# Patent

## Title
Unique global identifier header for minimizing prank emergency 911 calls

## Abstract

A prank call server that performs 911 prank call filtering over a 911 emergency call system, prior to routing a 911 call to a PSAP. The inventive prank call server identifies prank calling devices, regardless of current service subscription, by retrieving and analyzing emergency call data pertaining to detected prank 911 calls. The prank call server assigns a unique global identifier to each 911 call detected on the 911 emergency call system. Unique global identifiers enable a PSAP to uniquely identify prank 911 calls that are identified thereon. A PSAP transmits a prank call signal and a relevant unique global identifier to the prank call server, for each prank 911 call that is detected. A prank call signal/unique global identifier combination triggers the prank call server to store all available call data for a referenced prank 911 call in to a prank call database, for subsequent prank call filtering analysis.

## Background
The present application claims priority from U.S. Provisional No. 61/541,615, entitled “Unique Global Identifier Header for Minimizing Prank Emergency 911 Calls”, to Goswami et al., filed Sep. 30, 2011; the entirety of which is explicitly incorporated herein by reference.


BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to telecommunications. More particularly, it relates to distributed Emergency Call Systems.
2. Background of Related Art
A 911 emergency call system bridges local government entities and call service providers, to route 911 voice calls to proper emergency dispatch personnel.
In particular, the 911 emergency call system routes a 911 voice call to a Public Safety Answering Point (PSAP) (i.e. a 911 dispatcher/emergency call center) to administer proper emergency services. The 911 emergency call system preferably routes a 911 voice call to a Public Safety Answering Point (PSAP) within closest geographic proximity to an originating communication device.
FIG. 5 demonstrates a conventional 911 call system call flow.
In particular, a 911 voice call is placed via an originating communication device (e.g. a landline communication device, a wireless communication device, etc.), as depicted in step 500. In step 510, a call service provider servicing the originating communication device detects that a 911 voice call has been placed. If the originating communication device is not able to be serviced by an affiliated call service provider (e.g. the communication device is outside the service jurisdiction of an affiliated call service provider, the communication device is not subscribed to any service(s) provided by a call service provider, etc.), 911 call processing is defaulted to a call service provider servicing a geographic location established for the originating communication device. In step 520, an applicable call service provider routes the detected 911 voice call to an appropriate Public Safety Answering Point (PSAP) via conventional call routing procedures. In step 530, the detected 911 voice call is received on an appropriate Public Safety Answering Point (PSAP), and emergency service personnel are thereby dispatched accordingly.
Enhanced 911 (E911) is a reformed version of the 911 emergency call system, employed in response to advancements achieved in current communication technologies. In particular, Enhanced 911 (E911) provides accurate 911 call routing services to a wide array of previously unsupported communication devices (e.g. wireless devices, VoIP devices, etc.) In operation, Enhanced 911 retrieves E911 voice information and relevant emergency call data (e.g. a subscriber number and a geographic location) pertaining to each E911 voice call that is detected. Relevant call data is subsequently routed to an appropriate Public Safety Answering Point (PSAP).
Wireless Enhanced 911 is a particular denomination of Enhanced 911, responsible for routing 911 voice calls originated on a wireless communication device. Wireless Enhanced 911 identifies a Mobile Subscriber Identification Number (MSIN) and a current geographic location for each device that is party to a Wireless E911 voice call. Accordingly, an associated MSIN/geographic location combination is routed to an appropriate Public Safety Answering Point (PSAP) with each Wireless E911 call that is detected.
A Mobile Subscriber Identification Number (MSIN) identifying an originating 911 calling device is retrieved for Wireless E911 call processing via an Automatic Number Identification (ANI) Service.
In particular, a unique Mobile Subscriber Identification Number (MSIN) is assigned to each communication device that is subscribed to service(s) administered by a wireless/call service provider. Furthermore, each instantiation of a Mobile Subscriber Identification Number (MSIN) to a particular communication device is recorded in a database maintained by the Automatic Number Identification (ANI) service.
FIG. 6 conveys a conventional use of an Automatic Number Identification (ANI) service within a Wireless E911 call system call flow.
In particular, a Wireless E911 call is detected upon the 911 emergency call system, as depicted in step 600. Upon detection, the Automatic Number Identification (ANI) service retrieves a Mobile Subscriber Identification Number (MSIN) stored for an originating communication device, as depicted in step 610. Once retrieved, the Automatic Number Identification (ANI) service transmits the Mobile Subscriber Identification Number (MSIN) to a wireless service provider administering E911 call routing, as shown in step 620. The Mobile Subscriber Identification Number (MSIN) is subsequently received on an appropriate wireless service provider and forwarded to a Public Safety Answering Point (PSAP), as conveyed in step 630. The Mobile Subscriber Identification Number (MSIN) is thereafter received on a Public Safety Answering Point (PSAP) and emergency service personnel are thereby dispatched accordingly, as depicted in step 640.
A geographic location may be determined for an originating communication device via an active location service (e.g. GPS) residing on the calling handset. Moreover, a geographic location for an originating communication device may alternatively be determined based upon the location of a base station servicing a corresponding E911 call. A location for an originating communication device is conventionally used to route an E911 call to an appropriate Public Safety Answering Point (i.e. a Public Safety Answering Point (PSAP) within closest geographic proximity to an originating communication device). Furthermore, a geographic location for an originating communication device promotes efficient dispersal of emergency services when routed to a Public Safety Answering Point (PSAP) administering E911 call dispatching.
According to a Federal Communications Commission (FCC) mandate, all wireless devices must be permitted access to 911 emergency call services, regardless of current service subscription. Thus, the 911 emergency call system must be capable of detecting and routing 911 voice calls placed via wireless devices that are disconnected from service.
A geographic location for a disconnected wireless device may be determined for E911 call processing via conventional handset-based/network-based device location techniques. Yet, a source of an E911 voice call originated on a disconnected wireless device is not easily identifiable. In particular, a wireless device that is disconnected from service is not attributed a Mobile Subscriber Identification Number (MSIN) corresponding to a particular subscriber account. Therefore, identification of a 911 calling party may not be automatically obtained via the Automatic Number Identification (ANI) service. Moreover, it is not possible to accurately ascertain the ownership of a disconnected wireless device. Hence, 911 calls that are placed via a disconnected wireless device are fundamentally anonymous.
To reduce anonymity, wireless service providers often designate arbitrary number identifiers (e.g. MSIN, IMSI, etc.) to wireless devices that are not subscribed to service. An arbitrary number identifier is routed to a Public Safety Answering Point (PSAP) for each E911 voice call that is originated on a corresponding wireless device.
Unfortunately, the 911 emergency call system is currently afflicted with prank 911 calls originating on wireless devices that are disconnected from service.
Presently, the only information that is obtainable for an E911 voice call placed via a disconnected wireless device, is a geographic location and an arbitrary number identifier. Although a means of filtering prank 911 calls would be useful, prank 911 calls placed via disconnected wireless devices may not be filtered based solely upon an arbitrary number identifier (e.g. MSIN, IMSI, etc.) assigned to an originating communication device. First, a number identifier assigned to a disconnected wireless device is not guaranteed to be unique. Furthermore, a disconnected wireless device may change hands at any given time, e.g., a device may be sold, borrowed, traded, etc. Therefore, it is possible, e.g., that a non-prank caller may purchase a disconnected wireless device with a number identifier depicting a device used to generate prank 911 calls. In this case, if a prank 911 call placed via a disconnected wireless device is filtered according to a device's arbitrary number identifier, it is likely that a non-prank caller may be denied access to E911 emergency call services.
Due to a lack of source information, it is difficult to prevent the routing of prank 911 calls originating on wireless devices that are disconnected from service. Hence, there is a need for a solution that may accurately identify prank 911 calling devices, regardless of current service subscription, and filter the routing of 911 calls that are placed thereon.
SUMMARY OF THE INVENTION
In accordance with the principles of the present invention, a method and apparatus to provide 911 prank call filtering over a 911 emergency call system comprises transmitting, to a physical prank call server, a prank call signal associated with a unique global identifier assigned to a given 911 call, if the given 911 call is detected at a PSAP to be a prank 911 calling device. A prank call database is queried for correlation between a calling device of said given 911 call with a pre-identified prank calling device. If information maintained within the prank call database correlates a detected 911 call with an identified prank calling device, then the detected prank 911 call is dropped.



BRIEF DESCRIPTION OF THE DRAWINGS
Features and advantages of the present invention will become apparent to those skilled in the art from the following description with reference to the drawings, in which:
FIG. 1 depicts an exemplary network structure for a prank call server implemented over the 911 emergency call system, in accordance with the principles of the present invention.
FIG. 2 demonstrates an exemplary call filtering process performed by a prank call server implemented within the 911 emergency call system, in accordance with the principles of the present invention.
FIG. 3 portrays exemplary data accumulation performed by the prank call server for a prank 911 call detected on the 911 emergency call system, in accordance with the principles of the present invention.
FIG. 4 depicts an exemplary call filtering process for a 911 call placed by a communication device that is subscribed to wireless service(s), in accordance with the principles of the present invention.
FIG. 5 demonstrates a conventional 911 call system call flow.
FIG. 6 conveys a conventional use of the Automatic Number Identification (ANI) service within a Wireless E911 call system.



DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
The present invention provides a prank call server that administers 911 prank call filtering over a 911 emergency call system. In particular, the inventive prank call server identifies prank calling devices (i.e. devices generating prank 911 calls) by retrieving and analyzing emergency call data (i.e. a subscriber number, an arbitrary number identifier, a geographic location, etc.) pertaining to prank 911 calls detected on the 911 emergency call system.
In accordance with the principles of the present invention, the inventive prank call server is implemented during 911 emergency call routing to prevent 911 calls originated on identified prank calling devices from being routed to a public safety answering point (PSAP).
In accordance with the principles of the present invention, the inventive prank call server assigns a unique global identifier to each 911 call that is detected on the 911 emergency call system. Global identifiers attributed to detected 911 voice calls permit a public safety answering point (PSAP) to uniquely reference each prank 911 call that is identified thereon. A public safety answering point (PSAP) transmits a prank call signal and a relevant unique global identifier to the prank call server, for each prank 911 call that is detected. A prank call signal/unique global identifier combination, triggers the inventive prank call server to retrieve emergency call data pertaining to a corresponding prank 911 call. Prank call data is logged in an inventive prank call database.
The inventive prank call database is queried for each 911 call that is detected on the 911 emergency call system, in accordance with the principles of the present invention. If information maintained within the prank call database correlates a detected 911 voice call with an identified prank calling device, then the detected 911 voice call is dropped, and corresponding call data is logged in the prank call database for subsequent call filtering analysis.
FIG. 1 depicts an exemplary network structure for a prank call server implemented over the 911 emergency call system, in accordance with the principles of the present invention.
In particular, a prank call server 110 is integrated within the 911 emergency call system 100 to mitigate the volume of prank 911 calls routed to a public safety answering point (PSAP) 120. A public safety answering point (PSAP) 120 transmits a prank call signal and a relevant unique global identifier to the prank call server 110, each instance a prank 911 call is detected.
The inventive prank call server 110 utilizes a prank call database 130 to store data pertaining to prank 911 calls detected on the 911 emergency call system 100. The prank call server 110 additionally queries the prank call database 130 to determine if emergency call data retrieved for a detected 911 voice call, corresponds to information stored for an identified prank calling device. The prank call server 110 utilizes information compiled within the prank call database 130 to perform 911 prank call filtering, prior to routing a 911 voice call to a public safety answering point (PSAP) 120.
In a preferred embodiment, a prank calls and caller audit system 140 is implemented to provide a user interface to the prank call database 130. In particular, a prank calls and caller audit system 140 preferably permits an authoritative entity (e.g. a law enforcement officer, an emergency call dispatcher, etc.) to view and/or modify (e.g. add and/or delete) prank call data maintained within the prank call database 130.
FIG. 2 demonstrates an exemplary call filtering process performed by a prank call server implemented within the 911 emergency call system, in accordance with the principles of the present invention.
In particular, a 911 voice call is detected on the 911 emergency call system, as depicted in step 200. Upon detection, the inventive prank call server designates a unique global identifier to the 911 call, as shown in step 210. In step 220, the prank call server queries the prank call database, using conventional emergency call data (i.e. a subscriber number, an arbitrary number identifier, a geographic location, etc.) retrieved for the detected 911 voice call. The prank call database is queried to determine if call data pertaining to the 911 voice call correlates with data stored for an identified prank calling device.
If the query to the prank call database (performed in step 220) indicates that the 911 voice call is originated on an identified prank calling device (step 230), the 911 call is dropped, as depicted in step 240. Relevant emergency call data is subsequently logged in the inventive prank call database, as shown in step 250.
Alternatively, if the query to the prank call database (performed in step 220) does not indicate that the 911 call is originated on an identified prank calling device (step 230), the 911 call and an assigned unique global identifier are routed to an appropriate public safety answering point (PSAP), as shown in step 260.
FIG. 3 portrays exemplary data accumulation performed by the prank call server for a prank 911 call detected on the 911 emergency call system, in accordance with the principles of the present invention.
In particular, a 911 voice call and a unique global identifier are received on a public safety answering point (PSAP), as depicted in step 300. If the 911 call (received in step 300) is not a prank 911 call (step 310), the public safety answering point (PSAP) performs conventional 911 call dispatching services, as depicted in step 320.
Alternatively, if the 911 call (received in step 300) is a prank 911 call (step 310), the public safety answering point (PSAP) transmits a predetermined prank call signal and a corresponding unique global identifier to the prank call server, as depicted in step 330. Upon receipt, the prank call server retrieves all information available to the 911 emergency call system for the 911 call referenced by the received unique global identifier, as depicted in step 340. The prank call server subsequently logs all data retrieved for the prank 911 call in to the prank call database, as depicted in step 350.
In accordance with the principles of the present invention, the prank call server may identify prank calling devices for the performance of 911 prank call filtering, regardless of a particular device's current service subscription. In particular, 911 calls generated on prank calling devices that are affiliated with a particular subscriber account, may be filtered via a corresponding subscriber identification number, e.g., MSIN, IMSI, etc. Alternatively, calls generated on prank calling devices that are not subscribed to service, may be identified via prank call trends and prank call history, established/accumulated within the inventive prank call database.
Communication devices that are subscribed to service(s) provided by a wireless/call service provider are assigned a unique mobile subscriber identification number (MSIN), corresponding to a particular subscriber account. In a particular embodiment, once a communication device affiliated with a wireless/call service provider has exceeded a maximum number of permissible prank 911 calls, that particular communication device is classified as an identified prank calling device. Consequently, when the 911 emergency call system detects that a mobile subscriber identification number (MSIN) retrieved for an originating communication device, matches a mobile subscriber identification number (MSIN) stored for an identified prank calling device, the 911 call is dropped, thereby blocking the prank calling device from accessing 911 emergency call services.
FIG. 4 depicts an exemplary call filtering process for a 911 call placed by a communication device that is subscribed to wireless service(s), in accordance with the principles of the present invention.
In particular, a 911 call is detected on the 911 emergency call system, as depicted in step 400. Upon detection, the prank call server assigns the 911 call a unique global identifier, as shown in step 410. In step 420, the automatic number identification (ANI) service retrieves a mobile subscriber identification number (MSIN) affiliated with an originating communication device. In step 430, the prank call server queries the prank call database to determine if the mobile subscriber identification number (MSIN) identified for the originating communication device, matches a mobile subscriber identification number (MSIN) stored for an identified prank calling device. If the query to the prank call database indicates a match (step 440), the detected 911 voice call is dropped and corresponding emergency call data is logged in the prank call database, as depicted in step 450. Alternatively, if the query to the prank call database does not indicate a match (step 440), the relevant 911 call and a corresponding unique global identifier are routed to an appropriate public safety answering point (PSAP), as depicted in step 460.
Alternatively, wireless devices that are disconnected from service are not assigned a mobile subscriber identification number (MSIN) corresponding to a particular subscriber account. Yet, wireless service providers often designate arbitrary number identifiers (e.g. MSIN, IMSI, etc.) to disconnected wireless devices, to aid 911 emergency call processing.
In accordance with the principles of the present invention, an originating geographic location (e.g. exact geographic coordinates, cell-tower information, PIDF-LO, etc.) and an arbitrary number identifier (e.g. MSIN, IMSI, etc.) are stored in the prank call database, for prank 911 calls placed by wireless devices without subscription to wireless/call service(s). Prank call trends may then be identified based upon geographic location/arbitrary number identifier combinations maintained within the prank call database. For instance, if an arbitrary number identifier and a geographic location retrieved for a 911 call detected on the 911 emergency call system, are both stored in combination in the prank call database, then the prank call server recognizes that the 911 call has been originated on an identified prank calling device, and the 911 call is dropped. Relevant emergency call data is then stored in the prank call database for future call filtering analysis.
Furthermore, if multiple prank 911 calls originating from various geographic locations, are affiliated with the same arbitrary number identifier (i.e. the calling device is moving), then all calls affiliated with that particular arbitrary number identifier may be blocked for a given period of time.
Being that wireless devices that are disconnected from service may change hands at any given time (e.g. a device may be sold, borrowed, traded, etc.), a geographic location/arbitrary number identifier combination stored in the prank call database for a particular disconnected wireless device, should expire after a given period of time. Requiring prank call data stored for disconnected wireless devices to expire, may potentially prevent non-prank callers from being denied access to 911 emergency call services.
In an alternate embodiment, rather than dropping a 911 call originated on an identified prank calling device, the emergency call routing system may alternatively route the particular 911 call to a public safety answering point (PSAP), accompanied by an appropriate indicator (i.e. warning). A public safety answering point (PSAP) may then decide on an appropriate punitive action, depending, e.g., on present call volume, 911 call policy, etc.
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 providing 911 prank call filtering over a 911 emergency call system, comprising:
receiving at a physical prank call server, a prank call signal associated with a unique global identifier assigned to a given 911 call, when said given 911 call is detected at a PSAP to be a prank 911 calling device;
obtaining a location of said detected prank 911 calling device;
querying a prank call database for correlation between a location and unique global identifier of a calling device of said given 911 call with a pre-identified prank calling device; and
dropping said detected prank 911 call from said prank 911 calling device when information maintained within said prank call database correlates said given 911 call with an identified prank calling device.

2. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, further comprising:
in response to said prank call signal, triggering retrieval of emergency call data pertaining to said prank 911 call.

3. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, further comprising:
logging prank call data in a prank call database for subsequent prank emergency call filtering.

4. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, further comprising:
assigning said unique global identifier to said given 911 call at a 911 call server.

5. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, wherein:
said 911 call is a voice call.

6. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, further comprising:
filtering said prank call data via a corresponding identification number.

7. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, wherein:
said corresponding identification number is at least one of an MSIN or IMSI.

8. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, wherein:
said prank call server identifies a prank 911 calling device regardless of a particular device's current service subscription.

9. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, further comprising:
identifying a given 911 call as a prank 911 call based on a correlation to a known prank call trend.

10. The method of providing 911 prank call filtering over a 911 emergency call system according to claim 1, further comprising:
identifying a given 911 call as a prank 911 call based on a correlation to an aggregate prank call history.

11. Apparatus to provide 911 prank call filtering over a 911 emergency call system, comprising:
means for receiving at a physical prank call server, a prank call signal associated with a unique global identifier assigned to a given 911 call, when said given 911 call is detected at a PSAP to be a prank 911 calling device;
means for obtaining a location of said detected prank 911 calling device;
means for querying a prank call database for correlation between a location and unique global identifier of a calling device of said given 911 call with a pre-identified prank calling device; and
means for dropping said detected prank 911 call when information maintained within said prank call database correlates said detected prank 911 call with an identified prank 911 calling device.

12. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, further comprising:
means for triggering, in response to said prank call signal, retrieval of emergency call data pertaining to said prank 911 call.

13. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, further comprising:
means for logging prank call data in a prank call database for subsequent prank emergency call filtering.

14. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, further comprising:
means for assigning said unique global identifier to said given 911 call at a 911 call server.

15. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, wherein:
said 911 call is a voice call.

16. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, further comprising:
means for filtering said prank call data via a corresponding identification number.

17. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, wherein:
said corresponding identification number is at least one of an MSIN or IMSI.

18. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, wherein:
said prank call server identifies a prank 911 calling device regardless of a particular device's current service subscription.

19. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, further comprising:
means for identifying a given 911 call as a prank 911 call based on a correlation to a known prank call trend.

20. Apparatus to provide 911 prank call filtering over a 911 emergency call system according to claim 11, further comprising:
means for identifying a given 911 call as a prank 911 call based on a correlation to an aggregate prank call history.