The present invention is directed to telecommunication systems, and especially to abbreviated or special number telecommunication systems, such as abbreviated number emergency services notification and dispatch operation telecommunication systems. One example of such an abbreviated or special number is the emergency services notification and dispatch system commonly known as the 9-1-1 system in the United States.
Emergency services notification and dispatch operations, commonly known in the United States as 9-1-1 Service, has its genesis in a 1957 recommendation by the National Association of Fire Chiefs for a single number for reporting fires. In 1967, the President""s Commission on Law Enforcement and Administration of Justice recommended that a single number should be established nationwide for reporting emergency situations. The use of different telephone numbers for different types of emergencies was considered to be contrary to the purpose of using a single, universal emergency notification number. Other federal agencies and several government officials supported and encouraged the recommendation. The President""s Commission on Civil Disorders charged the Federal Communications Commission (FCC) with finding a solution. In November 1967, the FCC met with the American Telephone and Telegraph Company (ATandT) to establish a universal number that could be implemented quickly. In 1968, ATandT announced the establishment of the number 9-1-1 as the emergency notification number nationwide. The 9-1-1 code was chosen because it was considered to be brief, easily remembered, and could be dialed quickly. It was also a unique number that had never been employed as an office code, area code or service code, and it met long range numbering plans and switching configurations of the telecommunication industry. The 9-1-1 number met the requirements of all parties, in government and in private industry.
Congress supported the ATandT plan and passed legislation allowing use of only the numbers 9-1-1 when creating an emergency calling service. The 9-1-1 number was thus established as a nationwide standard emergency number. The first 9-1-1 call in the United States was completed by Senator Rankin Fite in Haleyville, Ala., using the Alabama Telephone Company. Nome, Ak. Implemented 9-1-1 service in February 1968.
In 1973, The White House Office of Telecommunication issued a policy statement recognizing the benefits of 9-1-1, encouraging the nationwide adoption of 9-1-1, and establishing a Federal Information Center to assist governmental units in planning and implementing 9-1-1 service.
A basic 9-1-1 System provides for programming with special 9-1-1 software a telephone company end office (also known as a xe2x80x9ccentral officexe2x80x9d or a xe2x80x9cClass 5 officexe2x80x9d) to route all 9-1-1 calls to a single destination. The single destination was termed a Public Safety Answering Point (PSAP). In such an arrangement, all telephones served by the central office would have their 9-1-1 calls completed to the PSAP. However, the areas served by respective telephone company central offices do not line up with the political jurisdictions that determine the boundaries for which PSAP may be responsible. That is, a municipal fire department or police department may geographically include an area outside the area served by the central office, a condition known as underlap. Likewise, the municipal fire or police department may encompass an area of responsibility that is less expansive than the area served by the central office, a situation known as overlap. Further, the original basic 9-1-1 systems did not provide any identification of the caller; the PSAP human operator had to obtain such information verbally over the line after the call was connected. The major shortcoming of the basic 9-1-1 systems was that they could not support interconnection to other telecommunication providers such as independent telephone service companies, alternate local exchange carriers (ALECs), or wireless carriers. The xe2x80x9cbasicxe2x80x9d nature of the basic 9-1-1 system also indicates that the system does not have Automatic Location Identification (ALI) capability or Automatic Number Identification (ANI) capability with a call back capability.
Similar abbreviated number systems are in place for handling emergency service calls in countries other than the United States. The abbreviated number system established in Canada is the foreign system most similar to the system established in the United States. There are other abbreviated number calling systems in place in the United States and abroad for such purposes as handling municipal information and services calls (3-1-1) and for other purposes. All of these special or abbreviated number call systems that have geographic-based content suffer from similar shortcomings in their abilities to automatically place incoming calls to an action-response facility geographically proximate to the locus of the caller. It is for this reason that the 9-1-1 emergency call system of the United States is employed for purposes of this application as a preferred embodiment of the system and apparatus of the present invention.
Automatic Number Identification (ANI) is a feature for 9-1-1 services that allows the caller""s telephone number to be delivered with the call and displayed at the PSAP. This ANI feature is sometimes referred to as Calling Party Number (CPN). The feature is useful for identifying the caller and, if the caller cannot communicate, for callback. A signaling scheme known as Centralized Automatic Message Accounting (CAMA), originally used to identify the originator of a long distance call for billing purposes, was adapted to facilitate ANI delivery to the PSAP. CAMA uses multi-frequency (MF) signaling to deliver 8 digits to the PSAP. The first digit (called the Number Plan Digit-NPD) specifies one of four possible area codes. Digits 2-8 represent the caller""s 7-digit telephone number. The ANI is framed with a key pulse (KP) at the beginning and a start (ST) at the end in the format: KP-NPD-NXX-XXXX-ST.
The multi-frequency (MF) signaling used in connection with the ANI feature (referred to herein as Enhanced MF signaling) is not the same as the Dual Tone Multi-Frequency (DTMF) signaling also encountered in telecommunication systems. Both signaling schemes use a combination of two specific tones to represent a character, or digit, but the tones are different. There are 16 DTMF tones (0-9, #, *, A, B, C, D); there are a greater number of MF tones (including 0-9, KP, ST, STxe2x80x2, STxe2x80x3, and others). DTMF tones represent signals from a user to a network; MF tones are control signals within the network. An enhanced MF arrangement has recently been used in connection with 10-digit wireless telephone systems.
The original 911 systems used only CAMA trunks from the 911 tandem access switch that was connected to specialized hardware located at the PSAP. This specialized 911 PSAP equipment, sometimes referred to as an ANI Controller, was capable of receiving the caller""s ANI and then querying an ALI database to obtain the caller""s identification. PSAP technology has been improved in that the CAMA trunks and ANI Controller have been replaced with 911-formatted ISDN (Integrated Services Digital Network) telephones directly connected to the 911 access tandem, as described in U.S. Pat. No. 5,311,569 to Brozovich et al. for xe2x80x9cLine-Based Public Safety Answering Pointxe2x80x9d, issued May 10, 1994.
The availability of the caller""s telephone number to the PSAP (the ANI feature) led quickly to providing the caller""s name and address as well. This was straightforwardly accomplished using the subscriber information stored by telephone companies based upon telephone number since the 1980""s. A computer, often embodied in a personal computer (PC), is used by a PSAP operator (situated at the PSAP answering position) to access an automatic location identifier (ALI) database to obtain location information relating to the caller. Such equipment at the PSAP enabled queries of an Automatic Location Identification (ALI) database using the caller""s number provided by the ANI feature to ascertain name and address information. The ALI databases are typically maintained by the respective telephone company serving the PSAP. This was an improvement, but a problem still remained where several telephone company central offices served a town or county. Other problems also developed with the growing volume of mobile callers using wireless phones, satellite phones and communications over the Internet. Information regarding the locus of the origin of the call merely identified the locus where the call entered the wireline network; even such limited location information is not always provided. No indication was presented to identify the geographic location of such mobile callers.
As the situation of multiple central offices serving a PSAP occurred more frequently, it was clear that it was inefficient to build communication trunks from several central offices to a PSAP. As a result the 9-1-1 Tandem was developed. With that equipment, trunks from central offices are concentrated at a tandem office (a 9-1-1 tandem) from which a single trunk group serves a given PSAP. Often a 9-1-1 tandem comprises an otherwise common Class 5 telephone system end office (EO), with added software to configure it for 9-1-1 operations. Such concentration of trunks reduces size and cost of PSAP equipment. The tandem is a telephone company switch that provides an intermediate concentration and switching point. Tandems are used for many purposes, including intra-LATA (Local Access and Transport Area) toll calls, access to other local exchange carriers (LECs), and access to long distance carriers and telephone operators.
A significant development in 9-1-1 services has been the introduction of Enhanced 9-1-1 (E9-1-1). Some of the features of E9-1-1 include Selective Routing, ANI, ALI, Selective Transfer and Fixed Transfer. Selective Transfer enables one-button transfer capability to Police, Fire and EMS (Emergency Medical Service) agencies appropriate for the caller""s location listed on the ALI display. Fixed Transfer is analogous to speed dialing.
Selective Routing is a process by which 9-1-1 calls are delivered to a specific PSAP based upon the street address of the caller. Selective Routing Tandems do not directly use address information from the ALI database to execute decisions regarding which PSAP to connect. Recall that emergency services (Police, Fire and EMS) are typically delivered on a municipality basis. Often there will be one Police Department (e.g., municipal, county or state), but there may be several Fire Departments and EMS Agencies. The town will be divided into response areas served by each respective agency. The response areas are overlaid and may be defined as geographic zones served by one particular combination of Police, Fire and EMS agencies. Such zones are referred to as Emergency Service Zones (ESZ). Each ESZ contains the street addresses served by each type of responder. The ESZs are each assigned an identification number (usually 3-5 digits), known as Emergency Service numbers (ESN).
The Assignment of ESZs and corresponding ESNs enables the compilation of selective routing tables. The street addresses are derived from a Master Street Address Guide (MSAG), a database of street names and house number ranges within associated communities defining Emergency Service Zones (ESZs) and their associated Emergency Service Numbers (ESNs). This MSAG enables proper routing of 9-1-1 calls by the 9-1-1 tandem; this is Selective Routing as implemented in a 9-1-1 system. Thus, the telephone company must have an MSAG valid address to be assigned the appropriate ESN for selective routing purposes and that information must be added to the 9-1-1 ALI database. It is by using such information that the selective routing capability of the Selective Routing Tandem can properly route a 9-1-1 call to the correct PSAP. If the information is not available in the ALI database, the record is placed into an error file for further manual handling.
A portion of the ALI database may be loaded into a Selective Routing Data Base (SRDB) for use by the 9-1-1 tandem. The SRDB may be located in the tandem, in an adjunct processor, or in the ALI database.
Reliability is a very important factor considered in designing 9-1-1 systems. One approach to providing reliability is to provide diversely routed trunk groups from each central office to its respective 9-1-1 tandem. Preferably, each trunk group is large enough to carry the entire 9-1-1 traffic load for the respective central office. However, some systems are designed with less than full traffic capacity on trunk groups to xe2x80x9cchokexe2x80x9d or xe2x80x9ccongestion managexe2x80x9d incoming calls to a tandem in order to avoid overloading a PSAP. In some arrangements, parallel 9-1-1 tandems are provided so that a central office has capable 9-1-1 tandem ready for use (albeit with 50% call handling capacity) without interruption if one of the 9-1-1 tandems fails. Switched bypass to an alternate 9-1-1 tandem, commonly using digital crossover switches, is another approach to providing reliability in 9-1-1 systems.
Another approach to providing redundancy and robustness for a 9-1-1 system is the employment of Instant Network Backup (INB). Using INB, if a call does not complete to the 9-1-1 network for any reason (e.g., trunk failure, facility problem, 9-1-1 tandem failure or port failure), the INB takes over and completes the call to a predesignated 7- or 10-digit number. Using this INB alternate path, ANI and ALI information are not delivered, but the call is completed to a local public safety agency, usually the local PSAP.
The interface between Operator handled calls and a 9-1-1 system is addressed in several ways. One system provides a direct connection between an Operator tandem and the 9-1-1 tandem. The operator forwards the call with the caller""s ANI to the 9-1-1 tandem. The 9-1-1 tandem treats the call as though the caller had dialed the call. A second way to effect the desired interface is by using pseudo numbers. A pseudo number is a number that, when dialed, will reach a specific PSAP as a 9-1-1 call. Pseudo numbers have some special ALI information associated with them; for example, there may be a pseudo number associated with each municipality in a state. Dialing the pseudo number, usually from outside the LATA (Local Access and Transport Area), will generate a 9-1-1 call to the PSAP for that municipality. The ALI display will indicate that it is a third party conference call from an unknown address in that town. The caller is not identified, but the call goes to the PSAP where the caller is believed, or claims, to be. Pseudo numbers are useful for Alternate Local Exchange Carrier (ALEC) or Competitive Local Exchange Carrier (CLEC) operators who may be located anywhere in the country.
A third method for effecting an interface for operator handled calls with a 9-1-1 system is through the public switched telephone network (PSTN), dialing the directory number for the PSAP. This is often referred to as the xe2x80x9cback doorxe2x80x9d number by ALEC and CLEC operators. Besides the delivery of emergency (i.e., 911) calls to a PSAP, other calls (i.e., xe2x80x9cback doorxe2x80x9d calls) must be handled by a PSAP. This is so because some callers choose to call for police, ambulance or other emergency service using a conventional telephone number (usually a 7- or 10-digit phone number) instead of calling 911. Calls to such conventional telephone numbers are routed to a PSAP operator over usual telephone lines (sometimes referred to as xe2x80x9cadministrative linesxe2x80x9d) employed for routing such conventional phone calls. Having to be able to answer such calls received over administrative lines has historically required PSAP operators to have a second telephone available to answer such calls. This need for addressing administrative calls (i.e., calls not cast in emergency call 911 format and routed over ANI-capable lines) gave rise to the use of a specialized Private Branch Exchange (PBX) by the PSAP to replace the specialized 911 ANI controller hardware or the ISDN phones connected directly to the 911 tandem. Such employment of a PBX for use by a PSAP is described in U.S. Pat. No. 6,101,240 to Blair et al for xe2x80x9cArrangement for Public Safety Answering Pointsxe2x80x9d, issued Aug. 8, 2000. Blair""s 911-capable PBX is configured for connection directly with a 911 tandem using CAMA or 911-formatted ISDN trunks and provides many typical PBX Centrex-like functions such as call holding, forwarding, conferencing, and parking found in most commercial PBXs used by businesses today. One additional advantage of Blair""s PBX is that xe2x80x9cadministrative linesxe2x80x9d may also be connected to the PBX, thereby allowing the PSAP operator to require only a single phone for handling both types of callsxe2x80x94emergency service 911 calls and administrative calls. Many PSAP installations have employed the Blair 911-capable PBX and find that its employment is cost effective and easier to support as they reduce the diversity of their installed equipment.
The same issues encountered in implementing a 9-1-1 system for identifying user location are also extant in other telecommunication systems where user location (or other locations) is important.
The advent of wireless communications has further exacerbated the difficulty of ascertaining caller location in telecommunication systems. The xe2x80x9cpatchworkxe2x80x9d solutions described above regarding 9-1-1 systems have been mirrored in other special or abbreviated number systems to a significant extent. The xe2x80x9cpatchworkxe2x80x9d solutions have created a capability-limited telecommunication system that cannot ascertain geographic information as fully or as easily as it should for all types of callers. This capability limitation has been especially felt in connection with wireless telephone systems. The system is overly dependent upon human intervention to properly route calls to appropriate receivers, such as a proper PSAP. New modes of communication, such as Voice Over IP (Internet Protocol), further contribute to telecommunication traffic not identifiable regarding geographic origin using present telecommunication routing systems.
It remains that current 911 access tandem equipment used in the United States is only capable of delivering a 911 call to a PSAP using certain trunk types. These trunks types are CAMA, a specific version of ISDN called Custom ISDN BRI (hereinbefore referred to as 911-formatted ISDN) and Enhanced MF. Custom ISDN BRI is only available on certain specific communication switches produced by limited manufacturers. If a PSAP wants to use a PBX to service 911 calls and the selected PBX does not provide telephone trunk support for the specific trunks required for 911 service from 911 tandem equipment (i.e., CAMA, Custom ISDN BRI or Enhanced MF), then the PBX cannot be used. It is desirable for PSAPs to have a single telecommunications vendor solution for all standard telephony needs as well as the handling off 911 calls. Such a single-vendor approach contributes to unity of design, efficiency of operation and economy in replacement parts and other maintenance related expenses. If a vendor cannot provide a PBX configured for connection with a 911 tandem, then this desirable common telecommunications solution cannot be met.
One solution to non-911 compatible PBXs has been to implement a two-PBX solution. A non-911 compatible PBX is used for all general business telephony functions and as the reception point for administrative trunks. A second, 911-compatible PBX or ANI controller is used as the reception point for only 911 lines. The two PBXs are interconnected together using TIE (Telephone Interconnect Equipment) lines such as a T1 line or other data-compatible line. In this configuration, a PSAP operator is disadvantageously required to have two telephones installed at a PSAP answering position: one phone is used for general purpose communications (i.e., administrative calls) and a second, different telephone is used for handling 911 calls. Requiring two PBX""s and two phone instruments per answering position as well as requiring extra cabling for connecting all of the required hardware renders this a relatively expensive solution for supporting emergency system 911 calls and administrative calls. Moreover, by not having a single PBX and telephone for both types of calling traffic, the PSAP operator (the human operator manning the PSAP answering position) loses the ability to perform inter-PBX transfers and conferences by simply dialing a 3 or 4-digit extension for the additional party. Typically a full 7 (or 10) digit number must be dialed. When calls are answered on the 911 telephone, the PSAP operator has no ability to use speed dial lists relating to the non-911 PBX. Other functionality such as prioritization of 911 call delivery (ahead of administrative calls) to the PSAP operator and automatic route selection for outgoing calls is also lost by not having a unified PBX capability associated with the call handling equipment at the PSAP answering positions for handling both 911 calls and administrative calls.
Similar limitations will likely occur in other abbreviated number or special number telephone systems handling location-based calls with resulting adverse operational shortcomings. Other such abbreviated number systems include emergency call systems in countries other than the United States, abbreviated number calling systems for reaching telephone maintenance services, abbreviated number calling systems for municipal information and services, and similar systems.
There is a need for an improved telecommunication system and apparatus for providing telephone communication between a caller and a special number call answering facility that can ascertain caller location or other geographic information with less human intervention than is presently required.
There is also a need for an improved telecommunication system and apparatus for providing telephone communication between a caller and a special number call answering facility that can ascertain caller location or other geographic information with less human intervention than is presently required when involving wireless, Internet, satellite or other non-geographically fixed communication technologies.
There is yet a further need for an improved telecommunication system and apparatus for providing telephone communication between a caller and a special number call answering facility that share user location or other geographic information with other call answering stations using PBX-type call handling capabilities.
A system is for providing communication between a caller and a special number call answering facility including special number call answering positions. Calls are effected in a first special number call format including caller identification information or a second administrative call format not including identification information. The system includes: (a) A first switching apparatus coupled with a special number switch in a network. The first switching apparatus receives a first incoming call in the first call format from the special number switch. The first switching apparatus converts the first incoming call to an interim call cast in an interim call format maintaining the identification information in the second call format. The first switching apparatus presents the interim call at an output locus. (B) A second switching apparatus coupled with the call answering facility, coupled with the first switching apparatus and coupled with at least one administrative number switch in the network. The second switching apparatus receives second incoming calls from the at least one administrative number switch in the second call format. The second switching apparatus distributes the incoming administrative calls among the special number call answering positions. The second switching apparatus receives the interim call from the output locus and distributes the interim call among the special number call answering positions.
It is, therefore, an object of the present invention to provide an improved telecommunication system and apparatus for providing telephone communication between a caller and a special number call answering facility that can ascertain caller location or other geographic information with less human intervention than is presently required.
It is a further object of the present invention to provide an improved telecommunication system and apparatus for providing telephone communication between a caller and a special number call answering facility that can ascertain caller location or other geographic information with less human intervention than is presently required when involving wireless, Internet, satellite or other non-geographically fixed communication technologies.
It is yet a further object of the present invention to provide an improved telecommunication system and apparatus for providing telephone communication between a caller and a special number call answering facility that share user location or other geographic information with other call answering stations using PBX-type call handling capabilities.
Further objects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings, in which like elements are labeled using like reference numerals in the various figures, illustrating the preferred embodiments of the invention.
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