111111
`
`1111111111111111111111111111111111111111111111111111111111111
`US008199740B2
`
`c12) United States Patent
`Dabbs, III et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,199, 740 B2
`*Jun. 12, 2012
`
`(54) METHOD AND APPARATUS FOR EFFICIENT
`AND DETERMINISTIC GROUP ALERTING
`
`(56)
`
`(75)
`
`Inventors: James M. Dabbs, III, Stockbridge, GA
`(US); Brian Claise, Alpharetta, GA (US)
`
`(73) Assignee: Critical Response Systems, Inc.,
`Norcross, GA (US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`This patent is subject to a terminal dis(cid:173)
`claimer.
`
`(21) Appl. No.: 13/154,138
`
`(22) Filed:
`
`Jun. 6, 2011
`
`(65)
`
`Prior Publication Data
`
`US 2011/0299403 Al
`
`Dec. 8, 2011
`
`Related U.S. Application Data
`
`(63) Continuation of application No. 11/303,025, filed on
`Dec. 16, 2005, now Pat. No. 7,969,959.
`
`(60) Provisional application No. 60/636,094, filed on Dec.
`16, 2004.
`
`(51)
`
`Int. Cl.
`H04W4100
`(2009.01)
`(52) U.S. Cl. ..................... 370/349; 455/519; 455/404.1;
`455/410; 340/7.46; 340/539.1; 340/442; 340/445;
`340/441; 370/390; 370/310; 709/206; 709/207
`(58) Field of Classification Search ............... 455/404.1,
`455/410, 519; 370/349, 310, 390; 340/7.46,
`340/539.1, 442, 441, 445; 709/206, 207
`See application file for complete search history.
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`5,278,539 A
`111994 Lauterbach et a!.
`1111998 Diachina
`5,835,860 A
`10/2001 Lauzon eta!.
`6,304,649 B1
`6,529,735 B1
`3/2003 De Brito
`6,710,702 B1
`3/2004 Averbuch eta!.
`6,714,636 B1
`3/2004 Baiyor eta!.
`6,804,332 B1
`10/2004 Miner et a!.
`7,337,146 B2 *
`2/2008 Heelan eta!. ................... 705/52
`7,657,253 B2 *
`2/2010 Lewis ........................ 455/412.2
`7,808,378 B2 *
`10/2010 Hayden ......................... 340/506
`(Continued)
`
`OTHER PUBLICATIONS
`
`M 1520, Product Brochure, Critical Response Systems™, Copyright
`2005, 2 pages, www.critresp.com.
`
`(Continued)
`
`Primary Examiner- Pierre-Louis Desir
`(74) Attorney, Agent, or Firm- Roylance, Abrams,
`Berdo & Goodman, LLP
`
`ABSTRACT
`(57)
`A system and method are provided for reliable, wireless
`group alerting in a system having a database, switch, wireless
`network, and a plurality of intelligent mobile receivers, and
`preferably employing a modified two-way paging based on
`ReFLEX™ protocol information service (IS) messages and a
`novel ALOHA command for multicast acknowledgement
`from mobile receivers. An encrypted message is broadcast to
`a group address and received by a selected number of the
`mobile receivers. The network replies to the sender with
`detailed information about the individual members in the alert
`group. Each of the mobile receivers in the group then
`acknowledges the common message back to the system,
`decrypts the message, displays it to the user, and allows the
`user to respond. The system employs centralized manage(cid:173)
`ment to simplify the roles of the mobile users and adminis(cid:173)
`trators, minimizing configuration and operational human
`errors that would otherwise result in confusion or lost mes(cid:173)
`sages.
`
`21 Claims, 7 Drawing Sheets
`
`General Electric Co. 1002 - Page 1
`
`

`
`US 8,199,740 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`2001/0010490 A1 *
`8/2001 Bellin .......................... 340/7.46
`2002/0177428 A1
`1112002 Menard eta!.
`2003/0153343 A1
`8/2003 Crockett et a!.
`2004/0087300 A1
`5/2004 Lewis
`9/2004 Chen
`2004/0180654 A1
`7/2005 Chandhok eta!.
`2005/0157720 A1
`2005/0198183 A1
`9/2005 Zilliacus eta!.
`2006/0105740 A1
`5/2006 Puranik
`2006/0178128 A1
`8/2006 Eaton eta!.
`
`2006/0273893 A1 * 12/2006 Warner ......................... 340/531
`2010/0146057 A1 * 6/2010 Abu-Hakima et al ........ 709/206
`
`OTHER PUBLICATIONS
`M 1501, Product Brochure, Critical Response Systems™, Copyright
`2005, 3 pages, www.critresp.com.
`"Mobile Data and Paging for First Responders", Sparkgap™. Copy(cid:173)
`right 2004, 2 pages, www.tga.com.
`* cited by examiner
`
`General Electric Co. 1002 - Page 2
`
`

`
`U.S. Patent
`
`Jun.12,2012
`
`Sheet 1 of7
`
`US 8,199,740 B2
`
`20
`
`Q
`
`CLIENT
`
`11
`
`10
`
`I
`
`18 RECEIVER DATABASE
`
`14 WIRELESS NETWORK
`
`15 I
`
`era:
`
`' •
`SWITCH i
`MOBILE RECEIVER 16~ a a
`!81 ~
`!81
`16
`
`FIG.1
`
`18
`
`I
`
`22
`I
`RECEIVERS
`PK PERSONALADDRESS
`CRYPTOKEY
`PARAMETERS
`
`26
`I
`MEMBERSHIP
`PK, FK2 GROUPADDRESS
`PK, FK1 PERSONALADDRESS
`cc
`
`24
`I
`
`GROUPS
`l-...+ PK GROUPADDRESS
`NAME
`CRYPTOKEY
`
`FIG. 2
`
`General Electric Co. 1002 - Page 3
`
`

`
`U.S. Patent
`
`Jun. 12, 2012
`
`Sheet 2 of7
`
`US 8,199, 740 B2
`
`1'\.~n
`"0~"0
`
`0
`0
`0
`
`• 0
`
`0
`
`• • •
`
`-
`
`FIG. 3
`
`10'
`
`I
`
`20'
`
`12'
`
`~
`g ,...__ __ ..._ c,__--§~ ... .......__
`
`CAD CLIENT
`
`SPARKGAP SERVER
`CONNECT
`REQUEST 1 (LOGINJ ~
`RESPONSE 1
`REQUEST2
`RESPONSE 2
`EVENT
`EVENT
`EVENT
`
`~
`
`~
`
`.....
`'-
`
`--
`-
`
`FIG. 4
`
`General Electric Co. 1002 - Page 4
`
`

`
`;I
`;I
`;I
`GPS/AVL
`GPS/AVL
`GPS/AVL
`0
`0
`;I
`;I
`0
`GPS/AVL
`GPS/AVL
`0
`0
`D ~
`~(Bl
`on
`~ --
`~ ~
`~ ~ob:J(9) D ~ ~ (9)
`D .... j __
`
`;I
`GPS/AVL
`Q
`
`10"
`
`I
`
`(9)~
`
`;I
`GPS/AVL
`
`-.....!.-
`
`-... J ...
`
`~16
`
`14'
`
`-....!.-
`
`;I
`GPS/AVL
`0
`
`p
`
`9
`
`~ L,(
`
`TRANSMITIER
`
`MODEL2100
`RX1- t
`1
`RX2-
`RECEIVER
`TX--~
`~
`
`FIG. 5
`
`TANDEM ~-___r
`LINK
`PRIMARY
`(OPTIONAL) SPARKGAP
`SERVER
`12'b
`
`REDUNDANT
`(OPTIONAL)
`SPARK GAP
`SERVER
`12'a
`
`9-1-1 CENTER
`
`20
`
`~
`00
`•
`~
`~
`~
`
`~ = ~
`
`2'
`:= ....
`0 ....
`
`~
`
`N
`N
`
`N
`
`rFJ =(cid:173)
`.....
`
`('D
`('D
`
`(.H
`
`0 .....
`-....l
`
`d
`rJl
`"'010
`""""'
`\C
`\C
`~
`
`~ = = N
`
`General Electric Co. 1002 - Page 5
`
`

`
`I Rx/TxANTENNA ~
`
`AND INTERFACE
`
`30
`
`12
`
`MEMORY
`
`14
`
`NETWORK
`
`20
`I
`
`CLIENT
`
`I •
`
`I
`
`'I I PROCESSOR rt34
`
`-
`
`1
`
`16
`I
`
`r
`
`MEMORY
`
`l'+-36
`
`/
`
`I
`
`I PROCESSOR
`
`l'+-38
`
`I
`
`Rx 1 T x ANTENNA
`AND INTERFACE
`
`40
`
`~
`00
`•
`~
`~
`~
`
`~ = ~
`
`2'
`:= ....
`0 ....
`
`N
`
`N
`
`N
`
`~
`
`rFJ =(cid:173)
`.....
`
`('D
`('D
`
`.j;o.
`
`..
`
`--1
`
`,...__
`
`DATABASE ]18
`
`'-----
`
`FIG. 6
`
`I
`
`DISPLAY
`
`N-.44
`
`0 .....
`-....l
`
`I
`I
`
`f
`1 ...
`USER
`1-..
`INTERFACE I '-42
`
`-
`
`d
`rJl
`"'010
`""""'
`\C
`\C
`~
`
`~ = = N
`
`General Electric Co. 1002 - Page 6
`
`

`
`U.S. Patent
`
`Jun.12,2012
`
`Sheet 5 of7
`
`US 8,199,740 B2
`
`RECEIVE CAD
`REQUEST TO SEND
`GROUP MESSAGE
`
`REPLY WITH
`GROUP INFORMATION
`
`BROADCAST
`MESSAGE TO
`GROUP
`
`56
`
`y
`
`ASSOCIATE
`ACKWITH
`MESSAGE
`
`SENDACK
`TO CAD
`
`50
`
`52
`
`54
`
`58
`
`60
`
`ASSOCIATE
`RESPONSE WITH
`MESSAGE AND
`NOTIFY CAD
`
`64
`
`62
`
`FIG. 7
`
`General Electric Co. 1002 - Page 7
`
`

`
`U.S. Patent
`
`Jun.12,2012
`
`Sheet 6 of7
`
`US 8,199,740 B2
`
`86
`
`DISPLAY BUT
`DON'T RESPOND
`
`START
`
`RECEIVE GROUP
`ALERT MESSAGE
`
`80
`
`82
`
`N
`
`N
`
`SEND
`MULTICAST
`ACK
`
`RESPOND I
`DISPLAY
`
`88
`
`90
`
`FIG. 8
`
`General Electric Co. 1002 - Page 8
`
`

`
`U.S. Patent
`
`Jun.12,2012
`
`Sheet 7 of7
`
`US 8,199,740 B2
`
`44
`
`16
`
`6:52:51 PM
`DEC. 13, 2005
`VIEW RECEIVED MSGS
`VIEW TRANSMIITED MSGS
`SEND A MESSAGE
`DEVICE SETTINGS
`T.dl SJ
`
`a
`
`;o
`
`44
`
`11:09 AM
`JUNE 28,2005
`VIEW RECEIVED MSGS
`VIEW TRANSMITIED MSGS
`SEND A MESSAGE
`DEVICE SETTINGS
`liil
`
`T.111
`
`a Kl181
`
`100
`
`FIG. 98
`
`FIG. 9A
`
`[OLWWl @ NO SVC
`Onvirs'Dcense Wants &
`Warrants
`LastName:=.loh:::...n __
`First: Clle
`MI:X SDO~B: 6'"'117;;;:;;/59~Sex-: ;:-F -
`Waii~ NYSPIN?: Y -
`Local?!!
`-
`Order of Protection I!!Juiry?
`
`0
`0
`oooooooooo
`oooooooooo
`oooooooooo
`c.JC)C)C)~
`C)
`
`102
`
`FIG.10
`
`General Electric Co. 1002 - Page 9
`
`

`
`US 8,199,740 B2
`
`1
`METHOD AND APPARATUS FOR EFFICIENT
`AND DETERMINISTIC GROUP ALERTING
`
`This patent application is a continuation of U.S. patent
`application Ser. No. 11/303,025, filed Dec. 16, 2005, now
`U.S. Pat. No. 7,969,959 which claims the benefit of U.S.
`provisional application Ser. No. 60/636,094, filed Dec. 16,
`2004, the entire disclosures of which are incorporated herein
`by reference.
`
`BACKGROUND OF THE INVENTION
`
`The ability to alert and mobilize first responders is central
`to the readiness of any public safety agency. In the aftermath
`of recent major public safety events, including natural and
`man-made disasters, the public safety community has thor(cid:173)
`oughly examined all aspects of wireless interoperable voice
`communications. However, first responder alerting has
`remained largely unexamined for over a decade, and in com(cid:173)
`munities relying on volunteer first responders, the critical
`importance of first responder alerting rivals that of interoper(cid:173)
`able voice communications.
`Shortcomings with current alerting technologies are well
`documented in the public record. One analysis of communi(cid:173)
`cation failure during periods of profound crisis, the Arlington
`County After-Action Report on the Response to the September
`11 Terrorist attack on the Pentagon available from Arlington
`County, Virginia, notes failures in all forms of communica(cid:173)
`tions, from initial alerting to tactical voice communication.
`As stated in this report, during the events of Sep. 11, 2001,
`radio channels became oversaturated, and interoperability
`problems among
`jurisdictions and agencies persisted
`throughout the entire response process. Otherwise compat(cid:173)
`ible portable radios were preprogrammed in a manner that
`precluded interoperability. Cellular telephone systems and
`even the public switched telephone network (PSTN) became
`congested and unusable.
`This report cited traditional, 1-way paging systems as the
`most reliable method of alerting and notification. However,
`the lack of a paging response channel left responders relying 40
`on other, less reliable forms of communication to escalate,
`reply to, or even confirm receipt of their instructions. These
`problems with cellular telephone networks and the PSTN
`limited the overall effectiveness of 1-way paging as an alert(cid:173)
`ing system. This created serious operational challenges dur(cid:173)
`ing the Sep. 11, 2001 series of events, and they will create
`similar problems in any such future events.
`Even during day-to-day public safety activity, these alert(cid:173)
`ing system limitations are problematic. In most cases, when
`volunteer groups are alerted by pager, incident commanders
`do not know who will actually respond until personnel begin
`to arrive on scene. This delay postpones decisions regarding
`escalation and mutual aid, letting critical time slip by before
`commanders can identify and correct problems with the
`response. This time period can define the success or failure of
`the response process, presenting a critical need for simple,
`inexpensive, pager-type devices that can reply to group mes(cid:173)
`sages.
`However, public safety agencies still rely on 25-year old,
`1-way paging technology as their core alerting solution. 60
`Many newer technologies are available, but for alerting, for a
`variety of reasons, these technologies do not provide a mean(cid:173)
`ingful improvement over 1-way paging. Existing mobile data
`systems are too expensive and too bulky for continual per(cid:173)
`sonal use. Digital and analog 2-way voice systems are simi- 65
`larly impractical for widespread, continuous deployment to
`volunteer forces. Several contemporary PCS technologies
`
`2
`have integrated voice, data, and paging, but their complete
`dependence on commercial networks runs counter to com(cid:173)
`monly accepted reliability standards (e.g., NFPA-1221). Pri(cid:173)
`vate broadband solutions (such as IEEE 802.11 and 802.16)
`provide high-capacity data capabilities, but they lack the cov(cid:173)
`erage, portability, and resilience required for wide-area alert(cid:173)
`ing of large volunteer forces. Contemporary 2-way paging
`systems perhaps come closest to meeting the alerting needs of
`public safety agencies. Like 1-way systems, these pagers are
`10 small, inexpensive devices that operate for long periods on
`battery power. However, these systems have no ability to
`acknowledge group messages.
`More importantly, beyond the limitations described above,
`none of these systems provide a network interface sufficient
`15 to support acknowledged group messaging. Requiring that
`the message originator individually alert each recipient adds
`considerable setup delay when alerting large groups. This
`delay is eliminated when using network-supported call group
`or common address messages, but the message originator
`20 must have prior knowledge of group membership. If ames(cid:173)
`sage originator does not know the membership of the paged
`group, there is no context to know whether enough manpower
`is responding, or whether key individuals have been mobi(cid:173)
`lized. Manually maintaining accurate group membership ros-
`25 ters between networks and message originators would be
`impractical since this is time consuming, difficult, and prone
`to errors. For a communications system to provide usable,
`acknowledged group alerting capabilities to public safety
`agencies, the network interface must provide group member-
`30 ship details when the group message is sent. Even if the
`mobile devices were capable of acknowledging group mes(cid:173)
`sages, current systems do not provide message originators
`this membership information regarding the alerted group.
`Simply guaranteeing that a message will be eventually deliv-
`35 ered to all recipients is insufficient for public safety alerting
`applications. The message originator (dispatcher, incident
`commander, etc.) needs immediate feedback as to who has
`been alerted and how they have replied, as well as information
`concerning those who cannot be reached.
`A need therefore exists for a 2-way paging system that
`could be improved with group message acknowledgement
`and a suitable system interface. Such a system would address
`the current shortcomings of public safety alerting systems,
`and could also provide other benefits. For instance, it could
`45 act as an improved personnel accountability system (PAS) for
`on-scene communications. Incident commanders could
`instantly notify responders of imminent threats, such as
`impending chemical release or structure failure, and verify
`receipt by all personnel. Responses could be expanded to
`50 include location information and health or equipment status
`information. Such systems, made practical because of the
`high performance and low cost of 2-way pagers, would both
`obviate traditional problems with interoperable on-scene
`communications and enable central oversight of critical real-
`55 time safety data.
`While public safety's need for a system capable of
`acknowledged group alerting system is clear and well docu(cid:173)
`mented in the public record, no such system yet exists but for
`the present invention described herein.
`
`SUMMARY OF THE INVENTION
`
`The above-described deficiencies in the prior art are over(cid:173)
`come and a number of advantages are realized by the present
`invention. In accordance with an aspect of the present inven(cid:173)
`tion, a method of efficient and deterministic alerting of a
`group of recipients over a wireless network is provided. Each
`
`General Electric Co. 1002 - Page 10
`
`

`
`US 8,199,740 B2
`
`3
`recipient comprises a mobile device capable of transmitting
`and receiving data. The method comprises the steps of: stor(cid:173)
`ing for each recipient an assigned primary identifying address
`and one or more group addresses that are shared with selected
`ones of the other recipients; receiving a communication from
`a network client requesting wireless transmission of a mes(cid:173)
`sage to recipients sharing a selected one of the group
`addresses; transmitting a communication to the network cli(cid:173)
`ent comprising group information relating to the selected
`group addresses, the group information comprising at least 10
`one of the number of the recipients having the selected group
`address and the identifYing addresses of the recipients having
`the selected group address; broadcasting the message to the
`selected group address via a wireless network; receiving 15
`acknowledgment responses from the recipients sharing the
`selected group address via the wireless network; and provid(cid:173)
`ing the acknowledgment responses to the network client.
`In accordance with another aspect of the present invention,
`an apparatus for efficient and deterministic alerting of a group 20
`of recipients over a wireless network is provided. Each recipi(cid:173)
`ent comprises a mobile device capable of transmitting and
`receiving data. The apparatus comprises: at least one of a
`memory device and an interface to an external memory device
`for storing for each recipient an assigned primary identifying 25
`address and one or more group addresses that are shared with
`selected ones of the other recipients; a network client inter(cid:173)
`face for receiving a communication from a network client
`requesting wireless transmission of a message to recipients
`sharing a selected one of the group addresses; a wireless 30
`communication network interface for communicating with
`the recipients via a wireless communication network; and a
`processing device connected to the memory device, the net(cid:173)
`work client interface and the wireless communication net-
`work interface, the processing device being programmed to
`transmit a communication to the network client comprising
`group information relating to the selected group addresses,
`the group information comprising at least one of the number
`of the recipients having the selected group address and the 40
`identifying addresses of the recipients having the selected
`group address, broadcast the message to the selected group
`address via the wireless communication network and the
`wireless communication network interface, receive acknow 1-
`edgment responses from the recipients sharing the selected
`group address via the wireless communication network, and
`provide the acknowledgment responses to the network client.
`In accordance with yet another aspect of the present inven(cid:173)
`tion, a mobile device for efficient and deterministic alerting of
`a group of recipients over a wireless network is provided.
`Each recipient comprises a mobile device capable of trans(cid:173)
`mitting and receiving data. The mobile device comprises: a
`memory device for storing an assigned primary identifying
`address for its corresponding recipient and one or more group
`addresses that are shared with selected ones of the other
`recipients; a wireless communication network interface for
`communicating with a switch via a wireless communication
`network to receive messages therefore and to transmit
`responses to the switch; and a processing device connected to
`the memory device and the wireless communication network
`interface, the processing device being programmed to receive
`a message broadcast by the switch to a selected group address
`via the wireless communication network, to determine if it
`shares the selected group address, and to transmit an
`acknowledgment response to the switch via the wireless com(cid:173)
`munication network if it shares the selected group address.
`
`35
`
`4
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The present invention can be further understood with ref(cid:173)
`erence to the following description and the appended draw(cid:173)
`ings, wherein like elements are provided with the same ref(cid:173)
`erence numerals:
`FIG. 1 is a diagram of a group alerting system constructed
`in accordance with an exemplary embodiment of the present
`invention;
`FIG. 2 is a diagram of a database used in a group alerting
`system constructed in accordance with an exemplary embodi(cid:173)
`ment of the present invention;
`FIG. 3 is an isometric view of a switch or server used in a
`group alerting system constructed in accordance with an
`exemplary embodiment of the present invention;
`FIG. 4 is a diagram of communication between a client and
`a server used in a group alerting system constructed in accor(cid:173)
`dance with an exemplary embodiment of the present inven(cid:173)
`tion;
`FIG. 5 is a diagram of a group alerting system constructed
`in accordance with an exemplary embodiment of the present
`invention;
`FIG. 6 is a block diagram of a group alerting system con(cid:173)
`structed in accordance with an exemplary embodiment of the
`present invention;
`FIG. 7 is a flow chart illustrating a sequence of operations
`for broadcasting a group message and group message
`acknowledgment in accordance with an exemplary embodi(cid:173)
`ment of the present invention;
`FIG. 8 is a flow chart illustrating a sequence of operations
`for receiving, acknowledging and processing group message
`at a mobile receiver in accordance with an exemplary embodi(cid:173)
`ment of the present invention; and
`FIGS. 9A, 9B and 10 are views of mobile receivers con(cid:173)
`structed in accordance with exemplary embodiments of the
`present invention.
`
`DETAILED DESCRIPTION OF THE
`EXEMPLARY EMBODIMENTS
`
`Overview
`In accordance with the present invention, a system and
`method are provided for reliable, wireless group alerting in a
`system that comprises a database, switch, wireless network,
`45 and a plurality of intelligent mobile receivers, and employs a
`modified two-way paging protocol based on group messaging
`capability of the Motorola ReFLEX™ protocol and a novel
`ALOHA command for multicast acknowledgement (ACK)
`from mobile receivers. An encrypted message is broadcast to
`50 a group address. This message is received by a number of
`mobile receivers, each of which then acknowledges back to
`the system, decrypts the message, displays it to the user, and
`allows the user to respond, if they belong to the group address.
`The system employs centralized management to simplify the
`55 role of the mobile users and administrators, minimizing con(cid:173)
`figuration and operational human errors that would otherwise
`result in confusion or lost messages. It also employs novel
`mechanisms to compress the responses from the receivers to
`use minimal airtime. The system is particularly relevant to
`60 public safety and critical infrastructure operators, where large
`group dispatches must be delivered quickly and determinis(cid:173)
`tically to a heavily distracted mobile workforce, and their
`responses must be delivered to the dispatch center efficiently.
`As such, this system provides a comprehensive, meaningful
`65 solution to support distracted users with simple, resilient
`group messaging. It is to be understood that, while an exem(cid:173)
`plary embodiment is described herein that uses paging tech-
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`US 8,199,740 B2
`
`5
`no logy, the present invention can also be implemented using
`a cellular system, a wireless local area network or more spe(cid:173)
`cifically WiFi, or other wireless communication technology.
`In accordance with an exemplary embodiment of the
`present invention, a system for group alerting employs a
`SPARKGAP™ network which utilizes a modified version of
`a protocol called ReFLEX™ developed by Motorola, Inc. for
`two-way paging and Narrowband PCS (NPCS). This system
`uses a 12.5 KHz channel pair operating in the 900 MHz band.
`It is to be understood, however, that the group messaging of
`the present invention can be implemented using other types of
`protocols and network devices.
`In accordance with an aspect of the present invention, a
`SPARKGAP™ Dispatch Protocol (SDP) is provided as a
`streamlined means for a computer aided dispatch (CAD)
`system to communicate with two-way pagers on a SPARK(cid:173)
`GAP™ ReFLEX™ network. SPARK GAP™ is a ReFLEX™
`network solution designed to control one or more base sta(cid:173)
`tions and provide two-way paging and mobile data coverage
`over an arbitrary geographical area. While this solution is
`similar in some ways to traditional one-way paging, two-way
`paging also differs significantly from its one-way counter(cid:173)
`part. Two-way pagers acknowledge and reply to messages
`they receive, and they can originate their own messages.
`These additional capabilities outperform traditional paging
`input protocols (e.g., SNPP, TAP and TNPP). In addition,
`while more suitable second generation paging protocols exist
`(e.g., SMTP, SMPP, and WCTP), these newer protocols do
`not expose group membership information necessary for
`effective, acknowledged group messaging.
`The SDP of the present invention is a transactional, TCP/IP
`protocol where the CAD system is the client and the SPARK(cid:173)
`GAP™ is the server. It features synchronous, client-initiated
`request/response transactions as well as asynchronous server(cid:173)
`driven events, minimizing latency and complexity and deliv(cid:173)
`ering a rational solution to the public safety space.
`A Dispatch/Response Layer (DRL) is also provided in
`accordance with the present invention as a layer above the
`ReFLEX™ Air Protocol to support group messaging. The
`SDP and DRL are analogized as book ends in that they oper(cid:173)
`ate on either side of the ReFLEX™ network.
`ReFLEX™ supports personal and information service (IS)
`messages. Personal messages involve a single recipient, and
`ReFLEX™ enables the receiving pager to acknowledge
`reception, notifY that the user has read the message, and relay 45
`multiple-choice responses from the user. IS messages involve
`an arbitrary group of recipients sharing common group
`addresses called IS addresses. ReFLEX pagers can be con(cid:173)
`figured with one personal address and multiple IS addresses.
`IS messages are strictly one-way and ReFLEX™ does not
`support any response or acknowledgement from the recipient
`group. The present invention, however, adds message
`acknowledgement, message read notification, and multiple(cid:173)
`choice response capability to IS messages, creating an infra(cid:173)
`structure for reliable multicast messaging within the
`ReFLEX™ protocol. As described further below, the present
`invention implements two significant changes to conven(cid:173)
`tional 2-way paging. First, it defines a new ALOHA com(cid:173)
`mand ('Multicast ACK Command') used by a pager to reply
`to an IS message. Second, it defines a flag to select which 60
`devices are allowed to use this feature.
`System Description
`A system 10 configured in accordance with an exemplary
`embodiment of the present invention is depicted in FIG. 1.
`With reference to FIG. 1, a central switching system (herein(cid:173)
`after referred to generally as 'Switch') 12 connects to a Wire(cid:173)
`less Network 14 and communicates with a number of sub-
`
`6
`to generally as
`(hereinafter referred
`scriber devices
`'Receivers') 16 such as pagers, cell phones, or wireless per(cid:173)
`sonal data assistants (PDAs), or portable computer running
`WiFi. Each Receiver is assigned one identifying Primary
`Address and one or more multiple Group Addresses, and is
`capable of receiving broadcast alert messages directed to any
`of its addresses. The Switch 12 comprises a Receiver Data(cid:173)
`base 18 comprising stored information describing receivers,
`their group membership, and connects to a Wireless Network
`10 14 such as a PCS network employing cell broadcast, a paging
`network, or a broadcast-capable data network employing
`group addressing.
`With reference to FIG. 2, the Receiver Database 18 com-
`15 prises an independent table of Receivers 22 and an indepen(cid:173)
`dent table of Groups 24. Each Receiver row in table 22 con(cid:173)
`tains an identifying personal address, as well as other
`information specific to a single device 16 and its Wireless
`Network architecture. Each Group row in table 24 contains an
`20 identifying group address, an encryption key, and a symbolic
`name. A dependent table of Membership 26 provides the
`many-to-many relationship between Receiver and Group
`rows. Each Membership row assigns one receiver to one
`group. Membership rows contain GroupAddress and Person-
`25 alAddress columns, identifYing a Group and Receiver row,
`respectively. Each Membership row also contains a Receiv(cid:173)
`erGroupNumber colunm, a small nmemonic value that
`uniquely identifies the Group from other Groups pro(cid:173)
`grammed into the same Receiver, and CC ('carbon copy') flag
`30 to define specific behavioral aspects of the Receiver. Receiv(cid:173)
`ers do not respond to messages received by group addresses if
`their CC flag is set, while they can respond to messages
`received by group addresses if their CC flag is clear. This
`mechanism allows users to monitor alerts to specific groups,
`35 without expectation by the source of the alerts for a response.
`As administrative changes occur to the Receiver Database
`18, configuration transactions are executed over the air with
`individual Receivers 16 to synchronize their configuration
`memory with the corresponding data in the Receiver Data-
`40 base 18. The system 10 therefore maintains an up-to-date
`image in the configuration memory of each Receiver 16,
`including a list of Group addresses, their ReceiverGroup(cid:173)
`Number values, their symbolic names, encryption keys, and
`CC flags.
`With reference to the flow charts in FIGS. 7 and 8, a
`'Client' (e.g., a computer-aided dispatch center, a human user,
`or other network client 20) uses this system 10 to broadcast
`alert messages to groups of Receivers 16. To do so, the client
`20 composes a message, preferably including display content
`so and a list of response strings. The Client 20 then connects to
`the Switch 12 and requests transmission of the message to a
`particular group name (block 50). Depending on the archi(cid:173)
`tecture of the Wireless Network 14, either the Client 20 or the
`Wireless Network 14 assigns an identifYing field to themes-
`55 sage such that user responses can be associated with the
`correct message.
`Upon receipt of the message, the Switch 12 responds to the
`Client 20 with detailed information on the group such as a list
`or a connt of group members (block 52). It then encrypts the
`Group Message, assigns a cyclical message sequence num(cid:173)
`ber, and transmits the message to the Group Address (block
`54). As described in more detail below in connection with the
`SPARKGAP™ dispatch protocol (SDP), the Switch 12
`receives group message acknowledgment responses from the
`65 receivers 16 (block 56) that are associated with the broadcast
`group message (block 58) and provided to the Client 20
`(block 60). Similarly, other types of responses generated as a
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`US 8,199,740 B2
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`7
`result of the group message are associated with the broadcast
`group message (block 62) and provided to the Client 20
`(block 64).
`Upon receiving the Group Message (block 80), the Receiv-
`ers 16 decrypt the message and display the content, group
`name, and multiple choice options to the user. Receivers
`employing paging technology that are not addressed in the
`group do not receive the message. Alternatively, a system 10
`employing cellular broadcast of the message can receive but
`ignore the message if it is not in the addressed group (block
`82). Each Receiver 16 with a CC flag offalsetransmits one or
`more acknowledgement codes through the Network 14 back
`to the Switch 12, specifYing message received, message read
`notifications, and enumerated multiple-choice responses 15
`(block 84, 88 and 90). The datagram carrying the acknowl(cid:173)
`edgement code also includes the personal address of the
`receiver 16, the ReceiverGroupNumber of the group address,
`and the message sequence number of the message, which
`together efficiently and uniquely identify the specific group
`message at the specific Receiver 16. Each Receiver 16 in the
`group with a CC flag of true does not transmit an acknowl(cid:173)
`edgment reply to the Switch 12 but rather merely displays the
`group message (blocks 84 and 86).
`Each receiver 16 provides a configuration display for the
`user. This display allows the user to specifY, by group name,
`how notification should occur for messages received by each
`group address. Similarly, the Switch provides an administra(cid:173)
`tive human interface that allows a system administrator to set
`up and maintain the Receivers 16 belonging to each Group.
`An Exemplary Computer Aided Dispatch (CAD) System
`The foregoing system description discusses the high-level
`organization and data flow of an exemplary group messaging
`system 10 that can use any of a variety of network types. With
`reference to FIGS. 3, 4 and 5, the following is a description of
`an exemplary type of network, that is, a ReFLEX™ two-way
`paging network that incorporates the new group messaging
`layer of the present invention. FIG. 3 is a SPARKGAP™
`network controller 12' which is configured to implement
`group messaging in accordance with an exemplary embodi(cid:173)
`ment of the present invention. FIG. 4 illustrates the use of a
`SP