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CROSS-REFERENCE TO RELATED APPLICATIONS
G. J. Grimes, "Public Emergency Call Telecommunication Switching System";
U.S. patent application, Ser. No. 08/113946; and
G. J. Grimes, "Cellular Telecommunication Switching System For Providing
Public Emergency Call Location Information" U.S. patent application, Ser.
No. 08/113948, U.S. Pat. No. 5,388,147.
These applications are filed concurrently with this application and are
assigned to the same assignee.
1. Technical Field
This invention relates to cellular telephone terminals for providing public
emergency service; and, in particular, to the identifying the location of
calling cellular telephone terminals.
2. Background of the Invention
Providers of emergency services such as in fire, police, and rescue
departments have been greatly aided in their efforts to provide service to
individuals in need by the introduction of the 911 emergency number which
is now prevalent in the United States. One of the important aspects of the
911 emergency service is the fact that the public safety answering point
(PSAP) system utilized by the emergency provider obtains from the
telephone system ate calling parties' calling telephone numbers. Utilizing
this calling telephone number, the PSAP system accesses a remote database
containing information relating telephone numbers to users' names and
addresses and obtains from this remote database the calling telephone
user's name and billing address. For a wired telephone, the billing
address is the address where the telephone is located. Of course, the
address information, which effectively is location information, is the
most important, since often the calling party is incapable of supplying
the location information or does not have sufficient time to supply this
information. The location information allows the emergency service
provider to direct assistance to this location. Unfortunately, when the
calling telephone is a cellular telephone, the telephone billing address
is of no value in determining the present location of the cellular
telephone.
U.S. Pat. No. 5,122,959 discloses a vehicle location system for utilization
by an owner of a fleet of vehicles. The disclosed system is utilized to
determine the location of vehicles based on information that is
transmitted from the vehicle to a central computer. A unit in the vehicle
determines its position using the global positioning system (GPS) or other
position locating devices. Geo-coordinates that are obtained from GPS are
transmitted back to the central computer by a radio link. The central
computer then displays the location of the vehicle on a map displayed on a
computer display. In a similar system sold by PacTel Teletrac, the
transceiver in the vehicle is equipped with an alert button which when
pressed by the driver of the vehicle instantly alerts the dispatcher at
the central computer of an emergency. The dispatcher at the central
computer can then determine the location of the vehicle by utilizing the
computer display.
Clearly, there is a need in the art for a cellular terminal that can supply
information about its location and other information that will assist
emergency service personnel in responding to a 911 call.
SUMMARY OF THE INVENTION
This invention is directed to solving these and other disadvantages of the
prior art. In accordance with the invention, a cellular terminal includes
a GPS device; and upon the user of the cellular terminal placing an
emergency telephone call, the cellular terminal interrogates the GPS
device to obtain the geo-coordinates. The cellular terminal then transmits
the geo-coordinates to a cellular telecommunication switching system. The
cellular switching system or a PSAP system responds to the 911 call by
converting the geo-coordinates into location information. In addition, the
cellular terminal transmits to the cellular telecommunication switching
system pre-defined vehicle description information if the cellular
terminal is being utilized within a vehicle. This pre-defined vehicle
description information is entered by the user of the cellular terminal.
If the cellular terminal is a hand held unit, the cellular terminal can be
programmed to transmit personal characteristics of the person using the
cellular terminal. The cellular telecommunication switching system is
responsive to the vehicle or personal information to relay that
information to PSAP handling the emergency call. If the PSAP or cellular
switching system does not have the capability to accept digital data, the
information is transmitted to the PSAP in audio form after the cellular
terminal has converted the digital information to audio information.
In addition, the user of the cellular terminal can originate a 911 call in
response to actuation of a police button or a medical button. The cellular
terminal automatically places the 911 call. After the agent of the PSAP
has answered the 911 call, the cellular terminal transmits an audio
message requesting police or medical assistance depending on whether the
police or medical button, respectively, was actuated. Also, the user can
enter predefined medical information that is also transmitted to the PSAP,
when the medical button is actuated.
In another embodiment, the cellular terminal obtains the geo-coordinates
from the GPS device and converts the geo-coordinates to location
information using data stored internal to the cellular terminal. The
location information is transmitted to the PSAP via the cellular switching
system rather than the geo-coordinates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a first embodiment of a public emergency call
telecommunication switching in accordance with the invention;
FIG. 2 illustrates a second embodiment of a public emergency call
telecommunication switching in accordance with the invention;
FIG. 3 illustrates, in block diagram form, a cellular terminal;
FIG. 4 illustrates, in block diagram form, an emergency service cellular
telephone for utilization in an emergency service vehicle;
FIG. 5 illustrates, in block diagram form, a cellular switching system;
FIGS. 6 and 7 illustrate, in flowchart form, a program executed by
controller 121 of PSAP 117 in accordance with the invention;
FIGS. 8 and 9 illustrate, in flowchart form, a program executed by a first
embodiment of controller 301 of cellular terminal 133, in accordance with
the invention;
FIGS. 10 and 11 illustrate, in flowchart form, a program executed by a
second embodiment of controller 301 of cellular terminal 133, in
accordance with the invention;
FIG. 12 illustrates, in flowchart form, a program executed by a third
embodiment of controller 301 of cellular terminal 133, in accordance with
the invention;
FIG. 13 illustrates, in flowchart form, a program executed by a fourth
embodiment of controller 301 of cellular terminal 133, in accordance with
the invention; and
FIGS. 14 and 15 illustrate, in flowchart form, a program executed by
controller 501 of cellular switching system 134.
DETAILED DESCRIPTION
FIG. 1 illustrates a cellular terminal, such as cellular terminal 134, for
use with a public emergency call telecommunication switching system. When
originating an emergency call, cellular terminal 134 establishes digital
communication through cellular switching system 134 to public safety
answering point (PSAP) 117. Cellular terminal 134 then transmits
geo-coordinates for its present location to PSAP 117 which converts the
geo-coordinates to location information defining the location in terms of
standard municipality or rural destinations. If cellular terminal 134 is
unable to establish digital communication with PSAP 117 cellular terminal
134 transmits the geo-coordinates in audio form to the emergency agent of
PSAP 117 after the agent has answered the 911 call. As will be explained
in subsequent paragraphs, cellular terminal 134 transmits additional
information to assist emergency service personnel in responding to the 911
call.
PSAP 117 is the facility at which emergency telephone calls are answered
and the provisioning of emergency services is initiated. Whereas, the 911
number is the most common emergency number, various local governmental
agencies have set up other emergency telephone numbers which are also
transferred to PSAP 117. PSAP 117 responds to emergency telephone calls
received when these other emergency telephone numbers are dialed in the
same manner as it responds to an emergency call dialed using the 911
number. The illustrative PSAP 117 shown is an E911 emergency system.
Systems of this kind are well known. (See, for example, "E911 Public
Safety Answering Point: Interface Between a 1/1AESS.TM. Switch and
Customer Premises Equipment", Technical Reference TR-TSY-000350, Issue 1,
November 1987, by Bell Communications Research). PSAP 117 includes 911
automatic number identification (ANI) controller 121. Controller 121 is
illustratively the AT&T System 85/E911 running AT&T automatic call
distribution (ACD) software. Controller 121 provides private branch
exchange (PBX)-type functions for the incoming emergency calls, including
call-switching functions and call-distribution functions to emergency
service agents' positions 127-128. Since controller 121 is based on a PBX
such as the AT&T System 85, controller 121 may also be functioning as a
conventional PBX and serving non-emergency calls, and a community of users
135 other than agents responsible for handling emergency calls, along with
the emergency calls and the emergency call-handling agents. In that case,
controller 121 switches received emergency calls (identified as such by
the trunks over which they are received at controller 121) to the
emergency call-handling agents, and switches other calls to the other
users in a conventional PBX-like manner.
PSAP 117 includes a plurality of agent positions 127-128 for answering the
emergency calls. Each position 127-128 includes a voice terminal 131, such
as a multi-function telephone set, for answering the emergency voice
calls, and a display monitoring unit (DMU) 132, such as a data terminal,
for displaying data information associated with the call. Each agent
position 127-128 is illustratively the AT&T display management system
(DMS).
Unlike a conventional PSAP, PSAP 117 is capable of providing emergency
service not only for wired telephones such as telephone 10 but also
cellular terminals such as cellular terminal 133 in accordance with the
invention. When an emergency call is received from telephone 10, local
central office 11 provides automatic number identification (ANI) which
results in the telephone number of telephone 110 being transmitted to PSAP
117. PSAP 117 then accesses automatic location identification (ALI)
processor 114 and ALI computer 119 to obtain the location information. In
accordance with the invention, if the emergency call is from cellular
terminal 133, cellular terminal 133 determines its geo-coordinates using
an attached GPS device and transmits these coordinates along with the
emergency call information to cellular switching system 134. In response,
cellular switching system 134 transmits this information to PSAP 117. PSAP
117 is responsive to the geo-coordinate information to access GPS computer
124 via multiplexer 126. GPS computer 124 maintains a database that
defines the conversion from geo-coordinates to location information in
terms of municipal and rural designations. GPS computer 124 can be an
integral part of PSAP 117 or can be an externally located computer such as
ALI computer 119. In another embodiment of the invention, which is
illustrated in FIG. 2, cellular switching system 134 has an attached GPS
computer 124. Upon receiving the geo-coordinates from cellular terminal
133, cellular switching system 134 accesses GPS computer 124 obtains the
location information and transmits that information to PSAP 117 The
following paragraphs first describe the conventional manner in which a
PSAP provides emergency service when calls are received from a wired
telephone and, then, describes how emergency service is provided when the
emergency call is from a cellular terminal.
For conventional emergency calls, PSAP 117 receives emergency calls through
tandem central office 113 located on local exchange carrier premises 112.
Tandem central office 113 is connected by central office and E911 trunks
116 to PSAP 117 as well as to other PSAPs, and by interoffice trunks 116
to telephony local central offices 111, of which one is shown. The local
central offices are in turn connected to terminal equipment 110 of
telephony service subscribers. Local central offices 111 provides
automatic number identification (AND which is to provide a called party
with the telephone number of the calling party.
A local central office 111 which receives a "911 " call from telephone 110
automatically connects the call over a trunk 116 to tandem central office
113 and forwards to office 113 the calling telephone number. Based on the
received telephone number, office 113 connects the call over trunk 116 to
one of the PSAPs and forwards to that PSAP the calling telephone number.
Office 113 also connects non-911 calls destined for PSAPs to the
appropriate PSAPs over trunks 116. For any PSAP, however, the non-911
calls are connected over trunks 116 which are different from trunks 116
over which the 911 calls are connected.
Assuming that the call comes to PSAP 117 it is received by controller 121.
If it is a non-911 call, it is connected by controller 121 to
call-destination one of the community of users 135, in a conventional
manner. If it is a 911 call and includes the calling telephone number, it
is stored in first-in, first-out conventional queue 122 to await the
freeing of an agent at one of the positions 127-128 to receive the call.
The presences of the calling telephone number or geo-coordinates
determines the type of 911 call. In the present example, the calling
telephone number of the call is captured and is stored in memory along
with other information about the call by controller 121. Calls are
retrieved from queue 122 and distributed to positions 127-128 by
controller 121. When controller 121 assigns a call to a position 127-128,
controller 121 also formulates and sends a message to multiplexer 126
requesting information on the calling number be obtained from ALI computer
119 and transmitted to the assigned position by multiplexer 126. The
calling number of the call and the identification of the position 127-128
to which the call has been assigned are provided by controller 121 in the
message.
Multiplexer 126 is connected by one or more links 115 to ALI node processor
114. Multiplexer 126 forwards the message to ALI node processor 114. ALI
node processor 114 is located on local exchange carrier premises 112 and
is connected by links 115 to PSAP 117 and to other PSAPs, and also to ALI
computer 119. ALI node processor 114 acts as a concentrator and
deconcentrator, forwarding messages received from the PSAPs to ALI
computer 119 and forwarding message responses received from ALI computer
119 to the appropriate PSAPs.
ALI computer 119 is located at computer center 118 of the local exchange
carrier. Center 118 is typically remote from premises 112 and from PSAPs.
ALI computer 119 manages database 120 which contains information
associated with telephone numbers. The associated information includes
items of information such as the name and the address of the subscriber to
whom the number is assigned, personal data concerning the subscriber that
may be of help to emergency service personnel, and the phone numbers of
the subscriber's local police, fire and rescue departments.
In response to receipt of a message requesting the information associated
with a telephone number, ALI computer 119 retrieves the information from
database 120, formats it into a response message, and sends the response
message to ALI node processor 114. Processor 114 in turn sends the
response to the appropriate PSAP--the PSAP 117 in this example--where it
is received by multiplexer 126 and forwarded to the agent position 127-128
that has been assigned to handle the call. When the agent at the position
127-128 answers the call, the data associated with the call's originating
number are displayed on the position's DMU 132.
For cellular emergency calls, PSAP 117 receives emergency calls from
cellular switching system 134 via tandem central office 113. When the
cellular emergency call comes to PSAP 117 it is received by controller
121. Since it is a cellular 911 call, controller 121 detects the
geo-coordinates in the call information and determines that it is a
cellular 911 call. Since the call is a cellular 911 call, it is stored in
first-in, first-out cellular queue 123 to await the freeing of an agent at
one of the positions 127-128 to receive the call. The geo-coordinates are
stored in memory along with other information about the call. When the
call is retrieved from queue 123 and assigned to one of the positions
127-128 by controller 121, controller 121 also formats and sends a message
to multiplexer 126 requesting municipal location information concerning
the geo-coordinates be obtained from GPS computer 124. The geo-coordinates
of the call and the identification of the position 127-28 to which the
call has been assigned are provided by controller 121 in the message.
Multiplexer 126 is connected via link 125 to GPS computer 124. Multiplexer
126 forwards the message to GPS computer 124, and GPS computer 124
accesses an internal database and converts the geo-coordinates to location
information. This location information is then transmitted by GPS computer
124 to the agent position 127-128 that has been assigned to handle the
cellular call. When the agent at the assigned position answers the
cellular call, the municipal location information is displayed on that
position's DMU. Controller 121 had previously alerted the assigned agent
to the incoming 911 cellular call.
With respect to FIG. 2, a 911 cellular call is handled in a similar manner
to that described for FIG. 1 with the following exceptions. Upon receiving
a 911 cellular call, cellular switching system 134 accesses GPS computer
124 to determine the location information. That location information is
then transmitted along with the call to PSAP 117 via tandem central office
113. Controller 121 is responsive to the location information to store
that information in memory along with other information about the call
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