Note: Descriptions are shown in the official language in which they were submitted.
CA 02560755 2006-09-22
1 "APPARATUS AND METHOD FOR DISABLING RF
2 SIGNAL TRANSMISSIONS FROM WIRELESS NETWORK MODEMS"
3 Inventor: Amr Khaled Nasr
4 FIELD OF THE INVENTI/ON
The field of the present invention relates to an apparatus and method
6 for disabling radio frequency ("RF") signal transmissions from wireless
7 network modems. Specifically, the present invention is related to disabling
RF
8 signal transmissions from global positioning system ("GPS") modems when in
9 proximity to oil and gas wells where down-hole perforation devices are being
detonated.
11 BACKGROUND
12 When drilling oil or gas wells, a well may pass through one or more
13 formations that contain oil or gas deposits. When the well is cased in, the
14 formations are then sealed in and can only be accessed if the well casing
is
perforated to allow substances within the formation to be withdrawn. To
16 perforate a well casing, a perforation device containing explosives is
placed
17 down the well to a location adjacent to the formation. The device is
detonated
18 resulting in a perforation in the well casing to allow access to the
substances.
19 It is known that devices that emit RF signals, such as radios, pagers,
cellular
phones, GPS modems and the like can accidentally cause the perforation
21 device to detonate prematurely. This can damage the well casing and impair
22 the ability to withdraw substances from down-hole formations as the well
23 casing will not be perforated at the correct location. This is also a
safety
24 concern as perforation devices may be prematurely detonated prior to being
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1 inserted into the well causing a significant hazard to personnel in
proximity to
2 the perforation operations. Electronic devices that emit RF signals are also
a
3 hazard in the mining especially where explosives are used in blasting
4 operations to collect ore.
In respect of vehicles equipped with GPS modems, some currently
6 available units have the ability to manually disable the modem so as to
7 terminate RF transmissions but this feature usually results in the total
8 shutdown of the modem. Fleet vehicles equipped with GPS modems are
9 often configured to monitor operational parameters of the vehicle that are
transmitted to the fleet headquarters using the GPS modem as a method of
11 tracking the vehicle and its usage. This information can include when the
12 vehicle is operating, the location of the vehicle, when the vehicle exceeds
13 posted speed limits among other operational parameters pertinent to the
14 control and management of the fleet vehicle. The known manual shutdown
function usually shuts down the ability of the GPS modem to monitor these
16 operational parameters thereby negating the ability to monitor and record
17 vehicle parameters when the modem is disabled.
18 It is, therefore, desirable to provide an apparatus and method to
19 manually disable RF signal transmissions from a GPS modem that still allows
the GPS modem to collect vehicle operational parameters that can be
21 transmitted once the GPS modem is re-enabled after travelling a safe
22 distance from the perforation operations.
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1 SUMMARY
2 An apparatus and method for disabling RF signal transmissions from a
3 GPS modem is provided.
4 For the purposes of this specification, the term "GPS modem" shall
include wireless GPS communications devices comprising both RF signal
6 transmitters and receivers integrated into the modem. The term "GPS
7 modem" shall also include stand-alone RF signal transmitting devices that
are
8 used in conjunction with GPS receiver-only devices to form a functional GPS
9 modem. These transmitting devices can include transmitters for use with
satellite communications networks and terrestrial communications networks
11 such as global systems for mobile communications ("GSM") networks. These
12 transmitting devices may be incorporate any form of data communication
13 transmission technology such as code division multiple access ("CDMA")
14 transmitters or time division multiple access ("TDMA") transmitters as
representative examples as well as many others known to those skilled in the
16 art.
17 In one embodiment, an apparatus is provided comprising an input
18 command means for generating a modem transmit disable command signal.
19 The input command means is connected to a first circuit means for conveying
the transmit disable command signal to a GPS modem via a first connection
21 means. A second connection means is provided for connecting the first
circuit
22 means to the GPS modem via a digital input/output port disposed on the GPS
23 modem. In a further embodiment, the input command means comprise an
24 electrical switch, such as a push button switch, that can close or open an
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1 electrical circuit that can cause a transition from a low voltage to a high
2 voltage or vice versa. This can represent a transition from a logic "zero"
to a
3 logic "one" or vice versa. In another embodiment, the switch can be a
4 momentary single-pole, single-throw switch or equivalent as well known to
those skilled in the art. In other embodiment, the input command means can
6 comprise a visual indicator disposed therein to visually indicate when the
GPS
7 modem is disabled. In one embodiment, the visual indicator is a light
emitting
8 diode connected to the GPS modem through the second connection means, a
9 second circuit means disposed on a circuit board comprising the first
circuit
means and the first connection means. In another embodiment, both first and
11 second connection means are multi-conductor cables. When a GPS modem
12 is disabled from transmitting RF signals, the visual indicator is turned on
to
13 alert a user that the GPS modem is so disabled. When the GPS modem is
14 moved beyond a pre-determined distance from the location where it was
disabled, the GPS modem will then re-enable RF signal transmissions and
16 turn off the visual indicator.
17 The method of disabling RF transmissions from the GPS modem
18 comprises the following steps. A user operates the input command means to
19 generate a modem transmit disable command signal that is conveyed to the
first circuit means by the first connection means. The first circuit means
21 conveys the modem transmit disable command signal to the input/output port
22 of the GPS modem by the second connection means. The GPS modem is
23 configured to disable RF signal transmissions upon receiving the modem
24 transmit disable command signal. In one embodiment, RF signal
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1 transmissions is disabled by disabling the RF transmitter portion of the GPS
2 modem. This can be accomplished by disconnecting power to the transmitter,
3 muting the transmit oscillator of the RF transmitter or any other way that
4 would be known to a person skilled in the art to disable the RF transmitter
5 portion of the GPS modem. In another embodiment, the RF transmitter is
6 tuned to a non-existent or null gateway on a satellite communications
network
7 thereby effectively muting RF signal transmissions from the GPS modem.
8 In another embodiment, a visual indicator is provided when the GPS
9 modem is disabled from transmitting RF signals. This can include generating
a modem disabled signal on an output signal port on the input/output port of
11 the GPS modem. The modem disabled signal is conveyed to the second
12 circuit means via the second connection means period. The second circuit
13 means conveys the modem disable signal to the import command means via
14 the first connection means to energize a visual indicator that can be a
light
emitting diode ("LED"). The led remains lit while a GPS modem is disabled.
16 When the GPS modem is moved a predetermined distance from the location
17 is was disabled, the GPS modem is re-enabled to transmit RF signals upon
18 becoming re-enabled, either by turning the RF transmitter on or by tuning
the
19 RF transmitter to an active gateway on the satellite communications
network.
The modem disabled visual indicator is then turned off.
21 In one embodiment, the predetermined distance is programmed into
22 the GPS modem at the time of manufacture. In another embodiment, the
23 predetermined distance can be programmed in the GPS modem by a user
24 having a general purpose personal computer operatively connected to the
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1 GPS modem, the computer having a software program configured to edit the
2 operational parameters of the GPS modem. The computer can be connected
3 to the GPS modem with an interface cable or it can be connected via a
4 wireless communications network. Embodiments of this can include wireless
local area networks (ie, "Bluetooth ", Wi-Fi, etc.), GSM networks and
satellite
6 communications networks. The predetermined distance is set such that the
7 GPS modem is re-enabled at a safe distance from the location where the
8 perforation operations are being conducted. This distance can be in the
order
9 of 300 meters to 500 meters or more as determined by a person skilled in the
art as to the appropriate safe distance required to move away from a well site
11 where perforation operations are being conducted.
12 In another embodiment, the apparatus is a stand-alone device that
13 works with commercially available GPS modems. Another embodiment, the
14 apparatus is part of kit including computer readable medium containing
software configured to work on a general purpose personal computer
16 operatively connected to a GPS modem. The software enables a user to edit
17 and set operational parameters of the GPS modem, including other things,
the
18 predetermined distance the GPS modem must travel in order to re-enable RF
19 signal transmissions after being disabled.
In another embodiment, the apparatus is disposed within a GPS
21 modem whereby the input command means is disposed on the GPS modem
22 itself. The first and second connections means and the first and second
23 circuit means are all disclosed within the GPS modem.
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1 Broadly stated, one aspect of an apparatus for disabling RF signal
2 transmissions from a GPS modem comprises: input command means for
3 generating a transmit disable signal for a GPS modem; first connection means
4 for operatively connecting said input command means to a first circuit
means;
first circuit means for conveying said transmit disable signal to said GPS
6 modem; and second connection means for operatively connecting said first
7 circuit means to said GPS modem whereby a user operating said input
8 command means generates said transmit disable signal that is conveyed to
9 said GPS modem through said first connection means, said first circuit means
and said second connection means, said GPS modem configured to disable
11 RF signal transmissions therefrom upon receiving said transmit disable
signal.
12 Broadly stated, a method for disabling RF signal transmissions from a
13 GPS modem is provided, the GPS modem comprising at least one external
14 signal input port and at least one output signal port, said modem
configured to
disable RF signal transmission therefrom upon receiving a modem disable
16 signal on an external signal input port, said modem further configured for
17 storing user-defined parameters for the operation of said modem, the method
18 comprising the steps of: generating a transmit disable signal; conveying
said
19 transmit disable signal to an external signal input port disposed on said
modem; and disabling RF signal transmissions from said GPS modem upon
21 said GPS modem receiving said transmit disable signal on said external
22 signal input port.
23 Broadly stated, a GPS modem having a RF signal transmitter, a
24 microprocessor, and a memory for storing user-defined parameters used in
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1 the operation of said GPS modem is provided, said GPS modem comprising:
2 input command means for generating a transmit disable signal; first
3 connection means for operatively connecting said input command means to a
4 first circuit means; first circuit means operatively connected to said
microprocessor for conveying said transmit disable signal from said input
6 command means to said microprocessor; and a memory operatively
7 connected to said microprocessor, said memory comprising instructions
8 executable by said microprocessor configured to cause said GPS modem to
9 disable said RF transmissions from said GPS modem when said
microprocessor receives said transmit disable signal.
11 Broadly stated, a kit for disabling RF signal transmissions from a GPS
12 modem is provided, the GPS modem having a microprocessor, a memory for
13 storing instructions executable by said microprocessor, at least one
external
14 signal input port and at least one output signal port, said modem further
configured for storing at least one user-defined parameter for the operation
of
16 said GPS modem, said kit comprising: input command means for generating a
17 transmit disable signal for a GPS modem; first connection means for
18 operatively connecting said input command means to a first circuit means;
19 first circuit means for conveying said transmit disable signal to said GPS
modem; second connection means for operatively connecting said first circuit
21 means to an external signal input port disposed on said GPS modem whereby
22 a user operating said input command means generates said transmit disable
23 signal that is conveyed to said external signal input port through said
first
24 connection means, said first circuit means and said second connection
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1 means, said GPS modem configured to disable RF signal transmissions
2 therefrom upon receiving said transmit disable signal; and computer readable
3 medium with computer executable instructions stored thereon for use with a
4 general purpose computer operatively connected to said GPS modem, said
executable instructions configured for enabling said general purpose
6 computer to program said GPS modem to disable RF signal transmissions
7 from said GPS modem when said transmit disable signal is received on said
8 external signal input port.
9 Broadly stated, a method for disabling RF signal transmissions from a
GPS modem is provided, the GPS modem operatively mounted in a motor
11 vehicle, said GPS modem comprising an RF transmitter, a microprocessor, a
12 memory, at least one external signal input port and at least one output
signal
13 port, said GPS modem further configured for storing user-defined parameters
14 for the operation of said GPS modem, said method being embodied on a
computer-readable medium such that, when implemented on a general
16 purpose computer operatively connected to said GPS modem, said general
17 purpose computer is capable of programming said GPS modem to carry out
18 the method of disabling RF signal transmissions therefrom upon receiving a
19 modem disable signal on said at least one external signal input port, the
computer-readable medium characterized by: a code segment for determining
21 if the ignition of said vehicle is turned off; a code segment for
determining if
22 the ignition of said vehicle is turned on and if said vehicle is
stationary; a code
23 segment for determining if the ignition of said vehicle is turned on and if
said
24 vehicle is moving; and a code segment for disabling RF signal transmissions
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1 from said GPS modem if a modem disable signal is received on said at least
2 one external signal input port.
3 BRIEF DESCRIPTI/ON OF THE DRAWINGS
4 Figure 1 is a block diagram depicting one embodiment of a GPS
5 modem disabling apparatus.
6 Figure 2 is a wiring schematic depicting the cable of the apparatus of
7 Figure 1 connected to the GPS modem.
8 Figure 3 is a wiring schematic depicting a cable of the apparatus of
9 Figure 1 located between the push button and the circuit board.
10 Figure 4 is a schematic depicting the circuit board from the apparatus
11 of Figure 1.
12 Figure 5 is a logic state diagram depicting one embodiment of a
13 method to disable a GPS modem.
14 Figure 6 is a block diagram depicting a GPS modem connected to a
general purpose computer.
16 Figure 7 is a perspective view depicting a GPS modem comprising an
17 apparatus for manually disabling RF signal transmissions therefrom.
18 DETAIL DESCRIPTION OF EMBODIMENTS
19 An apparatus and method for manually disabling RF signal
transmissions from a GPS modem is provided.
21 Referring to Figure 1, an embodiment of the apparatus is shown.
22 Apparatus 10 comprises push button 12 attached to cable 14 having
23 connector 16. Connector 16 releasably connects with connector 20 disposed
24 on circuit board 18. Apparatus 10 further comprises cable 24 that
operatively
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1 connects circuit board 18 to GPS modem 30. Connector 26 on cable 24
2 releasably connects with connector 22 disposed on circuit board 18.
3 Connector 28 on cable 24 releasably connects to input/output ("I/O") port 32
4 disposed on modem 30. A representative embodiment of modem 30 is the
model ST2500 GPS modem manufactured by Stellar of Herdon, Virgina,
6 U.S.A.
7 Referring to Figure 2, an embodiment of cable 24 is shown. In one
8 embodiment, cable 24 comprises a plurality of conductors. In the illustrated
9 embodiment, cable 24 can comprise 6 conductors, one conductor for each
conductor position in cable connector 26 attached to one end of cable 24.
11 The other end of cable 24 comprises cable connector 28. In the illustrated
12 embodiment, wiring legend 34 shows the wire connections between cable
13 connector 26 and cable connector 28. The connections to various positions
of
14 connector 24 and pins of connector 28 will be discussed in further detail
below.
16 Referring to Figure 3, an embodiment of cable 14 is shown. Cable 14
17 can comprise a plurality of conductors. In the illustrated embodiment,
cable
18 14 comprises at least four conductors, one conductor for each conductor
19 position in cable connector 16 attached to one end of cable 14. The other
end
of cable 14 is operative connected to push button switch 12. Disposed within
21 push button switch 12 are switch contacts 38 and LED 40. A representative
22 example of push button switch 12 is model KB 15 miniature push button
23 switch from NKK switches of Scottsdale, Arizona, U.S.A. although it should
be
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1 obvious to a person skilled in the art that any functionally equivalent
switch
2 can be used.
3 Referring to figure 4, an electronic schematic of circuit board 18 is
4 shown. In one embodiment, circuit board 18 comprises first circuit means 42
and second circuit means 44 although it should be obvious to a person skilled
6 in the art that first circuit means 42 and second circuit means 44 can be
7 located on separate circuit boards.
8 First circuit means 42, as shown in the representative embodiment in
9 figure 4, can include capacitor 48, voltage regulator 50 and capacitor 52.
First
circuit means 42 operatively connects positions J1-3 and J1-5 on connector
11 22 with position J2-3 and J2-2, respectively, on connector 20. Battery 46
12 provides direct current ("DC") voltage to supply circuit board 18. As modem
13 30 is typically located in a motor vehicle, therefore, battery 46 can be a
14 nominal 12 volts DC or 24 volts DC depending on the vehicle modem 30 is
mounted in. Capacitor 48 filters the battery current from battery 46 prior to
16 flowing through regulator 50. Regulator 50 regulates the battery voltage
from
17 battery 46 to a fixed voltage level. In the illustrated embodiment,
regulator 50
18 is a "7805-type" five-volt DC regulator as well known to those skilled in
the art
19 although any functionally equivalent regulator can be used. Capacitor 52
further filters the output voltage 51 from regulator 50. Output voltage 51 is
21 connected to switch contact 38 of push button 12 by connectors 20 and 16
22 and cable 14. In the illustrated embodiment, push button 12 is a momentary
23 push button switch and contacts 38 are normally closed. In this embodiment,
24 output voltage 51 is connected through contacts 38 to digital input port 54
on
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1 I/O port 32 of modem 30. In this configuration, +5 VDC is connected to input
2 port 54 under normal operational conditions. When a user operates push
3 button 12, contacts 38 are opened thereby removing output voltage 51 from
4 input port 54. When the user releases push button 12, contacts 38 close
thereby reconnecting output voltage 51 to input port 54. In one embodiment,
6 the change voltage on input port 54 provides a signal to modem 30 to
7 increment a digital counter disposed within the hardware and/or software of
8 modem 30. In this configuration, modem 30 is programmed to interpret a
9 change in the digital counter as a request to disable RF signal
transmissions
from modem 30. It should be obvious to a person skilled in the art that push
11 button 12 and contacts 38 can be configured with first circuit means 42
such
12 that contacts 38 can normally be open and close a circuit when push button
13 12 is depressed. In another embodiment, contacts 38 can be configured to
14 cause a transition from a low voltage to a high voltage or vice versa when
push button 12 is depressed. In yet another embodiment, contacts 38 can be
16 configured to cause a transition from a logic "zero" to a logic "one" or
vice
17 versa.
18 In one embodiment, second circuit means 44 comprise resistor 58,
19 transistors 60 and 62 and resistor 64. Transistor 60 and 62 can be
configured
as a Darlington pair to operate as an electrical switch in the illustrated
21 embodiment although it should be obvious to a person skilled in the art
that
22 any suitable semiconductor device can be used as an electrical switch.
23 Representative examples of suitable semiconductor devices can include field
24 effect transistors, bipolar junction transistors, triacs, opto-couplers and
light
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1 dependent resistors to name but a few as known to those skilled in the art.
2 The collectors of transistor 60 and 62 are connected to output voltage 51.
3 The emitters of transistors 62 are connected to the anode of LED 40 via
4 resistor 64, connectors 20 and 16 and cable 14. One end of resistor 58 is
connected to the base of transistor 60 while the other end of resistor 58 is
6 operatively connected to digital output port 56 on I/O port 32 of modem 30
via
7 connectors 22 and 26, cable 24 and connector 28. Digital output port 56 is
8 normally set at a low voltage or ground potential. When a user depresses
9 push button 12 to disable RF signal transmissions from modem 30, modem
30 is programmed to cause digital output port 56 to change from ground to a
11 high voltage such as +5 VDC or any other suitable voltage. Upon output port
12 56 being raised to a high voltage, current will flow through resistor 58 to
the
13 base of transistor 60 thereby turning transistor 60 on. This, in turn,
causes
14 transistor 62 to turn on and allow current to flow through resistor 64 to
LED 40
thereby turning LED 40 on and thereby providing a visual indication that RF
16 signal transmission have been disabled on modem 30. It should also be
17 obvious to persons skilled in the art that in place of transistors 60 and
62 to
18 turn LED 40 on and off, electro-mechanical devices such as a relay can be
19 used.
In one embodiment, a kit for use with a GPS modem that can disable
21 RF transmission from the modem include the apparatus as described above
22 and computer readable medium containing software that is used to configure
23 modem 30 to carry out a method for disabling RF signal transmissions.
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1 Referring to Figure 5, a logic state diagram of representative software
2 for use with a GPS modem is shown indicating modes of operation of a GPS
3 modem configured to operate with an apparatus used to disable RF signal
4 transmissions from the modem. As shown in Figure 5, logic state diagram
5 100 can comprise four modes: "TORPOR MODE 104", "STOP MODE 108",
6 "MOVE MODE 112" and "PERF MODE 116". GPS modem 30 is in Torpor
7 Mode 104 when the ignition of the vehicle, that modem 30 is mounted in, is
8 turned off. When modem 30 is in Torpor Mode 104, modem 30 is in sleep
9 mode, hence, the functions of modem 30 are limited to conserve battery
10 power. Modem 30 will still check for incoming user commands. It will also
11 check for external power voltage input to determine when the vehicle's
ignition
12 is turned on.
13 In Stop Mode 108, the ignition of the vehicle is turned on but the
14 vehicle is not moving. In this mode, modem 30 will check the status of the
15 engine being started on the vehicle. It will also check for incoming user
16 commands.
17 In Move Mode 112, the vehicle that modem 30 has its ignition turned
18 on and is moving. In this mode, modem 30 monitors the speed of the vehicle
19 as well as monitoring input user commands.
In Perf Mode 116, modem 30 has received an input command to
21 disable RF signal transmissions from modem 30. In this mode, modem 30 will
22 still generate and accumulate messages regarding the operational parameters
23 concerning the vehicle and hold them in a queue. It will disable the RF
24 transmitter section of the modem or re-tune the RF transmitter portion of
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1 modem 30 to a non-existent or null satellite communications network gateway
2 that effectively disables all RF signal transmissions from modem 30. Modem
3 30 will continue to receive GPS signals from the GPS satellite communication
4 system and upon the vehicle being moved a user-defined safe distance from
the location where RF signal transmissions were disabled, modem 30 is then
6 re-enabled automatically to send RF signal transmissions. Messages stored
7 in the queue will then be transmitted.
8 From each of Torpor Mode 104, Stop Mode 108 and Move Mode 112,
9 modem 30 can be shifted to Perf Mode 116 upon a user depressing push
button 12 of apparatus 10. In Torpor Mode 104, modem 30 can be powered
11 down at step 105 or it can move to Stop Mode 108 when the ignition of the
12 vehicle is turned on at step 107. In Stop Mode 108, modem 30 can revert
13 back to Torpor Mode 104 if the ignition is turned off at step 106.
Conversely,
14 modem 30 can change from Stop Mode 108 to Move Mode 112 when the
vehicle begins moving beyond a predetermined threshold shown at step 110.
16 In Move Mode 112, modem 30 can revert back to Stop Mode 108 if movement
17 of the vehicle decreases below a predetermined threshold as shown in step
18 109. In addition, while the vehicle is moving in Move Mode 112, messages
19 concerning the vehicle are scheduled for transmission by modem 30 at step
113. Modem 30 can revert from Move Mode 112 to Torpor Mode 104 if
21 ignition of the vehicle is turned off at step 111. In each of Torpor Mode
104,
22 Stop. Mode 108 and Move Mode 112, modem 30 can shift to Perf Mode 116
23 when push button 12 is depressed as shown at step 114. In Perf Mode 116,
24 modem 30 monitors its position on the GPS communication system as shown
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1 in step 117. In Perf Mode 116, as noted above, RF signal transmissions from
2 modem 30 are disabled. When the vehicle moves beyond a user-defined
3 predetermined distance as programmed in modem 30, modem 30 will revert
4 from Perf Mode 16 back to its former mode as shown at step 115. This
means the vehicle has moved a safe distance away from where perforation
6 operations are taking place and that RF signal transmissions from modem 30
7 are automatically re-enabled.
8 As noted above, one embodiment of the method and apparatus to
9 disable RF signal transmissions from a GPS modem includes a kit to allow a
user to configure a GPS modem to work with an apparatus to disable RF
11 signal transmissions. This requires programming modem 30 with software to
12 operate the logic states described above and as shown in Figure 5. Figure 6
13 illustrates how this is accomplished. A personal computer 66 is used with
14 modem 30 to program modem 30. Interface cable connects modem 30 at
interface port 70 to interface port 71 on computer 66. As is well known to
16 those skilled in the art, interface ports 70 and 71 may be a serial data
port or a
17 universal serial bus connection or any other suitable method of data
18 communication between computer 66 and modem 30. Computer medium
19 disk 72 is inserted in personal computer 66 and is configured to allow a
user
to program modem 30 with the necessary software to allow modem 30 to
21 carry out the logic flow diagram as set out in Figure 5. It also allows a
user to
22 program the predetermined safe distance that a vehicle must travel away
from
23 a location where RF signal transmissions were disabled from modem 30.
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1 In another embodiment, apparatus 10 may be disposed within modem
2 30. Figure 7 illustrates the simple block diagram of modem 30 comprising
3 push button 12 mounted on modem 30. In this embodiment, functional
4 equivalents of circuit board 18 and first and second connection means 14 and
24 are all disposed within modem 30.
6 Although a few embodiments have been shown and described, it will
7 be appreciated by those skilled in the art that various changes and
8 modifications might be made without departing from the scope of the
9 apparatus and method described herein. The terms and expressions used in
the preceding specification have been used herein as terms of description and
11 not of limitation, and there is no intention in the use of such terms and
12 expressions of excluding equivalents of the features shown and described or
13 portions thereof, it being recognized that the scope of the invention is
defined
14 and limited only by the claims that follow.
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