CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation of co-pending U.S. patent application Ser. No. 10/843,203, filed May 10, 2004, which is a Continuation-in-Part of co-pending U.S. patent application Ser. No. 09/975,898, filed Oct. 10, 2001, which is a Divisional of U.S. patent application Ser. No. 09/364,557, filed Jul. 29, 1999, now issued as U.S. Pat. No. 6,321,091.
BACKGROUND OF THE INVENTION 1. Field of the Invention
This disclosure pertains generally to locating and tracking systems.
2. The Prior Art
Wireless devices of all kinds have been in use for pinpointing objects, people and animals on the surface of the earth, under water, or in space. Some wireless devices also provide navigational information such as whether or not a moving vessel or vehicle is “on course” to its predetermined destination. Radio frequency (RF) location and navigation systems are the oldest, and more recently developed devices function at infrared (IR) and visible wavelengths. Acoustic location and navigation systems such as sonar also exist.
Traditional radiolocation is the process of determining the position of a vehicle, aircraft, or vessel. Radionavigation is the use of radio apparatus, by personnel aboard moving vessels, for the purpose of plotting and maintaining a course.
The simplest method of radiolocation is known as the “directional method” wherein two or more fixed receiving stations, which are separated by a fixed distance, receive radio transmission signals from a transmitter that is mounted on a vessel. The vessel location is determined from the intersection of great circles drawn outward from the receiver station points in the appropriate directions.
A second implementation for determining the position of objects involves radar. The term “radar” is an acronym derived from the words “radio detection and ranging.” Electromagnetic (EM) waves having certain frequencies reflect from various objects, particularly if those objects contain metals or other electrical conductors. Using a transmitter, receiver, and a display at a fixed station, the location of flying objects with respect to the fixed location may be determined by ascertaining the directions from which radio signal are returned, and by measuring the time it takes for an EM pulse to travel from the transmitter to a target and back. However, such radar systems are not useful for tracking a ground moving objects, or objects that have poor EM reflective properties. Additionally, radar systems are not normally useful for differentiating the identity of objects, particularly when there is a plurality of objects.
The most sophisticated radiolocation and radionavigation techniques employ the global positioning system (GPS). The GPS is a network of radiolocation and radionavigation apparatus that operates on a worldwide basis. The GPS system employs several satellites and allows determination of latitude, longitude, and altitude.
Most recently, vehicle location and navigation systems have been adapted to track the location of automobiles using the GPS system. Such systems include sensors, which are fixed to the automobile and draw power from either the car battery or a second large power source. The purpose of fixing the automobile tracking sensor to the vehicle is primarily for security reasons. Because one main purpose of the tracking system to locate the vehicle in cases of theft, it is important that the sensor systems of the tracking systems be mounted or otherwise fixed to the vehicle, making such sensor systems not easily removed or transportable from a first object to a second object. Furthermore, because a large power source such as a car battery is normally available to such tracking systems, intelligent power saving or conserving features are not provided.
Accordingly, there is a need for a tracking and locating system and method which provides for a lightweight and portable tracking locator device, which is easily transferable from user to user or object to object, which provides power saving and conserving features associated with the locator device, and which further provides positional information of such locator devices in the form of hypertext markup language pages viewable on the Internet. The present invention satisfies these needs, as well as others, and generally overcomes the deficiencies found in the background art.
BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood by reference to the following drawings, which are for illustrative purposes only.
FIG. 1 is a block diagram of a locating system in accordance with the present invention.
FIG. 2 is a block diagram of an alternative portable locator device.
FIG. 3 is a flowchart showing generally the steps involved in carrying out the power management means of the invention.
FIG. 4 is a diagram of aprior art 911 system.
FIG. 5 is a diagram of a prior art E911 system.
FIGS. 6A-6C are diagrams of prior art E911 systems using network-based location methods.
FIG. 7 is a diagram of a prior art E911 system using a terminal-based location method.
FIG. 8 is a diagram of a locator system configured in accordance with the teachings of this disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the system shownFIG. 1 throughFIG. 2 and the method outlined inFIG. 3. It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to details and the order of the steps, without departing from the basic concepts as disclosed herein. The invention is disclosed generally in terms of a tracking and locating system and method, although numerous other uses for the invention will suggest themselves to persons of ordinary skill in the art.
Referring first toFIG. 1, there is shown generally a block diagram of a tracking and locatingsystem10 in accordance with the invention. Thesystem10 comprises alocator device12 having means for generating positional information of the locator device. The present system is configured to locate and track one or more locator devices, each operating aslocator device12 as described herein, and each having a unique identifier or serial number associated therewith. The positional information generating means comprises areceiver14 connected to anantenna16 and a central processing unit (CPU)18 connected tomemory20. Thereceiver14 is operatively coupled for communication with theCPU18.
Acontrol interface21 is provided to accept input commands from a user of thelocator device12. Thecontrol interface21 in connected to theCPU18 for processing of input commands issued at thecontrol interface21 by the user oflocator device12 and to apower source30 for providing typical activation means for thelocator device12.
Theantenna16 comprises a standard radio-frequency (RF) transducer as is known in the art for receiving electromagnetic wave signals from a plurality of visible radiolocation transmitters. The term “visible” refers to the ability of the locator device to receive synchronization signals and timing signals and other informational data from the radiolocation transmitter. In the preferred embodiment, the radiolocation transmitters comprise global positioning system (GPS)satellites22athrough22n, although land-based radiolocation transmitters may also be used. The GPS satellites transmit signals in the UHF part of the radio spectrum, thus theantenna16 of the preferred embodiment is structured and configured to receive signals in the UHF frequency range.
Thereceiver14 comprises standard circuit stage components or like hardware for detecting and receiving radio frequency signals as in known in the art and carries out the operation of scanning the input stream received byantenna16 and demodulating GPS signal data into serial data for use by theCPU18. In an illustrative embodiment thereceiver unit14 is an ASHTECH® G-8 model unit. This serial data produced by thereceiver unit14 is then communication to theCPU18 for further processing as described in more detail below.
GPS satellites22athrough22ntransmit signals having special codes containing information used by various receiving apparatus for calculating position. The CPU includes program means running thereon for determining the location of thelocator device12 as in known in the art. In general, theCPU18 calculates the distance between thelocator device12 and theGPS satellites22athrough22nusing the timing signals provided by theGPS satellites22athrough22n, and carries out standard radiolocation calculations to formulate “positional data” which is the location of thelocator device12 relative to the positions of theGPS satellites22athrough22n. The timing signals as well as the positions of the GPS satellites are communicated to thelocator device12 though the code signals transmitted by theGPS satellites22athrough22n. The positional data formulated by theCPU18 includes latitude, longitude, and altitude information about thelocator device12. The positional data formulated by theCPU18 is further maintained or recorded in a log in thememory20 for later computation as described in conjunction withFIG. 3. TheCPU18 also carries out the operation periodically communicating the computed positional data to a wireless modem device for further transmission as described below.
Thelocator device12 further comprises acellular modem24 operatively coupled theCPU18. Thecellular modem24 includes anantenna26 and may be any cellular modem or personal communication services (PCS) modem, however a cellular modem is preferred because of the pervasiveness of cellular service availability. In an illustrative embodiment, thecellular modem24 comprises a MOTOROLA® 505sd modem. Thecellular modem24 carries out the operation of transmitting the positional data received from theCPU18 and communicating such positional data to a wireless service provider. Preferably the wireless service provider is acellular service provider28. The cellular frequency for such communication is typically designated by thecellular provider28.
Thelocator device12 also comprises apower source30 provided therein. Thepower source30 is normally a standard battery. Thepower source30 provides power to the various elements of thelocator device12 including thereceiver14, theCPU18, thememory20 and thecellular modem24. TheCPU18 communicates withpower source30 vialine32 and includes program means residing thereon for managing power usage and consumption ofdevice12 as described below in conjunction withFIG. 3.
Preferably, thereceiver14, theCPU18, thememory20, thecellular modem24 are mounted on a circuit board or like hardware device and is housed within a casing unit (not shown). Thepower source30 is also provided within the casing unit. Thecontrol interface21 may be provided integral with the casing unit or provided on the outer surface of the casing unit and preferably includes switches or other similar controls (not shown) for accepting external input from a user of thelocator device12.
Thecellular provider28 is in wireless communication with thelocator device12 via radio signals transmitted by thecellular modem24 for the purposes of receiving the positional data information transmitted the bylocator device12. As noted above, in the preferred embodiment, the wireless modem oflocator device12 comprisescellular modem24, and the wireless service provider iscellular provider28. Generally,cellular provider28 comprises a network ofantennas34a through34n each of which includes means for receiving from and transmitting data to thecellular modem24 as is generally known in the art. A base device36 is provided with thecellular provider28 and is operatively coupled to the receiving and transmitting means of theantennas34athrough34nthus forming a “cellular network”. The base device36 includes means for managing the communication exchange of the devices participating in the cellular network as in known in the art. Thecellular provider28 communicates positional data received from thelocator device12 to aserver computer38 for further processing.
Theserver computer38 comprises a standard computer such as a minicomputer, a microcomputer, a UNIX® machine, mainframe machine, personal computer (PC) such as INTEL®, APPLE®, or SUN® based processing computer or close thereof, or other appropriate data processing means.Server computer38 also includes typical components (not shown), such as a motherboard, central processing unit (CPU), random access memory (RAM), hard disk drive, display adapter, other storage media such as diskette drive, CD-ROM, flash-ROM, tape drive, PCMCIA cards and/or other removable media, a monitor, keyboard, mouse and/or other user interface means, a modem, network interface card (NIC), and/or other conventional input/output devices.
Theserver computer38 is operatively coupled with thecellular provider28 to receive positional data information, normally through a fast data connection means, such as T1, T3, multiple T1, multiple T3, or other high-speed conventional data connection means.Server computer38 andcellular provider28 can alternatively connect to each other using a standard Internet connection means, cable means, telephone means, wireless means, or other means for establishing a communication network.Server computer38 is also operatively coupled to the Internet shown generally as41 via a fast connection means, such as T1, T3, multiple T1, multiple T3, or other high-speed conventional data connection means. Alternative methods forconnection server computer38 to the Internet as is known in the art may also be used.
Server computer38 also has loaded in it RAM a conventional server operation system (not shown) such as UNIX, WINDOWS NT, NOVELL, SOLARIS, or other server operating system. Server computer also has loaded in its RAMweb server software40 anddatabase software42. Theweb server software40 carries out the operation of handing hypertext transfer protocol (HTTP) or Web page request as described further below.
Thedatabase software42 carries out the operation of storing, retrieving, accessing, deleting and updating database information stored indatabase44. Thedatabase44 contains information related to eachlocator device12 of thesystem10. Positional data information about locator devices is stored in a tracking table (not shown) within thedatabase44.
The tracking table includes, for example, a plurality of LID numbers corresponding to each locator device's identifying code or serial number, data location information such as latitude, longitude, and altitude, the date and time when such data location information was entered, and other pertinent information associated with each LID number. Subscriber data information about subscriber users is stored in a subscriber table (not shown) within thedatabase44.
The subscriber table includes, for example, a plurality of SID number corresponding to each subscriber user, with a username or screen name, e-mail address, password, the LID or locator devices the subscriber may track, and other pertinent subscriber user information. The subscriber table is related to the tracking table via the common LID field residing in both tables. Thus positional data information related to a subscribe SID in the subscriber table may be obtained by querying the positional data information in the corresponding LID field in the tracking table.
As positional data is received byserver computer38 from thecellular provider28, thedatabase software42 parses the data information into locator device identity information and positional data information, and stores such information along with the current date and time into the corresponding fields in the tracking table. Thus the tracking table constantly maintains current positional data information of the various locator devices participating in thesystem10.
Asubscriber computer46 is provided in the system for allowing a subscriber user wishing to track a particular locator device.Subscriber computer46, likeserver computer38, preferably comprises as standard computer such as a minicomputer, a microcomputer, a UNIX® machine, mainframe machine, personal computer (PC) such as INTEL®, APPLE®, or SUN® based processing computer or close thereof, or other appropriate data processing means.
Server computer38 also includes typical components (not shown), such as a motherboard, central processing unit (CPU), random access memory (RAM), hard disk drive, display adapter, other storage media such as diskette drive, CD-ROM, flash-ROM, tape drive, PCMCIA cards and/or other removable media, a monitor, keyboard, mouse and/or other user interface means, a modem, and/or other conventional input/output devices.Subscriber computer46 also loaded in its RAM an operating system (not shown) such as UNIX, WINDOWS98 or the like.
Subscriber computer46 further has loaded in ram aWeb browser program48 such as NETSCAPE, INTERNET EXPLORER, AOL, or like browsing software for client subscriber computers.Subscriber computer46 is normally embodied in conventional desktop or “tower” machine, but can alternatively be embodied in a portable or “laptop” computer, a handheld personal digital assistant (PDA), a cellular phone capable of browsing Web pages, a Internet terminal capable of browsing Web pages such as WEBTV, or other Web browsing devices.
Subscriber computer46 is operatively coupled for communication with theserver computer38, typically via theInternet41 through a phone connection using a modem and telephone line (not shown), in a standard fashion. The subscriber user ofsubscriber computer46 will typically dial the user's Internet service provider (ISP) (not shown) through a modem and phone line to establish a connection between thesubscriber computer46 and theInternet41. As described above,server computer38 is operatively coupled for communication to theInternet41. Since computers connected to theInternet41, are themselves connected to each other, theInternet41 establishes a network communication link between thesubscriber computer46 and theserver computer38. Generally,subscriber computer46 andserver computer38 communicate using the TCP/IP (transfer control protocol/internet protocol). More specifically, theWeb browser software48 residing in thesubscriber computer46 communicates with theWeb server software40 residing in theserver computer38 via the HTTP protocol. However, other protocols for communication may also be utilized, including PPTP, NetBEUI over TCP/IP, and other appropriate network protocols.
The subscriber user ofsubscriber computer46 requests positional data information by accessing theWeb browser software48 and contacting theWeb server software40 residing onserver computer38. Normally, a subscriber user will make a request to theserver computer38, which is received byWeb server software40.Web server software40 validates the identity of subscriber user to ensure that the user requesting positional data information is the appropriate authorized user. This validation or authorization is normally carried out though standard challenge/response security authentication involving a user name and a password.
Once the subscriber user is validated, theWeb server software40 issues a query to thedatabase software42 for positional data of locator devices that the subscriber user is authorized to track or locate. Responsive to this query request, thedatabase software42 formulates a query to extract positional data from the tracking table in thedatabase44 and returns the query result to theWeb server40. After receiving the positional data from thedatabase software42, theWeb server40 merges the positional data with textual information and convolves the positional data with a map overlay to produce a image having the positional data superimposed on a map image. Various mapping software programs available in the art may be used for convolving the positional data information. TheWeb server40 then transmits the textual and image positional data information in the form of hypertext markup language (HTML) to the subscriber user accessing thesubscriber computer46 for viewing thereon using theWeb browsing software48.
The HTML page presented to the subscriber may also include a Java™ applet, which shows the positional information in a form of an image. The Java applet may dynamically depict the positional movement of the device by updating or refreshing the image of the positional information as thelocator device12 changes location. Various other means known in the art may be used to dynamically update the image of the positional information including, for example, a refresh rate which reloads new positional data images on the HTML page, or streaming video such as RealVideo™, Quicktime™, VDO™, MPEG or other like streaming video technologies. Such steaming videos depict the movement of the locator device over a map background.
Referring now toFIG. 2, a block diagram of an alternative locator device is shown and designated as50.Locator device50 carries out substantially the same functions as described above forlocator device12. To this end, thelocator device50 includes means for generating its positional data information connected tomemory52, acellular modem54 connected to the positional information generating means, apower supply56, acontrol interface58 connected to the positional information generating means, andpower management module59.
The means for generating positional data information comprises aGPS receiver60 connected to anantenna62, and a radio detection finding (RDF)unit64 connected to theGPS receiver60. The GPS receiving60, likereceiver14, comprises standard circuit stage component for detecting and receiving radio frequency signal as in known in the art and carries other operation of scanning the input stream received byantenna62. Thereceiver60 demodulates GPS signals from the input stream into serial data for use by theRDF unit64 to ascertain the positional data oflocator unit50 as described further below. Theantenna62, likeantenna16, comprises a RF transducer as in known in the art and is structured and configured to receive GPS signals produced bysatellites22athrough22n.
TheRDF unit64 comprises circuitry or like hardware having means for calculating its distance fromvisible GPS satellites22athrough22nusing the timing signals provided by theGPS satellites22athrough22n. The calculating means of theRDF unit64 comprises standard radiolocation calculation methods as is known in the art. The calculation means of theRDF unit64 further formulates its positional data in the form of latitude, longitude, and altitude, from the above mentioned calculation methods. This positional data is maintained or recorded in a log in thememory52 for later computation, and is communicated to thecellular modem54 for further transmission as described below.
Thepower supply56 is normally a battery supply and provides power to the various elements of thelocator device50, including theGPS receiver60, theRDF unit64, thepower management module59, thememory52, and thecellular modem54.
Thecontroller interface58, likecontrol interface21, carries out the operation of interpreting external commands issued by the user oflocator device50 and communicating such commands to theRDF unit64 and thepower management module59. For example, when the user oflocator device50 activates the unit by pressing an activation switch (not shown) on the control interface, a signal is communicated to thepower management module59 to activate thepower supply58, which provides power to the corresponding elements of thedevice50. Alternatively, a simple switch (not shown) connected to thepower supply56 could be provided at thecontrol interface58, to provide similar activation means.
Thecellular modem54, likecellular modem24, comprises standard circuitry for cellular communication and modulation and includes anantenna66 connected thereto. In an illustrative embodiment, thecellular modem54 comprises a MOTOROLA® 505sd modem. Thecellular modem54 carries out the operation of transmitting the positional data received from theRDF unit64 and communicating such positional data to thecellular provider28.
The method and operation of the invention will be more fully understood by reference to the flow chart ofFIG. 3.FIG. 3 illustrates generally the steps associated with the power management means of the invention. The order of steps as shown inFIG. 3 are only exemplary, and should not be considered limiting.
Referring now toFIG. 3, as well asFIG. 1, the method of managing or conserving power provided to thelocator device12 is shown.
Atstep100, a user of thelocator device12 accessing thecontrol interface21 to signal an activation or “power on” signal. This activation signal is communicated from thecontrol interface21 to thepower source30. As described above, switches or other controls may be provided at thecontrol interface21 to allow the user to communicate control signals, such as “power on” to thelocator device12.
Atstep110, responsive to this activation signal from thecontrol interface21, thepower source30 provides power to, inter alia, thewireless receiver14, theCPU18, thememory20, and thecellular modem24. The locator device is capable at running at a plurality of power levels including at least a “normal” level and a “low” level. At the “normal” level, theCPU18 is running at its highest clock speed and power is provided at the highest level to all the elements of thelocator device12, including thewireless receiver14, theCPU18, thememory18, and thecellular modem24 among others. At the “low” level”, theCPU18 is running at a reduced clock speed which is normally half the speed of the highest clock speed, and one or more of the other elements are disabled, shutdown or otherwise provided less power by the power supply. More particularly, communication to thecellular provider28 via thecellular modem24 is temporarily interrupted. Normally the power delivered to thecellular modem24 is interrupted.
Various other intermediary levels may be arranged to provide various power level consumption of thepower source30. TheCPU18 carries out the operation of the managing the power level in which thelocator device12 operates by communicating power level signals to the various elements of thelocator device12, including thepower source30, thewireless receiver14, and the cellular modem. Initially, during the power on stage ofstep110, theCPU18 sets the locator device to operate at the “normal” level.
Atstep120, theCPU18 carries out an internal check of thelocator device12. The internal check comprises steps of checking the functionality of thewireless receiver14, thememory20, theCPU18, thecellular modem24, thepower source30, and thecontrol interface21, among other elements. TheCPU18 also ascertains its serial number or identification number, which may be preprogrammed into a circuit or like hardware device (not shown) such as a ROM chip, which connected to theCPU18 and provided in thelocator device12. TheCPU18 also loads intomemory20 software or program means for computing positional data. The software may be provided internally in a circuit or like hardware (not shown) connected to theCPU18 and provided in thelocator device12, or may alternatively be downloaded during this step from thecellular provider28 via thecellular modem24.
Atstep130, thewireless receiver14 attempts to synchronize with thevisible GPS satellites22athrough22n. Thewireless receiver14 examines the input stream received into theantenna16 to ascertain synchronization signals or codes, which are transmitted by theGPS satellites22athrough22n. These synchronization codes are used by thereceiver14 to ascertain, among other things, the timing signals necessary to calculate positional data of thelocator device12. Normally, the locator device requires the timing signals from at least two (2) visible GPS satellites in order to calculate its positional data. As noted above, the term “visible” refers to the ability of thelocator device12 to receive synchronization signals, timing signals and other informational data from theGPS satellites22athrough22n. The accuracy of the calculation of the positional data is proportional to the number of GPS satellites “visible” to thewireless receiver14.
Atstep140, theCPU18 make a determination whether thewireless receiver14 has synchronized with at least two visible GPS satellites as carried out during the synchronization step of130. If theCPU18 determines that thewireless receiver14 has synchronized with at least two visible GPS satellites,steps140 through170 are carried out, otherwise steps180 through210 are carried out.
Atstep150, thewireless receiver14 carries out the steps of receiving input stream data from theantenna16 and demodulating GPS signals into serial data as described above. This serial data is then communicated to theCPU18 for further processing instep160.
Atstep160, theCPU18 carries out the steps of receiving the serial data fromwireless receiver14 and computing positional data of thelocator device12, as described above. In general the software running onCPU18 and inmemory20 calculates the distance between thelocator device12 and the GPS satellites synchronized with instep130 or step190 using the timing signals provided by the GPS satellites, and carries out standard radiolocation calculations to formulate the positional data which is the location of thelocator device12 relative to the positions of theGPS satellites22athrough22n. The calculated positional data is internally stored in a log or record in thememory20 for future comparison. Also atstep160, theCPU18 compares the currently calculated positional data with the previously calculated positional data if any to ascertain the velocity or the relative “positional change” oflocator device12.
Atstep170, theCPU18 makes a determination of whether the relative “positional change” calculated instate160 has increased. As noted above, thelocator device12 periodically communicates positional data to thecellular provider28. In order to conserve thepower source30, thelocator device12 will decrease the rate of periodic transmission tocellular provider28 when thelocator device12 is relatively stationary. Conversely, in order to provide accurate positional data to theserver computer38 viacellular provider28, the rate of periodic transmission fromlocator device12 tocellular provider28 is increased when the relative “positional change” determined to have increased. If thelocator device12 remains at a relatively contact rate of velocity, then the rate of transmission remains relatively constant as well. If the “positional change” has increased,step220 is carried out, otherwise,step230 is carried out.
Atstep220, the periodic rate at which thecellular modem24 transmits positional data to thecellular provider28 is increased. This step provides theserver computer38 with an increased rate of positional data where the locator device is found to be moving rapidly.Steps130 and140 are carried out again.
Atstep230, theCPU18 makes a determination of whether the relative “positional change” calculated instep160 has decreased. If the “positional change” has decreased,step240 is carried out, otherwise, steps130 and140 are carried out again.
Atstep240, the periodic rate at which thecellular modem24 transmits positional data to thecellular provider28 is decreased. This steps conserves power consumption in thelocator device12 when thedevice12 is relatively stationary.Steps130 and140 and then repeated.
Steps180 through210 are carried out when theCPU18 determines that thewireless receiver14 has not synchronized with at least two visible GPS satellites instep140.
Atstep180, thelocator device12 is set to the “low” level of operation described above in order to conserve the power usage drawn from thepower source30. At this level theCPU18 runs at a reduced clock speed, which is normally half of the highest clock speed. The power to the cellular modem is also terminated or otherwise reduced. Additionally, cellular communication betweencellular modem24 and thecellular provider28 is temporarily interrupted.
Atstep190, thelocator device12 attempts to synchronize with visible GPS satellites using the same steps as carried out instep130.
Atstep200, theCPU18 makes a determination whether thewireless receiver14 has synchronized with at least two visible GPS satellites during the synchronization step of190. If theCPU18 determines that thewireless receiver14 has synchronized with at least two visible GPS satellites,step210 is carried out, otherwise steps190 and200 are carried out again.
Atstep210, thelocator device12 is restored to the “normal” level of operation described above. At this level, theCPU18 operates at its fastest clock speed, and power is delivered at the “normal” to the elements oflocator device12 as described earlier in the power onstep110. Cellular communication betweencellular modem24 and cellular provider is also resumed.Steps150 through170 are then carried out.
One challenge facing wireless users is placing effective 911 calls. As cell phones replace traditional landline phones for many users, determining the location of a wireless phone in order to direct emergency response personnel is a key issue.
When a caller dials 911, typically the address and phone number of the caller is displayed on a screen at the 911 center.Enhanced 911 or E911 provides dispatchers with the location of callers and their phone number. This is also known as ANI/ALI— automatic number information and automatic location information. Currently, many 911 centers do not receive important location data from wireless telephone calls, resulting in confusion and problems for emergency dispatch services. Also, areas that have multiple 911 centers may have problems routing calls as a result of insufficient location data. Therefore, wireless E911 is one of the most pressing challenges facing the public safety community.
In response, the FCC has developed a set of rules to mandate a series of steps to migrate wireless carriers to 911 capability. The wireless Enhanced 911 (E911) rules seek to improve the effectiveness and reliability ofwireless 911 service by providing 911 dispatchers with additional information onwireless 911 calls.
The wireless E911 program is divided into two parts—Phase II and Phase II. Phase I requires carriers, upon appropriate request by a local Public Safety Answering Point (PSAP), to report the telephone number of awireless 911 caller and the location of the antenna that received the call. Phase II requires wireless carriers to provide far more precise location information, within 50 to 100 meters in most cases.
The deployment of E911 requires the development of new technologies and upgrades to local 911 PSAPs, as well as coordination among public safety agencies, wireless carriers, technology vendors, equipment manufacturers, and local wireline carriers. The FCC established a four-year rollout schedule for Phase II, beginning Oct. 1, 2001 and to be completed by Dec. 31, 2005.
However, wireless carriers have experienced some difficulty in complying with the mandate, and FCC has granted various limited waivers of the Phase II rules to wireless carriers, subject to revised deployment schedules and quarterly reporting requirements.
FIG. 4 is a block diagram of a wireline E911 system.FIG. 4 includes a Plain Old Telephone Service (POTS)telephone410 placing a 911 call into the Public Switched Telephone Network (PSTN)420. Typically, the call will be directed to a Central Office (CO)430 of a service provider, where asubscriber database440 is maintained, listing every assigned telephone number, the subscriber's name, address and billing information. Moreover, the service provider already identifies the telephone number for every call placed in order to properly bill the subscriber each month, referred to as Automatic Number Identification (ANI).
An E911 system further includes a Master Street Address Guide (MSAG)database450 for database cross-referencing every assigned telephone number, subscriber's address and the block number ranges for every street, in every jurisdiction served by the telephone company. Additionally, service provider may provide dedicated switches and networks to carry 911 traffic through a 911 tandem network.
When the caller dials 911, the call is identified by the telephone company central office switch and routed to the 911 network. The ANI (telephone number) information is decoded through a subscriber database to obtain the caller's address and other information. The call is then processed through the MSAG to obtain the ID code of the agency that should handle the call. The 911 network then routes the voice and ANI/ALI information to the correct agency or Public Safety Answering Point (PSAP)460.
The ANI/ALI information is displayed when the call-taker at the PSAP answers, providing crucial information to direct emergency personnel.
FIG. 5 is a block diagram of a Phase 1-compliantwireless E911 system500.
UnderPhase 1 mandates, wireless carriers must provide to PSAPs the telephone number of awireless 911 caller and cell site or base station receiving awireless 911 call. In thesystem500, when acaller510 places a 911 call, the call is routed to the Mobile Switching Center (MSC) throughtower520. UnderPhase 1, towers are programmed to immediately send any 911 call to the appropriate 911tandem540. Additionally, a Pseudo ANI (PANI) is provided that identifies the cell sector (up to three per tower) or just the tower itself.
When the call is relayed to thePSAP550, the callback number and cell tower of origination to be relayed to the PSAP. Accuracy can range from several hundred square meters to several square kilometers, thereby providing at least location information to a particular region of town.
Under Phase 2 mandates, wireless carriers must also provide to PSAPs the location of a 911 caller by latitude and longitude using either a terminal-based or a network-based technology, resulting in an accuracy of 50 square meters to 300 square meters depending on the technology.
FIGS. 6A-6C depict typical ways wireless carriers can use their network to determine a caller's location.FIGS. 6A-6C represent what is typically erred to as network-based solutions.
FIG. 6A depicts the Time Difference Of Arrival (TDOA) method. Eachtower620 in a TDOA system is configured to measure the amount of time it takes to receive the signal fromcaller610.
A typical manner used to locate a wireless caller to use the network of fixed base stations in a wireless provider's network to triangulate the caller's location. In this scenario, each station in a carrier's network is configured to receive a signal from a particular phone making an active call. Two or more towers then compare signals from the active phone and locate it based on relative readings. By cross-referencing this information from other towers in the system, a phone's position is expressed in X and Y coordinates based on longitude and latitude readings.
FIG. 6B depicts the Angle Of Arrival (AOA) method of location, in which the system uses the antenna arrays at a base station to determine the angle at which a wireless phone's signal arrives at the station. By comparing this angle of arrival data among multiple base stations, the relative location of a wireless phone can also be triangulated and expressed in X and Y coordinates.
FIG. 6C is a diagram of the Enhanced Observed Time Difference (EOTD) method. In this method, thephone610 is configured to determine its position from signals received from thetowers620. This determination made be made with the assistance of alocation server630. The phone then transmits itslocation information640 to the system. Under this scenario, a phone can be made ‘location-aware’, that is, it can continuously track its location throughout a system as long as the phone has sufficient tower visibility.
It will be appreciated that carriers may user combinations of all of the above location methods.
FIG. 7 depicts a terminal-based solution using the assistance of theconstellation730 of GPS satellites. The system ofFIG. 7 may operate in two manners. First, thephone710 may be configured to determined its own location as a stand-alone GPS terminal device and transmit its location to the 911network750 throughtower720 and ultimately to thecorrect PSAP760.
In an Assisted GPS system, the phone may only be required to transmit raw GPS data to the system throughtower720, and the location of the caller is determined with the assistance of alocation server740. Theserver740 may use any of the additional information from the network-based methods described above to more quickly determine the caller's location, such as tower location or triangulation data. This allows a much quicker first fix, and ultimately a more accurate location determination.
FIG. 8 is an overview of a typicalGSM wireless system800. The system includes a Mobile Station810 (MS) including the mobile equipment (ME)811 and a Subscriber Identity Module (SIM)card812. TheME811 comprises hardware for enabling radio communication with the network, and is typically identified by its International Mobile Equipment Identity (IMEI).
TheSIM card812 is typically configured to identify the subscriber in the network and stores information necessary for theME811 to access the network.
FIG. 8 further includes a Base Station System (BSS)820. TheBSS820 is configured to place the MS in wireless connectivity with the network. To enable transmission and reception on the network, theBSS820 includes a Base Transceiver Station (BTS)821 and a Base Station Controller (BSC)822. As is appreciated by those of ordinary skill in the art, theBTS821 is configured to enable the communication between theMS810 and the network, and comprises radio equipment and antennas to serve a cell. TheBSC822 is configured to manage a group of underlying BTSs.
FIG. 8 further includes aSwitching System830 for managing communications between mobile users and users of other networks or systems, such mobile users on different systems, or fixed telephony users on the Public Switched Telephony Network (PSTN)835. The switching system also includesdatabases832 needed for subscriber data and mobility management.
Theswitching system830 typically includes a Mobile Services Switching Center (MSC)831 for performing the switching functions within the network, connecting calls in the GSM network, or between the GSM network and another networks when necessary.
To provide connectivity between the GSM network and other networks, theswitching system830 may also include a Gateway Mobile services Switching Center (GMSC)833. TheGMSC833 is preferably configured to operate as a gateway between the GSM network and other networks, such as thePSTN835, or an IP-compliant network such as theInternet834.
As mentioned above, theswitching system830 may includedatabases832 for storing and retrieving system information. TheGMSC833 may locate in which part of the network theMS810 is located in by questioning a Home Location Registry (HLR) containing information about subscribers to the network. The HLR also includes information about the subscriber's current location and which MSC serving the user at the moment. Theswitching system830 may also include other databases, including a Visitor Location Registry (VLR). The VLR is a regional database, as compared to the HLR that is global, and is found together with every MSC. This register stores information about all subscribers that are registered in that MSC area at the moment.
When the HLR has provided theGMSC833 with which MSC service area the subscriber is registered in, a more detailed description of which Location Area (LA) the MS will be found in can be obtained from the VLR.
Theswitching system830 may also include security-related functionality, such as an Authentication Centre (AUC) for managing data for the authentication of subscribers and encryption. All MSs may be required to go through an authentication process before being provided access to the network. Additionally, an Equipment Identity Register (EIR) may also be provided for hardware security purposes. Information may be stored regarding whether a particular ME is valid, and verify that the equipment is not stolen.
In a preferred embodiment, theMS810 is GPS-enabled through aGPS chipset815 configured to determine location from received GPS signals816. Theswitching system830 may be configured to provide location-based services to a subscriber840, whereby the location of theMS810 may be provided to a subscriber840 over theInternet834. Thus, theswitching system830 is configured to provide the functionality provided by the server computer described above. It is desired in this disclosure that the location-based services be configured to access the E911 location information already present in an E911 compliant system. It is contemplated that the programming for causing the MS to determine its location may reside entirely on theSIM card812, or utilize memory andprocessor814.
In one embodiment, a commercial variant of a E911 protocol may be developed that causes the system to collect E911 information, but routes the location information to a commercial variant of the E911 tandem system. Such an E911 commercial protocol will indicate to the switching system that a particular request is a commercial request, and should not be forwarded to a PSAP. Instead such a protocol will indicate that the location request is of a commercial nature, and location information should be forwarded to the subscriber and the requested billed as a non-emergency provisioned service.
Additionally, theMS810 may include processor and associatedmemory814 for executing location-based services above and beyond those found in typical devices. For example, theMS810 may be configured to send its location as predetermined intervals to the subscriber840. For example, the MS may be configured to periodically determine its location and transmit location data to a subscriber, or alternatively, the MS may also be configured to transmit location data to a subscriber when nearing forbidden zones or traveling near boundaries as pre-defined by the subscriber.
It is contemplated that theMS810 may be configured to execute Java applications, or applications written in the operating system of the MS, such as Palm, Windows for mobile devices, or the Symbian OS.
It is contemplated that the location-based services of this disclosure may also be stored and executed directly or at least partially from theSIM card812. In this manner, the location-based services desired by subscriber840 may be provisioned and billed as are other wireless services. In this manner, a parent may activate location-based services without the knowledge of the child. Additionally, as a MS will not properly operate without a SIM card installed, the parent can be assured that a child cannot disable such features. For privacy reasons, the MS may also be configured to require that the remote user consent to enabling the remote tracking features. Additionally, the SIM card may be programmed to periodically determine the location of the MS and send location information to the subscriber, or respond to a location query from the subscriber, without intervention from the remote user.
The subscriber terminal may also be enabled to view the location of the MS through a web page as described above. Additionally, the subscriber may be allowed to enter locations of interest into the web page, and be notified when the MS is near a location. For example, a subscriber may be allowed to enter a street address into a web page, and the system will convert the address into location coordinates and store these coordinates into a database. The system may then query the location of the MS, and alert the subscriber if the MS arrives at the address. The subscriber may also be allowed to associate a time element with an address or series of addresses. In this manner, the system may be allowed to track a remote user's itinerary, and report back to the subscriber the remote user's progress. Thus if the remote user does not reach a desired destination by a specific time, the system will notify the subscriber. It is contemplated that the system may notify the subscriber through any manner provided by the carrier, such as through email, SMS, paging, or automated voice mail.
It is contemplated that the subscriber may also enter communication preferences, whereby the subscriber may enter a desired means of communication regarding the location of the remote user's MS. For example, the subscriber may enter various phone numbers or other information destinations in the order desired to be tried by the system. Additionally, if the network is enabled with the Session Initiation Protocol (SIP), the system may be configured to automatically attempt to contact the subscriber using alternate means.
As is known by those skilled in the art, SIP represents the capability to reach someone regardless of location or device. SIP may be used to signal multiple devices until it finds the subscriber. SIP resides at the application layer of the network and establishes, modifies, and terminates multimedia sessions between intelligent devices, and extends the intelligence of a data network out to the end user at the edge, while allowing the lesser intelligent core to forward communications requests without much effort.
Using SIP, if the subscriber is unavailable, the system may be configured to alert a second party, such as another family member or the subscriber's manager.
If the gateway is VoIP-enabled, then the subscriber may be able to receive location-based services in an IP-compliant environment, such as through a VoIP telephone, or a computer-resident “soft” phone. The gateway may also be enabled to provide VoIP services using either the SIP or H.323 protocols, or both.
Additionally, the system may be enabled to communicate using instant messaging software as is known in the art. Using any or all of the available technologies, a subscriber can be assured that location information regarding the remote user can reach the subscriber.
Thus, if both the remote user and subscriber have IP addresses, the location-based services may be accomplished without the need to provide a location server in the wireless switching system. As long as the E911 location information is available, software resident in the MS and subscriber computers may be configured to query the MS, retrieve location information from the wireless carrier, and forward the information to the subscriber.
However, a challenge still exists if the MS is indoors or otherwise not able to receive a GPS signal. In a further preferred embodiment, theMS810 may include a secondary means oflocation813. This secondary means may include a non-GPS method, such as RF-based means. In this embodiment, theMS810 is configured to receive secondary location information from anon-GPS source817 through anon-GPS signal818.
It is contemplated that secondary sources may be installed at locations where GPS signals are found to be unreliable, or locations where more precise location is desired. Examples include shopping malls, schools, hospitals, and the like. In such situations, while the GPS signal may be unreliable, wireless signals are often available. In one embodiment, the MS may be configured to sense and automatically utilize secondary location methods when GPS signals are unavailable. For example, the MS may also use any of the assisted-GPS location technologies describe above, resort to a network-based method, or use a secondary method.
An example of a secondary location method is an embodiment in which the Bluetooth protocol is employed. In this embodiment, the MS comprises a Bluetooth-enabled wireless phone, and thesecondary source817 represents a Bluetooth station. The MS is configured to discover and establish a connection when the MS is within range. Thestation817 transfers its precise location to the MS, which then forwards this information onto the subscriber. It will be appreciated that using a secondary source, precise location of the MS may be determined.
If the secondary source is indeed located in an area where GPS and wireless service is unavailable, the MS may be configured to store secondary location information received from thesource817 and retransmit such data to the subscriber when the MS is back in a service area.
Many automobiles are now Bluetooth enabled, allowing a wireless phone to interact with the control systems of the car. In a further embodiment, the MS may be configured to detect when it is in the car, and alert the subscriber to this fact, as well as when the phone leaves the range of the car. Furthermore, it is contemplated that the car may be configured to relay on-board information to the phone, such as information available through the On Board Diagnostic (OBD) system. Information such as speed and direction may then be forwarded to the subscriber.
It is contemplated that the location information may be sent to the subscriber through the most efficient means. For example, in a GSM system, the data may be sent using the GPRS data channel. However, to ensure that location data is transmitted, the phone may be configured to determine the best available method, and send information or alerts using alternate methods. For example, if the MS enters a forbidden zone as defined by the subscriber, the MS may be configured to send a SMS message, email, or other communication in addition to attempting to send the location information using the data channel of the particular system. If the MS is out of service range, it may be configured to store the alert, and send the alert as soon as service is detected.
In a further embodiment, the MS may be enabled to send multi-media messages using the MultiMedia Message Protocol (MMS). In this embodiment, theremote MS810 may be configured to determine its position, and create a multimedia message including a graphical representation of its location, such as a message including a map having an indication of the remote user's location thereon. It is contemplated that map information may stored in the phone's memory, and the phone may retrieve maps to create the message. Alternatively, the wireless system may be queried and the message created by the system for forwarding to the subscriber. This may be particularly advantageous when the subscriber unit840 comprises a wireless phone, allowing the subscriber to view the remote user's location graphically while away from a desktop computer.
Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing an illustration of the presently preferred embodiment of the invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents.