# Patent

## Title
Cellular augmented radar/laser detection using local mobile network within cellular network

## Abstract

A radar/laser emission detector is augmented with a cellular communications capability to provide the capability to share emission detection information amongst drivers to give other drivers even more advanced warning. A network of a plurality of cellular augmented radar/laser emission detector devices may be formed, each having the capability to source the location of radar or laser emission detections to others requesting access to such information, and each being warned when within a proximity of a recent radar or laser emission detection reported by at least one of the plurality of hybrid radar/laser detector devices. A local area, mobile area wireless network (MAWN) is formed in a cellular network to share radar/laser detection information among drivers. Mobile Position Centers (MPCs) are provided in ANSI-41 networks and Gateway Mobile Location Centers (GMLCs) (GSM networks), to determine other members that are proximate to a device that is detecting radar emission.

## Background
The present application is a continuation of U.S. application Ser. No. 11/405,579 to Pitt et al. entitled “Cellular Augmented Radar/Laser Detection Using Local Mobile Network Within Cellular Network”, filed on Apr. 18, 2006 now U.S. Pat. No. 7,899,450, which claims priority from U.S. Provisional Application 60/777,565 to Pitt et al. entitled “Cellular Augmented Radar/Laser Detection Using Local Mobile Network Within Cellular Network”, filed on Mar. 1, 2006, the entirety of both of which is are expressly incorporated herein by reference.


BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to wireless telecommunications. More particularly, it relates to the establishment of a local area network within a cellular network for use by radar/laser detection technology.
2. Background of the Related Art
Radar detectors are well known, as are laser detectors. Radar detectors detect radio frequency emissions in a given frequency range. Laser detectors detect an impinging laser beam directed toward the detector.
In a popular application, radar or laser detectors are used for automobiles, and are often quite small and many times are battery operated to eliminate the need for power cords. A modern radar or laser detector can run for 60 to 90 days on two AA 1.5v cell batteries, so their power needs are relatively small. Radar or laser detectors detect the presence of any of a variety of radar or laser emissions. They warn a driver of a vehicle of an impending radar trap by emitting an audible and/or visible warning indicating the detection of radar impinging upon the antenna of the radar device. For instance, different audio tones may be sounded representing each type of detection. Technology attempts to increase the amount of advance warning given to the driver.
Thus, any given radar detector warns the occupants and particularly the driver of any given vehicle, some giving more warning time than others. A driver of the vehicle must react immediately to avoid consequences related to being detected by the radar or laser. Ideally, this is sufficient time to avoid the consequences, but in many instances it may already be too late as at that point the speed of the vehicle may have already been measured. This is particularly true if the operator of the radar or laser emission is pointing and shooting once the driver's vehicle comes into range.
Vehicles to follow may suffer the same fate, especially since they at best will not receive any earlier warning of the detection of radar or laser than did the driver before. This is because a driver is warned about emissions that their device detects directly.
There is a need for providing earlier warning to users of radar and/or laser detectors.
SUMMARY OF THE INVENTION
In accordance with the principles of the present invention, a method of forming a local area network within a wide area network comprises determining a subset of members of the wide area network that are proximate to a given member. A local area network is established within the wide area network with only the determined proximate members.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a hybrid radar/laser detector device including cellular communications capability, in accordance with the principles of the present invention.
FIG. 2 shows a plurality of hybrid radar/laser emission detector devices each having the capability to source the location of radar or laser emission detections, and each being warned when within a proximity of a recent radar or laser emission detection reported by at least one of the plurality of hybrid radar/laser detector devices, in accordance with the principles of the present invention.
FIG. 3 shows an exemplary Cellular Augmented Radar Detector (CARD) local mobile net, in accordance with the principles of the present invention.
FIG. 4 shows figurative coverage of the Earth's surface with successively finer grained gridlines, in accordance with the principles of the present invention.
FIG. 5 shows an exemplary CARDloc table including identifier, location (latitude and longitude), and optimization indices, in a CARD local mobile net in accordance with the principles of the present invention.
FIG. 6 shows a matrix for Primary indices for a CARD nexus that maintains a collection of matrices in Random Access Memory (RAM), i.e., not in a relational database, in accordance with the principles of the present invention.



DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
The present invention isn't so much a remedy for a problem with the existing technology as it is a significant enhancement to the existing technology.
Being warned about radar or laser emissions detected by ones own device gives some advance warning. However, the present invention provides warnings about emissions detected by other detection devices on the road ahead of the driver. This significantly increases the amount of advance time of warning, giving the driver much more time to react.
In accordance with the principles of the present invention, automatic sharing of emission detection information is provided among drivers of separate vehicles by combining or augmenting an otherwise conventional radar or laser detector with a cellular communication front end. This makes it possible for one emission detector device to share its information with other devices, e.g., similarly capable cellular augmented radar devices.
Modern radar/laser detector devices have very low battery consumption requirements and provide some warning of nearby radar and/or laser emissions. Typically these devices emit an audio tone when emissions are detected. The warning tone is audible within the vehicle so that the driver (and any passengers) within the vehicle will receive warning.
Modern cellular communication devices have higher battery consumption requirements but also have much more powerful batteries. Cellular communication devices have the ability, through a wireless network, to share analog and digital information with other cellular communication devices.
A hybrid device in accordance with the present invention preferably has the ability to detect both radar and laser emissions, though detection of only radar emission or only laser emission is within the scope of the present invention.
Importantly, the device includes the ability to communicate via a cellular network. Such use of the cellular front end is relatively small, and wouldn't require any more battery capacity than is already provided for the cellular device. For instance, communication on the wireless network is preferably performed only when detection of emission occurs. Preferably, upon detection of emission, the cellular front end may be activated to allow the hybrid device to report to an established mobile network that detection has occurred.
Receiving devices may be provided with advance warning by polling their wireless network, e.g., by dialing a central database containing current detection information.
The size of the device need not be much bigger than an otherwise conventional radar detector devices, as a keypad and a large LCD display as provided by most mobile cellular devices is not required. The hybrid device need be larger only to include a cellular antenna, and if desired to include a larger battery, space for the cellular processor card, etc.
FIG. 1 shows a hybrid radar/laser detector device including cellular communications capability, in accordance with the principles of the present invention.
In particular, a cellular augmented radar/laser detection device 100 as shown in FIG. 1 provides the capability to share emission detection information amongst drivers to give those drivers even more advanced warning. The cellular augmented radar/laser detection device 100 includes a cellular processor front end 120 together with an associated cellular antenna 122. The cellular augmented radar/laser detection device 100 also includes otherwise conventional radar/laser emission detection components, including a laser emission detector 130, a radar emission detector 137, a battery 132, an emission signal processor 134, and front panel user interface 136 including LCD display and control buttons.
Of course, the cellular processor front end 120 and emission signal processor 134, and any other components within the cellular augmented radar/laser detection device 100, may be integrated with one another into a common physical component.
FIG. 2 shows a plurality of hybrid radar/laser emission detector devices each having the capability to source the location of radar or laser emission detections, and each being warned when within a proximity of a recent radar or laser emission detection reported by at least one of the plurality of hybrid radar/laser detector devices, in accordance with the principles of the present invention.
In particular, as shown in FIG. 2, radar or laser emissions 201 detected by a cellular augmented radar detector (CARD) device warns the driver of that vehicle 202a via audible tone, but also importantly relays the detection information digitally 202b to a cellular network system 200. For instance, in the given example of FIG. 2, relayed detection information is transmitted to other CARD devices 203a, 203b via the cellular network 200. The CARD devices 203a, 203b then warns their respective drivers in those vehicles of the remote detection of radar or laser by another networked CARD device 100a. The warning may be via audible tone 204a, 204b. Preferably, the audible tone 204a, 204b is distinctive from an audible tone otherwise emitted as a result of direct detection of radar or laser by the respective CARD device 100b, 100c itself.
Ideally, only CARD devices 100b, 100c within proximity of the source of a CARD device 100a directly detecting emission of radar or laser emission are notified. This may be accomplished in a number of different ways. For instance, CARD device users with given phone number area codes may be presumed to be primarily within a given physical area serviced by those area codes, but this is not at all accurate and can result in erroneous warning. Warning a CARD device owner that another CARD device has detected radar or laser emissions is impractical and at the least annoying if the detection isn't in relatively close proximity.
CARD devices themselves are unable to determine which other CARD devices are in close proximity. The problem is aggravated because the use of cellular technology enables CARD devices to communicate with other CARD devices anywhere in the world.
In accordance with the present invention, Mobile Position Centers (MPCs) are provided in ANSI-41 networks and Gateway Mobile Location Centres (GMLCs) are provided in GSM networks, to enable the capability to find CARD devices within a configurable proximity limit of any “announcing” CARD device (i.e. any CARD device that is broadcasting an emission detection warning). Thus, once a CARD device detects emission, it reports via a cellular network to an application that then identifies other proximate CARD devices via query to an MPC (or GMLC), and transmits a detection warning message to only the CARD devices that are identified as currently being proximate to the detecting CARD device at the time of the detection and query.
MPCs and GMLCs are known and currently in operation to enable location services for locating a given mobile device. However, current MPCs or GMLCs do not provide a proximity determination service. In accordance with the principles of the present invention, location information available from MPCs and/or GMLCs for every querying CARD device provides the identity of all other CARD devices that are in close proximity to the querying (and emission detecting) CARD device. This enables the formation of a temporary local “network” based on a current proximity to one another. In this way, CARD devices are able to share emission detection information with only those CARD devices that will find the information useful and practical.
Thus, practical localized sharing of digital information is accomplished over a network of physically proximate devices, all of which being part of a global network. This local area network, otherwise called a mobile area wireless network (MAWN), makes interaction of Cellular Augmented Radar Detector (CARD) devices practical. Armed with proximity information, emission detection broadcasts are transmitted only to CARD devices in close proximity to the sourcing CARD device.
FIG. 3 shows an exemplary Cellular Augmented Radar Detector (CARD) local mobile net, in accordance with the principles of the present invention.
In particular, as shown in FIG. 3, a “CARD announcement coordination processor” or “CARD Nexus” gateway 300 ensures that CARD announcements are relayed only to those CARD devices for which the relevant announcement is pertinent.
The CARD Nexus gateway 300 may be a fully qualified Mobile Position Center (for ANSI-41 networks) or a fully qualified Gateway Mobile Location Centre (for GSM networks). The CARD Nexus gateway 300 also includes proximity evaluation logic. In an alternative, more practical architecture, only the proximity evaluation logic is implemented in the CARD Nexus gateway 300. A CARD Nexus interface is implemented with an MPC/GMLC 320 to get the location(s) for each of the operating CARD devices. The given embodiments show a system utilizing a CARD Nexus gateway 300 that works with a separate MPC/GMLC 320.
The disclosed embodiments prefer that CARD devices that are powered off will not interact with the CARD Nexus in any way. The disclosed embodiments also presume that any CARD device that is not enabled for cellular broadcast will not interact with the CARD Nexus in any way. CARD devices that are powered on but not enabled for cellular broadcast would function in otherwise the same manner as otherwise conventional radar detectors, i.e., they detect radar and laser emissions and emit an audible warning tone only to the driver and passengers within the vehicle in which the CARD device is mounted.
CARD devices that are powered on and enabled to broadcast via its cellular subsystem periodically connect (z in FIG. 3) to the cellular system to allow the CARD Nexus gateway 300 to determine that CARD device's current location. The CARD Nexus gateway 300 accesses the MPC/GMLC 320 to determine the CARD's location, and then saves the CARD's identity with its newly determined location (hereafter referred to as “CARDloc”) in a relational database for easy retrieval during proximity evaluation.
When a CARD device (e.g., device B in FIG. 3) that is powered ON and enabled to broadcast via its cellular subsystem detects either radar or laser emissions 301, it issues an emission detection announcement 302. The emission detection announcement 302 is routed through the hosting cellular carrier's core network 303, 304 to the CARD Nexus gateway 300.
The CARD Nexus gateway 300 determines the current location of the announcing CARD device by interfacing 305, 306 with the MPC/GMLC 320, and then accesses a relational database to identify other CARD devices in close proximity to the announcing device (C and D but not E).
The term “close proximity” may be predefined by the CARD Nexus system operator based on linear distance. Alternatively, close proximity may be defined on a device by device basis, or even defined within each query from the announcing CARD device to the CARD Nexus gateway 300.
Close proximity may alternatively be defined as a shortest distance based on length of roads to the announcing CARD device, but this approach requires route calculations for each CARD device and thus will be significantly slow unless the processor of the CARD Nexus is capable of making such route calculations in a timely manner.
The CARD Nexus gateway 300 then issues warnings 307, 308a, 308b to those CARD devices within the designated proximity so that relayed warnings 309a, 309b will alert the passengers of those vehicles.
For the purposes of this invention, close proximity evaluation methodology is designed for speed of performance during proximity evaluation processing. Thus, the CARD Nexus gateway 300 reduces a CARD device's location, represented in decimal degrees of latitude and longitude, into indices of latitude and indices of longitude within four (4) layers, and makes a simple calculation of a linear distance between an announcing CARD device and each potentially proximate CARD device:
1) Primary: tens of degrees ( ̃700 statute mile resolution)
2) Secondary: Degrees ( ̃70 statute mile resolution)
3) Tertiary: minutes ( ̃6000 foot resolution)
4) Quaternary: seconds ( ̃100 foot resolution)
FIG. 4 shows figurative coverage of the Earth's surface with successively finer grained gridlines, in accordance with the principles of the present invention.
In particular, as shown in FIG. 4, seconds of latitude and longitude yield a grid whose vertices are approximately 100 feet apart at the equator and somewhat closer together the farther away from the equator (North or South) the CARD device is located. Should the need arise to attain even finer granularity than seconds, a fifth (Quinary) and even sixth (Senary) layer can be added to represent 10ths of seconds ( ̃10 feet) and 100ths of seconds ( ̃12 inches).
FIG. 5 shows an exemplary CARDloc table including identifier, location (latitude and longitude), and optimization indices, in a CARD local mobile net in accordance with the principles of the present invention.
In particular, every time a CARD device notifies the CARD Nexus gateway 300 (CARDloc) or makes an emission detection announcement, the CARD Nexus gateway 300 saves that CARD's identifier, location (latitude and longitude), and optimization indices in a CARDloc table as exemplified in FIG. 5.
The Lat and Lon values are normalized to be decimal degrees in the range −90.0 through +90.0 for Latitude and −180.0 through +180.0 for Longitude. The indices are computed as follows:

PrimaryX=int(round((Lon/10.0)−0.5))

PrimaryY=int(round((Lat/10.0)−0.5))

SecondaryX=int(truncate(Lon−(PrimaryX*10.0)))

SecondaryY=int(truncate(Lat−(PrimaryY*10.0)))

TertiaryX=int(truncate((Lon−((PrimaryX*10.0)+SecondaryX))*60.0))

TertiaryY=int(truncate((Lat−((PrimaryY*10.0)+SecondaryY))*60.0))

QuaternaryX=int(truncate((Lon−((PrimaryX*10.0)+SecondaryX+(TertiaryX/60.0)))*3600.0))

QuaternaryY=int(truncate((Lat−((PrimaryY*10.0)+SecondaryY+(TertiaryY/60.0)))*3600.0))

These equations presume that the round ( ) function always rounds an “n.5” value up, so that 0.5 becomes 1.0, 2.5 becomes 3.0, −3.5 becomes −3.0, etc. Some adjustments might be necessary to accommodate specific hardware architectures, operating systems, and compilers.
The intent, though, is to compute an index based on the lower left corner of the square in which the CARD is located. The primary square (Q) is a 10 degree by 10 degree square. The secondary square (R) is a one degree by one degree square located within the primary. The tertiary square (S) is a one minute by one minute square located within the secondary. The quaternary square (T) is a one second by one second square located within the tertiary.
These computations produce values in the following ranges:
−18<=PrimaryX<=18 −9<=PrimaryY<=9
0<=SecondaryX<=9 0<=SecondaryY<=9
0<=TertiaryX<=60 0<=TertiaryY<=60
0<=QuaternaryX<=60 0<=QuaternaryY<=60
FIG. 6 shows a matrix for primary indices for a CARD Nexus gateway 300 that maintains a collection of matrices in temporary memory such as Random Access Memory (RAM), i.e., not in a relational database, in accordance with the principles of the present invention.
A collection of matrices in accordance with the principles of the present invention preferably always includes a matrix for the primary indices, as shown in FIG. 6.
The primary matrix is preferably accompanied by a PrimaryCount indicating how many CARDS are present.
The Primary Matrix is also preferably accompanied by an array or list of the primary matrix elements in which CARDs can be found (list will be empty if PrimaryCount is zero).
Each element in the 36×18 Primary matrix preferably contains: (1) A count of how many CARDs are present in that particular 10 deg×10 deg area; and (2) reference to a secondary matrix (reference will be NULL if count is zero).
Secondary (10×10 matrix), tertiary (60×60), and quaternary (60×60) matrices will be allocated, maintained, and eliminated as needed to manage memory use in the CARD Nexus gateway 300.
Each secondary matrix is preferably accompanied by a SecondaryCount indicating how many CARD devices are present in that 10 deg×10 deg area.
Each secondary matrix is also preferably accompanied by an array or list of the secondary matrix elements in which CARDs can be found. (Note that the list will be empty if its SecondaryCount is zero.)
Each element in a 10×10 secondary matrix preferably contains: (1) count of how many CARDs are present in that particular 1 deg×1 deg area; and (2) reference to a tertiary matrix. (Note that the reference will be NULL if the count is zero).
Each tertiary matrix is preferably accompanied by a TertiaryCount indicating how many CARDs are present in that 1 deg×1 deg area.
Each tertiary matrix is preferably accompanied by an array or list of the tertiary matrix elements in which CARDs can be found. (Note that the list will be empty if its TertiaryCount is zero.)
Each element in a 60×60 tertiary matrix preferably contains: (1) A count of how many CARDs are present in that particular 1 minute×1 minute area; and (2) a reference to a quaternary matrix. (Note that the reference will be NULL if the count is zero.)
Each quaternary matrix is preferably accompanied by a QuaternaryCount indicating how many CARDs are present in that 1 min×1 min area.
Each quaternary matrix is preferably accompanied by an array or list of the quaternary elements in which CARDs can be found. (Note that the list will be empty if QuaternaryCount is zero.)
Each element in a 60×60 quaternary matrix preferably contains: (1) A count of how many CARDs are present in that particular 1 second×1 second area; and (2) An array or list of CARD Identifiers that are present in the 1 sec×1 sec area. (Note that the list will be empty if count is zero.)
This four (4) tier data structure makes it possible for the CARD Nexus gateway 300 to rapidly identify all of the CARD devices in close proximity to an announcing CARD device so that warnings can be relayed in a timely manner. Maintenance of this four (4) tier structure is complex but will be clearly understood by those of ordinary skill in data structures.
Proximity can be a configured reference value defined in terms of hundreds of feet, thousands of feet, tens of miles, hundreds of miles, etc. Regardless of the defined distance for ‘proximate’, the CARD Nexus gateway 300 is able to rapidly identify which CARD devices meet the criteria. The broader the proximity value is defined, though, the longer it will generally take the CARD Nexus gateway 300 to send all the notifications due to latencies imposed by the carrier's core network.
The invention has particular applicability with people driving ground transportation. Moreover, the use of a mobile area wireless network using cellular technology can be expanded to include the sharing of other relevant vehicle information with proximate other vehicles communicating together on a cellular local area network. For instance, vehicles may advertise to other proximate vehicles that they are accelerating, braking, emergency braking, or beginning to change lanes. This technology may also lead to the ability to foster auto-piloting of a vehicle. Buses may advertise to their next bus stop how far away they are and what their estimated arrival time is. Airplanes may advertise to other planes what their speed is, what their altitude is, and what their heading is, to provide more automated collision avoidance.
While the invention has been described with reference to the exemplary embodiments thereof, those skilled in the art will be able to make various modifications to the described embodiments of the invention without departing from the true spirit and scope of the invention.

## Claims

1. A method of forming a local area network in motion within a wide area network, comprising:
populating a physical warning database with current location information for each of a plurality of transmitter augmented warning detectors in motion;
querying said physical warning database to determine a subset of said plurality of transmitter augmented warning detectors in motion that are proximate to a given transmitter augmented warning detector in motion; and
transmitting an emergency braking warning to only said subset of transmitter augmented warning detectors in motion.

2. The method of forming a local area network in motion within a wide area network according to claim 1, further comprising:
transmitting detection of a radar emission by a given transmitter augmented warning detector in motion to only said plurality of determined proximate transmitter augmented warning detectors in motion.

3. The method of forming a local area network in motion within a wide area network according to claim 1, further comprising:
transmitting detection of a laser emission by a given transmitter augmented warning detector in motion to only said plurality of determined proximate transmitter augmented warning detectors in motion.

4. The method of forming a local area network in motion within a wide area network according to claim 1, wherein:
said proximity is determined based on a linear distance between said given transmitter augmented warning detector in motion and all other said plurality of transmitter augmented warning detectors in motion.

5. The method of forming a local area network in motion within a wide area network according to claim 1, wherein:
said proximity is determined based on a driving distance between said given transmitter augmented warning detector in motion and all other said plurality of transmitter augmented warning detectors in motion.

6. The method of forming a local area network in motion within a wide area network according to claim 1, wherein:
said wide area network is a cellular phone network.

7. The method of forming a local area network in motion within a wide area network according to claim 1, wherein:
said local area network relates to drivers within a given area.

8. The method of forming a local area network in motion within a wide area network according to claim 1, further comprising:
querying a gateway to determine transmitter augmented warning detectors in motion that are proximate to a querying transmitter augmented warning detector in motion.

9. The method of forming a local area network in motion within a wide area network according to claim 1, further comprising:
querying a mobile positioning center (MPC) in an ANSI-41 wide area network.

10. The method of forming a local area network in motion within a wide area network according to claim 1, further comprising:
querying a gateway mobile location centre (GMLC) in a GSM wide area network.

11. A transmitter augmented warning detector forming a local area network in motion within a wide area network, comprising:
a physical warning database to provide current location information for each of a plurality of transmitter augmented warning detectors in motion, and to provide a determination of a subset of said plurality of transmitter augmented warning detectors in motion that are proximate to a given transmitter augmented warning detector in motion; and
a transmitter to transmit an emergency braking warning to only said subset of transmitter augmented warning detectors in motion.

12. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, wherein:
said transmitter transmits detection of a radar emission by said given transmitter augmented warning detector in motion to only said plurality of determined proximate transmitter augmented warning detectors in motion.

13. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, wherein:
said transmitter transmits detection of a laser emission by said given transmitter augmented warning detector in motion to only said plurality of determined proximate transmitter augmented warning detectors in motion.

14. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, wherein:
said proximity is based on a linear distance between said given transmitter augmented warning detector in motion and all other said plurality of transmitter augmented warning detectors in motion.

15. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, wherein:
said proximity is based on a driving distance between said given transmitter augmented warning detector in motion and all other said plurality of transmitter augmented warning detectors in motion.

16. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, wherein:
said wide area network is a cellular phone network.

17. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, wherein:
said local area network relates to drivers within a given area.

18. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, wherein:
said transmitter transmits a query to a gateway to determine transmitter augmented warning detectors in motion that are proximate to a querying transmitter augmented warning detector in motion.

19. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, wherein:
said current location is derived from querying a mobile positioning center (MPC) in an ANSI-41 wide area network.

20. The transmitter augmented warning detector forming a local area network in motion within a wide area network according to claim 11, further comprising:
said current location is derived from querying a gateway mobile location centre (GMLC) in a GSM wide area network.