshold, control passes back to504.

At508, the RF power sensor22detects the transmission power of the wireless communications device6and provides the drive circuit12with the signal indicative of the transmission power of the wireless communications device6. At510the comparator40determines whether the transmission power is above the defined power threshold (e.g., 0.1 Watt, 0.2 Watt, 0.3 Watt, etc.). The signal indicative of the transmission power is compared to the defined power threshold. If it is determined that the transmission power is below the defined power threshold, control passes back to504.

At512, the timer42is enabled and sends a signal indicative of the duration of time the transmission power is above the defined power threshold to the third comparator44. The timer42remains enabled for the duration of time the transmission power remains above the defined power threshold. Optionally, the timer42remains enabled for the duration of time the transmission power remains above the defined power threshold while the vehicle8is moving above the defined movement threshold. If the transmission power subsequently drops below the defined power threshold or optionally if the vehicle8is moving below the movement threshold, the timer42is reset and disabled. The timer is re-enabled when the transmission power subsequently rises back above the defined power threshold and optionally while the vehicle8is moving above the defined movement threshold.

At514the third comparator44determines whether the signal indicative of the duration of time the transmission power is above the defined power threshold exceeds the defined time limit (e.g., 100 milliseconds). If the duration of time does not exceed the defined time limit, control passes back to504.

Optionally at516, in the event that the wireless communications device6is in use, the frequency detector50detects the frequency of operation of the wireless communications device6.

Optionally at518, based upon a signal generated by the frequency detector, the at least one variable circuit element34of the interference generation circuit32is adjusted to produce interference within the at least one wireless communications band of frequencies that approximately matches the frequency band used by the wireless communications device6, as detected.

Optionally at520, a signal is supplied to the multiplexer52, for example, from the frequency detector50to cause the multiplexer52to select the respective input corresponding to the interference generation circuit32designed to produce interference within the at least one wireless communications band of frequencies that approximately matches the frequency band used by the wireless communications device6, as detected.

At522, the comparator24triggers the interference generation circuit32to cause the active antenna element14to produce interference within the at least one wireless communications band of frequencies that approximately matches the frequency band used by the wireless communications device6, as detected. The produced interference is in response to the determination that the transmission power of the wireless communications device6is greater than or equal to the defined power threshold for a duration of time that exceeds the defined time limit, which may optionally occur while the vehicle8is moving above the movement threshold. If there are at least two interference generation circuits32in the drive circuit12then the comparator24or may trigger each of the at least two interference generation circuits32to generate interference within the respective wireless communications band of frequencies to the respective input of the multiplexer52. The multiplexer52selects the respective input corresponding to the interference generation circuit32designed to cause the active antenna element14to produce interference within the at least one wireless communications band of frequencies that approximately matches the frequency band used during operation of the wireless communications device6. The interference is transmitted by the active antenna element14at sufficient power to interfere with communication between the wireless communications device6and the destination device4. The destination device4may be located less than approximately 22 meters from the wireless communications device6.

The method500passes control to504and waits for the transmission power to be above the power threshold for at least the defined time limit or optionally waits for the transmission power to be above the power threshold for at least the defined time limit while the vehicle8is moving above the movement threshold.

It will be apparent to those of skill in the art, that the acts of the method500may be performed in a different order. It will also be apparent to those with skill in the art, that the method500omits some acts and/or may include additional acts.

FIGS. 6A and 6Bshow a flowchart of a method600of disabling operation of the wireless communications devices6within the vehicle8, according to one illustrated embodiment.

The method600starts at602, for example in response to the starting up or movement of the vehicle8. Optionally, at604, the sensor24sends the signal indicative of the movement of the vehicle8to the drive circuit12. The signal may be indicative of position, speed and/or acceleration of the vehicle8or a component thereof, for example, a drive shaft or axle.

Optionally, at606, the comparator24determines whether the movement of the vehicle8exceeds the defined movement threshold. As discussed above, the movement threshold may be defined via the movement threshold input20. The signal indicative of the movement of the vehicle8is compared to the defined movement threshold. If it is determined that the vehicle8is moving below the defined movement threshold, control passes back to604.

At608, the RF power sensor22detects the transmission power of the wireless communications device6and provides the drive circuit12with the signal indicative of the transmission power of the wireless communications device6. At610, the comparator40determines whether the transmission power is above the defined power threshold (e.g., 0.1 Watt, 0.2 Watt, 0.3 Watt, etc.). The signal indicative of the transmission power is compared to the defined power threshold. If it is determined that the transmission power is below the defined power threshold, control passes back to604.

At612, the timer42is enabled and sends a signal indicative of the duration of time the transmission power is above the defined power threshold to the third comparator44. The timer42remains enabled for the duration of time the transmission power remains above the defined power threshold. Optionally, the timer42remains enabled for the duration of time the transmission power remains above the defined power threshold while the vehicle8is moving above the defined movement threshold. If the transmission power subsequently drops below the defined power threshold or optionally if the vehicle8is moving below the movement threshold, the timer42is reset and disabled. The timer is re-enabled when the transmission power subsequently rises back above the defined power threshold and optionally when the transmission power subsequently rises back above the defined power threshold while the vehicle8is moving above the defined movement threshold.

At614, the third comparator44determines whether the signal indicative of the duration of time the transmission power is above the defined power threshold exceeds the defined time limit (e.g., 100 milliseconds). If the duration of time does not exceed the defined time limit, control passes back to604.

At616, the interference device10transmits interference within one of the frequency bands licensed for wireless communications in the geographic location in which the vehicle8is operated, in response to the determination that the transmission power of the wireless communications device6is greater than or equal to the defined power threshold for a duration of time that exceeds the defined time limit, which may optionally occur while the vehicle8is moving above the movement threshold. The interference device10transmits the interference within the selected frequency band for a predefined period of time.

At618, the interference device10cycles to another one of the frequency bands licensed for wireless communications, different from the selected frequency band at616.

The method600passes control to604and waits for the transmission power to be above the power threshold for at least the defined time limit or optionally waits for the transmission power to be above the power threshold for at least the defined time limit while the vehicle8is moving above the movement threshold.

It will be apparent to those of skill in the art, that the acts of the method600may be performed in a different order. It will also be apparent to those with skill in the art, that the method600omits some acts and/or may include additional acts.