Methods and system for routing emergency calls through the internet

A system (100) and method for routing an emergency request message from an Internet user (50) to an emergency-call-answering center (31) consisting of Public Service Access Points (PSAPs). An emergency request message is transmitted to an IP network (60) which is received by an emergency call handling function (172). The emergency call handling function (172) queries a database (170) and returns the physical location information associated with the IP address of the user (50). The call is formatted into a format compatible with the emergency call answering center (31) and transmitted via the PSTN (20) to the PSAP (36) serving the correct emergency service zone for the user (50).

TECHNICAL FIELD

This invention relates generally to data communications over the Internet, and more particularly to a method and system of routing an emergency related message request from a user of an Internet device to a telephonic based emergency call answering center.

BACKGROUND OF THE INVENTION

The Internet has become a popular tool for sending and receiving information. In essence, the Internet comprises a worldwide network of communications equipment and service providers, which use a common protocol for communicating. On the Internet, messages are transmitted from one user to another over a vast infrastructure of routers, servers, gateways and other similar devices. Typically, users on either end of the network operate computers equipped with appropriate software, devices and other components. Examples of such components include a modem and Internet browser application. Often, a user establishes a connection to the Internet through an Internet Service Provider (ISP). The underlying link level protocol stacks handle the messaging functions on both ends of the channel.

With most Internet Protocol (IP) applications, the network routes messages from one user to another using the IP address of the intended recipient. Thus, the physical address, phone number and other geographic location indicators are not critical to the message routing functions in an IP network. On the other hand, other communications mediums, such as the Public Switched Telephone Network (PSTN), support connections by tying a user with his or her phone number. An example are the Public Service Access Points (PSAPs) which support a network of emergency call answering centers throughout the United States. With such centers, the user is able to get emergency assistance by dialing a special number such as 9-1-1. The PSTN routes the call to the appropriate center serving the emergency zone of the caller based on their phone number. The center, in turn, dispatches the appropriate emergency personnel to the caller's location.

At the same time, the widespread use of the Internet as a communications tool has led to an intense push for the integration of Internet services with those offered through the existing telecom infrastructure of the PSTN.

SUMMARY OF THE INVENTION

A problem associated with Internet use is that, in case of an emergency, such as a medical emergency, fire, or intrusion by a criminal, the Internet user may not place an emergency call to a PSAP through the Internet. The current PSAP infrastructure utilizes Centralized Automated Message Accounting (CAMA) protocols containing the calling party's number information in a specified format. With CAMA protocols, information regarding the caller's address can be independently determined using an Automatic Location Identification (ALI) database, thus enabling the PSAP to choose the correct emergency response agency. The present invention solves the disadvantages associated with the prior art by providing a method and system for routing emergency calls from a user of an Internet device through the Internet to a PSTN connected PSAP.

According to one embodiment, disclosed is a method of routing an emergency request message from a user of an Internet device to an emergency call answering center. The method includes the steps of transmitting an emergency request message to a network supporting Internet Protocol (IP), and routing the message to an emergency call handling function. The emergency call handling function is configured to examine the message's IP address and return physical location information of the device which transmitted the emergency request message. The emergency request message is then formatted and routed to the emergency call answering center over the Public Switched Telephone Network (PSTN).

The emergency call handling function can return the telephone number associated with the serving PSAP for the calling user. Thus, the method may also include the step of routing the emergency request message through the PSTN to the emergency response service zone serving the Internet user. Once received, the PSAP can dispatch emergency personnel to assist a user at his or her location.

In one embodiment, the Internet device may be a client terminal in a multiple user environment such as a Local Area Network (LAN). If so, either the client's IP address is dynamically assigned upon login to the IP network, or the client's IP address may be dedicated and used each time access to the Internet is established. In either case, the method includes the step of determining the physical location of the user based on the IP address assigned to the client so that an the emergency request message may then be routed to a PSAP in the proper format. The emergency call handling function may perform a query to a database containing the physical location information of the Internet user.

According to another embodiment, disclosed is a method of converting Internet Protocol emergency messages to protocols compatible with PSTN connected PSAPs. The method includes the steps of detecting an emergency message transmitted by an Internet device to reveal the IP address associated with the message. Next, the IP address is used to query a database containing geographic location information for Internet users. Corresponding physical location information associated with the IP address of the Internet device is returned. The message is then formatted into a number format corresponding to the PSTN subscriber line serving the correct emergency response server zone. The formatted messages can then be routed to serving-PSAP through the PSTN using well known means.

According to another embodiment, disclosed is a communication system for delivering emergency messages placed through the Internet to an emergency call answering center, where the system comprises a central office, an IP network, and a signal pathway between the central office and the IP network. At least one entry gateway is communicably accessible in the IP network and configured to receive Internet emergency messages from IP users. An emergency call handling function is linked to the entry gateway and configured to convert messages into a format compatible with existing PSAP protocols. A database stores a plurality of Internet user records including the physical location of a user associated with their IP address. The physical location information may include the number of the PSAP associated with the central office within the service zone of the caller. The Internet device may be a client terminal in a multi-user environment such as a LAN, wherein the client's IP address is dynamically assigned, by an Internet Service Provider (ISP). The communication system may include a gateway, to the PSTN by which emergency calls are transmitted to the emergency call answering center.

An advantage of the present invention is that Internet users now have access to emergency services over the Internet, without having to use the telephone to place such emergency phone calls.

Another advantage of the present invention includes providing a physical location of a Internet user based on the IP address of a message received from the user.

Corresponding numerals and symbols in the different figures refer to corresponding parts unless otherwise indicated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1illustrates a traditional telephone system10how a user of a Plain Old Telephone System (POTS) can access an emergency call answering center31through access tandem or Public Switched Telephone Network (PSTN)20. The POTS12is coupled to phone lines14which are often analog twisted pair of the type employed in many PSTN applications. A serving system16received calls from the POTS12through lines14. The serving system16may be the central office for wireline subscribers, a Mobile Switching Center (MSC) for wireless subscribers, or other similar call exchange facility serving the location where the POTS12is located. In essence, the serving system16receives calls from the POTS12and routes them to emergency call answering center31using well known switching and routing means.

As shown, a second POTS28may be used from a second location for placing calls to the emergency call answering center31. Although the physical location of the POTS12and POTS28differ, the emergency call answering center31is still able to dispatch emergency services to the correct location based on the location information associated with the phone number of the calling party. Thus, calls placed from the POTS28are received at the serving system24through phone lines26. As before, the PSTN20routes the emergency calls (e.g. 9-1-1) to the emergency call answering center31.

The emergency call answering center31receives call from the PSTN20and routes it to a selective router30. As shown, a Public Service Access Point (PSAP)36is coupled to the selective router30using a Centralized Automated Message Accounting (CAMA) protocol over the trunk34. Typically, a PSAP36is provided for every service zone in the system10.

The CAMA protocol typically includes the calling party digit information associated with the calling party. Typically, the CAMA trunk34can only convey 8 digits of information. An Automatic Location Identification (ALI) database38contains the necessary location information for a caller based on the calling party digit information.

The Selective Routing Database32converts a telephone number into an Emergency Service Number (ESN) representing an emergency service zone associated with the calling party. Each emergency service zone is served by a primary and alternate PSAP (not shown inFIG. 1). Typically, the emergency zone has a predetermined set of emergency response agencies, one for each type of emergency response required (e.g. fire, police, medical, poison control, etc.).

For a wireline 9-1-1 call, a query to the ALI database38is made using the A (calling party) Number Identification (ANI) as the key. The query provides location information such as the street address of the calling party and subscriber information such as the name.

Turning now toFIG. 2, the telephone system10ofFIG. 1is expanded to include an Internet device50which is utilized by an Internet use to access the Internet Protocol (IP) network60. As shown, the Internet device50employs a computer system52with monitor, processor, software applications and other communications facilities necessary to cause the modem54to access lines56leading to central office58. The lines56are typically analog twisted pair used in traditional telephone applications. In other configurations, a dedicated digital line, such as and E1/T1 connection or ISDN, may be used. The central office58is coupled to the IP network60through link59. The IP network60includes the various services and resources associated with the Internet which are made available to the Internet device50.

The problem is that there is no readily available means for the Internet device50to access the emergency call control center31and provide the location information associated with the Internet device50. Likewise, the Internet device50is unable to call or send messages to POTS12or28through the PSTN20. Thus, a means for routing emergency requests from the Internet to 9-1-1 or other public emergency service systems is needed.

Turning now toFIG. 3, the system for routing IP formatted messages to the emergency call center31is shown and denoted generally as100. The communication system100has an Internet device50with computer52utilizing modem54or other suitable Internet device to access central office58over connection56. The connection56is often twisted pair wiring. In other embodiment, a dedicated digital connection such as an E1/T1, ISDN or other connection type may be employed. The central office58is coupled to an IP network60which provides the various features and services of Internet.

The central office58routes calls placed by the Internet device50to an Internet Service Provider (ISP)102within the IP network60that acts as the entry gateway to the IP network60for Internet users. The ISP102is the a point of access or node for the Internet device50to the IP network60. Typically the Internet device50is assigned an address, which is associated with the user for the duration of an Internet session. The address is utilized by the Internet device50to perform basic Internet functions such as sending and receiving e-mail messages through the IP network60. The IP address assigned is typically of the numeric format aa.bb.cc.dd. for example. With most common IP addressing schemes, an IP address is not associated with the physical location of the user50; rather, the IP address provides a handle by which the user50can be identified within the IP network60.

Many users can obtain an account with the ISP102which provides on-demand access to the IP network60. Typically, an ISP102obtains the users' accounting information, such as address, phone number and other user information that is associated with the user's account. According to one embodiment of the invention, such user information can be relayed to an emergency call handling function172implemented to handle emergency message requests through the IP network60. Specifically, the emergency call handling function172provides a translation of the user's IP address to their physical location information.

The translation function172can employ a database170containing geographic location information for users of the IP network60. Thus, the database170is accessed by the emergency call handling function172once a call for emergency services is placed by the Internet device50through the IP network60.

According to one embodiment, the IP network60includes an exit gateway162to the PSTN20that permits transmission of Internet messages to the PSTN20using protocols and signaling means compatible with current telephone numbering standards. In order to format the Internet messages so that they may be properly routed and utilized by the PSTN20, the IP network60utilizes the database170in communication with the emergency call handling function172. Thus, the fact that database170is contained in IP network60permits the routing of emergency calls from the Internet device50to an emergency call answering center31. In one embodiment, the emergency call handling function172is a separate element outside the IP network60and maintained by a third party administrator.

Thus, when an Internet device50sends an emergency request message through the IP network60, it reaches the emergency call handling function172which, in turn, queries the database170for the physical location indicator associated with the IP address associated with the Internet user as revealed in the emergency request message. The database170returns the corresponding physical location information to the emergency call handling function172. In one embodiment, the physical location information is encapsulated within a PSAP formatted message containing the corresponding telephone number for the PSAP assigned to the requesting user's physical location. The PSAP formatted message can then be routed to PSTN gateway162and on into the PSTN20. The PSTN20routes the call as it would any other emergency call (e.g. 9-1-1) to the emergency call answering center31via the gateway162.

FIG. 4is a process flow diagram illustrating a method of routing an emergency call from an Internet user to an emergency call answering center31according to one embodiment of the invention. Assuming Internet device50is in need of emergency service such as police, fire, medical or other similar emergency assistance, Internet device50transmits an emergency request message through the IP network60at step191. Next, at step192, the message is routed to the emergency call handling function172. At step193the emergency call handling function172queries the database170which returns the physical location information associated with the user's IP address as well as a PSAP-compatible phone number associated with the user's IP address.

The caller's location information is delivered to the access tandem or PSTN20via gateway162. Next, in step195, the exit gateway162sends a PSAP formatted message to the PSTN20. The PSTN20receives the message, step196, and routes it to the emergency call answer center31. The selective router30within the emergency call answering center31utilizes the caller's location information and routed the call to the appropriate PSAP within the service zone of the user50, step197. Finally, the selected PSAP138responds to the user's request for emergency service by sending emergency personnel to assist the user150, step198.

As mentioned, an ISP (not shown) can provide the physical location information associated with a requesting user's IP address. The information can be stored in a database170, for example, accessible by the emergency call handling function172. It should be understood that other methods of obtaining the physical location information of the Internet device50are contemplated.

One aspect of the invention is that it may be implemented in various user configurations. For example, inFIG. 5a configuration with multiple Internet users, or clients, connected in a Local Area Net (LAN)280is shown and denoted generally as200. As shown, client terminals282,284and286have access to the central office58through hub290which can be a router, switch or other similar call exchange mechanism. Often the connection288between the hub290and the central office58is a high speed digital link.

The configuration200allows clients282,284and286on the LAN280to access the IP network60through a central node. The hub290acts as a gateway to the central office58through connection288, which may be a dedicated digital connection such as an E1/T1 or ISDN line, for example, to a central office58. Other connection methods may be employed.

The central office58directs traffic to Internet Server Provider (ISP)102which provides each client terminal282,284and286access to the IP network60. Typically, an IP address is dynamically assigned to a client terminal282,284,286during a log-in sequence to the ISP102. The ISP102verifies the client's account information and assigns an IP address that is associated with the client terminal for the duration of the session. In this way, a client terminal obtains access to the IP network60. In other configurations, IP addresses are dedicated to a specific client (e.g., static) so that the same IP address is used every time.

The invention contemplates use in a networked environment where a client terminal is assigned a different IP address each time the client is granted access to the IP network60. Thus, according to one embodiment of the invention, the emergency call handling function172is configured to return physical location information about a client regardless of the specific IP address assigned to that client terminal for an IP session.

The configuration of clients282,284,286is typical of many networked environments where multiple users are connected to the Internet through a common hub or centralized access point. For example, clients282,284and286may work at the same company, yet reside on different floors of a building, or different buildings within a complex. Users on a LAN280particularly benefit from the present invention because database170can be utilized to track the physical location of a user to the assigned IP address for each particular Internet session.

Turning now toFIG. 6, a process flow diagram for the method of routing emergency calls from a client in a networked environment such as configuration200ofFIG. 5is shown. Assuming a client terminal is in need of emergency services, the user of the client terminal logs on to the ISP102and transmits a emergency message to the IP Network60at step291. The emergency call handling function172receives the emergency message, step292, and queries the database170for the physical location information associated with the client terminal. The information may be provided by the ISP102utilizing the client's account information. The database170returns the information indicating the physical location of the client terminal.

At step293, the gateway162formats a message using a protocol compatible with the emergency call answering center31. For example, the message can be translated to the appropriate telephone number format, step293. The formatted message is directed to the PSTN20by the gateway162at step294. The PSTN20selects the route path corresponding to the PSAP associated with the location information of the client terminal, steps296and297. The appropriate PSAP responds to the clients request for emergency-service by dispatching the appropriate emergency personnel, step298.

The database170can include a look-up table indicating which users are connected to the IP network, their assigned IP address, and their physical location. The novel method and system of routing an emergency request message from an Internet client to an emergency-call-answering center permits the routing IP formatted emergency messages to traditional emergency-call-answering centers, such as those accesses by dialing 9-1-1 using a Plain Old Telephone System (POTS).

While the invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications in combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. For example, although it is preferable to have the translation270database in the Internet, it may be placed elsewhere in the system, for example, external to the Internet, or within the Intranet of a LAN. It is therefore intended that the appended claims encompass any such modifications or embodiments.