U.S. patent application number 15/167249 was filed with the patent office on 2016-09-22 for reverse 911 using multicast session internet protocol (sip) conferencing of voice over internet protocol (voip) users.
The applicant listed for this patent is TELECOMMUNICATION SYSTEMS, INC.. Invention is credited to DREW MORIN.
Application Number | 20160277589 15/167249 |
Document ID | / |
Family ID | 40753276 |
Filed Date | 2016-09-22 |
United States Patent
Application |
20160277589 |
Kind Code |
A1 |
MORIN; DREW |
September 22, 2016 |
REVERSE 911 USING MULTICAST SESSION INTERNET PROTOCOL (SIP)
CONFERENCING OF VOICE OVER INTERNET PROTOCOL (VoIP) USERS
Abstract
A reverse 911 system uses voice over Internet Protocol
(VoIP)/Session Internet Protocol (SIP) conferencing. An emergency
alert message may be a text, video, MMS, hyperlink and/or image
communicated simultaneously to multiple VoIP users via a SIP
conference. Multiple SIP conferences may be cascaded to communicate
with a larger number of users in a relevant group of users to be
communicated with.
Inventors: |
MORIN; DREW; (DAVIDSONVILLE,
MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TELECOMMUNICATION SYSTEMS, INC. |
ANNAPOLIS |
MD |
US |
|
|
Family ID: |
40753276 |
Appl. No.: |
15/167249 |
Filed: |
May 27, 2016 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12292719 |
Nov 25, 2008 |
9369294 |
|
|
15167249 |
|
|
|
|
61006014 |
Dec 14, 2007 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04M 3/5116 20130101;
H04L 65/1096 20130101; H04L 65/403 20130101; H04M 2242/04 20130101;
H04L 12/1818 20130101; H04L 65/1069 20130101; H04M 11/04 20130101;
H04L 65/1006 20130101 |
International
Class: |
H04M 11/04 20060101
H04M011/04; H04M 3/51 20060101 H04M003/51; H04L 29/06 20060101
H04L029/06 |
Claims
1. A reverse 911 emergency alert system, comprising: a SIP
conference focus server to establish a SIP conference triggered by
an appropriate reverse 911 trigger event; and a Session Internet
Protocol (SIP) conference bridge, initiated by said SIP conference
focus server, to establish a listen-only SIP conference with said
SIP conference focus server as host; wherein said SIP conference
focus server is adapted to issue a SIP INVITE to each of a
plurality of user agent devices designated in a user agent database
for listen-only participation in said listen-only SIP conference;
wherein said SIP conference focus server further establishes
another listen-only SIP conference triggered by said appropriate
reverse 911 trigger event, and issues a SIP INVITE to each of a
plurality of user agent devices designated in said user agent
database for listen-only participation in said another listen-only
SIP conference; wherein said SIP conference focus server cascades
said listen-only SIP conference with said another listen-only SIP
conference; and wherein said plurality of user agent devices are
provided listen-only access to said SIP conference bridge.
Description
[0001] The present invention is a continuation application of U.S.
Ser. No. 12/292,719, filed Nov. 25, 2008, which claims priority
from U.S. Provisional Application No. 61/006,014, entitled
"MULTICAST SESSION INTERNET PROTOCOL (SIP) FOR VOICE OVER INTERNET
PROTOCOL (VoIP) REVERSE 911" to Drew Morin, filed on Dec. 14, 2007,
the entirety of which is expressly incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to IP based communications
for emergency 911 services. More particularly, it relates to
emergency alert (e.g., Emergency alert.TM. type services) and
technology for landbased and/or wireless phones, including and
particularly Voice Over Internet Protocol (VoIP) phones.
[0004] 2. Background of Related Art
[0005] Many communities have, or are in the process of,
implementing what is known as an emergency alert system. An
emergency alert system allows an emergency center to rapidly notify
by telephone residents and businesses within a given geographical
area affected by any given emergency. The larger the emergency, the
larger the affected community and number of telephones to be
notified. Public safety access points (PSAPs) typically employ
emergency alert in emergency situations where it is necessary to
contact thousands of citizens to alert them of pending or potential
dangers, such as neighborhood evacuations, tornado warnings,
etc.
[0006] FIG. 4 shows a conventional emergency alert system for
implementing reverse 911.
[0007] In particular, the conventional emergency alert system 400
for implementing reverse 911 includes a dialing controller 420, a
phone number database 410, a modem bank 430, and a plurality of
users 440. Generally speaking, as shown in FIG. 4, there are a
given number of phone numbers 1 through Z to be called using a
smaller number N of modems in the modem bank 430.
[0008] Current emergency alert systems 400 employ banks of
telephone dialers (e.g., modem bank 430 for dialing out) to quickly
work through a list of hundreds, and even thousands (or more) of
telephone numbers associated with users 440, playing an audio
recording to each answered phone. Some emergency alert systems 400
will leave an emergency message on an answering machine if that is
what answers the line. Emergency alert systems 400 will keep track
of which telephone numbers in a list from phone number database 41
O that are not answered after a predetermined number of rings, and
will attempt to redial those phone numbers a predetermined number
of times in an attempt to make contact with a user 440.
[0009] Currently, banks of outdialing "phones", i.e., modem bank
430, are used to implement reverse 911. This type of service is
used to notify people in a local area of an emergency event such as
a Tornado, chemical spill, terrorist attack, etc. The bank of
phones from modem bank 430 dial specific phone numbers, play a
prerecorded message, disconnect and then dial the next number in a
sequence of provisioned numbers meeting a specific criteria from
phone number database 410.
[0010] But the present inventor has appreciated that the current
approach to reverse 911 relying on such an emergency alert system
400 may be slow to complete if an exceedingly large number of
phones must be called through a proportionately small number of
modems since each phone, associated with respective users 440, is
individually dialed and the complete transaction must be executed
before moving on to the next number. The number of simultaneous
calls that can be completed is limited to the number of modems
because each executes a single phone call at a time.
[0011] There is a need for a better emergency alert system capable
of quickly and reliably alerting phones currently within a region
affected by a given emergency message.
SUMMARY OF THE INVENTION
[0012] In accordance with the principles of the present invention,
a reverse 911 emergency alert system comprises a conference server
triggered by an appropriate event. A Session Internet Protocol
(SIP) conferencer, initiated by the conference server, establishes
an initial SIP conference between a source of an emergency message
and a plurality of user agents. A source generates an emergency
message that is transmitted into the SIP conference.
[0013] A method of providing a reverse 911 service in accordance
with another aspect of the invention comprises receiving a trigger
for issuing an emergency alert. A first Session Internet Protocol
(SIP) conference call is established between a source of an
emergency message and a plurality of user agents selected to
receive the emergency message. The emergency message is issued to
the plurality of user agents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] 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:
[0015] FIG. 1 shows an exemplary reverse 911 system using a SIP
conference, in accordance with the principles of the present
invention.
[0016] FIG. 2 shows a cascade of SIP conferences for implementing
reverse 911 services, in accordance with the principles of the
present invention.
[0017] FIG. 3 shows a process for initiating a SIP conference based
emergency call, in accordance with the principles of the present
invention.
[0018] FIG. 4 shows a conventional reverse 911 solution.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0019] The present invention provides reverse 911 using voice over
Internet Protocol (VoIP)/Session Internet Protocol (SIP)
conferencing. The disclosed embodiments include a method and
apparatus for enabling a single source to communicate
simultaneously to multiple recipients or subscribers using a
limited broadcast (SIP multicast) capability for the purpose of
group notification for a potentially large number of
subscribers.
[0020] The invention takes advantage of Voice over IP technology to
establish a conference call across multiple phone numbers
simultaneously. The SIP conference bridge is used to "push" a SIP
invite to SIP conference bridge participants that rings their
phones, and connects multiple users at once in a conference call
that plays the announcement simultaneously to those in the
conference.
[0021] Thus, reverse 911 is implemented for use in a VoIP phone
network. Many reverse 911 situations require notification to those
subscribers that are currently located within a given geographic
area. In such an implementation, the entity that knows the location
of any given VoIP phone is the VoIP positioning center (VPC).
However, in the case of a completely wireless phone (e.g.,
cellular, WiFi), there may not be any network entity that knows the
current location of a mobile user.
[0022] Reverse 911 requires the communication of time critical
information to a potentially large quantity of subscribers. Voice
over Internet Protocol (VoIP) enables a different paradigm for
communications that abstracts from the analog systems based
telecommunications architecture of the past to enable voice or
other historically analog sessions to be encapsulated into digital
data sessions and transported over the Internet in a much more
efficient manner.
[0023] This invention applies concepts developed in support of
conference call establishment under the SIP in an innovative way to
address the specific needs of Reverse 911 in a manner that improves
the speed of the service, broadens the information available, and
expand services beyond its current capabilities while reducing the
total cost to implement.
[0024] FIG. 1 shows an exemplary reverse 911 system using a SIP
conference, in accordance with the principles of the present
invention.
[0025] In particular, the reverse 911 system 100 includes a SIP
conference focus server 102 that can access a user agent database
101, various user agents 125, an IP communication medium 110 such
as the Internet, a message transfer agent (MTA) 104, a personal
computer 106, an instant messaging (IM) gateway 108, a media
gateway 112, and a wireless messaging gateway (WMG) 120.
[0026] Any appropriate event may be used to trigger a reverse 911
message transmission, e.g., a public emergency such as a natural
disaster or terrorist attack. In the event of a reverse 911 trigger
event, the SIP conference focus server 102 establishes a conference
bridge, i.e., a SIP conference bridge 150 for conducting a reverse
911 conference call with a plurality of recipients simultaneously.
The SIP conference bridge 150 allows a plurality of VoIP user
agents 125 to simultaneously connect to an established conference,
allowing the user agents 125 to simultaneously receive an emergency
message.
[0027] While not a requirement, the SIP conference is preferably a
listen-only conference for all user agents, with the exception of
the source of the reverse 911 emergency information which can be
delivered in many different forms (e.g., voice message, text,
video, etc.).
[0028] The SIP conference focus server 102 invites user agents 125
that are accessible through an IP communication medium 110, such as
a VoIP client 116 and a personal computer 106. The SIP conference
focus server 102 also invites user agents 125 that are accessible
through various intermediary devices, such as an MTA 104, an IM
gateway 108, a media gateway 112, and a WMG 120.
[0029] The media gateway 112 performs Voice Over Internet Protocol
(VoIP) soft-switching to allow VoIP access to user agents 125 with
an analog telephone device connected to plain old telephone server
(POTS) lines 114.
[0030] The SIP conference focus server 102 retrieves a list of user
agents 125 from a user agent database 101. The SIP conference focus
server 102 uses subscriber lists to identify and contact applicable
user agents 125.
[0031] The subscriber list can be either static or dynamic. A
subscriber list is static if it is based upon opt-in, call lists,
defined community (enterprise), etc. A subscriber list is dynamic
if it is based on some changeable set of criteria such as
geographic proximity, group membership, common likes/dislikes,
health vulnerabilities (asthmatics), etc.
[0032] Similarly, the user agent database 101 may include either a
static user agent list, a dynamic user agent list or a combination
of both. A dynamic user agent is preferably a list of phone numbers
that are provisioned at the time of the event, making the
provisioning process very quick without the need to rely on a
static list that must be updated periodically, though a static user
agent list is possible. But a dynamic user agent list comprises a
data set that can be generated in real time based on a specific
event and best data available.
[0033] The SIP conference focus server 102 establishes a SIP
conference bridge 150 for a conference call preferably based on the
capabilities of particular user agents 125. The capabilities of the
particular user agents 125 can be stored in an appropriate user
agent database 101 and retrieved by the SIP conference focus server
102.
[0034] As an example of a user capability that can be used to group
a number of users in a user agent list, the SIP conference focus
server 102 may establish a video conference call with user agents
125 that are capable of, or otherwise support, video messaging.
Another example, with respect to voice messaging, the SIP
conference focus server 102 may establish a voice conference call
with user agents 125 that support voice messaging.
[0035] Mixed mode conferencing may also be implemented such that
the SIP conference focus server 102 establishes a SIP conference
call transmitting in a common mode with user agents that support
the common mode within the various platforms. For instance, the SIP
conference focus server 102 may be provisioned to form a SIP
conference to broadcast a voice emergency message to user agents
capable of voice only as well as user agents capable of video
(using only the audio channel). In this way a reverse 911 emergency
alert may be employed across several types of formats that support
such alert. Thus, a text message that can be received by user
agents 125 of various platforms may be transmitted to user agents
in a common SIP conference.
[0036] Alternately, the SIP conference focus server 102 can
establish a conference bridge 150 for a SIP conference call
irrespective of the capabilities of particular user agents 125. In
such case, the SIP conference focus server 102 can issue a
plurality of emergency messages in a plurality of formats, with the
user agents 125 receiving whatever emergency message they have the
capability to receive based on the particular capabilities of an
end device employed by user agents 125.
[0037] The definition of a user agent as referred to herein
includes any SIP enabled device (either directly or via a format
conversion entity) that can be engaged in a SIP conference. The
user agents 125 associated with an end device include addressable
devices beyondmerely analog devices to include VOiP devices, PCs,
Email and SMS clients (through gateways), IM clients, and other IP
addressable devices.
[0038] A user agent 125 may be implemented in any electronic device
capable of receiving an emergency message having an appropriate
format, e.g., a pager, a cellular telephone, a portable computer, a
desktop computer, a personal data assistant (PDA), a VoIP phone,
etc.
[0039] The types of reverse 911 messages that can be sent to a
particular user agent 125 is limited only by the capabilities of
the particular receiving device running any given user agent 125.
For example, a pager can receive a text alert message, but may not
be capable of receiving a video alert message. Likewise, a cellular
telephone may lack the capability to receive a video alert message,
but may have the capability to receive a text alert message and/or
the ability to receive a voice message.
[0040] A user agent 125 may be implemented in an automobile that is
equipped with a networked navigation or other addressable
communications system. In this way drivers may be alerted to
emergency situations appropriate to them, e.g., an amber alert, a
warning to clear the roadway because of a high speed chase in
progress, etc. Further, this user agent 125 could act autonomously
on the information received from the conference. In this case, the
user agent 125 implemented within a networked navigation system
might automatically take appropriate action in response to an
emergency alert, e.g., to reroute the driver.
[0041] Similarly, an Internet connected device (such as a personal
computer or internet TV) might take the direct action on receipt of
an emergency message to display additional information from an
emergency responder web site. The user agent 125 may also be
implemented within the First Responder community such that receipt
of the reverse 911 message could trigger map downloads or the
execution of automated emergency response procedures,
[0042] The SIP conference focus server 102 is itself a member in
the conference established to transmit an emergency message, so the
SIP conference focus server 102 itself includes a user agent 125,
but in its case is preferably capable of initiating and hosting a
SIP conference.
[0043] Because the SIP conference focus server 102 is able to
participate and host a SIP conference, it preferably allows for
cascaded conferencing, i.e., repeated establishment of subsequent
SIP conferences, communicating an emergency alert message to a
given group of user agents, breaking down the SIP conference,
starting a subsequent SIP conference of another group of user
agents, communicating the same emergency alert message (in a same
or different format), etc. Subsequent SIP conferences may be
cascaded one after another until a total list of user agents to be
communicated with have had the emergency message transmitted to
them (or attempted to be transmitted to them). In this way reverse
911 is extended to a broad set of users and devices in a short
time.
[0044] The disclosed SIP conference focus server 102 is preferably
capable of initiating multicast. Multicast is a protocol definition
within the Internet Protocol (IP) that defines a limited scope
broadcast requiring participants to join a particular group in
order to participate.
[0045] An out calling mechanism, in accordance with the principles
disclosed herein, includes a SIP conference call with direct
INVITE, a multicast conference call, and a cascading conference
call. In operation, the SIP conference focus server 102 issues an
INVITE to user agents 125 designated in a user agent list
formulated dynamically from user agent database 101 or retrieved
from user agent database 101.
[0046] Preferably the SIP conference call established by a SIP
conference focus server 102 in accordance with the principles
disclosed herein allows provision of additional emergency
information to those user agents capable of receiving such
additional information. For instance, the emergency alert
information includes not only a message such as "An armed robber is
loose in your neighborhood-lock your doors!", but it may also
provide other suitable information of any appropriate type. For
example, an emergency alert voice message may be followed by, or
included with, an image of a suspect, most wanted person, or person
of interest; a map indicating a place where a robbery or other
recent crime occurred; a map of recommended evacuation routes; etc.
Alternatively, a hypertext link may be included with a reverse 911
emergency text message hyperlinking an Internet user to a web page
hosting additional information with respect to the current
emergency alert message.
[0047] FIG. 2 shows a cascade of SIP conferences for implementing
reverse 911 services using an IP solution to reverse 911, in
accordance with the principles of the present invention.
[0048] In particular, as shown in FIG. 2, the invention makes it
possible to "cascade" a SIP conference bridge capability to connect
potentially all of the user agents 125 at the same time, enabling a
single, direct and live communication with all relevant users.
[0049] In particular, a cascade of SIP conferences 200 for
implementing reverse 911 services can include a focus
server-established conference 210, focus-enabled user agents 220
and 240, a cascade conference 230, a cascade conference 250, and
various user agents 125.
[0050] As discussed above, a user agent as described herein
includes any SIP enabled device that can be engaged in a SIP
conference. However, in accordance with the principles disclosed
herein, at least some of the user agents 125 can further include
the ability to act as a conference focus server 102 themselves. A
first focus enabled user agent 220 and a second focus enabled user
agent 240 are two such exemplary specialized user agents 125 that
have the additional ability to act as a SIP conference focus server
102.
[0051] In the event of a trigger event triggering a reverse 911
emergency message, an initial focus-established conference 210 is
established by the SIP conference focus server 102. The various
relevant user agents 125 to be included in the reverse 911
communication are determined from a suitable database, and are
invited to participate in the initially established SIP
conference.
[0052] In accordance with the principles disclosed herein, the
focus enabled user agent 220 that is invited to participate in the
initial focus-established conference 210 not only participates in
the focus-established conference 210 but also establishes its own
cascade conference 230.
[0053] Likewise, as discussed above, the focus enabled user agent
240 that is invited to participate in the established cascade
conference 230 not only participates in the cascade conference 230
but also establishes its own cascade conference 250.
[0054] Parameters for establishing additional conferences can be
passed to the focus enabled user agent 220 and the focus enabled
user agent 240 from the SIP conference focus server 102
establishing the initial focus-established conference 210.
Alternately, parameters for establishing additional conferences can
be retrieved by the focus enabled user agent 220 and the focus
enabled user agent 240 from the SIP conference focus server 102
that initiated the focus-established conference 210. A request can
be transmitted from the focus enabled user agents 220, 240 to the
SIP conference focus server 102 to retrieve any necessary
parameters for establishing a conference.
[0055] FIG. 3 shows a process for initiating a SIP conference based
emergency call, in accordance with the principles of the present
invention.
[0056] In particular, as shown in FIG. 3, a SIP conference based
reverse 911 emergency call begins with step 310. In step 310, a
trigger event generates a need to communicate an emergency reverse
911 message. Any suitable type of trigger event can generate the
emergency reverse 911 communication, e.g., a weather emergency, a
terrorist alert, a public announcement such as a school closing,
road closure, etc. The SIP conference focus server 102 receives
notice of a trigger event.
[0057] In step 320, a determination is made as to whether or not a
static list of user agents 125 exists. To determine this, the SIP
conference focus server 102 searches a user agent database 101 for
a static list of user agents 125. If such a static list exists, the
process branches to step 330 to begin processing of the user agent
list. If such a static list does not exist, the process branches to
step 330 to create a dynamic list of user agents 125.
[0058] In step 330, criteria for a dynamic list is gathered. To
accomplish this, the conference focus server 102 searches user
agent database 101 to determine criteria for the dynamic list. The
criteria for the dynamic list can include, e.g., a geo-code
location of the trigger event and notification boundary, a search
list of provisioned subscribers, a search for mobile subscribers,
or any additional searches that may be necessary to provide an
emergency alert to the user agents 125.
[0059] Criteria for the dynamic list can further include, e.g., a
method of contacting the user agents 125 (analog voice_call, VoIP
call, IM, etc.), the time(s) that a particular method of contacting
the given user agent 125 may be used, any alternate methods of
contacting the given user agent 125, whether the given user agent
125 desires a voice message to be left on an answering machine, the
type of user agent 125, (e.g., phone, automobile navigation
systems, pagers, TTY devices), etc.
[0060] Preferably the user agents 125 can pre-establish their
preferences criteria through a variety of means, e.g., through a
web site interface, through a voice prompt system, etc.
[0061] From the criteria gathered in step 330, a list of user
agents 125 is compiled. The conference focus server 102 initiates a
database query with the criteria gathered in step 330 as a database
search criteria. The database query is passed to a user agent
database 101 to retrieve any/all user agents 125 that meet the
criteria established in step 320, with the database 101 providing a
list of user agents 125 that meet the database search criteria.
[0062] In step 340, the user agent 125 list compiled in step 330 is
provided to the SIP conference focus server 102 to parse the user
agent 125 list and establish a conference bridge 150. Once the SIP
conference focus server 102 has determined what user agents 125 to
contact, a conference bridge 150 can be established.
[0063] The established conference bridge 150 executes SIP call flow
with the user agents 125. Specialized user agents 125 can handle
SIP INVITE and ACKnowledgements. Specialized user agents 125 can
include SMS Gateways, Email Gateways, MMS Servers, SoftSwitch for
analog devices, Enterprise VOiP Servers, etc. Call flow can be
managed as a proxy server or as a cascading conference, as shown in
FIG. 2.
[0064] Preferably return communications from the user agents 125
are suppressed so that communication is one way only (TO the user
agents 125), with the user agents 125 able to only receive the
reverse 911 emergency alert communication.
[0065] In an advancement foreseen by the present inventors, twoway
reverse 911 communication is a possibility. In such a case, one or
more select user agents 125 might be allowed return participation
in the SIP conference call to share knowledge concerning an
emergency event.
[0066] Once communications are established between the conference
bridge 150 initiated in step 340 and the relevant user agents 125
designated to receive an emergency call, an emergency message can
be delivered to the user agents 125 in step 350. The conference
focus server 105 preferably issues an appropriate emergency message
to the user agents 125 depending upon the particular type of
trigger event and preferably formatted to the specific requirements
of the User Agent 125. For example, a Tornado Warning emergency
message may be formatted for delivery to a plain old telephone
service (POTS) phone as a canned verbal message, e.g., "Tornado
Warning". In this example, the same message would also be formatted
as text for delivery to a TTY device, as a warning banner or the
like for a video enabled mobile phone, and/or as an SMS text
message. It is forseen that the different formats could be
delivered simultaneously over the same conference.
[0067] The conference focus server 102 may issue either a static
(i.e., pre-canned) or a dynamically (i.e., live) emergency alert
message to the user agents 125 participating in a given SIP
conference (or cascaded SIP conference).
[0068] As an example of a static message for a given trigger event
to be communicated to all employees within a given company
facility, a possible reverse 911 emergency alert message might be,
e.g., : "a fire has been detected in the building"; or "Emergency:
There is a fire in the building and everyone is to evacuate as
quickly and orderly as possible."
[0069] As an example of a dynamic message for a given trigger event
to be communicated to all users currently on a given stretch of a
given highway, an upcoming road closure on that particular
interstate may be communicated to user agents currently located
within a vicinity of the highway. In such a case, the reverse 911
emergency message might be an announcement of such road closure and
possibly include alternate routes to avoid the road closure. Such
an emergency message can be dynamic in that it can be changed
according to road conditions or other dynamic aspects, e.g.,
"Interstate 495 is closed in the southbound direction, traffic
backups start 3.7 miles south, authorities advise use of interstate
395 as an alternate route."
[0070] SIP conference bridge 150 may communicate a reverse 911
emergency alert message including both a static message and a
dynamic message to the user agents 125. Alternately, or in
conjunction with a text data message, multimedia data (photos,
maps, video) can also be delivered to the user agents 125 if the
user agent 125 supports receipt of such types of data.
[0071] In step 360, the SIP conference focus server 102 issues a
termination instruction to user agents 125 instructing them that
the SIP conference call is terminated. The SIP conference bridge
150 itself may be disconnected by the SIP conference focus server
102.
[0072] The present invention substantially reduces the cost of the
an overall solution for implementing reverse 911. Moreover,
multiple different types of user agents 125 can be included in the
reverse 911 communication beyond just dialing sequences used in
typical telephone systems such as IM and email clients, TTY
devices, and mobile phones using SMS.
[0073] The invention has particular applicability in Public Safety
Answering Points (PSAPs), Emergency Preparedness Organizations,
Homeland Security and other Government entities involved in public
safety and security. It .cndot. may also be implemented by
commercial corporations to notify employees, or by college campuses
to notify students.
[0074] 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.
* * * * *