CA2102077C - Call billing and measurement methods for redirected calls - Google Patents

Abstract

A call processing and billing method where the two billing records generated for a redirected call are transmitted to the same billing center or to the same network of interconnected billing centers, and where the two billing records are correlated to generate a single billing record for use in billing the call. The method is extensible for calls that are redirected more than once. In an alternative method, call history information is transferred and updated to follow a call as it is redirected.
The updated information is used in billing the redirected call, providing measurements concerning the redirected call, and/or in controlling the call, forexample when the call is subsequently returned to the station that initiated a transfer.
The alternative method is also extensible for calls that are redirected more than once.

Description

210207~

CALL BILLING AND MEASUREMENT METHODS FOR
REDIRECTED CALLS
Technical Field This invention relates to teleconll~ ncations.
5 R~~ ound of the Invention As stored plo~lm controlled switching systems have evolved, a wide variety of useful features have been developed to extend the cGIlllllunication capabilities such systems provide. One class of features relates to redirecting calls.
Refer to FIG. 33 and consider an example where a CusLolller at a calling station10 (lstStation) calls a business using an 800 number and the call is answered at a general customer leplesentative's station (2nd station). The representative and the customer taLtc for a few minutes and the representative determines that the customer should taLlc to a specialist employed by the same business but located in another city.
The representative then transfers the call to the specialist's station (3rdStation) and 15 disconnects from the call. Assume that the three stations are served by threedirr~ nt switches 110, 120, 130. In present day practice, switch 110 serving theCUSI~Ilh,l'S station (lstStation) ~ncl~tes a first billing record in billing sub~y~le.ll 141 which includes both the time that the custome~ and ~pl~,sel-tali~fe taL~c as well as the time that the customa and the specialist taL~ (FIG. 37). Switch 120 serving the 20 representative's station (2nd station) generates a second billing record in billing sub~y~t~lll 142 which inclndes the time that the c~ ,.n~ and the specialist talk(FIG. 37). Assume, for example, that swilcLes 110 and 120 are connected to billing centers 161 and 162 r~i.~cli.~ely. The first and second billing records are tr~ncmitte~l to billing centers 161 and 162, l~ ;,pe~ /ely, and two s~le bills are 25 gel cl~led. The first bill may be for twelve minutes and the second bill for ten minutes, a total of 22 ...;.~ul~s, even though the caller was only taL~cing for twelve minutes This arrangement provides no flexibility in billing calls involving callredirection.
Solution This problem is solved and a technical advance is achieved in accol~nce with the principles of the invention in an illustrative method where the two billing records gel-~ laled for a l~iir~,led call are tr~n~mitte~ to the same billing center or to the same n~lwc,lL of inte~olmect~d billing centers, and where the two billing records are advantageously correlated to gellcldte a single billing record for 35 use in billing the call. In the above eY~mrl~y call scenario, a single bill for twelve minuteS may be g~n- l~ted. The method is extensible for calls that are redirected . 2 ~ O~Q7 7 more than once. The single bill may alternatively reflect other discounting plans. In an alternative method referred to and described herein as Service 4, call history information is transferred and updated to follow a call as it is redirected. Theupdated information is used in billing the redirected call, providing measurements 5 concerning the redirected call, and in controlling the call, for example when the call is subsequently returned to the station that initi~t~d a transfer. The alternative method is also extensible for calls that are redirected more than once.
A call processing and billing method in accordance with the invention includes connecting a call from a first station to a second station.
10 ConLelnpolaneously with connecting the call to the second station, a first billing record for the call is initi~ted The call is then connected to a third station.
Conte~ol~leously with connecting the call to the third station, a second billingrecord for the call is initi~t~ The first and second billing records are completed proximate to the end of the call. After the billing records are completed, 15 they are correlated to generate a single billing record for use in billing the call.
The invention is used in an illustrative service described herein and referred to as Service 5. The invention is also used in three illustrative services described herein and referred to as Services 1, 2, and 3, each of which also involves a switch having a new, transfer-with-automatic-return feature.
The connection of the call to the third station may involve conferencing the third station into the call, or transferring the call to the third station. A call transfer is effected in one of three ways: blind transfer, consultation, or conference.
With blind transfer, one of the first and second stations is not connected to the third station for an initial two-way consultation before the other of the first and second 25 stations is connected to the third station. With consultation, the one station and the third station are connected for an initial two-way consultation and thereafter the other station and the third station are connected. With conference, the one station, the other station, and the third station are initially connected for a conference and the one station subsequently drops out.
Illustratively, the correlation comprises modifying one of the billing records based on the other. Alternatively, information from the two billing records is in some fashion combined to generate a single billing record. Further, the two billing records may be compared and only one of them used, either unaltered or with some modification, as the single billing record. An identifier, e.g., a flag or other 35 identifier, is included in either one or both of the first and second billing records for use in the correlation. Rather than having a billing center perform the correlation, ~"-21~2~d77 the two billing records may be correlated by a switching system, e.g., a system serving one of the stations involved in the redirected call.
As a further example, the first bill may be completed pr~ ate to the call redirection.
S A further alternative method used in the arrangement of FIG. 40 includes conne~ling a call from a first station to a second station.
Colllem~l~neously with connecting the call to the second station, the tr~n~mi~ion of first call segment event messages is initi~ted to a billing center, e.g., a nationwide billing center. The call is then conn~cte~l to a third station. Conteln~~ eously with 10 connecting the call to the third station, the tr~ncmi~sion of second call segment event messages is ini~ti3tçd to the same billing center. After all of the first and second call segrnent event messages have been tr~n~mitte~l, the billing center correlates them to generate a single billing record for use in billing the call.
Drawin~ Description FIG. 1 is a hanl~ diagram for an arrangement where Service 1 described herein is implemented;
FM. 2 is a call flow diagram for Service l;
FIGS. 3-11 are action-event diagrams for a number of states used to implement the call flow for Service l;
FIGS. 12 is a state diagram su~ .;7ing transitions between the states of FIGS. 3-11;
FIG. 13 iS a h~lwal~ diagram for an arr~ngement where Service 2 described herein is imr~le...~ t~l, FIG. 14 is a call flow diagram for Service 2;
FIG. 15 is a hal~lwa~e diagram for an arrangement where Service 3 described herein is imI~le...~.n~e~
FIG. 16 is a call flow diagram for Service 3;
FIG. 17 is a hal~w~e diagram for an arrangement where Services 4 and S described herein are illlpl~,me.-ted;
FIG. 18 is a call flow diagram for Service 4;
FIG. 19 is a state diagram sul~lld~ g transitions be~,. e~,n a number of states used to implement the call flow for Service 4;
FIGS. 20-27 are action-event diagrams for each of the states of FIG. 19;
FM. 28 is a call flow diagram for Service S;

2102~)77 FIG. 29 is a state diagram for Service 5 for an example referred to herein as Scenario A;
FIG. 30 is an event timing diagram for Scenario A;
FIG. 31 is a state diagram for Service S for an example referred to 5 herein as Scenario B;
FIG. 32 in an event timing diagram for Scenario B;
FIG. 33 is a h~-lwale diagram for an arr~ngçment that implements a prior art billing service;
FIG. 34 is a state diagram ~ .izing transitions bel~,ell a number of 10 states used to implement the prior art service;
F M. 35 is a call flow diagram for the prior art service;
FIGS. 36-37 are event timing diagrams for Scenario A with the prior art service;
FIG. 38 is an event timing diagram for Scenario B with the prior art 15 service;
FIG. 39 is a h~dw~e diagram of a host ~wilching system and a switch adjunct, e.g., a service circuit node described herein; and FIG. 40 is a h&~ ; diagram for an arrangement that imple..-- ~l~ a new, alternative billing method.
20 Detailed Description Terminolo~
The terms, lstStadon, 2ndStation, and 3rdStation are used herein to refer to stadons of a calling party, called (and ~lal~sr~ g) party, and transferred-to party, les~eclively. The lstStadon origin~tes a call to a 2ndStation, which in turn 25 transfers the call to a 3rdStadon, establishing a talking path between the lstStation and the 3rdStation. The services described herein also apply to cases where a lstStation originates a call to a 2ndStation, the lstStation transfers the call to a 3rdStation, est~hli~hing a taLking path bet~een the 2ndStadon and the 3rdStadon.The ~ansr. lling station is also referred to as one of the first and second stadons 30 while the non-transferring stadon is referred to as the other of the first and second stations.
The terms lstStadon, 2ndStadon, and 3rdStation should be read broadly as referring to customer and network e~lui~ nt, telephones, coll~pu~ , PBXs, andnetwork and third-party switch adjuncts.

- 210 2 0 ~ ~
-Services The following description relates to five new telephone services:

Service 1: Attçn-i~nt Service with Transfer-with-Return In this service description, transfer-with-return and call-history S features are illustrated in the context of a service center, in which cuslo~ (lstStations) call an ançnd~nt (2ndStations), who in turn can transfer the call to service specialists (3rdStations). Upon some design~tY~ signal (e.g., a flash, DTMF, or disconnect from the lstStation or 3rdStation) the lstStation and/or 3rdStation are reconnected to the 2ndStation.

Service 2: SCN use of Transfer-with-Return feature so that SCN can be information gateway In this service description, the notion of an ~ttentl~nt (2ndStation) is generalized to include switching adjuncts, in this case, a Service Circuit Node (SCN) that can invoke the llatlsfer-with-return and call-history features on a host switch. In such a case, the SCN is able to establish independent call legs from or to a lstStation and a 3rdStation (the SCN acts as the 2~dStation), to apply a variety of service circuits (e.g., annolln~e~ , f~ccimile, and confelcnce facilities), and to transfer the two call legs back to the host switch, so that the SCN is no longer part of the talking path between the lstStation and 2ndStation. Upon some designated signal (e.g., a flash, DTMF, or discolmecl from the lstStation or 3rdStation) the lstStation and/or 3rdStation are reconnecte-l to the 2ndStation as a conference of 1st, 2nd, and 3rdStations or two call paths--a co~ tion path belween the 1st and 2ndStations and an independent co~ mication path ~L~ ,n the 2nd and 3rdStations.

Service 3: ESM use of Transfer-with-Return feature so that ESM can be infollllation & service circuit ~ateway In this service, a service circuit node (SCN) is generalized to less ~o~elrul service adjuncts or CPE, e.g., automated telecommunications systems referred to herein as external service modules (ESMs).

Service 4: Service gateway without switch-based transfer-with-return capability In this service, a ll~n~Çer-with-return sequence (lstStation calls 2ndStation that transfers call to 3rdStation that, in turn, transfers call back to 2ndStation) is accomplished without the transfer-with-return feature. Call history infollllalion is transferred and ~ ted (either by the stations or the associated ~wilchcs) as the call is successively transferred. The infc.~ alion is usable in billing the call, generating measul~l,~nls for the call, and/or controlling the call.

Service 5: Correlated billin~ records for call transfer sequences In this service, a first billing record is initi:~te~ when a call is connected from a lstStation to a 2ndStation. A second billing record is initi~tetl when the call is connected to a 3rdStation. The first and second billing records are completed before or plo~imate to the end of the call and are tr~n~mitted to a billing center or network of hllelco~ P~led billing centers where they are correlated to generate a single billing record for billing the call.

Service 1: Attendant Service with Transfer-with-Return These featules are used by a group of 2ndStations (e.g., a group of service auendan~s) to llan~rel calls to service agents who specialize in a particular area, and to then have the call transferred back to them for service follow-ups,25 quality audits, etc. Four sets of fealu~es are identified:

- transfer-with-return feature - return Llall~Ç.,I triggers, in particular a call-termination trigger - call-history feature - call-termination notification Feature Descriptions:
A) transfer with return This feature allows a subscribing ~ttend~nt (a 2ndStation) to transfer a call (from a lstStation) to a 3rdStation, allowing a talking path between the 1st and 3rd Stations and allowing the 2ndStation to disconnect from the call. However, following the disconnection by the 2ndStation, the lstStation and 3rdStation arel~connected to the 2ndStation, if the 1st or 3rdStadon signals applopliately; or the 10 lstStation or 3rdStation are reconnected to the 2ndStation, if the 3rdStation or lstStation disconnects.
The feature works as a line-subscribed feature, that can be invoked on a per-call basis or autom~tic~lly invoked on all calls. If subscribed to on a per-call basis, the ~tt~nA~nt (2ndStation) may signal transfer with no return, transfer with 15 return, or other subscribed to ~ttend~nt fealules, e.g., con~l~nce, hold, etc. If the en~l~nt is part of a multi-line hunt or ACD group, the return-~ansrer is made to the ~ttend~nt that initially h~n-lle~ the call. If the atten-l~nt is busy, the call is fol walded to an approl,liate co-worker.
B) return transfer lr;~~,e~s Recol~eclion to the 2ndStation is triggered in several ways:
disconnection by the 1st or 3rd Station, and ~ipn~ling (e.g., flash or DTMF) by the 1st or 3rdStation. If the feature allows the lstStations or 3rdStations to signal (e.g., flash or DTMF) l~,connection to the attenA~nt, then the transfer-with-return feature works in conjunction with 3-way calling. The 2ndStation could drop out of the 25 conr~lence and then be asked to come back into the conference. In some cases, a 3rdStation may be an ~ o.~ eA service module, e.g., a mail system. To permit thelstStation to signal a return to the 2ndStation while Aisconne~ling the 3rdStation, a call-termination trigger is needed.
C) call-history feature on returned transfer So that the 2ndStation (the service ~ttend~nt) knows that the call is a previously h~nAleA call, and so that the 2ndStation is able to quickly identify which call is being r~tullled, the llansr~r-with-return feature provides call-history and call-id~ntification inforrnation in the call-setup message. It also provides a reason - 210207~

message that specifies the reason for the return, e.g., 3rdStation disconnected,1 stStation request, etc.
D) call-term;nqtion notification In some call scçn~rios~ both the 1st and 3rd Stations might disconnect 5 before either is reconnected to the 2ndStation. In such cases, the 2ndStation (the service attendant) might still be int~ d in the call history between the 1st and 3rd Stations. Thus, the feature permits the attendant to specify (perhaps during service subscription) whether or not they should be notified if the caller and the called party both drop the call.
Note that in the call flow of FIG. 2, the 2ndStation(the attendant) places the lstStation (the caller) on hold; orig-n~tes a call to a 3rdStation (e.g., a service agent); con~l~,.-ces toge~ the three stations; and finally disconnects the 2ndStation, leaving a talking path ~l~,.~. the 1st and 3rd Stations. The serviceconcept also applies to other call flows. In particular, the 2ndStation could 15 disconnect as soon as the call to the 3rdStation is set up but not an~r.e.~d, thus leaving the 1st and 3rdStations in a ringing state. Further, the 2ndStation could connect to the 3rdStation for two-way consultation prior to connecting the lstStation and 3rdStation.
FIG. 1 is a diagram of an exemplary nelwulk configuration. The lstStation, 2ndStation and 3rdStation are connected to switches 10, 20, and 30, respectively. Switches 10 and 20 and swil~hes 20 and 30 are inte~onne~led by trunks 15 and 25, l~,spc~;lively, which may include int~rmeAi~te ~wilches. Billing center 40 and billing subsystems 41, 42, and 43 are discussed later herein with respect to Service 5.
FIGS. 3- 11 provide a state chart of how the call-with-return and call-history featul~,s operate within swilcl ing system 20 for Service 1. FIG. 12 provides a sull~aly of the state transitions.
To improve readability, the following descriptions are partitioned by state. The notation for each state title should be read as: service concept nul~30 state number, state name, e.g., 1-1. state Initial, in(lic~tes that Initial is the name of the first state in the state model describing service 1.
1-1. state ~itial (~IG. 3) The call flow begins in the state Initial, with the initial event, Incoming_call. This initial event initiates call ~ cessing 210207~
g The first action taken in this state is to translate the digits dialed by the lstStation (i.e., the caller) into a specific dh~cloly number, and to then initiate a call-setup to the 2ndStation represented by the dialed dile~,Lol.y nulllber.
If the call to the 2ndStation is answered (i.e., an event answered is 5 received from the 2ndStation), then connect 1st and 2nd Stations and transition the state model to another state, 2way.
If the event disconnect is received from either station, then the call ends.
1-2. state 2way (FIG. 4) If the event disconnect is received from either station, then the call ends.
If the 2ndStation sends an app~pliate signal (e.g., a flash or DTMF), and the 2ndStation is a subscriber to the transfer-with-return feature, then place the lstStation on hold, and transition the state model to another state, 2way_2ndStationActive.
1-3. state 2way 2ndStationActive (~IG. 5) The lstStation (caller) is on hold.
Several events are possible in this state:

- event Initial Event The state begins by proces~ing the intern~lly ~nela~d event, Initial_Event.
Processing this event results in a tone!collect_digits action that delivers a stuttered 20 tone to the 2ndStation. The stuu~l~d tone prolllpls the 2ndStation for a feature code, one of which is transfer-with-return, another is transfer-without-return (i.e., call-transfer as it is cull~nlly done).

- event collected di~its The digits signaled by the 2ndStation are received as the event collected_digits. If 25 the collected digits in-lir~te a request for llausrer-with-return, a Return_active in~ t~r is set to true. If the transfer-with-return or -without-return feature is requested, then a second tone!collect_digits action delivers dial tone to the 2ndStation. The dial tone pn~lllplj the 2ndStation for a directory number. If a valid l y number is received from the 2ndStation, a call-setup procedure is invoked 30 and the state model then transitions to a new state, 3way_2ndStationActive 3rdStationSetUp - event signal If the appropliate signal (e.g., a flash) is received by the switch from the 2ndStation, - '- 2102~77 the call is returned to the previous 2-way taL~cing path between the lstStation and 2ndStation, and state model transitions back to the state 2way.

NOTE: the feature may be impl~ nted so that infiir~ting a request for starting transfer procedures is implied by the 2ndStations's (i.e., the subscriber's) initial S feature request (flash or DT~ff~). In this case, call flow would proceed directly from points (1) to (2) in FIG. 5.
1-4. state3way 2ndStationActive 3rdStationSetUp (FIG. 6) The lstStation is on hold, and the 2ndStation has initi~ted transfer procedures. Several events are possible in this state:

10 -eventcall failed The call could not be connected to the design~e~1 directory num~, perhaps because the 3rdStation was busy or did not answer. In this event, busy or ringing (as appl~,pliate) is delivered to the 2ndStation. The state model then transitions to state 2way_2ndStationActive.

15 -eventcall answered The 3rdStation answers the call. In this case, the switch establishes a 2-way path between the 2nd and 3rd stations. The state model then transitions to an new state, 3way_2ndStationActive_3rdStationActive.

- event disconnect received from 2ndStation 20 The 2ndStation disconnects. In this event, the switch establishes a 2-way connection between the lstStation and the 3rdStation. Since the 3rdStation has not yet an~cd, the lstStation receives audible ringing The state model then transitions to an new state, 2way_1stStationActive_3rdStationActive.
.

- event signal received from 2ndStation 25 The 2ndStation (the subscriber) signals (typically, but not nçcess~rily, by flashing) a request to return to the 2-way call with the lstStation. In this event, a talking path is established ~I..~n the 1st and 2nd stations, and the state model transitions back to the state 2way.
In the next two states, the 2ndStation has a two-way conversation with 30 either the lstStation or the 3rdStation. The 2ndStation's signal (flash or DTMF) acts a toggle between these two states. If the 2ndStation signals a confe~ellce request, procedures for a 3-way conversation are initi~t~
1-5. state 3way 2ndStationActive 3rdStationActive (FIG. 7) In this state the lstStation is on hold, while the 2nd and 3rd Stations are connected in a taL~ing path. Two events are significant in this state:

5 - event si~nal for tog~le received from 2ndStation If the 2ndStation signals a single flash (or some DTMF equivalent) then the switch opens the path bel~een the 2nd and 3rd Stations, and connects a path belween the 1st and 2nd Stations. The state model then transidons to a new state 3way_1 stStationAcdve_2ndStationActive.

10 - event si~nal for conre~.-ce received from 2ndStation If the 2ndStation signals a double-flash (or some DTMF equivalent) then the switch creates a 3-way call be~ ,n the 1st, 2nd, and 3rd Stations. The state model thentransitions to a new state 3way.
1-6. state 3way lstStationActive 2ndStationActive (~IG. 8) In this state the 3rdStation is on hold, while the 1st and 2nd Stations are connected in a taL~cing path. Two events are ~ignifi~nt in this state:

- event si~nal for to~le received from 2ndStation If the 2ndStation signals a single flash (or some DTMF equivalent) then the switch opens the path bel~eell the 1st and 2nd Stations, and connects a path between the 20 2nd and 3rd Stations. The state model then transitions back to the state 3way_2ndStationActive_3rdStationActive.

- event si~nal for co~ ence received from 2ndStation If the 2ndStation signals a double-flash (or some DTMF equivalent) then the switch creates a 3-way call belw~c;n the 1st, 2nd, and 3rd Stations. The state model then 25 transitions to a new state 3way.
1-7. state 3way (FIG. 9) In the 3way state, all three stations are connecteA together in a 3-way conrel~,nce.
If the 2ndStation disconnects, a 2-way call is created between the 30 lstStation and the 3rdStation and the state model transitions to state 2way_1stStationActive_3rdStationActive.

2 1 0 2 0 ~ l If the lstStation or 3rdStation disconnects, a 2 way call is created between the two rem~ining stations (between the 2ndStation and 3rdStation, or belween the lstStation and 2ndStation, respectively). If 3rdStation disconnects, the state model transitions back to state 2way. If the lstStation disconnects, the state 5 model transitions to the state 2way, but consider the 3rdStation as if it were the lstStation (the original lstStation is no longer part of the call), except of course, the 2ndStation is now the call originator.
Not shown are procedures that allow the 2ndStation (the subscriber who established the 3-way confcl- nce) to request the switch to create a 2-way call 10 between the 2ndStation and lstStation (or bel~,en the 2ndStation and 3rd Station), while placing the 3rdStation (or lstStation) on hold.
1-8. state 2way lstStationActive 3rdSt~ion~ctive (FIG. 10) In this state, the 2ndStation is not part of the call.
Initially, the connection bel~en the 1st and 3rd station is either in a 15 ringing state or in a talking state (depending upon whether or not the 2ndStation disconnected before or after the 3rdStation ans~e.~,d; or in terms of the state model, depending on whether the previous state was 3way_2ndStationActive_3rdStationSetUp or 3way).
Five events are ~ignific~nt~

20 - event no answer received from 3rdStation If the 3rdStation does not answer, the lstStation continues to hear ringing until the lstStation signals a request to return the call to the 2ndStation, or the lstStation disconne~,ls. No state transition is required.

- event answer received from 3rdStation 25 If the 3rdStation answers, then the switch est~bli~hes a talking path b~lween the lstStation and 3rdStation. No state transition is required.

- event si~nal for return to 2ndStation received from lstStation The 3rdStation is released (disconnected) from call. If the transfer-with-returnfeature is active, then the state model transitions to the Return_Call state; if the 30 feature is not active, then the call is le~ ~.h~ted and the 1st station is disconnected.

- event si~nal for return to 2ndStation received from 3rdStation If the transfer-with-return feature is active, then the state model transitions to the '- 210~77 Return_Call state; if the feature is not active, then the call is termin~te~l and the 3rd station is disconnected.

- event disconnect received from lstStadon or 3rdStation If the transfer-with-return feature is active, then the state model transitions to the S Return_Call state; if the feature is not active, then the call is termin~te~l and the rem~ining stations are disconnected.
1-9. state Return Call (FIG. 11) Prior to this state, the 1 st or 3rd Station disconnected or signalled a request to reconnect a talking path to the 2ndStation (the service attendant and10 subscriber in Service 1). In this state, the 2ndStadon is sent an information message ~let~iling call history hlfol,lladon. This hlfollllalion allows the 2ndStation to separate new calls from return calls, to construct service bills if ayyl~pliate~ or to send billing hlfolll~alion back to the host switch.
If the 1st or 3rd Station has disconl-~t~ and the 2ndStation answers, 15 the state model transitions back to the state 2way and a two-way talking path is established bclwcen the 2ndStadon and the rem~ining stadon.
If neither the 1st or 3rd Stadon has discol~ne~,led and the 2ndStadon answers, the call to the 2ndStadon results in a 3-way call involving the 1 st, 2nd, and 3rd Stadons and a state model transidon to the state 3way.
Please note, the lstStadon can force a discomlecl of the 3rdStadon by sending the ayyl~pliate signal, e.g., a desi n~ted DTMF sequence.
Service 2: SCN use of Tr....~.fe~-with-Return feature so that SCN can be info~ ...&tion ~ateway (~IG. 13) The featul~s det~il~ in Service 2 are the same as those specified for 25 Service 1:

- transfer-with-return feature - return Llansrcl triggers, in particular a call-terminAtion trigger - call-history feature - call-termination notific~tion In Service 1, these featun,s were delllol~ ated with a human at each stadon. In contrast, in Service 2, the human ~ttendAnt at the 2ndStation is replaced with aService Circuit Node (SCN).

An arrangement comprising an ISDN switching system 300, a service circuit node 400, and a database 500 is shown in FIG. 39. ISDN switching system 300 is of the type disclosed in U. S. Patent 4,592,048 issued to M. W. Beckner et al.
on May 27, 1986. Service node 400 is of the type disclosed in the AT&T A-I-NetTM5 Service Circuit Node (SCN) System Description and the AT&T A-I-NetTM Service Circuit Node (SCN) Product Technical Specifications Release 1, both of April 15,1992. System 300 comprises a control arrangement 310, a ~witching nGIwol~ 320, and line units 330 and is connected to analog station sets 211, 212, and 213 as well as other station sets not shown. System 300 is also connected to service node 400 by 10 a number of ISDN basic rate interface (BRI~ lines. Service node 400 comprises a control co~ ulel 440, a switch fabric 420, and service circuits 430. Service circuits 430 provide the following capabilities: 1) digit collection, 2) tone detection/generation, 3) FAX receipt, storage, and tr~n~mitt~l, 4) voice recording, storage, and playback, 5) text-to-speech (TTS) announcel-.~ nl~, 6) call setup through 15 the switch fabric 420, 7) confil~,nce bridging, 8) transferring a call to a second party, and 9) returning call control to system 300. Database 500 provides a reverse white pages di~eclo. y which returns a calling party name when a calling party nulll~l is provided. Although not shown in FIG. 39, service node 200 may be connected to a plurality of ISDN ~witching ~y~L~ ls in addition to system 100. System 300 with the 20 transfer-with-return and call history features added, together with SCN 400 are used as switch 20 and the 2ndStation in FIG. 13.
The features illu~llated in the call flow of FIG. 14 can be used by the SCN (the 2ndStation in these examples) to transfer calls back to a host switch (thus increasing service reliability and decreasing traffic capacity), and then regain call 25 control when the lstStation or 2ndStation disconnects (or appn~pliately signals).
These features also allow the SCN to act as an infol~l~aLion gateway to a variety of external service modules which are in~lepçnd~nt and which have no knowledge of the SCN.
This permits several extensions to the basic call flow described earlier:

30 1. The call could be an in-band or out-of-band data call. This allows the concept to support both voice and data applications.

2. Because many automated systems can operate on multiple concurrent calls, the call flow described previously can be broadened so that the caller (the lstStation) need not be placed on hold during the conversation between the 2ndStation (in this - 21~20~7 case, a SCN) and the 3rdStation (i.e., service agent or ESM). Instead the SCN could m~int~in parallel conversations with the lstStation and the 3rdStation before establishing a talking path between the 1st and 3rd Stations. When the 1st or 3rdStation requests reconnection to the 2ndStation (i.e. the SCN) the reconnection 5 could either be a conference including all three parties or two separate calls(lstStation to SCN, and SCN to 3rdStation). This option for reconnection may be provisioned at subscription time. In the case of the SCN, the service is provisioned to support reconnection as separate calls, because the SCN could apply its own conference circuits if necessary.

10 3. Because a SCN is used as the automated ~tten(l~nt, the interactions between caller and SCN could allow services in which the SCN:

- plays voice or text-to-speech announcem~nts (e.g., service options);

- collects information that influences service behavior. For example, information might be collected via, - dtmf digit reception, - speech recognition, - speaker verification, - out-of-band signals from another swilching center.

- collects information for storage and subsequent analysis, conversion, or retrieval 20 (i.e., playback), e.g., - voice l~cor~i"g/playback - ascii-to-fax conversion - f~csimile l~conling/playback - text-to-speech conversion 25 - create conÇele.lces.
The number of di~r~,~nl services ~up~olled by an SCN is very large.
For example, the SCN may provide an infc~llllalion gateway service in which userchoices are co~ llnicated. As each choice is recognized, the transfer-with-return procedures executes allowing the user access to the chosen service and to return to -- 210~077 the SCN after completing the service transaction.
Feature Descriptions:
A) transfer with return This feature allows the SCN (acting as a 2ndStation, in the current 5 terminology) to call a lstStation or answer a call from a lstStation. The SCN may apply a mnltitude of service circuits to the call (as required by a particular service flow), and eventually may ~ srcr the call to a 3rdStation (possibly an external service module (ESM)). As part of the transfer pl~c~lulç, the SCN signals that the call should be returned to the SCN under a variety of conditions.
In ~lAition, if the SCN and the 3rdStations need to co.. ~ ic~te call-related data, the data could be tr~n~mitte~ to the 3rdStations either as part of the call-setup or could be sent over a RS232 link, a X.25 network, or through the D-channel on ISDN. An ~ltçrn~tive would be to tl~~ lit the data via a voice channel prior to transferring the lstStation call to the 3rdStation.
15 B) return transfer tr;~~
Reconnection to the 2ndStation can be triggered in several ways:
disconnection by the 1st or 3rd Station, ~ign~ling (e.g., flash or DTMF) by the 1st or 3rdStation. If the feature allows the lstStations or 3rdStations to signal (e.g., flash or DTMF) reconnection to the 2ndStation, then the transfer-with-return feature can 20 work in conjunction with 3-way calling. The 2ndStation may drop out of the conference and then be asked to come back into the conrelcnce. In some cases, a 3rdStation may be an ESM, e.g., a mail system. Some of these ESMs may not provide a method by which a caller can request the ESM to initiate a disconnect.Therefore, to permit the lstStation to signal a return to the 2ndStation (the SCN) and 25 disconnect the 3rdStation (the ESM) from the call, a call-tçrrnin~tion trigger is needed.
C) call-history on r~t~r ed transfer As part of the return transfer procedure, the switch alerts the 2ndStation (the SCN) with a call set-up message con~ g the caller's DN and a transaction_id30 (possibly the account code). A reason message is provided that specifies the reason for the return, e.g., 3rdStation disconnected, caller-initi~te~l return, etc. The 2ndStation (the SCN) can then process the call using the appropliate customer logic, and deterrnine the call history and billing records from internally stored data. (Note the call-history capability referred to in Service 1 could be provided through an 35 SCN, if all call-transfers return to the SCN, or all call-history records are sent to the SCN).

- - 211)2~77 D) call-termination .-o~;fi~tion If the caller disconnects, then a m~ss~ge is sent to the 2ndStation (the SCN), so that the 2ndStation (the SCN) can track service Inea~u~c.~c~lL~ and 3rdStation usage (if this important for the service).
5 Service 3: ESM use of Transfer-with-Return feature so that ESM can be h.ro ..~lion & service circuit ~ateway (~IG. 15) The features detailed in this service are the same as those specified for Service 1:

- transfer-with-return feature - return transfer triggers, in particular a call-termination trigger - call-history feature - call-termin~tion notification In Service 2, the 2ndStation was operated by a Service Circuit Node. In contrast, Service 3 uses a simple external serv*e module (gateway-ESM) as the 2ndStation.
15 The gateway-ESM is capable of concull~l.tly answering multiple calls (by sending the a~pr~liate control message) and transferring them to various locations. There is no need for the gatcway-ESM to provide announcetn~nt circuits or a switch ne,Lwcl]~.
The 3rdStations that receive the transferred calls can be operated by service agents or service-circuit ESMs that provide announce-, .f ~ , record/send voice or facsimile, 20 etc. The call flow is shown in FIG. 16.
Feature Description A) transfer with return This feature allows the gateway-ESM (acting as a 2ndStation, in the current terminology) to call a lstStation or answer a call from a lstStation. The 25 ESM can only answer and l~ansre~ calls to a 3rdStation (possibly a service-circuit or external service module (ESM)). As part of the transfer procedure, the gateway-ESM signals that the call should be returned to the gateway-ESM under a variety of conditions.
In addition, if the gale~,vay-ESM and the 3rdStations need to 30 co... ~ ~te call-related data, the data could be tr~n~mitte~ to the 3rdStation either as part of the call-setup or could be sent over a RS232 link, a X.25 network, orthrough the D-channel on ISDN. An alternative would be to tldllSIlfit the data via a voice channel prior to transferring the lstStation to the 3rdStation.

- - 21~J077 B) return transfer Ir;a~
Reconnection to the 2ndStation can be triggered in several ways:
disconnection by the 1st or 3rd Station, sign~ling (e.g., flash or DTMF) by the 1st or 3rdStation. If the feature allows the lstStations or 3rdStations to signal (e.g., flash or 5 DTMF) reconnection to the 2ndStation, then the transfer-with-return feature can work in conjunction with 3-way calling. The 2ndStation may drop out of the conference and then be asked to come back into the conîel~nce. In some cases, a 3rdStation may be an ESM, e.g., a mail system. Some of these ESMs may not provide a method by which a caller can request the ESM to initiate a disconnect.10 Therefore, to permit the lstStation to signal a return to the 2ndStation and disconnect the 3rdStation (e.g., a voice mail ESM) from the call, a call-termination trigger is nee~e~l C) call-history on relur. ~ transfer As part of the return transfer procedure, the switch alerts the 2ndStation 15 (the gateway-ESM) with a call set-up message containing the caller's DN and atransaction_id (possibly the account code). A reason message is provided that specifies the reason for the return, e.g., 3rdStation disconnected, caller-initi~ted return, etc. The 2ndStation (the gateway-ESM) can then process the call using the ap~ ;ate customer logic, and ~l~;le~ e the call history and billing records from20 intern~lly stored data. (Note the call-history capability referred to in Service 1 could be provided through a galewdy ESM, if all call-transfers return to the gateway-ESM, or all call-history records are sent to the gateway-ESM).
D) call-ter~nination notification If the lstStation disconnecls, then a message is sent to the 2ndStation 25 (gateway-ESM), so that the 2ndStation. (the ~ tewdy-ESM) can track service measul~,~nls and 3rdStation usage (if this Lll~l ~ll for the service).
Please note, in this scenario, the human ~tten~l~nt is replaced with an automat~,d system. This permits several extensions to the basic call flow described earlier:

30 1. The call could be an in-band or out-of-band data call. This allows the concept to support both voice and data applications.

2. Because many aulolnated ~y~t~,ms can operate on multiple concurrent calls, the call flow described previously can be broadened so that the caller need not be placed on hold during the conversation bel~een the auloll-aled ~tt~n~l~nt (in this case, a - 19- 21~,077 ESM) and the third-party (i.e., service agent or another ESM). Instead the automated attendant could m~int~in parallel connections with the caller and the third party before establishing a talking path bel~eel the caller and third party.
Service 4: Service ~ateway without switch-based 5 transfer-with-return capability (FIG. 17) A ne~wolk~d arrangement of ESMs (or service agents) could have return-transfer and call history fealules without a switch-based transfer-with-return capability (switch 20') if each ESM knows about the ~lill~y ESM (the 2ndStation,in the current terminology), and possibly the other ESMs in the group and each 10 explicitly transferred the call back to the 2ndStation. An exemplary call flow is shown in FIG. 18. A ne~wulk arrangement of service circuits is provided without modifying existing swil~;hes. The described fea~ul~s and logic are not restricted to a network of ESMs, but could be applied equally well to a network external servicecircuits (ESCs, very similar to an IP, intelligent peripheral) and to a network of 15 telephone users, e.g., a n~Lwolk of service ~l~e ~d~n~!i and agents of a company.
Feature Descriptions A) Providin~ return-transfer capabilities without the transfer-with-return switch feature If each service provider (each 2nd and 3rd Station) subscribes to call-20 transfer, then a nelwolk of service providers can provide service-circuit based and gateway services without using an SCN and without any new switch features. The 2ndStation (a gateway-ESM or a service ~tt~n~l~nt) ans~ the initial call and sr~.~ the call to a 3rdStation (a service provider). The directory numbe. of the2ndStation is passed to the 3rdStation or this infollll&tion is stored in a ~t~b~ce on 25 the 3rdStation.
In ~A~lition, if the 2ndStation and 3rdStation need to co.. ~ te additional call-related data, the data could be tr~n~mitted to the 3rdStation either as part of the call-setup (if the amount of inrolllla~ion was slight; this may meanenhancing the call-setup info p~c~ge) or over a RS232 link, a X.25 network, or 30 through the D-channel on ISDN. An alternative would be to transmit the data of a voice channel prior to transferring the lstStation (the caller) to the 3rdStation.
After the service has been provided by a 3rdStation, the 3rdStation initi~tes a call transfer back to the 2ndStadon which could then transfer the call to another service provider (the equivalent of another 3rdStation).

- 2!L02377 B) Providin~ return-transfer tri~ers without the return-transfer tri~er feature Each 3rdStation is responsible for transferring the call back to the 2ndStation upon request by the lstStation, or as part of the 3rdStation disconnect 5 procedure.
C) Providin~ call-history feature As part of the transfer procedure, the switch sends additional call history information and call instructions back to the call-history subscriber that initi~teA the first transfer procedure.
10 D) Providin~ call-termination ,.~l;fi~ on without termination-n~tifi~ io~l feature If the lstStation (the caller) disconnects, then the 3rdStation receiving the disconnect signal is responsible for setting up a call to the 2ndStation with call history inforrnation, so that the 2ndStation can track service mea~ulelllenls and 15 3rdStation usage (if this important for the service).
FIGS. 20-27 provide a state chart model of service 4. FIG. 19 provides a :iUnl~ of the state tr~nsitiQm.
To improve rea~1~bility, the following deswiplions are partitioned by state. The notation for each state title should be read as: service number-state20 number, state name, e.g., 4-1. state Initial, in-lisat~s that Initial is the name of the first state in the state model describing service 4.
4-1. state Initial (FIG. 20) The call flow begins in the state Initial, with the initial event, Incoming_call. This initial event initiates call proces~ing The first action taken in this state is to translate the digits dialed by the lstStation (i.e., the caller) into a specific dirbclclly number, and to then initiate a call-setup to the 2ndStation l~plbsenled by the dialed di~eclol ~ numl~r.
If the call to the 2ndStation is answered (i.e., an event answered is received from the 2ndStation), then connect 1st and 2nd Stations and transition the 30 state model to another state, 2way.
If the event disconnect is received from either station, then the call ends.
4-2. state 2way (FIG. 21) If the event disconnect is received from either station, then the call ends.
If the 2ndStation sends an ap~lu~liate signal (e.g., a flash or DTMF), 35 and the 2ndStation is a subscriber to the transfer-with-return feature, then the lstStation is placed on hold, and transition state model to another state, - - 21 21~)2077 2way_2ndStationActive.
4-3. state 2way 2ndStationActive (FIG. 22) The lstStation (caller) is on hold.

Several events are possible in this state:

5 - event Initial Event The state begins by processing the intern~lly generated event, Initial_Event.
Processing this event results in a tone!collect_digits action that delivers a ~ul~,red tone to the 2ndStation. The ~lu~ ed tone plV~ the 2ndStation for a feature code,one of which is transfer-with-return, another is 11 ar,~r~l-without-return (i.e., call-10 transfer as it is ~;ul~ntly done).

- event collected digits The digits signaled by the 2ndStation are received as the event collected_digits. If the collected digits in~ te a request for transfer-with-return, a Return_active in~lic~tor is set to true. If the ~ sÇel-with-return or -without-return feature is 15 requested, then a second tone!collect_digits action delivers dial tone to the2ndStation. The dial tone plv-llpls the 2ndStation for a directory number. If a valid directory number is received from the 2ndStation, a call-setup procedure is invoked and the state model then transitions to a new state, 3way_2ndStationActive_3rdStationSetUp 20 - event signal If the appçvl)liate signal (e.g, a flash) is received by the switch from the 2ndStation, the call is returned to the previous 2-way talking path between the lstStation and 2ndStation, and state model transitions back to the state 2way.
4-4. state 3way 2ndStationAcave 3rdStationSetUp (~IG. 23) The lstStation is on hold, and the 2ndStation has initi~ted transfer procedures. Several events are possible in this state:

-eventcall failed The call could not be comlccted to the design~ted directory number, perhaps because the 3rdStation was busy or did not answer. In this event, busy or ringing (as 30 appr~liate) is delivered to the 2ndStation. The state model then transitions to state 2way_2ndStationActive.

- - 210;~77 -eventcall answered The 3rdStation answers the call. In this case, the switch establishes a 2-way path between the 2nd and 3rd stations. The state model then transitions to an new state, 3way_2ndStationActive_3rdStationActive.

5 - event disconnect received from 2ndStation The 2ndStation disconnects. In this event, the switch establishes a 2-way connection bclwcen the lstStation and the 3rdStation. Since the 3rdStation has not yet answered, the lstStation receives audible ringing The state model then tr~n~itions to an new state, 2way_1stStationActive_3rdStationActive.

10 - event si~nal received from 2ndStadon The 2ndStation (the subscriber) signals (typically, but not necess~nly, by flashing) a request to return to the 2-way call with the lstStation. In this event, a talking path is established bcL~,en the 1st and 2nd stations, and the state model transitions back to the state 2way.

15 In the next two states, the 2ndStation has a two-way conversation with either the lstStation or the 3rdStation. The 2ndStation's signal (flash or DTMF) acts a toggle bcl~,.een these two states. If the 2ndStation signals a confell_nce request, procedures for a 3-way conversation are initi~te l 4-5. state3way 2ndStationActive 3rdStationActive (FIG. 24) In this state the lstStation is on hold, while the 2nd and 3rd Stations are connecled in a talking path. Two events are significant in this state:

- event si~nal for to~le received from 2ndStation If the 2ndStation signals a single flash (or some DTMF equivalent) then the switch opens the path l;~l~een the 2nd and 3rd Stations, and connects a path between the 1st 25 and 2nd Stations. The state model then transitions to a new state 3way_1 stStationActive_2ndStationActive.

- event si~nal for conference received from 2ndStation If the 2ndStation signals a double-flash (or some DTMF equivalent) then the switch creates a 3-way call ~l~en the 1st, 2nd, and 3rd Stations. The state model then 30 transitions to a new state 3way.

2~207~

4-6. state 3way lstStationActive 2ndStationActive (FIG. 25) In this state the 3rdStation is on hold, while the 1st and 2nd Stations are connected in a talking path. Two events are significant in this state:

- event si~nal for tog~le received from 2ndStation S If the 2ndStation signals a single flash (or some DTMF equivalent) then the switch opens the path ~l~een the 1st and 2nd Stations, and connects a path between the 2nd and 3rd Stations. The state model then tr~n~ition~ back to the state 3way_2ndStationActive_3rdStationActive.

- event si~nal for conference received from 2ndStation 10 If the 2ndStation signals a double-flash (or some DTMF equivalent) then the switch creates a 3-way call bet~ n the 1st, 2nd, and 3rd Stations. The state model thentransitions to a new state 3way.
4-7. state 3way (FIG. 26) In the 3way state, all three stations are connected together in a 3-way 15 conference.
If the 2ndStation disconnects, a 2-way call is created between the lstStation and the 3rdStation and the state model transitions to state 2way_1stStationActive_3rdStationActive.
If the lstStation or 3rdStation disconnects, a 2 way call is created 20 between the two ~ inin~ stations (~l~.~,en the 2ndStation and 3rdStation, or belween the lstStation and 2ndStation, ~,s~c~ ely). If 3rdStation disconnects, the state model tr~n~ ons back to state 2way. If the lstStation disconne~;ls" the state model transitions to the state 2way, but consider the 3rdStation as if it were the lstStation (the origin~l lstStation is no longer part of the call), except of course, the 25 2ndStation is now the call originator.
4-8. state 2way lstStationActive 3rdStationActive (~G. 27) In this state, the 2ndStation is not part of the call.
Initially, the connection bet~ n the 1 st and 3rd station is either in a ringing state or in a talking state (depellding upon whether or not the 2ndStation 30 discom~e~,~ed before or after the 3rdStation answered; or in terms of the state model, clepending on wh~,lLel the previous state was 3way_2ndStationActive_3rdStationSetUp or 3way. If either station disconnects, the call is tennin~ted, and call-history infolm~lion is returned to the 2ndStation.

2102~77 Note: In Service Concept-4, the lstStation and 3rdStation cannot recall the subscriber explicitly by flashing or implicitly by disconnecting. In ServiceConcept-4, the 3rd party must subscribe to the transfer feature and must independently invoke the transfer back to the initial called party (the subscriber). In 5 effect, in subsequent prucessillg, the 3rd party now becomes the call-transfer subscriber.
Four events are significant:

- event no answer received from 3rdStation If the 3rdStation does not answer, the lstStation continues to hear ringing until the 10 lstStation signals a request to return the call to the 2ndStation, or the lstStation disconnects. No state transition is required.

- event answer received from 3rdStation If the 3rdStation answers, then the switch establishes a talking path between the lstStation and 3rdStation. No state transition is required.

15 - event disconnect received from lstStation or 3rdStation The call is terrnin~ted and the le.-~ining stations are disconnected. However, if the call-history feature is active then a call history il~follllation message is sent to the station that requested call history infol~llation.

- event si~nal (flash or DTMF) received from call-transfer subscriber 20 (e.~., 3rdStation) If the station that signaled is a call-transfer subscriber, then the call is placed on hold, and the call-transfer subscriber can set up a second call. The state modeltransitions to state 2way_SubscriberActive (with an initial event, Initial_Event).
Ser~ice 5: Service ~ateway without switch-based 25 transfer-with-return capability and without the call-history feature (~IG. 17) Service 5 is distinguished from Service 4 by the absence of the call-history feature in Service 5.
Consider the case in which a caller (a lstStation) is connected to a 30 2ndStation (e.g., a service attendant or external service module) that has line subscription to the current practice call transfer feature. The 2ndStation ~lsr~.~ the call to a 3rdStation (e.g., a service agent or specialist, or another external service 21Q2~77 module). If the 3rdStation also subscribes to call transfer, the 3rdStation may at the end of the call, transfer the call back to the same 2ndStation that initially handled the call (or routed to a co-worker, if the 2ndStation is busy/no-answer). The call flow is shown in FIG. 28. Two assumptions are made that place this scenario in today's 5 network.
Assumptions:
1. If party A calls Party B, and B transfers the call to Party C, then two calls are concurrently active, even though B has disconnected and A is talking with C. Thetwo calls are the call setup by A, notated here as (A to B), and the call setup by B, 10 notated here as (B to C). Using the terms lstStation, 2ndStation, and 3rdStation, this means that, in the current telecol.. ,lic~tions environment, (lstStation to 2ndStation) is billed to the lstStation, and (2ndStation to 3rdStation) is billed to the 2ndStation. Moreover, the call (lstStation to 2ndStation) does not terminate when the 2ndStation disconnects, but when the lstStation or 3rdStation disconnects.

15 2. The 3rdStation is provided information about the identity of the 2ndStation so that the 3rdStation can l~lir~ the call back to the 2ndStation.

The description of the service concept is structured into two scenarios:

- In Scenario A, the 3rdStadon termin~tes the tran~ction with the lstStation;

- In Scenario B, the 3rdStation transfers the call back to the 2ndStation 20 Each scen~rio is further pal lilioned into two services:

- the Bill Correlation Service, in which the se~ ale billing records that are genelaled by each call (the initial call and each subsequent call-transfer) are correlated and combined into a single billing record.

- the Bill Discounting Service, in which particular bills are discounted based upon 25 their association with well-defined criteria (e.g., call-transfers originating from a 2ndStation).

Scenario A (FIG. 29) 1. 1st Station dials 2ndStation (or hunt group that termin~tes to 2ndStation) 2. 2ndStation answers; 1st and 2ndStation talk 3. 2ndStation places call to 3rdStation (if the 2ndStation is a person, this may5 require first placing the lstStation on hold) 4. 3rdStation answers; 2ndStation and 3rdStation taL~

5. 2ndStation creates 3-way call involving lstStation, 2ndStation, and 3rdStation 6. 2ndStation disconnects; 1st and 3rd Station talk 7. 1st or 3rd Station disconne~

10 Billing Records:

The billing records created for this scenario are:

a. (lst to 2nd Stations) for n~,lwc,lL lesoul~e usage spanning events (2) through (7) b. (2nd to 3rd Stations) for nelwu~k r~soulce usage sp~nning events (4) through (7) Assume that all billing records are accessible to the same billing center (or 15 in~e~onnected network of billing centers) for further analysis, and that both types of billing records are applied to the 2ndStation accouilt (as in reverse-charged calls or free phone calls, e.g., 800 calls).
There are two billing and Illeasule.llcnt service sets that are provided as an illustration of how new billing and ,llea~ m~ services could be realized using 20 current (or slightly mo lifi~) transfer capabilities. These services are applied to the billing records created for each call in the Scenario A call flow. After a discussion of these services in the context of the Scenario A call flow, the same services will be considered in another call flow context, Scenario B. In Scenario B, the transferred-to party, i.e., the 3rdStation, transfers the call back to the initial transferring party, the - 21Q2~77 2ndStation.
Service Set-5.1, Bill Correlation Service:
Using Scenario A, the Bill Correlation Service provides measurements on transfer operations and provides discount billing services.
Assume that each bill cont~ins:

- calling and T.om~in~ting DNs, - the time at which the call is answered -- referred to as Origination Time, - the time at which the call is ended -- referred to as Tennin~tion Time, - a call-transfer in-lic~tiQn flag that the call involved a call transfer, e.g., in the 10 scenario call (2nd to 3rdStation) involved a call transfer or inrlicating a call illçntification.
- the time at which the Termin~ting party disconnects -- referred to as the Disconnect Time (the service provider disconnecl time). Note, if this statistic is not provided in the billing record, the basic concept described herein is not seriously impacted. It 15 merely means that certain calculations are not pelÇolmed. In particular, the overlap time referred to herein is not c~ te~l The overlap time is the duration during which the 2ndStation is conducting two 2-way conversations (and fl~ching to ~ltern~te between taL~ing with the lstStation and the 3rdStation), or one 3way conversation.

20 Bill and Measurements Calculation Method for Service Set-5.lA

1. Search billing records for all calls in which the call-transfer indication is set to true. Such billing records will be referred to as a Transfer-Bills. All other bills are categorized as non-Transfer-Bills. In the present scenario, (lst to 2nd Station) is a non-Transfer-Bill, and (2nd to 3rd Stadon) is a Transfer-Bill 25 2. For each non-Transfer-Bill terminating to a subscriber, search the Transfer-Bills for the Transfer-Bill in which:

- the subscriber DN is equal to the origin~ting DN of the Transfer-Bill, and - the ori~in~ting time and termination time of the call is subsumed by the originating and termin~ting times of the call described by the non-Transfer Bill.

30 Note: the call-transfer in~ flon flag is not essenti~l~ it merely reduces the search - - 28 210207~
time for identifying Transfer- and non-Transfer-Bills. Another method is to:

1. locate all bills origin~ting from or termin~ting to subscribers;

2a. for each bill for a call origin~ting from a subscriber find a bill (if any) in which - the call termin~tes to that subscriber, and - the ~i~in~tion and te~ in~l;on times subsumes the origination and termin~tion times of the bill origin~ting from the subscriber 2b. for each located pair of bills, the bill for the call origin~ting from the subscriber is a Transfer-Bill, and the call termin~ting to the subscriber is a non-Transfer-Bill.

3. Create a composite call history with the following inrolma~ion: The format of the 15 following c~lcul~tions is relation (Billing record), where relation describes a type of information contained in the Billing record, and relation (Billing record) is the value of that infolllla~ion. For example, caller DN (lstStation to 2ndStation) is the directory number of the caller, and Origination Time (lstStation to 2ndStation) is the time at which the call to 2ndStation was ans~ ~l. The symbols - and + have their20 standard ~;IIl.l.etir~ inle~ ta~ions. The symbol = may be in~ leted as is equal to.

a. Subscriber: caller DN (1 st to 2nd Station) b.TotalDuration = Te..n;,-~;onTime(lst to2ndStation) -Origination Time (lst to 2nd Station ) c. Calling Party = caller DN (lst to 2nd Station) 25 d. Transferring Party = Termin~ting DN (lst to 2nd Station ) = caller DN (2nd to 3rd Station) e. Transferred-to Party = Termin~ting DN (2nd to 3rd Station) - 2102~77 f. Call Segment 1: Calling Party and Transferring Party g. Segment 1 origination time = Origination Time (lst to 2nd Station) h. Segment 1 duration = Origination Time (2nd to 3rd Station) -Origination Time (lst to 2nd Station) S i. Call Segment 2: Calling Party and Transferred-to Party j. Segment 2 origin~tion time = Origination Time (2nd to 3rd Station) k. Segment 2 duration = Termination Time (lst to 2nd Station) - Origination Time(2nd to 3rd Station) 1. Calling Party call duration = Total Duration = Segl.len~l duration + Segment210 duration m. Transferring Party call duration = Disconnect Time (lst to 2nd Station) -Origination Time (lst to 2nd Station) n. Transferred-To Party call duration = Segment 2 duration o. Overlap (two concullenl 2-way calls, and/or one 3 way call involving caller, 15 transferring, and llansre~l~d-to parties): Discom~cl Time (lst to 2nd Station) -Origination Time (2nd & 3rd Station) The calculations can be visll~li7ed as shown in FIG. 30. Refer to Table 1.

-- 2 1 ~ ~ 0 7 1 Segment 1: origin~ting time=F0 terminating time=To Segment2: ori in~tingtime=T0 termin~ting time=Tt Overlap between Segments 1 and 2=S d-To Caller Total Duration: Ft-Fo 2ndStation actual Duration: (S d-S o) 3rdStation actual Duration: (Tt-To) current practice, Bill 1: Ft-Fo (origin~tor of call: lstStation) current practice, Bill 2: Tt-To (originator of call: 2ndStation) Table 1 4. Use composite call history to derive billing charges For example, certain subscribers (identifie~l by the origin~ting dn of a Transfer-Bill) who often act as transferring parties may subscribe to billing plans that calculate charges based only on the Calling Party call duration.
Other billing plans for usage charges are also possible, e.g, (Calling Party call duration + Overlap) which would more accu~dlely reflect the number oflogical calls in the system and would charge for the amount of time the transferring party is taL~ing to both the caller and the l~an~l,ed-to party.
A variety of mea~ mellts may be derived from the composite call 25 history, especially if the transferred-to parties can be grouped by specialty. For example:

(a.) Number of calls to a particular attendant which are subsequently transferred (b.) Number of calls to a particular attendant which are subsequently transferred, broken down by the number of calls transferred-to each set of specialists.
30 (c.) Number of calls transferred to a particular set of specialists 210'~(~7'1 (d.) Average length of overlap per attendant (transferring party) (e.) Number of calls from a particular geographic region to a particular speciality (i.e., a group of specialists) Mea~ure,llent (a) indicates how many calls required additional help from a specialist.
S A~suming calls are randomly distributed to ~ttçn~l~nt~, Mea~urelllellt (b) mayidentify attendants who transfer calls too quickly or who need additional training in particular areas. MeasulG,llent (c) could be used to indicate what areas of specialty are frequently beyond the e~?c.~-se of ~ttçnd~nts. This might be used to identify addidonal e~luc~tional needs for the alltndal~t co.. ~ r. Measu.Gll~nl (d) 10 intlic~tes the average time needed by an ~ttçn-l~nt to introduce the caller to a specialist. Attçnd~nts with relatively small or large values of measurement (d) may identify attendants with poor co--...~nnir~tion skills. Outlier values of Measurement (e) might in-lic~te a regional problem in servicing a product, distributing new releases of a product, or regional m~nllf~cturing of a product.
15 Service Set-5.2A, Bill Di~co~ t;-.p Service:
Using Scenario A, the following is a Bill discounting service that bills for only the call duration used by the caller.
Assume that each billing record contains:

- calling and Tçrmin~ting DNs, 20 - the time at which the call is ans~ referred to as Origination Time, - the time at which the call is ended -- referred to as Telmin~tion Time, - a call-transfer indic~tion flag that inflic~tes that the call involved a call transfer, e.g., the call (2nd to 3rd Station) involved a call transfer.

1. Search billing records for all calls in which the call-transfer indication is set to 25 true. Such billing records will be ~efel-~,d to as a Transfer-Bills. All other bills are catcgc";zed as non-Transfer-Bills. In the present scenario, (lst to 2nd Station) is a non-Transfer-Bill, and (2nd to 3rd Station) is a Transfer-Bill.

2. If the origin~ting dn of a billing record matches a list of prere,.~d subscribers, then discount entire amount of usage charge on that bill. This effectively means that a business customer pays only for usage derived from calls originated by the caller, and not for the internal redirecting of calls from one service provider (attendant or agent or ESM) or another.
Scenario B (FIG. 31) S 1. lstStation calls 2ndStation (or hunt group that tennin~tes to 2ndStation) 2. 2ndStation answers; lstStation and 2ndStation taLk 3. 2ndStation places call to 3rdStation (if the 2ndStation is a person, this may require first placing the 1 stStation on hold) 4. 3rdStation answers; 3rdStation and 2ndStation taLlc 5. 2ndStation creates 3-way call involving 2ndStation, 3rdStation, and lstStation 6. 2ndStation disconnect; 3rdStation and lstStation taL~
7. 3rdStation places call to 2ndStation (if the 3rdStation is a person, this 15 may require first placing the lstStation on hold) 8. 2ndStation answers; 3rdStation and 2ndStation taLlc 9. 3rdStation creates 3-way call involving 2ndStation, 3rdStation, and lstStation 10. 3rdStation disconncl;l, 2ndStadon and lstStation talk 11. 2ndStation and lstStation disconnect The billing records created for this scçn~rio are:

a. (lst to 2nd Station) for nelwolL l~sou~,e usage spanning events (2) through (11) b. (2nd to 3rd Station) for nelw~ resource usage spanning events (4) through (11) c. (3rd Station to 2nd Station) for n~,lwoll. resource usage spanning events (7)25 through (11) Assume that all billing records are ~ccessible to the same billing center for further analysis, and that all three types of bills are applied to the 2ndStations account (as in reverse-charged calls or free phone calls, e.g., 800 calls).

2l(~2077 Service Set-5.1B: Bill Correlation Service Using Scenario B, the Bill Correlation Service provides measurements on transfer operations and provides discount billing services.

Assume that each bill contains:

5 - calling and Tennin~ting DNs, - the time at which the call is answered -- referred to as Origination Time, - the time at which the call is ended -- referred to as Termin~tion Time, - a call-transfer indication flag that the call involved a call transfer, e.g., in the scenario call (2nd to 3rd Station) involved a call t.a,lsrer.

10 - the time at which the T~ min~ting party discom e~L~ -- referred to as the Service Provider Disconnect Time Assume that 2ndStation and 3rdStation are subscribers to the current-practice call-transfer feature and to the Bill Correlation Service.

1. Search billing records for all calls involving at least one subscriber. The resulting 15 set is referred to as the Subscriber set.

2. Search the subscriber set for all calls in which the call-transfer indication is set to true. Such billing records will be referred to as a Transfer-Bills. All other bills are caleg~ized as non-Transfer-Bills. In the present scenario, (lst to 2nd Station) is a non-Transfer-Bill, and (2ndStation to 3rdStation) is a Transfer-Bill.

20 3. For each non-Transfer-Bill tennin~ting to a subscriber, search the Transfer-Bills for any Transfer-Bill in which:

- the subscriber DN of the non-Transfer-Bill is equal to the origin~ting or termin~ing DN of the Transfer-Bill, and - the originating time and tçrmin~tion time of the call described in the Transfer Bill is subsumed by the originating and terminating times of the call described by the non-Transfer Bill.

Step (3) creates a set of bills cont~ining a non-Transfer-Bill and zero, one, or many Transfer Bills.

5 4. Create a composite call history with the following inro~ ation: The format of the following calculations is relation (Billing record), where relation describes a type of information contained in the Billing record, and relation (Billing record) is the value of that information.
For example, caller DN (lstStation to 2ndStation) is the directory 10 number of the caller, and Origination Time (lstStadon to 2ndStation) is the time at which the call to 2ndStation was answered. The symbols - and + have their standard arithmetic in~el~lelaLions. The symbol = may be int~ ,leled as is equal to.

a. Subscriber: caller DN (2nd to 3rd Station) b. Total Duration = Termination Time (lst to 2nd Station) - Origination Time (lst 15 to 2nd Station) c. Calling Party = caller DN (lst to 2nd Station) d. lstTransferring Party = Termin~ting DN (lst to 2nd Station) e. lstTransferred-to Party = Tennin~ting DN (2nd to 3rd Station) f. 2ndTransferring Party = Ori~in~tin~N (3rd to 2nd Station) 20 g. 2ndTransferred-to Party = Terminating DN (3rd to 2nd Station) h. Call Segment 1: Calling Party and Transferring Party i. Segment 1 origination time = Origination Time (lst to 2nd Station) j. Segment 1 duration = Origination Time (2nd to 3rd Station) - Origination Time(lst to 2nd Station) 210?,Q~7 k. Call Segment 2: Calling Party and Transferred-to Party 1. Segment 2 origination time = Origination Time (2nd to 3rd Station) m. Segment 2 duration = Origination Time (3rd to 2nd Station) - Origination Time(2nd to 3rd Station) 5 n. Call Segment 3: Calling Party and initial Transferring Party o. Segment 3 origin~tion time = Origin~tion Time (3rd to 2nd Station) p. Segment 3 duration = Termination Time (lst to 2nd Station) - Origin~tion Time(3rd to 2nd Station) q. Calling Party call duration = Total Duration = = Segmentl duration + Segment210 duration + Segment3 duration r. 2ndStation call duration = tDisconnect Time (lst to 2nd Station) - Origination Time (lst to 2nd Station)] + [Termination Time (3rd to 2nd Station) - Origination Time (3rd to 2nd Station)]

s. 3rdStation call duration = Disconnect Time (3rd to 2ndStation) - Origination 15 Time (2nd to 3rd Station) t. Overlap be~ en se~ ,nls 1 and 2 (two 2-way calls, and/or 3 way call involvingcaller, transferring, and transferred-to parties): Disconnect Time (lst to 2ndStation) -Ori in~tion Time (2nd to 3rd Station) u. Overlap ~l~e.l seg~nls 2 and 3 (two 2-way calls, and/or 3 way call involving 20 1st, 2nd, and 3rd Stations):
Disconnect Time (2nd to 3rd Station) -Origination Time (3rd to 2ndStation) The calculations can be Vi!C~ i7er~ as shown in FIG. 32. Refer to Table 2.

- 2~ZO '7 Segment 1: origin~ting time=FO
tç,rrnin~ting time=To Segment 2: origin~ting time=T0 termin~ting time=S'0 Segment 3: origin~ting time=S'O
tçrrnin~ting time=S't orFt Overlap bel~ ,n Segments 1 and 2=S d-To Overlap bel~.~e~ Segments 2 and 3=Td-S'o CallerTotalDuration: Ft-Fo 2ndstationactualduration:(sd-so)+(s t-S o) 3rdStation actual duration: (Td-To) current practice, Bill 1: Ft-Fo (originator of call: lstStation) current practice, Bill 2: Ft-To (origin~tor of call: 2ndStation) current ~laclice~ Bill 3: Ft-S 'o (originator of call: 3rdStation) Table 2 Service Set-5.2B Bill Discountin~ Service Using Scenario B, the following describes a Bill Discounting Service that bills for only the call duration used by the caller.

20 Assume that each billing record contains:

- calling and T~.. ;n~t;l-g DNs, - the time at which the call is ans~ ,d -- referred to as Origination Time, - the time at which the call is ended -- referred to as Terrnin~tion Time, - a call-transfer indic~tiQn flag that indicates that the call involved a call transfer, e.g., in the scenario (2nd to 3rd Station) involved a call transfer.

1. Search billing records for all calls in which the call-transfer indication is set to true. Such billing records will be referred to as a Transfer-Bills. All other bills are 5 categorized as non-Transfer-Bills. In the present scenario, (lst to 2nd Station) is a non-Transfer-Bill, and (2nd to 3rd Station) and (2nd to 3rd Station) are Transfer-Bills.

2. If the origin~ting dn of a Transfer Bill billing record matches a DN on a list of p~er~ Gd subscribers, then discount entire amount of usage charge on that bill. This 10 effectively means that a business customer pays only for usage derived from calls originated by the caller, and not for the internal redirecting of calls from one service provider (AttendAnt or agent or ESM) to another.

Note: the call-transfer indication flag is not essentiAI, it merely reduces the search time for identifying Transfer- and non-Transfer-Bills. Another method is to:

1. locate all bills originAting from or terminAting to subscribers;

2a. for each bill for a call ori in~ting from a subscriber find a bill (if any) in which - the call termin~tes to that subscriber, and - the origination and termination times subsumes the origination and t~rminAtion times of the bill origin~ting from the subscriber 2b. for each located pair of bills, the bill for the call originAting from the subscriber is a Transfer-Bill, and the call te~ ;nA~ g to the subscriber is a non-Transfer-Bill.

Description of Prior Art Billin~ Service (~IG. 33) Call transfer in a centrex or ISDN envilonlllent allows subscribers to receive or originate a call, receive or originate a second call conculTent with the first call, join the two calls together into a 3-way call, and disconnect from the call while ' ~ 2~02~77 allowing the other two parties to continue talking. A state diagram and call flow are shown in FIGS. 34 and 35.
Tern~inolo~y The following scenario will consider call-transfer from the perspective 5 of a 2ndStation that receives a call from a lstStation, and transfers that call to a 3rdStation, yielding a conversation between the lstStation and the 3rdStation (the 2ndStation has disconnected). In standard telecollullunications terminology the lstStation is frequently called the calling party, the 2ndStation is typically referred to as the transferring party, and the 3rdStation is often called the transferred-to party.
10 Network Routin~
In current practice, a tlansre~l~d call is routed from the switching office of the lstStation (termed the lstSwitch) to the 2ndSwitch to the 3rdSwitch, evenafter the 2ndStation has disconnected.
Billin~ Practices In current practice, the originating switch of the first call produces a bill that is handled independently from the bill generated by the originating switch of the second call (even if the same switch is involved for both call originations).
Each originated call g~ C~ ,S a billing record: the call from the lstStation to the 2ndStation; the call from the 2ndStation to the 3rdStation. Both 20 calls terminate when the lstStation or 3rdStation disconnect. The billing practice does not reflect the time at which the 2ndStation disconnects.
If the 3rdStation were to initiate a 3rd call (a second transfer) while talking with the lstStation, then a third bill would be created for the call from the 3rdStation to the 4thStation (the 4thStation may be equivalent to the 2ndStation if 25 the 3rdStation transfers the call back to the 2ndStation). In this case, all three bills would depend upon the disconnect time of the 1st or 4thStation (and would not reflect the disconnec~ times of the 2nd or 3rdStations). Event diagrams for Scenario A are shown in FIGS. 36 and 37. An event diagram for Scenario B is shown in FIG. 38. Refer to Table 3 for Scenario A and Table 4 for Scenario B.

210207~

Segment 1: origin~ting time=AO
terminating time=CO

Segment 2: originating time=CO
S termin~ting time=Ct Billing Practice:

current practice, Bill 1: At-Ao (originator of call: lstStation) bill based on tariff for lstStation to 2ndStation calls;
bill generated by lstSwitching office;
bill produced when lstStation or 3rdStation disconnect current practice, Bill 2: Ct-Co (originator of call: 2ndStation) bill based on tariff for 2ndStation to 3rdStation calls;
bill gen~lated by 2ndSwitching office;
bill produced when lstStation or 3rdStation disconnect No bill created based on lstStation to 3rdStation fii~t~n~e.
Bill for second call not dependent upon 2ndStation disconnect.
Table 3 210207 ~l Segment 1: originating time=AO
l~;"";,~ g time=Co Segment 2: origin~ting time=C0 termin~ting time=B'O

Segment 3: originating time=B'0 termin~ting time=B 't or A t Overlap beL~en Segments 1 and 2=Bd-Co Overlap bet~cell Segments 2 and 3=Cd-B'o Caller Total Duration: At-Ao 2ndStation actual duration: (B d-B o)+(B 't-B 'o) 3rdStation actual duration: (Cd-Co) current practice, Bill 1: At-Ao (origin~tor of call: lstStation) current practice, Bill 2: At-Co (ori in~tor of call: 2ndStation) current practice, Bill 3: At-B'o (ori~in~tor of call: 3rdStation) Table 4 A further ~ltern~tive method used in the arrangement of FIG. 40 includes connecting a call from a first station to a second station.
Con~ ,poldlleously with connecting the call to the second station, the tr~n~mission 20 of first call segment event messages is initi~te~ to a billing center, e.g., a nationwide billing center. The call is then connected to a third station. Contemporaneously with connecting the call to the third station, the tr~n~mission of second call segment event messages is ini~ti~ted to the same billing center. After all of the first and second call segment event messages have been trancmitted, the billing center correlates them to 25 generate a single billing record for use in billing the call.

Claims (10)

1. A call processing and billing method comprising connecting a call from a first station to a second station, contemporaneously with said connecting of said call to said second station, initiating a first billing record for said call, connecting said call to a third station, contemporaneously with said connecting of said call to said third station, initiating a second billing record for said call, completing said first and second billing records before or proximate to the end of said call, and after said completing, correlating said first and second billing records to generate a single billing record for use in billing said call.

2. A method in accordance with claim 1 where said connecting of said call to said third station comprises conferencing said third station into said call.

3. A method in accordance with claim 1 where said connecting of said call to said third station comprises transferring said call to said third station.

4. A method in accordance with claim 1 where said correlating comprises modifying one of said first and second billing records based on the other of said first and second billing records to generate said single billing record.

5. A method in accordance with claim 1 where said correlating comprises combining information from said first and second billing records to generate said single billing record.

6. A method in accordance with claim 1 where said correlating comprises comparing said first and second billing records and using only one of said first and second billing records to generate said single billing record.

7. A method in accordance with claim 1 further comprising including an identifier, in at least one of said first and second billing records, for use in said correlating.

8. A call billing method comprising initiating a first billing record for a call contemporaneously with a connection of said call from a first station to a second station, initiating a second billing record for said call contemporaneously with a connection of said call to a third station, completing said first and second billing records before or proximate to the end of said call, and after said completing, correlating said first and second billing records to generate a single billing record for use in billing said call.

9. A call processing and billing method comprising connecting a call from a first station to a second station, contemporaneously with and after said connecting, initiating transmission of first call segment event messages to a billing center, transferring said call from one of said first and second stations to a third station, contemporaneously with and after said transferring, initiating transmission of second call segment event messages to said billing center, after transmission of all of said first and second call segment event messages to said billing center, said billing center correlating said first and second call segment event messages to generate a single billing record for use in billing said call.

10. A method comprising during a call from a first station to a second station, generating call history information, transferring said call from a second station to a third station, enabling transfer of said generated call history information when said call is transferred, after said transfer of said generated call history information and before or proximate to the end of said call, updating said transferred call history information.