`US008588207B2
`
`c12) United States Patent
`Dabbs, III et al.
`
`(IO) Patent No.:
`(45) Date of Patent:
`
`US 8,588,207 B2
`Nov. 19, 2013
`
`(54) METHOD AND APPARATUS FOR EFFICIENT
`AND DETERMINISTIC GROUP ALERTING
`
`(75)
`
`Inventors: James M. Dabbs, III, Stockbridge, GA
`(US); Brian Claise, Alpharetta, GA (US)
`
`(73) Assignee: Critical Holdings, Inc., Norcross, GA
`(US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 13/476,641
`
`(22) Filed:
`
`May21, 2012
`
`(65)
`
`Prior Publication Data
`
`US 2012/0327781 Al
`
`Dec. 27, 2012
`
`Related U.S. Application Data
`
`(63) Continuation of application No. 13/154,138, filed on
`Jun. 6, 2011, now Pat. No. 8,199,740, which is a
`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)
`
`(2009.01)
`
`Int. Cl.
`H04W24/00
`(52) U.S. Cl.
`USPC ........................................... 370/349; 455/410
`( 58) Field of Classification Search
`USPC ............... 455/404.1, 410; 370/310, 349, 390,
`370/442, 445, 539.1
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`5,278,539 A
`5,835,860 A
`
`111994 Lauterbach et al.
`1111998 Diachina
`
`6,304,649 Bl
`6,529,735 Bl
`6,710,702 Bl
`6,714,636 Bl
`6,804,332 Bl
`7,337,146 B2
`7,657,253 B2
`7,808,378 B2
`200110010490 Al
`2002/0177428 Al
`2003/0153343 Al
`2004/0087300 Al
`200410180654 Al
`
`10/2001 Lauzon et al.
`3/2003 De Brito
`3/2004 Averbuch et al.
`3/2004 Baiyor et al.
`10/2004 Miner et al.
`2/2008 Heelan et al.
`2/2010 Lewis
`10/2010 Hayden
`8/2001 Bellin
`1112002 Menard et al.
`8/2003 Crockett et al.
`512004 Lewis
`912004 Chen
`(Continued)
`
`OTHER PUBLICATIONS
`
`M 1520, Product Brochure, Critical Response Systems™, Copyright
`2005, 2 pages, www.critresp.com.
`
`(Continued)
`
`Primary Examiner - Sam Bhattacharya
`(74) Attorney, Agent, or Firm -Roylance, Abrams, Berdo
`& Goodman, LLP
`
`ABSTRACT
`(57)
`Systems and methods 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
`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 management to simplify the roles of the
`mobile users and administrators, minimizing configuration
`and operational human errors that would otherwise result in
`confusion or lost messages.
`
`13 Claims, 7 Drawing Sheets
`
`10
`
`I
`
`18 RECEIVER DATABASE
`
`14 WIRELESS NETWORK
`
`15 I
`
`20
`
`~
`
`CLIENT
`
`1
`
`r=;t,
`I ~ 2
`SWITCH -1- l:l_. .,,"':
`
`MOBILE RECEIVER 16~
`l8J
`
`l8J
`
`e
`l8J ~
`16
`
`General Electric Co. 1004 - Page 1
`
`
`
`US 8,588,207 B2
`Page 2
`
`(56)
`
`References Cited
`
`2010/0146057 Al
`
`612010 Abu-Hakima et al.
`
`U.S. PATENT DOCUMENTS
`
`2005/0157720 Al
`2005/0198183 Al
`2006/0105740 Al
`2006/0178128 Al
`2006/0273893 Al
`
`7/2005 Chandhok et al.
`912005 Zilliacus et al.
`512006 Puranik
`8/2006 Eaton et al.
`12/2006 Warner
`
`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.
`
`General Electric Co. 1004 - Page 2
`
`
`
`U.S. Patent
`
`Nov. 19, 2013
`
`Sheet 1of7
`
`US 8,588,207 B2
`
`20
`
`~ CLIENT
`
`11
`
`10
`
`I
`
`18 RECEIVER DATABASE
`
`14 WIRELESS NETWORK
`
`15 I
`
`' '
`SWITCH iJ
`MOBILE RECEIVER 16_,.,..a
`
`9
`
`te
`
`FIG.1
`
`ceicei:
`te
`te ~
`16
`
`18
`
`I
`
`22
`)
`RECEIVERS
`PK PERSONALADDRESS
`CRYPTOKEY
`PARAMETERS
`
`-
`
`26
`)
`MEMBERSHIP
`PK, FK2 GROUPADDRESS
`PK, FK1 PERSONALADDRESS
`cc
`
`24
`)
`
`GROUPS
`r---+- PK GROUPADDRESS
`NAME
`CRYPTOKEY
`
`FIG. 2
`
`General Electric Co. 1004 - Page 3
`
`
`
`U.S. Patent
`
`Nov. 19, 2013
`
`Sheet 2 of7
`
`US 8,588,207 B2
`
`12'
`
`• 0 •
`
`• • •
`
`•
`•
`
`•
`
`•
`•
`
`0
`
`FIG. 3
`
`10'
`
`I
`
`20'
`
`iF4i
`~ ~----- c:
`
`CAD CLIENT
`-
`
`-
`
`-
`
`.
`-
`
`SPARKGAP SERVER
`CONNECT
`REQUEST 1 (LOGIN)
`RESPONSE 1
`REQUEST2
`RESPONSE 2
`EVENT
`EVENT
`EVENT
`
`12
`
`§ ~-----
`
`-
`-
`
`;:_
`
`FIG. 4
`
`General Electric Co. 1004 - Page 4
`
`
`
`/
`GPS/AVL
`0
`
`p
`
`~
`
`e
`L,,
`
`MODEL2100
`RX1~ I
`RX2~ 1
`RECEIVER
`TX-+-~
`~
`
`/
`/
`/
`/
`GPS/AVL
`GPS/AVL
`GPS/AVL
`GPS/AVL
`0
`0
`/
`GPS/AVL 0
`0
`o
`o
`~~a~
`~ ..
`~ .. ~
`(8) (8) (8) DI !J (8) . .
`IDl
`(8) ~ (8)
`a
`
`--.. J..,,
`
`i-
`
`i-
`
`10"
`
`I
`
`~16
`
`~
`00
`•
`~
`~
`~
`
`~ = ~
`
`z 0
`~ ....
`
`~v::i
`N
`
`0 ....
`
`(.H
`
`/
`GPS/AVL
`
`~
`
`'-"
`
`...__1_
`
`14'
`
`-.___/_
`
`1J1 =(cid:173)
`.....
`
`('D
`('D
`
`(.H
`
`0 .....
`-....J
`
`TRANSMITIER
`
`FIG. 5
`
`TANDEM ~-__J
`LINK
`PRIMARY
`(OPTIONAL) SPARKGAP
`SERVER
`12'b
`
`REDUNDANT
`(OPTIONAL)
`SPARK GAP
`SERVER
`12'a
`
`9-1-1 CENTER
`
`20
`
`d
`rJl
`00 u.
`
`00
`00
`
`'N = -....l = N
`
`General Electric Co. 1004 - Page 5
`
`
`
`Rx/TxANTENNA ~
`AND INTERFACE
`30
`
`MEMORY
`
`I
`
`12
`
`r---k__32
`I -
`
`(
`
`14
`I_
`
`NETWORK ~
`
`•I
`
`I PROCESSOR
`
`i'l.__34
`
`20
`
`CLIENT
`
`, ..
`
`e •
`
`00
`•
`~
`~
`~
`~
`
`=
`
`~
`
`z 0
`~
`....
`"°
`"'
`N
`....
`0
`
`(.H
`
`16
`I_
`
`I
`
`.I I MEMORY
`
`PROCESSOR
`
`I
`
`I 36
`
`38
`
`I
`
`Rx/TxANTENNA ~ 1J1 =-
`AND INTERFACE
`40
`
`('D
`('D
`
`.....
`
`.i;...
`
`DATABASE
`
`. -.. 18
`
`FIG. 6
`
`DISPLAY N44
`
`0 .....
`-....J
`
`i
`I
`
`USER
`INTERFACE
`
`42
`
`d
`rJl
`"'QIO
`tit
`QIO
`QIO
`
`'N = -....l = N
`
`General Electric Co. 1004 - Page 6
`
`
`
`U.S. Patent
`
`Nov. 19, 2013
`
`Sheet 5of7
`
`US 8,588,207 B2
`
`START
`
`RECEIVE CAD
`REQUEST TO SEND
`GROUP MESSAGE
`
`50
`
`REPLY WITH
`GROUP INFORMATION
`
`52
`
`BROADCAST
`MESSAGE TO
`GROUP
`
`y
`
`ASSOCIATE
`ACK WITH
`MESSAGE
`
`SEND ACK
`TO CAD
`
`54
`
`58
`
`60
`
`56
`
`62
`
`ASSOCIATE
`RESPONSE WITH
`MESSAGE AND
`NOTIFY CAD
`
`64
`
`END
`
`FIG. 7
`
`General Electric Co. 1004 - Page 7
`
`
`
`U.S. Patent
`
`Nov. 19, 2013
`
`Sheet 6of7
`
`US 8,588,207 B2
`
`86
`
`DISPLAY BUT
`DON'T RESPOND
`
`START
`
`RECEIVE GROUP
`ALERT MESSAGE
`
`80
`
`82
`
`N
`
`N
`
`SEND
`MULTICAST
`ACK
`
`RESPOND/
`DISPLAY
`
`88
`
`90
`
`FIG. 8
`
`General Electric Co. 1004 - Page 8
`
`
`
`U.S. Patent
`
`Nov. 19, 2013
`
`Sheet 7of7
`
`US 8,588,207 B2
`
`8:52:51 PM
`DEC. 13, 2005
`VIEW RECEIVED MSGS
`VIEW TRANSMITTED MSGS
`SEND A MESSAGE
`DEVICE SETTINGS
`liiiJ
`
`T.111
`
`ii
`
`7'
`
`(
`
`CJ)
`
`FIG. 9A
`
`44
`
`16
`
`B
`tJ
`0
`
`11:09AM
`JUNE 28, 2005
`VIEW RECEIVED MSGS
`VIEW TRANSMITTED MSGS
`SEND A MESSAGE
`DEVICE SETIINGS
`liil
`
`T.,11
`
`ii [] 181
`
`44
`
`100
`
`FIG. 98
`
`16
`
`44
`
`102
`
`[DLWW] @!) NO SVC
`bnvers' Dcensewants &
`Warrants
`LastName:=Joh"'--n __
`First~Doe~--
`Ml:X DOB: 6/17/59 Sex: F
`Wants NYSPIN?: y
`-
`Local? N
`-
`Order of Protection Inquiry?
`
`0
`0
`0000000000
`0000000000
`0000000000
`Oc:>c:>c:>O
`
`C)
`
`FIG.10
`
`General Electric Co. 1004 - Page 9
`
`
`
`US 8,588,207 B2
`
`1
`METHOD AND APPARATUS FOR EFFICIENT
`AND DETERMINISTIC GROUP ALERTING
`
`This patent application is a continuation of U.S. patent
`application Ser. No. 13/154,138, filed Jun. 6, 2011, now U.S.
`Pat. No. 8,199,740, which is a continuation of U.S. patent
`application Ser. No. 11/303,025, filed Dec. 16, 2005 now
`issued as 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 15
`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 chamiels 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
`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.
`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 65
`systems are too expensive and too bulky for continual per(cid:173)
`sonal use. Digital and analog 2-way voice systems are simi-
`
`2
`larly impractical for widespread, continuous deployment to
`volunteer forces. Several contemporary PCS technologies
`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
`10 systems perhaps come closest to meeting the alerting needs of
`public safety agencies. Like 1-way systems, these pagers are
`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
`to support acknowledged group messaging. Requiring that
`the message originator individually alert each recipient adds
`considerable setup delay when alerting large groups. This
`20 delay is eliminated when using network-supported call group
`or common address messages, but the message originator
`must have prior knowledge of group membership. If a mes(cid:173)
`sage originator does not know the membership of the paged
`group, there is no context to know whether enough manpower
`25 is responding, or whether key individuals have been mobi(cid:173)
`lized. Manually maintaining accurate group membership ros(cid:173)
`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,
`30 acknowledged group alerting capabilities to public safety
`agencies, the network interface must provide group member(cid:173)
`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
`35 this membership information regarding the alerted group.
`Simply guaranteeing that a message will be eventually deliv(cid:173)
`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
`40 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
`45 the current shortcomings of public safety alerting systems,
`and could also provide other benefits. For instance, it could
`act as an improved personnel accountability system (PAS) for
`on-scene communications. Incident commanders could
`instantly notify responders of imminent threats, such as
`50 impending chemical release or structure failure, and verify
`receipt by all personnel. Responses could be expanded to
`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
`55 obviate traditional problems with interoperable on-scene
`communications and enable central oversight of critical real(cid:173)
`time safety data.
`While public safety's need for a system capable of
`acknowledged group alerting system is clear and well docu-
`60 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-
`
`General Electric Co. 1004 - Page 10
`
`
`
`3
`tion, a method of efficient and deterministic alerting of a
`group of recipients over a wireless network is provided. Each
`recipient comprises at least one mobile device capable of
`transmitting and receiving data. The method comprises the
`steps of: storing data relating to recipients, groups and group
`members, in a memory device, the data comprising a recipient
`identifier for each of a plurality of recipients, one or more
`group identifiers corresponding to each of respective groups
`of recipients, the groups each comprising selected ones of the
`plurality of recipients, and group membership data compris- 10
`ing the recipient identifiers of the selected recipients corre(cid:173)
`sponding to each of the group identifiers; providing the
`mobile device corresponding to each of the plurality of recipi(cid:173)
`ents with at least a subset of the data stored in the memory
`device, the subset of the data being stored in the mo bile device 15
`and comprising its corresponding recipient identifier and the
`group identifier of each group to which that recipient belongs
`as a group member; wirelessly broadcasting a group message
`addressed with a selected one of the group identifiers, each of
`the mobile devices being configured to receive the broadcast 20
`group message, to analyze a group identifier provided with
`the group message, and send a response when the group
`identifier in the group message is determined to be for a group
`to which that mobile device belongs; monitoring for
`responses to the group message from the group members of 25
`the group identified by a group identifier provided in the
`group message; and storing acknowledgement data in the
`memory device for each of the group members, the acknow 1-
`edgement data comprising a listing of each of the group
`members and an indication of response for each of the group 30
`members, the indication of response comprising at least one
`of an indication of no response when that group member has
`not yet responded to the group message, and an indication of
`response when a response sent by the mobile device of that
`group member has been received.
`
`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 50
`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
`
`US 8,588,207 B2
`
`4
`at a mo bile 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,
`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
`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
`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
`public safety and critical infrastructure operators, where large
`group dispatches must be delivered quickly and determinis-
`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
`35 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(cid:173)
`nology, the present invention can also be implemented using
`a cellular system, a wireless local area network or more spe-
`40 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
`45 two-way paging and Narrowband PCS (NPCS). This system
`uses a 12.5 KHz charmel 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. SPARKGAP™ is a ReFLEX™
`55 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-
`60 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
`65 (e.g., SMTP, SMPP, and WCTP), these newer protocols do
`not expose group membership information necessary for
`effective, acknowledged group messaging.
`
`General Electric Co. 1004 - Page 11
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`US 8,588,207 B2
`
`5
`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 15
`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 30
`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(cid:173)
`scriber devices
`(hereinafter referred
`to generally as
`'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
`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(cid:173)
`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
`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(cid:173)
`alAddress columns, identifying a Group and Receiver row,
`respectively. Each Membership row also contains a Receiv(cid:173)
`erGroupNumber column, a small mnemonic value that
`uniquely identifies the Group from other Groups pro(cid:173)
`grammed into the same Receiver, and CC ('carbon copy') flag
`to define specific behavioral aspects of the Receiver. Receiv(cid:173)
`ers do not respond to messages received by group addresses if
`
`6
`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,
`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(cid:173)
`base 18. The system 10 therefore maintains an up-to-date
`10 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
`20 and a list ofresponse 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, eitherthe Client 20 or the
`Wireless Network 14 assigns an identifying field to the mes-
`25 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 count 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
`35 receives group message acknowledgment responses from the
`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
`result of the group message are associated with the broadcast
`40 group message (block 62) and provided to the Client 20
`(block 64).
`Upon receiving the Group Message (block 80), the Receiv(cid:173)
`ers 16 decrypt the message and display the content, group
`name, and multiple choice options to the user. Receivers
`45 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 of false transmits one or
`50 more acknowledgement codes through the Network 14 back
`to the Switch 12, specifying message received, message read
`notifications, and enumerated multiple-choice responses
`(block 84, 88 and 90). The datagram carrying the acknowl(cid:173)
`edgement code also includes the personal address of the
`55 receiver 16, the ReceiverGroupNumberofthe 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-
`60 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
`65 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.
`
`General Electric Co. 1004 - Page 12
`
`
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`US 8,588,207 B2
`
`7
`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
`SPARKGAP™ network controller or server 12' in a system
`configuration 10' similar to FIG. 1. FIG. 5 illustrates another
`system configuration 10" in accordance with another exem(cid:173)
`plary embodiment of the present invention.
`The SPARKGAP™ network controller or server 12' in
`FIG. 3 provides private two-way paging, mobile data, and
`wireless email over inexpensive channel pairs in the 900 MHz
`Enhanced Specialized Mobile Radio (ESMR) band or the 20
`Narrowband Personal Communication Services (N-PCS)
`band. Coverage can be configured for a single building, mul(cid:173)
`tiple counties, or state-wide service, for example, supporting
`small user devices such as pagers and personal data assistants
`(PDAs) with Motorola's proprietary ReFLEX™ protocol. 25
`Since the SPARKGAP™ server provides encrypted acknowl(cid:173)
`edgement paging, responders reply immediately to CAD
`events and other messages directly from their pagers, and
`Advanced Encryption Standard (AES) encryption protects all
`transmissions. Since the SPARKGAP™ server 12' supports 30
`mobile applications, law enforcement officers can use PDAs
`as receivers 16 to connect wirelessly with municipal, state,
`and federal databases to run license checks, warrants, and
`other mobile applications. Further, the SPARKGAP™ server 35
`is useful for automatic vehicle location. Small, inexpensive
`GPS sending units can be used as receivers 16 to monitor
`vehicles and heavy equipment, sending real-time location and
`status information on a 24 hour per day, 7 day per week basis.
`The SPARKGAP™ server 12' can also support wireless 40
`e-mail. Users can send and receive secure, wireless email
`using pagers and PDAs.
`The SPARKGAP™ server 12' can support one base station
`15 or hundreds of base stations 15 in a network 14', each
`consisting of a standard 900 MHz paging transmitter and 45
`ReFLEX™ base receiver as