Ulllted States Patent [19]
`Chen et al.
`
`US005943408A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,943,408
`Aug. 24, 1999
`
`[54] FLEXIBLE DIRECT SIGNALING SYSTEM
`
`OTHER PUBLICATIONS
`
`75
`r
`]
`
`-
`-
`_
`t .K-WH Ch SthPl
`I
`nven Ors N30, Tlfémgrlgallia P323 ralgrnwggzis’
`
`Thomas F. La Porta Malathi Veeraraghavan Direct Signal
`’
`’
`ling: ANeW Access Signaling Architecture, 1995 IEEE, pp.
`
`' "
`N.Y.
`
`'
`
`’
`
`’
`
`[73] Assigneez Lucent Technologies Inc_ Murray Hill
`N1
`’
`’
`
`[21] Appl. No.: 08/635,800
`[22] Filed
`Apr 22 1996
`
`.
`
`.
`
`,
`
`[51] Int. Cl.6 ............................ .. H04M 3/42; H04M 7/00
`[52] US. Cl. ........................ .. 379/207; 379/219; 379/229;
`379/209
`[58] Field of Search ................................... .. 379/201, 207,
`379/220, 221, 230, 216, 209, 229, 219;
`455/466; 370/352
`
`[56]
`
`References Cited
`
`U-S~ PATENT DOCUMENTS
`1/1990 Majmudar et a1. ................... .. 379/201
`4 897 866
`5:473j679 12/1995 La Pom, et a1_
`379/201
`5,563,938 10/1996 Soshea et a1.
`379/201
`5,563,939 10/1996 La Porta et a1. .
`379/201
`5,659,605
`8/1997 Voit et a1. ............................. .. 379/220
`
`93—98 Feb.
`’
`Bell Atlantic, Repeat Call, Mar. 1989.
`Bell Atlantic, Customer Satisfaction Guarantee, Dec. 1992.
`Bell Atlantic, Identa Ring, Feb. 1993.
`Bell Atlantic, Return Call, Feb. 1990.
`Primary Examiner—Harry S. Hong
`Assistant Examiner—Benny Q. Tieu
`[57]
`ABSTRACT
`
`A direct Signaling System for providing System Subscribers
`With the freedom to access service providers of their choice,
`regardless or their aeeess network arrangernerrb Wrrrr Sub‘
`stantially minimum change to existing telecommunication
`softWare and architecture. The system provides a home
`interface unit and a call server that enables a subscriber to
`send signaling messages to and receive messages from the
`service providers of their choice. The home interface unit
`and call server execute state machines that provide speci?c
`details or System Operation The can Server State machine
`triggers a state machine and thus operation of the service
`speci?c servers chosen by the subscriber.
`
`27 Claims, 9 Drawing Sheets
`
`15
`
`SERVICE-SPECIFIC
`SERVER
`
`15
`
`1
`
`SERVICE-SPECIFIC
`SERVER
`
`E
`
`15
`
`1
`
`SERVICE-SPECIFIC
`SERVER
`
`DIRECT SIGNALING LINK
`
`CALL SERVER
`
`1 er
`
`To OTHER SWITCHES
`
`\ CALL SERVER-SERVICE SPECIFIC
`SERVER SIGNALING LINKS
`13
`16 17‘ <—CALL SERVER-ATS SIGNALING LINK
`H1“
`ACCESS
`12/
`TRANSPORT/ TELECOMMUNICATION
`NETWORK
`SWITCH (ATS) \ 14
`LINK
`
`Bright House Networks - Ex. 1043, Page 1
`
`

`
`U.S. Patent
`
`Aug. 24, 1999
`
`Sheet 1 of9
`
`5,943,408
`
`FIG.
`1
`PRIOR ART
`
`D
`
`p_v n
`H n
`
`m I w F
`
`I S
`
`0/ \\\
`M m M S 0
`'0 Q‘. I O a G
`rr. - .I I N - I F
`S N
`00 Q S
`llll IIII TI
`
`
`lllllllll lllllll II m P P U
`L - m rr.
`.9 .m M .4, % m
`- C
`
`lllllu?Ill?nlllll
`
`
`
`\y I
`\s 00o
`
`s a
`
`P P S I _| N S S A
`
`k I’ m
`
`‘s S 00 S S S
`
`m N N
`0 S G .v?.
`- O
`n m. m 7 N T
`6
`I
`
`I
`
`n I
`
`L
`
`n 7
`
`A.» W S
`B G
`rr. m N B M M .h H H mm
`0 I. I
`S m L L I .Aln A S I. N I S G G AU
`D S N
`
`R N E 5 rr. W B W T M
`S E m U R Q C P E
`T
`
`----"-- SIGNALING LINK
`USER INFORMATION PATH
`
`R
`
`rf
`
`POINTS
`
`FIG. 2
`PRIOR ART
`
`CPE
`
`D55 1
`
`SETUP
`CALL PROCEEDING
`
`ALERT
`CONNECT
`
`DSSI
`
`ACCESS
`SWITCH
`
`PE
`
`SETUP
`ALERT
`CONNECT
`CONNECT AK
`
`IAM
`
`ACM
`ANM
`
`Bright House Networks - Ex. 1043, Page 2
`
`

`
`U.S. Patent
`
`Aug. 24, 1999
`
`Sheet 2 of9
`
`5,943,408
`
`FIG. 3
`
`15
`
`15
`
`15
`
`L0
`
`SERVICE-SPECIFIC
`SERVER
`
`SERVICE-SPECIFIC
`SERVER
`
`SERVICE-SPECIFIC
`SERVER
`
`DIRECT SIGNALING LINK
`
`_,- I8
`
`\ CALL SERVER-SERVICE SPECIFIC
`SERVERI\ 15 SERVER SIGNALING LINKS
`
`16 17_— <— CALL SERVER-ATS SIGNALING LINK
`
`ACCESS
`TRANSPORT/ TELECOMMUNICATION——-— ‘[0 OTHER SWITCHES
`NETWORK
`SWITCH (ATS) \ 14
`LINK
`
`FIG. 4
`
`1T
`
`12
`
`T3
`
`ELLE
`
`4| HIU L
`
`mans
`
`SETUPO
`
`DIAL
`SETUP
`
`CALL SERVER
`
`Q63
`
`a ACCESS SWITCH
`
`Bright House Networks - Ex. 1043, Page 3
`
`

`
`U.S. Patent
`
`Aug. 24, 1999
`
`Sheet 3 of9
`
`5,943,408
`
`F I G . 5
`
`11
`
`12
`
`EPE
`
`[ HIU
`
`13
`
`|—
`ICALL sERvER
`
`17
`
`14
`
`mans
`
`'
`
`SETUP‘)
`
`>
`
`j ACCESS SWITCH
`DIAL
`
`1AM
`'
`———>
`
`1‘
`
`EPE
`
`12
`
`HIU
`
`_
`
`ALERT
`SETUP]
`
`‘
`
`RING
`
`RING
`
`_
`
`'
`
`FIG. 7
`
`1 1
`
`12
`
`13
`
`FIG. 6
`
`13
`
`CALL sERvER
`
`‘4
`
`ACCESS SWITCH
`SETUP L W
`
`_ W
`—>
`
`SETUP
`
`ACCESS SWITCH
`
`‘
`
`IAM
`
`Bright House Networks - Ex. 1043, Page 4
`
`

`
`U.S. Patent
`
`Aug. 24, 1999
`
`Sheet 4 0f 9
`
`5,943,408
`
`FIG. 8
`
`HIU!DIAL(DIALED_DIGITS)
`
`?HSETUPOWIALEDJIGITSY
`
`mans == DIALED_D1GITS
`
`(HIU?SETUPi (CALLING_DIGITS))*
`RING_TYPE := STANDARD
`
`HIU!RING(RING_TYPE)
`
`(HIU?REMOTE_RELEASE) RINGING
`
`REM_RING]NG
`El
`
`H]U?ON_ HOOK
`
`HIU?REMOTE_RELEASE
`
`HIU?OFF_HOOK
`
`/AC'TIVE
`
`7
`s2
`
`Bright House Networks - Ex. 1043, Page 5
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`

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`Bright House Networks - Ex. 1043, Page 6
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`

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`Bright House Networks - Ex. 1043, Page 7
`
`

`
`Bright House Networks - Ex. 1043, Page 8
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`

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`Bright House Networks - Ex. 1043, Page 9
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`

`
`U.S. Patent
`
`Aug. 24, 1999
`
`Sheet 9 0f 9
`
`5,943,408
`
`FIG. 7 4
`
`,{ CALL BACK sERvER
`
`CPE ,
`#
`s
`
`9
`
`I
`
`HIU |_
`
`|cAELsERvER
`
`REPEAT DIAL SERVER
`
`'
`
`' SETUPO(DIALED_DIGITS =#69)
`
`DIAL(DIALED,DIGITS)
`SETUP(DIALED_DIGITS)
`
`RETRIEVE
`
`V
`
`SERVICE_AK(DIALED DIGITS)
`STORE(DIALED_DIGITS)
`FENCE-AK
`
`_
`
`ACCESS SWITCH
`
`1AM
`_
`—
`
`F I G. 15
`
`SUN
`__
`WORKSTATION
`
`ETHERNET
`
`@
`
`SUN _
`WORKSTATION
`
`SPEED-DIAL SERVER
`
`DISTINCTIVE RING/
`CALL SCREENING
`SERVER
`
`Bright House Networks - Ex. 1043, Page 10
`
`

`
`1
`FLEXIBLE DIRECT SIGNALING SYSTEM
`
`FIELD OF THE INVENTION
`
`This invention relates to communications systems.
`
`BACKGROUND OF THE INVENTION
`
`In today’s telecommunications environment, there are
`many value-added services available to subscribers. This
`includes information altering services such as speed dial and
`distinctive ring, and transport altering services such as call
`forwarding and call Waiting. In current telecommunication
`systems, a caller has access only to the value-added services
`that are provided by the transport provider to Which the
`caller subscribes. The transport provider is the service that
`handles the sWitching of the information communicated
`from the calling party to the receiving party. As a result, any
`service not provided by the transport provider is not avail
`able to the caller. Thus, the current telecommunication
`environment limits a subscriber’s ability to freely select
`these services and prevents subscribers from freely miXing
`and matching features from different carriers on a call by call
`basis or on a subscription basis. Moreover, current systems
`do not enable end-users, Who have access/egress facilities to
`multiple competing carriers, to specify a particular carrier
`from Which they Want to receive incoming communications
`services.
`The main cause of this limiting aspect of present day
`systems is the rigid communications environment dictated
`by the communication system architecture. This rigid envi
`ronment is illustrated in the architecture of modem Inte
`grated Services Digital NetWorks (ISDNs). A simpli?ed
`vieW of the current architecture for ISDN is shoWn in FIG.
`1. As shoWn, a subscriber can signal into the netWork to
`request calls (i.e. services and connections) through the
`User-NetWork Interface (UNI). This is done using the Digi
`tal Subscriber Signaling System No. 1 (DSS1) protocol suite
`over a dedicated point-to-point signaling link called the
`D-channel. The D-channel, and the entire DSS1 protocol
`suite, is terminated on the access sWitch to Which the
`subscriber is physically connected. The user information,
`such as voice, travels over a separate logical channel, called
`the B-channel. Both the B- and D-channels occupy the same
`physical transmission media. See FIG. 2 for a simpli?ed
`vieW of the ISDN message ?oW.
`Within a netWork, nodes signal to each other across the
`NetWork Node Interface (NNI) using the Signaling System
`No. 7 (SS7) protocol suite over a common channel signaling
`netWork. The common channel signaling netWork consists
`of packet sWitches, called Signaling Transfer Points (STPs),
`that interconnect intelligent nodes and sWitches in a highly
`reliable con?guration. Signaling information is transported
`betWeen processors through different sWitches, and likely
`different transmission media, than the user information. The
`signaling messages, hoWever, are routed to and processed
`Within the sWitches that Will eventually support the connec
`tion carrying the user information. Consequently, in present
`day systems, the routing of the signaling messages is depen
`dent on the route of the user connection.
`It is this relationship Which alloWs only the providers
`supplying the transport service of the user information on a
`particular call to offer the signaling dependent services on
`that call (i.e. automatic call back, distinctive ring/call
`screening, speed dial, and repeat dial). As described above,
`this limits the subscriber’s choices of services and service
`providers. That is, the subscriber may only choose services
`that are available from its transport provider.
`
`10
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`15
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`5,943,408
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`2
`A solution to this problem, called direct signaling, Was
`presented by T. LaPorta and M. Veeraghavan in an article
`entitled “Direct Signaling: A NeW Access Signaling
`Architecture,” in Proc. IEEE ICC ’95, Seattle; Wash., 1995.
`Basically, direct signaling provides the ability to route and
`process signaling information independent of the transport
`information for a particular call. As a result, through a direct
`signaling architecture, subscribers can send their signaling
`messages to request services and connections directly from
`any service provider, independent of their particular access
`transport provider. LikeWise, subscribers may receive sig
`naling messages, and hence services, from any service
`provider for incoming calls, independent of their access
`transport provider. Consequently, the direct signaling
`approach enables subscribers to choose from a variety of
`service providers for their signaling services, Without having
`to subscribe to each provider individually for a particular
`call.
`One implementation of the direct signaling approach Was
`disclosed in US. Pat. No. 5,473,679 issued to La Porta et al.
`on Dec. 5, 1995 (hereinafter LaPorta ’679), and incorporated
`herein by reference. LaPorta ’679 recogniZed that the root
`cause of the aforementioned prior art limitations on value
`added service selection is the dependency of end-user sig
`naling systems on end-user sWitching points. Speci?cally,
`the end-user sWitching points originate, process and termi
`nate signaling messages for end-user devices. Because of
`that dependency, the end points for user signaling are
`sWitching systems that are generally managed and oWned by
`a single communications carrier, such as a Local Exchange
`Carrier (LEC), a cellular communications provider or a
`cable television operator. Thus, the communications carrier
`that controls the local loop associated With the terminal
`device of a subscriber also controls the nature and type of
`signaling messages for all communications services
`received and requested by that subscriber over that loop.
`Hence, La Porta ’679 recogniZes that a subscriber in present
`day systems is at the mercy of the loop-controlling commu
`nications carrier (transport provider) for the type of com
`munications services and features available to that sub
`scriber.
`As a result, La Porta ’679 disclosed a communication
`netWork architecture in Which, a subscriber is alloWed to
`select a signaling provider independently of a) the transport
`carriers Which control the local loops (transport providers)
`for particular communication services, and b) the providers
`of those services. Basically, the architecture enables
`bi-directional signaling messages associated With commu
`nications services requested by, or destined for a subscrib
`er’s terminal device to be sent unprocessed to a signaling
`provider selected by the subscriber. The signaling provider
`then requests those services from the speci?c service pro
`viders selected by the subscriber.
`To achieve this, La Porta ’679 describes a neW telecom
`munications architecture Wherein the user establishes a
`signaling connection to a node of a signaling provider of his
`or her choice via a transport provider netWork. The signaling
`provider node processes call setup signaling messages to
`determine the type of connections and services desired by
`the user, and then retrieves a pro?le associated With the
`terminal device or user-identi?cation information contained
`in a signaling message. Through a look-up table operation,
`the pro?le identi?es the particular features and service
`providers selected by the user, on a call by call basis or on
`a subscription basis. Once the appropriate service providers
`have been identi?ed, the signaling provider node initiates
`and transmits service request signals to each of the signaling
`
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`

`
`5,943,408
`
`3
`nodes of those service providers networks to obtain the
`requested services and establish the appropriate connections
`for the user’s call.
`To implement the La Porta ’679 direct signaling system in
`current systems, hoWever, Would require substantial hard
`Ware changes/additions to both the local transport provider
`netWork and all the sWitching nodes along the communica
`tion path. More speci?cally, a MUX/DEMUX sWitch Would
`have to be installed at each transport provider (i.e. LEC), a
`signaling service provider node (SSP) Would have to be
`added to each signaling service provider, and a signaling
`service node (SSN) Would have to be added to each service
`provider along the communication path. Thus, it Would be
`substantially costly to incorporate the La Porta ’679 system
`into the architecture of present day systems.
`Another implementation of the direct signaling approach
`Was disclosed in pending application Ser. No. 08/164521,
`?led by La Porta et al. on Dec. 9, 1993 (hereinafter La Porta
`’521), and incorporated herein by reference. La Porta ’521
`discloses another netWork architecture for providing direct
`signaling. Basically, LaPorta ’521 calls for the integration of
`a signaling transfer device (STD) in the system architecture.
`The STD is electrically coupled betWeen the subscriber
`device and the carrier netWork to Which the subscriber
`communicates. For outgoing calls, the STD detects signaling
`indicia generated by the subscriber device and forWards
`those signaling indicia to a signaling provider netWork via
`the access facilities of a selected communications netWork.
`Upon receiving the signaling information, the signaling
`provider netWork processes that information, and returns to
`the STD other information that is used for the delivery of the
`communications to the user. Thus as With the La Porta ’679
`architecture, to implement the La Porta ’521 system in
`present day systems Would require substantial hardWare
`costs.
`Moreover, neither the LaPorta ’679 nor the LaPorta ’521
`system disclose speci?c details of hoW the direct signaling
`procedures are actually implemented. La Porta ’679
`describes the use of a MUX/DEMUX sWitch and a SSP
`node, but does not give the speci?cs of the operation of these
`hardWare devices. Similarly, La Porta ’521 describes hard
`Ware implementations, but no details of their operation (eg
`how the system actually provides the value-added services
`to the subscriber on a particular call).
`
`SUMMARY OF THE INVENTION
`
`Accordingly, the present invention is directed to a direct
`signaling method and architecture for providing subscribers
`With the freedom to access service providers of their choice,
`regardless of their access netWork arrangement, With sub
`stantially minimum change to eXisting telecommunications
`structure or softWare. To attain this, the present invention
`provides a home interface unit and a call server that enable
`a subscriber to send signaling messages to and receive
`messages from a service provider of their choice, regardless
`of the subscriber’s access netWork arrangement.
`In general, each subscriber has a home interface unit
`(HIU) Which handles all the signaling and user information
`associated With each call of a particular premises equipment.
`The HIU interfaces With the call server Which is the heart of
`the direct signaling system. The call server invokes and
`coordinates all services provided to the subscriber, and thus
`is responsible for all signaling transactions With the sub
`scriber premises equipment. The call server receives all
`outgoing call and service requests, and all incoming call
`requests. As a result, the call server ultimately requests
`
`4
`connections from the transport provider netWork on behalf
`of the subscriber.
`To accomplish this, the call server operates according to
`a state machine that it eXecutes for each subscriber it serves.
`That is, after each input event from the home interface unit,
`caused by either an action of the subscriber or the netWork,
`the call server performs certain processing according to the
`call server state machine. As a result, depending on the
`subscriber or netWork actions, the call server may invoke
`and coordinate actions in the service speci?c servers,
`Wherein the actions for each service speci?c server is
`dictated by a predetermined state machine for that service.
`This means that for each subscriber involved in a call, the
`call server may interact With a state machine in a service
`speci?c server Which provides a particular service to that
`subscriber. Thus, after each input event from the HIU,
`caused by either an action of the user or the netWork, the call
`server performs certain processing and may invoke and
`coordinate the running of a state machine in the service
`speci?c servers Which may execute on different processors
`or on the same processor. As a result, communications may
`require passing messages betWeen the processors, and a
`sharing of variables by passing parameters Within the inter
`processor messages.
`Consequently, the direct signaling system of the present
`invention implements system functions substantially
`through softWare, rather than through costly hardWare as
`With the prior art. In addition, the present invention provides
`speci?c system operation for the various services provided
`to the subscribers. Thus, the present invention overcomes, to
`a large eXtent, the limitations associated With the prior art.
`These and other features of the invention are described in
`more complete detail in the folloWing detailed description of
`embodiments of the invention When taken With the draW
`ings. The scope of the invention, hoWever, is limited only by
`the claims appended hereto.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is block diagram of the signaling architecture of
`modern Integrated Services Digital NetWorks (ISDN’s).
`FIG. 2 is a diagram of the message How of the ISDN
`architecture shoWn in FIG. 1.
`FIG. 3 is a block diagram of direct signaling architecture
`arranged in accordance With the principles of the present
`invention.
`FIG. 4 is a diagram of the message How of an outgoing
`call for the architecture of FIG. 3, Without a call server
`access sWitch signaling link.
`FIG. 5 is a diagram of the message How of an outgoing
`call for the architecture of FIG. 3, With a call server-access
`sWitch signaling link.
`FIG. 6 is a diagram of the message How of an incoming
`call for the architecture of FIG. 3, Without a call-server
`access sWitch signaling link.
`FIG. 7 is a diagram of the message How of an incoming
`call for the architecture of FIG. 3, With a call server-access
`sWitch signaling link.
`FIG. 8 is a state machine for the call server of the
`architecture shoWn in FIG. 3.
`FIG. 9 is a diagram of the state machine for an automatic
`call back service as implemented into the architecture shoWn
`in FIG. 3.
`FIG. 10 is a diagram of the state machine for a distinctive
`ring/call screening service as implemented into the archi
`tecture shoWn in FIG. 3.
`
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`
`15
`
`25
`
`35
`
`45
`
`55
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`Bright House Networks - Ex. 1043, Page 12
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`5,943,408
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`5
`FIG. 11 is a diagram of the state machine for a speed dial
`service according to the present invention.
`FIG. 12 is a diagram of the state machine for a repeat dial
`service according to the present invention.
`FIG. 13 is a graphical vieW of the service logic for the
`interaction of services shoWn in FIGS. 9—12.
`FIG. 14 shoWs the signaling ?oW for the case When a
`subscriber activates the automatic callback service shoWn in
`FIG. 9.
`FIG. 15 shoWs an implementation of the present inventive
`architecture.
`
`DETAILED DESCRIPTION OF ILLUSTRATIVE
`EMBODIMENTS OF THE INVENTION
`
`Referring noW to FIG. 3, there is shoWn a preferred
`embodiment of the direct signaling architecture according to
`the principles of the present invention, herein after referred
`to as direct signaling architecture 10. As shoWn, customer
`premises equipment 11 is electrically coupled to home
`interface unit 12. Home interface unit (HIU) 12 is electri
`cally coupled to call server 13 and access telecommunica
`tion sWitch (ATS) 14. Call server 13 is further electrically
`coupled to service-speci?c servers 15 and ATS 14. ATS 14
`is further electrically coupled to other sWitches (not shoWn).
`Customer premises equipment 11 may be a simple tele
`phone handset Which affects the services available to a
`subscriber. That is, the capabilities of CPE 11 may limit the
`services available to the subscriber using the CPE. For
`example, if the CPE 11 does not provide a display, the
`number of the calling party can not be delivered to a
`subscriber requesting caller id services. In general, hoWever,
`the vast majority of telecommunication services may be
`offered to subscribers independent of the CPE they use to
`communicate over the netWork.
`Call server 13 is the heart of the direct signaling system
`of the present invention. All signaling transactions for CPE
`11 involve call server 13. That is, call server 13 is respon
`sible for invoking and coordinating all services provided to
`the subscriber. Server 13 receives all outgoing call and
`service requests, and all incoming call requests. In addition,
`call server 13 ultimately requests connections to the trans
`port provider netWork on behalf of its subscribers.
`Home interface unit 12 terminates the transport provider
`and signaling service provider connections With CPE 11.
`Unit 12 routes signaling information betWeen CPE 11, call
`server 13, and the transport provider netWork. In addition,
`unit 12 routes user information, such as voice, fax, or
`voice-band data, to the transport netWork via access tele
`communication sWitch 14. Home interface unit 12 supports
`interfaces for CPE 11, the transport provider netWork, and a
`direct signaling link 16 to call server 13.
`Direct signaling link 16 provides transport for signaling
`messages betWeen home interface unit 12 and call server 13.
`Link 16 can be any type of communication link, including
`a Cellular Digital Packet Data (CDPD) link, an internet
`connection, a cable TV connection (CATV), a packet net
`Work link, a phone line, and a Wireless link.
`Access telecommunication sWitch 14 provides the basic
`sWitching function to the subscriber. Depending on the level
`of coordination betWeen service providers 15, sWitch 14 has
`varying functionality. At a minimum, sWitch 14 provides
`basic routing and transport of user information.
`Service speci?c servers 15 execute the service logic
`programs that provide services to the subscribers. For
`example, one service speci?c server 15 may provide the
`
`10
`
`15
`
`25
`
`35
`
`45
`
`55
`
`65
`
`6
`translation functions for an 800-number or a speed dial
`service. Communication betWeen call server 13 and service
`speci?c servers 15 is carried out over highly reliable com
`munication links 18. Ideally, call server 13 is directly
`connected to the service speci?c servers 15 from Which
`services are to be accessed. HoWever, in some cases, call
`server 13 and service speci?c servers 15 may communicate
`over a packet netWork, such as the Signaling System No. 7
`netWorks used in modem telecommunication netWorks.
`System 10, shoWn in FIG. 3 has a direct link 17 electri
`cally connecting call server 13 and access telecommunica
`tions sWitch 14. Link 17, along With the protocol de?ned for
`this interface, directly affects the performance of direct
`signaling system 10 and the services offered thereon. That is,
`the procedures for simple calls in direct signaling system 10
`are directly dependent on link 17. As a result, depending on
`the existence of link 17 betWeen call server 13 and ATS 14,
`the direct signaling system of the present invention Will
`provide varied performance and/or offer different services.
`The performance of system 10 (having a link 17) is com
`pared to another embodiment of the present invention,
`Wherein no link 17 exists betWeen the call server and the
`ATS, beloW. In comparing each embodiment, the Digital
`Subscriber Signaling System No. 1 (DSS1) of ISDN is used
`to signal betWeen the subscriber and the netWork, the ISDN
`User Part (ISUP) of SS7 is used to signal betWeen sWitches.
`FIG. 4 shoWs the outgoing call signaling procedure for an
`embodiment of a direct signaling system of the present
`invention, Wherein no signaling link 17 exists betWeen call
`server 13 and access telecommunication sWitch 14. As
`shoWn, a user dials the digits of the party With Which they
`Wish to communicate to initiate a call. HIU 12 intercepts the
`digits and routs them to call server 13 for the calling
`subscriber (SETUPO). The SETUPO message contains the
`digits of the calling party and the called party. Note that for
`certain services, the called party number may be replaced
`With a special dial code (such as *66 for repeat dial) or alias
`for the user (such as a speed dial code or 800 number).
`Call server 13 analyZes the dialed digits, invokes any
`services required for the call, and instructs home interface
`unit 12 to place a call through access telecommunication
`sWitch 14 to the called party (DIAL). The DIAL message
`includes the telephone number of the called party. Home
`interface unit 12 then signals to access telecommunication
`sWitch 14 to establish the connection (SETUP). The SETUP
`message contains the digits received in the DIAL message.
`The access sWitch 14 routes the connection to the terminat
`ing sWitch (IAM) using standard SS7 procedures. The call
`establishment then proceeds in normal fashion.
`FIG. 5 shoWs the outgoing call signaling procedure for an
`embodiment of the direct signaling system of the present
`invention, Wherein a link 17 exists betWeen call server 13
`and access sWitch 14. As shoWn, instead of routing the DIAL
`message to home interface unit 12, call server 13 requests a
`connection directly from the access sWitch 14. This reduces
`the number of signaling messages as compared to the
`embodiment Wherein no link 17 exists, as described above.
`Thus, link 17 reduces system 10’s dependency on the
`performance of the direct signaling link technology.
`Moreover, since call server 13 requests connection services
`only, link 17 eliminated the need for sWitch 14 to execute a
`state machine to check for service logic triggers. To achieve
`this, hoWever, an interface is required to provide third party
`connection control from the access sWitch 14.
`For incoming calls, the case in Which no link exists
`betWeen the call server and the access sWitch is shoWn in
`
`Bright House Networks - Ex. 1043, Page 13
`
`

`
`5,943,408
`
`8
`a bubble, With transitions betWeen states shoWn as arcs. The
`labels on the arcs identify the input events and conditions
`that enable the transitions, outputs, and variable assignments
`that are generated therefrom. The notation x!y indicates that
`message y is being sent to entity x. The notation x?y
`indicates that message y is being received by entity x. Entity
`x may be another server or another state machine executing
`in the local server. Other notation used includes x===y,
`Which indicates an equivalency test betWeen x and y, x!=y to
`test for inequality, and x:=y, Which indicates that the variable
`x is set to the value y. The Boolean AND and OR operators
`are represented by * and + respectively.
`In one embodiment of the invention, the state machines
`for different servers may execute on difference processors,
`Wherein communication is performed by passing messages
`betWeen the processors. In such an embodiment, parameters
`are passed Within the inter-processor messages to share the
`variables of the state machines.
`One embodiment of the state-machine for call server 13 is
`shoWn in FIG. 8, hereinafter referred to as machine 80. The
`inputs to and outputs from machine 80 are brie?y described
`in Table 1. The entities With Which the call server state
`machine communicates are the home interface unit 12 and
`the service-speci?c servers 15. Before any transition in
`machine 80 is executed, a trigger control point (tcp) is
`checked to determine if any service speci?c processing
`should be activated. The tcps are shoWn as boxes on the
`transition arcs in FIGS. 8—12. Note that for a tcp to be
`checked, the input event and conditions enabling the tran
`sition must be true. If a tcp is not triggered, the transition
`occurs normally. If the tcp is triggered, control is passed to
`a state machine executing for a speci?c service for process
`ing. As a result, control is passed by the tcp invoking an
`operation in the service speci?c server. That is, messages
`containing relevant parameters are sent to the service spe
`ci?c server to invoke operation of that servers state machine.
`The service speci?c state machines pass values back to the
`tcps in the their reply messages. The tcps then overWrite the
`variables maintained in the call server. The various tcps are
`shoWn in FIGS. 9—12.
`The call server state machine, shoWn in FIG. 8, differs
`from an Intelligent NetWork Basic Call State Model (IN
`BCSM) in tWo major respects. First, in the IN BCSM,
`separate machines are designed for incoming and outgoing
`calls. In the present invention, one machine
`
`input/output
`
`description
`
`setup1
`
`indicates an incoming call; contains calling party number
`as calling digits
`commands HIU to ring user CPE With ring of ringitype
`ring
`indicates the local user phone is off hook
`offihook
`remoteirelease indicates the remote user has gone on hook
`onihook
`indicates the local user has gone on hook/commands HIU
`to force local user on hook
`indicates an outgoing call With dialed digits
`commands HIU to dial dialed digits
`indicates that the remote user phone is busy
`indicates that the call is cleared
`indicates remote phone is ringing
`indicates remote phone has been answered
`
`setupU
`'
`busy
`clear
`remo teirin g
`answer
`
`7
`FIG. 6. As shown, a call is delivered to the customer
`premises using standard SS7 procedures. The SETUP
`message, Which Would normally cause the subscriber CPE to
`alert (i.e., the phone to ring), is intercepted by home inter
`face unit 12 and routed to call server 13 (SETUPI). Call
`server 13 invokes any terminating call services, such as
`distinctive ring, call screening, etc., and then instructs home
`interface unit 12 to alert the user (RING). The RING
`message contains information related to the ring-type. Home
`interface unit 12 then rings the CPE 11 and connects CPE 11
`to access sWitch 14 so that the end-to-end connection
`betWeen the calling and called party is complete.
`If, hoWever, a link 17 exists betWeen call server 13 and
`access sWitch 14, this How may be modi?ed as shoWn in
`FIG. 7. As shoWn, access sWitch 14 of the called party
`noti?es the call server 13 directly When an incoming call for
`a subscriber arrives. After providing service processing, call
`server 13 instructs the access sWitch 14 to complete the
`connection (SETUPI) and instructs the home interface unit
`12 to alert the CPE 11. Thus, as described above for
`outgoing calls, link 17 enhances system performance.
`The major concern With direct signaling systems is the
`system performance, including the time needed to establish
`connections on the system, and the number of services it can
`support. Present day systems place limitations on the num
`ber and types of services that are provided to the subscriber.
`For example, in present day systems a signaling service
`provider has access to only certain information about the
`call, and thus has no direct control over communication
`resources. In a direct signaling system of the present
`invention, hoWever, information-affecting services such as
`speed