CA2108581A1 - Method and apparatus for providing answer supervision and an autonomous pay telephone incorporating the same - Google Patents

Abstract

A method and apparatus for telephone call answer supervision, capable of detecting the completion of both national and international calls, which employ different answer confirmation formats, and provide confirmation that a placed call has been answered if least one of the following conditions occurs: 1) a tone of a given frequency, transmitted on the transmit line (18) of a telephone, is detected as received back on the receive line (22); and 2) audio activity having a non-repetitive cadence is detected on both the transmit and receive lines of the telephone.

Description

WO92/19~ 0 8 5 ~ 1 PCT/~S92/02~02 Description Method and Apparatus For Providinq Answer suPervision and An Autonomous PaY Tele~hone IncorPoratinq The Same Technical Field The present invention relates to both a method and apparatus for providing telephone answer supervision capable of detec~ing the completion of both national and international calls, which employ different answer conf irmation formats, ~s well as to an autono~ous pay telephone, such as a mobile telephone, incorporating the s~me~

Hack~round Art ~;: Conventional pay telephone service, which has generally been provided by major telephone companies, is : 15 becoming highly attractive ~o the private pay station owner as a re~ult of the continuing deregulation of such serviea and associated equipment as well as ~ue to the avaiIability of various mobile radio comm~nication metho~s and sy tems in~addi~ion to the traditional ;20 ~landl~ine ~elephone::systems now in service.

One important requirement for all telephone configurations, landline or mobile as well as pay or otherwise, is the~ability to determine if a placed call has-:~een answered, hereinafter re*erred to as answer 5~ 5up~rui8ion. ~ This:raquirement is essen~ial in order to determine when to charge the patron for a placed telephone call. I~:fact, due to the past failure to properly provide effective answer supervision, recent ; 1egi~1ation,passed~by the U.S. Congress has codified the req~irements for answer supervision in the United States.

Typically, the Central Office of the local telephone :: ompany detects when the called party lifts the hand-set ; creating an off-hook condition which completes an W~2/lgO~ PCT/VS92/0~8e ~ 2- ' !

electric loop from the Central Office. The telephone company starts billing the call fr~m the moment it detects the loop completion. This answer supervision information is passed on to inter-exchange carrisr~, S i.e., ~T&T, MC~, under what is called in the United States as Feature Group D interconnection. Oth~r methods us~d ~or detecting when a call has been answered includ~:
1) voice detection, ~) ring cadsnce interruption detectio~ plus busy cadence acknowledge, and 3) timing after last digit dialed.

Normally, the conventionaI landline pay telephone is provided with no answer supervision capability and is d~pendent on the Central offic~ e~uipment (compatible with the national format onlyj to detect a completed call. ~n this regard, once the Central office detects a compl~ted call, it generates standard tones or signals (mom~ntary reversal o~ polarity or signal tone~, ~u~h as at:lZ,000 Hz) which are detected by the pay telephone to i~d~ica~ the compIetion of a call. In the ca~e of 20 ~telephone companies following the North A~erica standards, the pay tel phone is connected to ~peci~l lines~a~ the Central~office which have the n~cessary equipme~t to provide the answer supervision si~nalling to the~:pa~y~telephone. ~:In the case of telephone companies 25;~:~foll~wing th~ inte~national CCITT/CEPT standards, the en~ral office either follows a similar reverse polarity method of an~wer supervision signalIing or sends the : tones to signal that the called party has answered, toge her with the appropriate rate information. Further, special cir~uits are generally provided at the Central Office that briefly reverse polarity of the line so that the pay telephone can collect deposited money once the Central Of~ice detects the completed call.

:

W092/1~X~ 21~,~5.~

In the case of customer owned pay phon~s (COCOT) or in the case of PBX, key systems, or even in the early days of MCI and US Sprint, the Central Office does not send any signal to the calling party indicating when the call has ~een an~wered. Therefora, the above-noted-methods of answer supervision have been used with various algorithms to try and improve their inherent shor~c~mings. False answer det~ction or no detection when a call i8 really answered, resulting in erroneous ~: 10 charges ox no charges at all, are the con~equences of inexact answer ~up~rvi~ion.

:~: U.S. Patent No. 4,9lS,733 discloses a telephone call answer supervi~ion apparatus which e~ploys the ringing : cadence interruption ~et~ction method wherein the an~wer : :
::: 15 sup~rvi~ion signal received from the Central office iæ
: employed: to de~ect when the call is nswsred using the U.S.~s~andard tone spec. only. This arrangement measures he~tim1ng~ cadence of tones~received and uses them ~s a re~erenGe for detecting a c~ll. However, if a call is 20~made~to a country with a different timin~ c~dence, this arrang~ment cannot~recognize and differentiate ~he tones one~:from another ~ecause no provision is made to identify hem.

U.S. Patent No~. 4,777,647, 4j924,497, 4,926,468 and 25~::4,~9~6,469 disclose~pay telephone interface circuits for aoup1ing ~ convéntional pay station telephone to a telephone swi~ching system, In this particular arrangement, the interface provides supervision signal detection functions normally provided by the switching : 30 system and *hus can be connected théreto by a l~ss costly b~siness line. ~ ~

:: , :~ :

::

W0~2/1~ PCT/VSg2/0~02 210~ 1 ~4~

U.S. Patent No. 4,920 r 562 discloses an arrangement which can locally generate records o~ individual kelephone call~ to facili~ate the billing of collect calls and call~ placed using credit cards and other S billing acce~s forma s on a pay telephone st~tion. The ~tation reaord~ the duxation of th~ call and other pertinent information in a billing record for later retrieval to pr~pare the billing of the call. However, no provision is mad~ ~or displaying the cost of the call : 10 in r~al time. Additionally, U.S. Patent No. 4,8gO,317 : i~ilarly relate to an arrange~ent for looally ~: : ganerating records of individual tel~phone call and : ~ includes an arrangement for d~termining the validity of : the billing account number by attempting to place a ~5 tslephone call using the billin~ account number to a contxolled t~lephone nu~ber.

U.S0 Patent Nos. 4,658,096, 4,737,975, 4,775,9~7 and 4,:922,~17 all di~cl~se aellular phone interface arrangem~nts for providing a connection to adapt a

2~0~ ta~dàrd telephone~set with a radio tranæ~eiver.
However~ uch an~arrangement would suffsr from the iss~vantage~ noted~above in that depend~nce on the t~aditional:telephone~landline systems i r~quired when pla~in~a~call using~such an arrangementO

2~5~ lso known~i~:a:cellular mobile telephone credit :card~:~ystem such as~disclosed, for examplP, ~y U.S.
Patent No. 4,776,003, in which the cellular pay stati~n, ~: from the viewpoint of the serving cellular carrier facility, is indistin~uishable from standard cellular 30~:mobile stations. In;~his arrangement, the activities of ;: the~: credit card station :are supported by an ~ administrative processor whi~h is connected to a standard : ~ :
, ~

: ~;:

WO92/1~ PCT/US~2/~2802 -5- ~1 O~

telephone line of the public switching telephone network.
Data me~sages are exchanged therebetween and u~ed to establi~h operating options, compilation of records for assignment of billing rPsponsibility to transient customers and control of the stations for administrative and commercial reasons~ ~s with the previously discu~sed pay telephone arrangements, the unit operates in dependence on the Central Office signaling schem2.

Becau e o~ the unique nature of a pay telephone using a ~obile telephone installed~ for example in a ;~ vehicle, special provi~ions are required for autonomous op~ration control in the areas:of tariffing, call generation and accounting, called party detection, i.e,O, answer supervision, ~a8 well as ~cQs~ing the ~o~t of the 8ervice o a u~er. In view of th~ foregoing, it is :
highly d~irablQ t~ pro~ide mobil~ pay ~el~phone eguipment capabls of a epting, on site, different ;:tarif~ing formats~as well a~ having ~he capa~ility of dét~cting any type of nat~onal and international answer :20 ~per~isi~n confirmation. Because mobile pay telephone e~uip~ent operates::in the radio environment, and h~erefore is high~mobile it is al~o de~irable that such an~;arra~ement operate i~dependently from~the Central :; office~:~signaling scheme by proYiding a ~reliable interface 25~ with~the particu1ar radio receiv~r and autonomously nera~e the necessary supervisory signals required to operàte~wi~h the telephone network~

Disclnsure of the Invention : One object of the present invention is to provide a 30:~ method:and apparatus for reliable answer supervision which~is capable of detecting the completion of ~oth natisnal and international call which employ different ~' :

~' :

W~9~/19~66 ~CT/~S92/02802 2~ ~ ~ 5 ~ ~ -6-answer confirmation schemes.

Yet another object of the present invention is to provide an autonomous pay tel~phone arrangement for processing a pay telephone call from, for example, a mobile telephone without the need for credit cards and in manner which eliminatas reliance on the telephone company'~ Central Office for either answer supervision or billing.

Th~refore, according to preferred embodiment~ of the present inYention, these and other objects, advantages and f~atures are achieved by a method for providing call answer supervision to determine if a placed call to a ;
given tsl~phone number has ~een answered by a called party at the giv~n ~lephone number, the method lS c~mprising ~.he stsps of: transmitting a tone of a given r~queney on a transmit line of a telephone; monitoring a .~
r~ceive line of the telephone to determine i~ the ton~ is re¢ei~d back on the r ceiv~ line; simultanesusly monitoring the transmit and receive lines to det~rmine the~presence of other ~udio activity; determining i~ the other~audio activity, present o~ the rec~ive line, has a rep~titive cadence; and determining that the plac~d call ha~ been answered if at laas~ one of the following cond~tions occurs:~l) the tone of the given fr~quency is 25~ received back on the receive line; and 2) ~udio acti~ity : having a nonrepeti ive cadence is detected both on the transmit and receiv~ lines of the telephone.

According to preferred embodiments of the pre~ent inven~ion there is:provi~ed an apparatus for providing 30 call answer supervi ion to determine if a placed call to a given telephone number has been answered by a called :

WOg2/19066 ~CT/~S9~/0~02 7-- 2 1 ~ 3 5 ~ ~

party to the given telephone number, the apparatus comprisin~: tone generating means for transmitting a tone of a giYen fr~quency on a transmit line of a telephon~;
tone detection means ~or monitoring a receive line of the telephone and for determining if the tone i~ received back on the recei~e line; audio activity de~ection means for ~imultaneously monitoring th~ transmit and receive line~ for the presence of other audio activity; cadence det~rmining means for determining if the other audio actiYity, present on the receive line, has ~ r~patitive cad~nce; and answer con irmation means for determining that the placed call has been answered if at least one of the following conditions occurs: 1) the tone of thP given ; fre~uency is detected as received back on the receiYe line ~y the tone detecting means; and 2) audio acti~ity having a non;-repetitive Gadence is detected both on the ~ :tr~nsmit and recei~e lines of the telephone by the : cadence determining means.

~: One advantageous feature of preferr~d emhodiments of ~:: 20: ~the~present invention is the provision that the answer ~uper~i~ion method and apparatus eliminate the re ~ irement for preidentification of a specific country~s ring back signal, th method being applicabl~ to any lephone arrang~ment, i.e., landline telephones 25 :aonn~ct~d to a standard tQlephone network as well as a radio-linked base communication arrangements, such as a mobile ~élephona.

According to further embodiments of the present in~ntion there is provided an arrangement for providing an autonomous pay telephone comprising: a memory for storing call rate information for determining a xate to be charged per unit of time for a call to a giYen :

WOg~ 6 PCT~U~92/02802 2 1 0 8 5 g ~ --B-telephone number; charging means for receiving the telephone given number and for determining the rate to bP
charge for a c~ll placed to the given number from the call rate information stored in the memory; and display means for displaying, in real-time as the call progresses, charges for the call placed to the given telephone number upon completion of the placed call to the given telephone numb r.

Advantageous features of the autonomous pay telephone arrangem~nt in~lude the provisions that ~he cumulative charges of each call placed or received are continuously displaying, in real-time, so that the user is advised of ~he cost during the telephone call, and : that a ~elephon~ equipped with the autonomous pay telephone arrangement i~ programmed, by the owner or service provider,:for different rates for billing purpose as well as to obtain acoess to charged amount totals for accounting purpoæes. ~ :

By being able~to control the ~ariff~ and charges for 20~ ser~ice. prov~ded, t~e:~ er or serviee providex can establish the desired mark-up without having to depend on thers. Fur~her, the ability to obtain charged amount totals providee a~reliable method for auditing money :col~ tions relating to the use of such a telephone 25~ arrangement~

Thus, the autonomous pay telephone arrangement of 1; 1 ~ ! ' :~ ~the present invention:envisions providing accurate pay telephone service-in locations previously unavailable.
: When ~he:autonomous pay telephone arrangement is applied , , to a mobile telephone provided in a taxi or other for-hir~ vehicle~, such ais rental cars, buses and trains, -~ :

WO92/1~ PCT/US92/028~2 ~ 21 ~8~81 patrons can place pay telephone call~ while traveling andwill be billed in~tantaneously and accurately for the ~ervic~ u~ed.

~his arrangement not only allows the owners of such for~hire ~ehicles to enhance their ~ervice and pro~itability, but also provides a ~eliable method for verification of cash money ollected from the use of such mobile telephones by proYiding retrieval of all call ; recordc and C08t information from a specific vehicle unit ~o that a final report, for a ~pecific period, can be : generated immediately at the end of a given work period.

In operation~ the autonomous pay telephone arrange~ent of ~he presen~ invention envi~ions pa~ment in : ca~:for servi~s received at the end of a placed or received te}ephone call or upon return of a rental v~h~cl@ ~o equipped.
,: ~ :
Another advantageous feature of th~ autonomous pay t~lep~one arrangement is that it int~rfa~es directly with th~audio c~rcuitry of a mobile telephone, such as, for :20~:e~ampl~e,; a cellular:telephone, which results in a stand-alon~product con~iderably cheaper to produce than prior art arxangements.

; The arran~ement~can be pro~ided options for operation with any type of full duplex convantional and 2S trunked radios, and radio telephone transceivers including cel1ular:transceivers compatible with the cel1ular format such~as: ~MPS, NMT 450l N~T 900, TACS, E-TACS as well as:with options for interpreting th~
tariffing signals, in the case of some NNT systems and in E-~ACS systems/ normally sent by the mohile telephone ;:::
, ;
:

WO92/19~66 PCT/US92/02~02 ", ~
21~5~ o-switch (MTX) applying the csrrespDnding call rate charge.

Brief De~cription of the Drawinas Figure 1 is a call progress detection flow diagram il}ustrating the operation of the answer supervision method of ~he present invention;

Figures 2A-2C are block diagrams illustrating the an~wer superviæion hierarchy for int~grating the : se~uential audio signal comparison ~upervision and tone an~wer supervision of the answer supervision method of ~0 the pr~sent inven~ion.
~:
Figure~ 3A-3E are block diagrams illu~trating thç
se~uential audio .ignal co~pari~on supervision of the an wer supervision m thod, Figur2 4 is a block diagram illus~r~ting the tone~ ~ lS answer supervision of the answer super~ision methodi and Figure~ is a chematic diagram illustr~ting one embodimen~ of an apparatus for performing the an~wer upervision method of the present invention; and Figure 6 i~ a ~ahematic diagram illuetrating one : 20 :~embodim~n* of an autonomous pay telephone arrangem~nt of the present invention as retrofitted to a mobile te1ephone.

est Mode for Carryina Out the Invention The answer supervision method of the present invention, which can be universally applied to any telephone, mobile, landline or otherwise, for use in ; answer supervision to detect the completion of local, national, and international calls routed through WOg2/1~066 PCT/US~2/02802 -11- 2 ~ 03~

different communication media, simultaneously utilizes seguential audio signal comparison ~upervision and tone answer supervision to dstermine when a call party has answe~ed. This dual answer supervision provides a high S level of reliability in determining the completion of a placed call.

The sequ2ntial audio signal omparison supervision is employed to verify that the same signal, i.e., busy signal, ring back signal, repetitive audio activity or the lik~, is b ing received in response to a placed call, in whi~h ca e, an indication is provided that the placed call has not been answered. If, during ~he comparison . process, the audio signal received shows an irregular~
timing caden~e, as in the case of a voice signal, an 15 :indication i8 provided that the call has been answered by the called party ~r an automatic network intercept message.

e tone answer supervision 9 simultaneously co~ducted with the sequential audio signal comparison supervision, is also employed to detect i~ the call has been answ~red. A ~pecial tone ~ ? n the audio range, is nt thrsugh the transmit line and khe receive line is ~onitored~to check if the pulse is rec~ived, If the ton~
is rec~ived back, it triggers the answer supervi~ion ~: 25 ci~cui~, indicating that the phone line is closed ~nd the : call ha~ been answered.

: This tone answer supervision is employed because the telephone circuit, between the Central office and the telephone subscriber who is being called, typically consists of a two wire loop which is open when the subscriber's telephone is on the hook. When the call ~V092/~90~ PCT/U~2rO2802 21~581 -12-party answers the telephone, i.e., the receiver is taken off tha hook~ the ircuit betw~an the Central Office and the subscriber's telephone i~ completed which not only allows for conversation to go through, but also permits the return of the tone genera~ed and employed by the tone answer sup~rvision.

The combina ion of the se~uential audio signal comparison supervisiQn and the tone-answer ~upervision provides a fail-~safe way of detecting an off-hook condition becaus~ call~ erroneously placed to the Central ~: office, which result in the receipf of a recorded announcement, do not trigger a false answer ~ignal even though the ~equen~ial audio signal comparison supervision will detect a voic~ s.~.gnal because, in most cases, there i~ no two wire closed loop, ~our line trunk circuit~
be~in~ ~mployed to connect the recorded announcement m~hine, and the method of the present invention takes t~hio into account as will beco~e more app~rent as th~
folIowing d~tailed description proceeds.

2Q ~ In operation, after a call is generated, the answer su~ervision ~ethod will start to ~2nd a precise audio pulse sf~ ~or ~xample, about 2,100 Hz for a maximum of about 1 second, and will check to see if the tone is received back. The 2,100 Hz tone disables the echo ; 25 canceling equipment in the telephone network, making it po sible ~or the tone signal to b~ detected back when the : loop i~ closed. If the tone is not rsceived back, the tone will continue:to be ~ent ever 2 seconds or so, until the call is ter~inated or answered by the called party or :30~ an automatic network intercept method.

If the tone is received back ~efore any audio , :: :

WOg~l90~ PCr/~S92/0~802 -13- 2~S~

ac~ivity is detecked, a flag will be set to indicate receipt of the tone, and ths tone will not be ~ent again.
Alternatively, i voic~ activity is detected by the sequential audio signal comparison supervision, the method will not send the tone again and a fl~g will be set which indicate~ that the tone was not received back.
A~ter voice activity i~ detected, the method will check to æee if the calling party answer to the called party.
~ the called paxty does answer to the calling partyJ ~he method check~ to ~ee if the tone wa6 received back. If th~ tone was receiv~d back, a gra~e period of, for example, 6 seconds, will be given befor~ starting to ~:~ charge the call to see if there is a disconnect. If the ~ tone was not received back and the calling party answers to the called party, a grace period of, for ~xa~ple, 10 econds, will be given before starting to charge the call ;to prevent fal~e answer supervision. If the tone is received b~ck after any audio actiYity is dek~cted, then the y~tem will start to charge the call immediately.

20~ Re~erring to Figure ~, a call progress det~ction : flow diagr~D, illustrating the operation of the answer upervi8ion me~hod o~ th~ present invantiQn, is :; illu~t~ated which æet~forth the aontrol level~ for the sequential signal comparison answer supervision and tone . - ~
25~an~wer~ up rvision. In this regard, the method remains a~ ~control level l, waiting for the called party to answ~r, if sequential audio activity, su~h as ring back : tone or busy signals are received. However, if any other ` condition occurs, such as some combination of no tone received back, tone re ei~ed back before any audio : activity, tone received back after any audio activity, no audio activity, voice activity, the method proceeds to ~; control level 2 as will be more fully described with :

WOg2/lg~ PCT/U~92/028~2 21S~r~ 1 particular reference to Figures 2A-2C.

Figures 2~-2C illustrate the answer supervision hierarchy provided at control level 2 of the answer supervision method of the present invention. Referring to Figure 2A, at level A of control level 2, if no tone is received back and no audio aativity is received during a pred~termined period of time, for example, 30 seconds, the ~ethod proceeds to level C and drops th2 call.
Additionally, at level ~, if no tone is received back and voic~ activity is detected, the method proceeds to level B and determines if both parties have spoken, i,e., the c~lling party answers to the called party. If this ~ action does not occur within a predetermined period of : time, ~or example, 10 æeconds, the method proc eds to lS lev~l C and drops the call.

: If, however, th alling p~rty answers to the called : p~rty, the method waits for a predetermined period of time~, for exa~plej:10 seconds, to see if a disconnect oc~ur~ within tha 10 ~econd period. If disconnect does : 20 occur during this~waiting period, the method proceeds to level C~and drops th2~call. If, however, a disconnect d~s~not occur wi~hin ~he predetermined period o~ time, th~n the method proceeds to level C and starts charging e call.

~ ~Referring to:Figure 2B, at level A of control level 2, i~ the tone is received back and no audio activity is detected, the method proceed to level B and waits for some audio activity to be d~tected within a predetermined period of time, for example, 10 seconds. ~If no audio activity is detected, the method proceeds to level B and ~ drops the call.

: ~
:~:

WO 92~19~66 PCrlUS92/02802 --15-- 2 ~

If, at level A, a tone is received back before any audio activity and audio activity i5 then detected from the called party, the method proceeds to level B to check if the calling party answers to the called party , i . e ., both parties have spoken. If no answer is received within at pr~determined periQd of time, for example, lO
~ec:onds ~ then the method proceeds to level C and drops the c:all. If an answer is detected, the mathod waits a predetermin d perio~ of time, for example, 6 seconds and c:hecks if a di~:connec~ occurs~. If a disconnect does occur, the ~ethod proc~eds to level C and drops the call.
However, if no discomlect occurs, the method proceeds to level C and ~;tarts to charge the call . Ref erring to Figure 2C, at level A, if the tone is received ba ::k after the audio activity is detected, then the method proceeds to lev~l B and start~ to charge th~ call .

The ~;equential audio ~ignal comparison supervision ; ~ of the method of the present invention will now lbe de~;cribed with particular reference to Figures 3A-3E. It ~;hould be noted that the sequential audio signal co~npa~ on supe~risicn of the present in~ention is employed to detect the irregular cadence of voice signals ~:: a~; is: b~st illustrated by the examples provided below and the following àPtailed description.

: 25 Referring to Figure 3A, in step 1, after a call has been ini iated, the method waits for the first audio activity to be received o~rer the te;lephone line~ In step 2, upon detection of an audio signal, this f irst audio signal is iynored bec:ause the f irst audio signal rec:eived

3 0 n~tentimes does not hav2 a complete cadence .

In step 3, the method continues checking the line to WO92t19~6 PCT/US92/02802 ``'`; !
2~Q~3~ -16- ~ .

determine when the audio activity has stopped. However, if the audio activity r~mains for more than, for example, 10 seconds, as determined at step 4, the method procseds directly to step A (~ee Figures 3D-3E). However, if the audio activity ends before the expiration of the predete~mined period, the method returns to step 3, and because the audio activity has stoppedO proceeds to ~tep 5 to check to see if further audio activity is detacted~
In step 6, if no activity is deteated for more than a predetermined period of ti~e, for example, 20 seconds, the method will proceed directly to step C and drop the ;~: call (see Figure 3D).
:
If, however, audio activity is detected in step 5, the method proceeds ~o step 7, and a timer (high timer) for~ctiYity:det~ction is started. In step 8, the method waits~ until the activity fini~hes and, if the activity remain~ ~or mor~ than 10 seconds, as determined in step 9, the method proceeds directly to st~p A. However, if thi8 ~i5 not the case, when ~he audio activity ends~ the 20~ mèthod~,:in st~p 10,~tarts the timer for no activity ~low timer~, and in step 11, saves the duration of time of the audio~activity ~easured~:by the high timer (first timer me~sure~ent) in,~for example, a first register or any suitable::data storage arrangements, for later reference 25~ and use as will be describe hereinafter.

:In t~p 12, the method resets the high timer for :~ further audio activity duration measurement. In step 13, ; the method checks for further audio activity on the line but, if no aotivity is detected for more than 10 seconds, 30 :as;determined in step 1~, the method jumps directly to step B (see Figure 3D). However, if audio activity is detected, the high timer for audio activity duration WO 92/19066 PCr/US92/~2~02 -17~ 3 J 3L

measurement is staxted again in step 15. In stap 1~ A, a f l~g is set to indicate that audio activity has been detected .

In step 16, the method continues checking for the S pxesence of ~he detecterl audio activity and, if the audio activity remains for ~ore than a predetermined period of time, for example, 10 ~;econds, as determined in step 17, jumps direatly to step ~. If the datected audio ac:tivity f ini~;heæ bef ore the expiration of the predetermined 10 perio~l of tim~, the ti~aer for no acti~rity detection, i . ~., low timer, is started in step lB . ~n step 19 , the duration of ime the audio activity measured by the high timer (ses::ond timer measurement) is saved in, for ~xa~ple, a æec:ond regiæter and in st:ep 2 0 ~ the high timer 15 is res~t ~Eor further activity.

In step 2 1, 1:he method checks to see i~ audio activity is pre ent on the line and, in step 22, if no acti~rity i~ deteeted for more than a predetermined period : of ~ tim~, for ~xample, 10 seconds, the method proc:eeds :: 20 direetly to tep B.: However, if activity has been de~eoted, the high timer ~or ac:ti~rity ~etectioll is tart~d again in step 23. In step 24, ~he m~thod ; aontinues tQ ch k for the present c:f the audio artivity and in ~step 25, if :the acti~ity re~ains for mo:re than a 25~ predetarmined period of time, for example, 10 seconds, th~` method jumps directly to step A.

:: 4 If the audio activity ends bef ore the expiration of the predet~rmined period of time, the low timer ror no activity i~; started in step 25A and in step 26, the 3 0 duration of the audio activity measured by the high timer (thir~ timer measDrement) is saved, in, for example, a :

: :

WO92/1906~ PCT/US92/02802 2~8~ 18-third register or the like, and in step 27, the high ti~er is re~et. In ~tep 28, th~ third timer measur~me~t is compared with the first timer measurement, for example, by comparing the contents of the first register wi~h the contents of the third register, to check to see if it is the ~ame signal, i.e., the first and third timer measurements are equal, and if it ic the same ~ignal, $he method proceeds back to step 21.

: However, if it is nst the same signal, the third : lO timer measure~ent i~ co~pared with the ~econd timer ;~ measurement in ~tep 29 r for example, by co~p~ring the ~`` content~ of the third register with the contents of the second regi~ter, and if both timer measurements are the æame, the method proceeds direckly back to ~tep 2~. I
15;~ the tim~r measurements are different, in tep 30, ~he third~timer me~surement r~places the first timer measur~ment, for exa~ple, by replacing the contents of the f~rst~register with the contents of the third register~and the method~w its ~or further ~ctivity in : 20 ~step 31 If~no~activity~is detected for more than lO seconds, a~ determined in step 32, the method will proce@d directly~to step B.~If audio activity is ~etected, the hi~h~t~mer:is activated in ~tep 33 and if khe audio :2~5~a~tivi~y~r~ains for more than, for examplQ, lO seconds, as~:determin~d in~step 35, the method proceeds directly to : s~ep A. If the audio activity finishes before expiration : of this lO second period, the method proceeds to step 36 to~actiYate the low timer. In step 37, the activity 30~ duration measured by the high timer is saved in, for example, the third register as the third timer measurement, and in step 38, the timer high ~or audio -19~ 3~

activity detection is reset.

In step 39, the timer measurement stored in the third regist~r is compared with the ~imer measurement in the first register and if both timer measurements are the same, the method proceeds to ~t~p 40. ~f th~ firs~ and third timer m~asur~ments are not the same, the third : timer mea~urement will be compared wi~h second timer mea urement in step 41. If the second and third timRr measurements are the same, the method proceeds to step 40. In step 40, the~method checks for audio activity on the line and ~mps:to step 33 upon detection of such audio activi~y. H:owever,~if no audio activity is detected for more than 10 seconds ~step 42), the method proceed directly to step B.

15~ In::step 41,~ if the second timer measurement and the third~ti~er meacur~ment are not~the sam~, the method proceeds to stap~43~and~the third timer measurement ed~i~ the ~hird:register will be saved as:the ~econd ;~easure~ent~stored~in the second register. Th~
2~0~ ~e~thod~walts, in~tep~44 for further audio activity on the~line:~and, i~ ~no~audio~activity is detected for more than~l0~seconds;in~s~p~45, the method procéeds dir~ctly to~step:~B.:

If~audi~ activity is detected in step;44, th~ high ;25~ :timer~for~:mea~uring~;~the~duration of the audio aetivity is tarted in step 46 and in step 47, the methoa continues : ch cking for'the~detected audio activity. In step 48, if :audio~activity is present ~for more than, for example, 10 seconds:, the ~ethod proceeds directly to step A. If the 30 ~audio:activity ends before the expiration of this predete~mined period of time, in step 4~, ~he low tlmer ; , W~ 92/lgO66 PCr/USg2~0280~

2 1 ~ 20-for measurin~ the duration of no activity is started and in step 50, th~ count of the high timer is saved in the third register as the third timer measurPment.

Thereafter, in step 51 ~he high timer is reset. In step 52, the content~ of the third register, i.e., the third timer measurement, is co~pared with the contents of th~ fir~t regi~ter, i.e. the first time measurement and if they ar~ the ame, the method proceeds to step 53. In step 53, th~ method waits for further audio activity and if more audiQ activity is det~cted, it wi}l proceed to step 46. If no audio activity is detected for more than, : for example 10 ~econds, as determined in step 54, the method proceeds directly to step B.

If, howev~r, the content vf the third register, i.e.
W e t~ird ti~e ~easurement, is not the same as the content of th~ first register, i.e, the first imer : ~asu~em~nt, a~ de~ermined in step 52, the system co~pares the contents of the second and thir~ register in step ~5. If both ~he second and third timer measurements are~the sa~e, the method proceeds back to step 53~ but if both:ti~er measurements are different, the m2thod proceeds to ~t~p 56.

~: :; In ~tep 56, the method verifies if the called party ~:: ; makes a pause of 0.5 seconds, i.e., no audio activity for the stated time period~ If a pause of at least 0~5 ~econds is detected, the method proceed to step 57 and veri~ies if the calling party speaks to the called party and if not, the meth~d proceed to step 5~ to determine if the called party has spoken.

~ 30 In step 58, if the called party does not speakl in :

WO g~ P~r/VS92/~ 2 -21~ 5 ~ ~

step 59, ~he method will verify if a predetermined time period of, f or example , ~0 seconds , has expixed in which no one has ~;poken and if so, th~ method proceeds to step D and disconnects t:he call. However, if audio activity 5 i~: detected prior to the expiration of this predete~irled period t the slethod proceeds back to step 57 to ~;ee if the calling party speaks.

In step S~, if the called party has ~poken, the m~thod proceeds to tep 56 and will again check if a 0. 5 ~0 sec:ond pau~e has oc:curred. In ~tep 56 if, after the e~piration of a predetermined perio~ of, for example 10 seconds, the method proceeds to step D in step 66 and diss::onnects the call. In step 57, if t~e calling par~y ~peaks to the calle~ party, the m2thod proceeds t~ step 15 6~ to chsck to see if a tone ha~; b~en receiv~d ba lc as will be more fully des ::ribed hereinafter with particular reference to Figure 4.

the tone has been received back the method proae~ds to step 61 and waits 6 seconds beiEore proc:eeding 20 ~to~ step 62 to check to ~;ee if a disconnect has occurred.
::: :: In: s~ep 63 i~ a di~;connec:t has occurred, no charge is ~ade. In stsp S0, if the tone ha~; not bee~a received back, the method waits 10 seconds ir tep 64 before checking, in step ~2, ~or a dis onnect. Tn step 65, if 2~5~ ~no~di is:onnect has occurred, the method starts to charge in st~ip 65.

1 i ~ ~ , ' I ; ~
Referring to Fi~re 4, the tone answer supervision method is illustratèd. In step 1, a dete~mination is :
: ~ : miade, u-~ing the sequential audio activity ~upervision, to 3 0 det~rmirle if vc~ic:e activity has already been dete ::ted and if audio activity is detected, a flag is, preferably, set WO 92/19066 P~/US92/~2~02 21~58:~ -22-to indicate that an audio received back status has b en set. ~f no voice ac~ivity is detected, a 2 . l KHz tone is transmitted ~very 2 seconds in step 2 and the method c:he~ks if the tone is r~ceived back in step 3. If the 5 tone is received back, that indicates that the currellt loop ha~ been clo~Qd and the method proceeds tc~ turn of f the ~oner generator in ~;tep 4 and set the tone received back ~;tatus in step 5. If audio activity was detected bQfore the tone was rec~ived back, the presence of the 0 audio detected ~:tatus, i.e., ~he presenc:e of the flag set in step 1, is determined in step lO, and in step ll a f lag is set to indic:ate that the call has been answered and conf irmed by tone back detection only l. The method ~ will then jump to step 65 tFîgure 3E) as indic:ated by the 15 symbol E in step l2 of Figure 4.

;; : If no tone is received baclc in tep 3 ~ the mathod proc~eds to ~;t~p 6 and r~transmits the tone f or one second whic:h il; turned of f at the end of the 1 second period in ~;tep 7 . The method then waits f or 2 seconds in 20 ~ step 8 before proceeding back to step 1 to r~tran~:mit the ton~. If acltivity iæ: detected in step l, then, in step a no tone received back f lag is set and unless a tone rsceiYed bach and detected, tha method ~xits tone answer supervision.

:: ~ 25 ~
The following is a first example on how the answer ~;upervision would interpret a ring baok tone (U. S. 2 sec.
on~ 4 sec. off) followed by a busy tone (.5 sec on/off).
: ~ Although a signalling change occurs during the sequence, 3 û the answer cupervision method is able to adapt and provide the proper status. The sec:ond example shows how a foreign country signalling plan will be interpreted by WO92/1~ ~ ~CTJUS~2/~2802 - 2 ~

the answer s~per~ision. The second seguence represents a call placed in the country of Malta ~h~re the ring back tone has a cadence of o 22~ sec. on, .525 sec. off, .4 sec. on, and .3 sec off. After ringing a couple of times, he call has been answered therefore the answer ~upervi~ion is triggered.

. ~ , i; : :

-~: :

WO9~/19~66 PCT/US~2/Q2802 2 1~5 8 24 irst ~xample ON 2 2 2 2 2 2 .5 ~5 .5 5 STEP A ~ R CK5 ¦¦ 5 7 - 8 ING BA I - BUSY
STEP A- The firæt signal will always be ignored~

5~EP 1- Timer 1=2 sec.

10 ST~P 2- Timer 2=2 sec.

; : STEP 3- Timar 3=2 ~ecO, Compare Timer 3 with Timer 1, they are the same.

ST~P 4- Timer 3=2 sec.; Compare Timer 3 with Timer 1, they are the same 15~STEP 5- Timer 3=2 sec.; Co~pare Timer 3 with Timer 1, they are th same:

STEP:6-:Timer 3=.5~sec.; Compare Timer 3 with Timer 1, they are not the same Csmpare Timer 3 with Timer 2, they are not the 20 ~ : ama ~: ~
S~v~ Timer 3 in Timer 1 Timer 1=.~ sec.
, Timer 2=2 sec.

~: STEP 7- Timer 3=O5 Gec.; C~mpare Timer 3 with Timer 1, ~:::
::

~VO g2/~9066 PC~/US92/02~02 -25- 2 ~ 5 ~J) l they are the same STEP 8- Timer 3-. 5 ~ec.; Compare Timer 3 with Timer 1, they are the ~ame The ~ystem will continue ehecki~g the l;ame ~;equenc and it 5 will be assumed khat the call has not been answered.

Second Exam~le Call to ~qalta - Rinsl Back Followed By Voice ON ~ . 4 . ~ 2 5 . 4 . 225 ~ 1 12 . 3 : : OYF' . 525 . 35 525 35 525 ........ . 3 ~ 6 . 8 ; ¦ _R C~--~ 'VO E~
ING BA IS:~
`15 ~
:STEP 1- Timer 1=. 4 ses~.
:, :STEP 2- Timer =. 225 ~ec.

STEP~3- Timer 3=. 4 sec.; Compare Timer 3 with Timer 1 J
they are the same 20 :STEP ~4-~ Timer 3=.225~sec.; Compare Timer 3 with Timer 1, y are not~ the same Compare Timer 3 with Timer 2, they are $he same The $ystem will continue checking the ~ame sequence a~;suming that the call has not been answered. When the 25 ~ call~ed party answers the call, (53 the ~ollowing sequence will be followed.

STEP 5- Timer 3=. l sec.; Compare Timer 3 with Timer 1 , ,~ ~

~:: :

WO 92/190~ PCr/lJS92tO2802 21~'31 they ~re not the ~;am~.

Compare Timer 3 with Timer 2, they are not the same .

Timer 3 will be aved in Timar 1.

5 Timer 1=.1 sec.

Timer 2=. 225 sec.

STEP 6- Timer 3--. 12 sec., Compare Timer 3 with Timer 1, they are no~ the -~ame.

Cs~mpare Tim~r 3 with Timar 2 t they are not the ; 10 ~am~. :

: The Timer 3 will be saved in Tilaer 2 .

~er l=. 1 S8~

: Timer 2=.12 ~;ec.

STEP: 7- Timer ~3-.3 sec., Co~pare Timer 3 with Timer 1, 15 ~ th~y are no~ the same.

Compare Timer 3 with Timer 2 I they are not the :~ :
~ ~ : same.

, The system detects that the call has been answered.

Figure 5 illu~trates one erabs: diment of an 2 0 appara~us f or perf orming the above described answer supervision of the method of the pr~sent invention. The , WO92/1~66 PCT/US92~02802 -2~ 5~ 5 apparatus, generally indicated at 12, comprises a CPU 1 which is appropriately programmed to perform the above described method ~teps. Connected to the CPU 14 is a tone generator 16, which is activated by the CPU 14 to generate the 2,100 ~z tone employed by the tone answër super~ision, the tone generator 16 being connected tc a trans~it line 18 of a telephone (not shown). A tone detector i proYided to detect the return of the transmitted tone, the tone detector being connected to the receive line ~2 o~ the telephone (not sho~n) as well as the CPU 14.
:~
: ~ tran~mit line audio signal detector 24 is provided ~or detecting audio activity on the transmit;
li~e 18, and a r~cei~e line audio signal detector 26 is provid~d ~or detecting audio ac~ivity on the receiv~ line 22, each o~ th~ audio detector~ 24, 26 being connected to the ~PU 14. Al~o~connected to the CP~ 14 are a high timer 28 for ~easur;ing the duration of audio activity detected on eith~r the transmit or receive lin~s 18, 22 ;20~ as~well as a low ti~e~ 30 ~or measuring ~he duration of no~audio activity on lines 1~, 22. A memory ~torage ar~a~gement, genera~lly indicated at 32, is connected to `: the~PU 14 and include~ a first register 32 A, or the like, for storing ~first timer duration measurement, a 25 ~eoond regis~er 32 B,~ or the like, for storing a ~econd im~r ~uration measurement, and a third register 32 C, or the likF, ~or storing a third timer~duration measurem~nt.

, Because it is essential that an autonomous pay telephone arrangement correctly recognize the answering of a call, the call answer supervision method and apparatus described above, which can be universally applied to any telephone, mobile or otherwise, for use in ~:

WO92~1~K~ PCT/US92/0~02 ~8~8~ -28-answer supervision to detect the completion of local, national, and international ~alls routed through different communication media, are envisioned for use with the autonomous pay telephone arrangement to be S d~scribed in detail hereinafter with particular reference to Figure 6.

:
~: Figure 6 illustrates one embodiment of the autonomous pay telephone arrangement of the present invention, generally indica ed at ll~ as applied to a ~obile telephone generally indicated at 13. In this ; particular embodiment of the pre~ent invention, the autonomous pay telephone arrangement ll is adapted to be ~ ~: retrofitted to any st~ndard mobile telephone arrangemqnt.
; ~H~weve~, it should~be understood that the au~ono~ous pay 15~ telephone arrangement of the present invention can be eas1:1y incorporated into~any tal~phone, mobile or otherwisè, durin~its manufacture so as to areate a dedic~ted 6tand:~alone,~:pay telephone. Depending on the needs~;of~the~wner of such ~ dedicated~stand alone pay 20~ telephone,~programming:of call superv~sion can be ta:~ ored~as needed,~such a-~, for example, to require p ~ ent~in~advance~of~call placement, or a~terwards, as discussèd~:hereinafter~

A mobile telephone, as used herein, is defined 25~ as;a~communication tevice:for ~epr~ducing sounds at a d~stance~whi~h is~capable of being~moved, such as, for eYa~ple ~ a cellular telephone, a radio telephone and other co~munication devices for communicating with telephones con~ected~:to landlines and/or ~ther mobile : 30~;te~1ephones, qnd has ~ source of power which pe ~ its a su~stantially unrestricted transport of the~mobile telephone, such:a , for example, a portable:batt~ry or -~ .

W~ 92/19066 PCr/US92J0280?

~1~8~

the likeO Stationary telephone, a~; used hereinafter, is a device f or reproducing sounds at a dist~nce, ~pecif ically one ~rhich converts ound into electrical impulses f or transmission over tel~phone wires, which due 5 to its direct conn~c:tion to the telephone wires, lack of a mobile power ~;ource, or for any other re son, ic fixad at a given station.

The arrangement 11 includes an appropriately programmed C~?U control board 9 contained in, f or example, 10 a cabinet 15, the CPU control ~oard 9 being conn~cted to : ~ a display 17, a transaeiver 19 of the mobil~ phone 13, a hand-set 21 of the mobile telephone 13 a~: well a to a : power sc~urc:e (not shown) via a power cable 23. The conn~c:l;iorl of the CPU c:on~rol board 9 ~Q the mobile 15 tella~hone ~3 is acco~plish~d via a c:ommunication cont:rol circuit ~(not :~;ho~ omprising dedicated ~ardware and software, a~ i known in the art, ~hich permits the tran mi~ion and receipt of control ~ignal~; betwe~n l:he ar~ange~ent 11 and ~he ~;pecific mobile ~elephone ~3 using:, for example,~a parallel cable 5. Preferably, the di~play 17 has, for sxample, an LED d}splay as w~ll as a coun~er and driver.

The CPU control board 9 is provided with a c~mpu er access port 25 ~or connecting the CPU control board 9 to a p:luggable outboard PC co~puter which per~its, through use of various pass~ords, programming of all programmable parameters ~uch as bill rates and tariffs as well as appropriate access to charge and accounting informakion. Alternatively, programming of ~ 30 he arrangement 11 can be performed via the keypad oX the : telephone hand~set 21 and ehe LED display of dlsplay 17.

:

WOg2/1~66 PCT/~S92/~2 21~8~ -30- ~

When the arrangement 11 is applied to a mobile telephona located in a land ba ed vehicle, such as, ~or example, a taxi rental car or bus, the power ~ource comprises a standard 12 volt DC battery. The displ~y 17 includes both a reset button 27 as well a~ a set button 29. Wh~n the display 17 is an LED display, high vi~ibility is provi~d for reading both during day and night. Additionally, the reset button 27 returns the ~: readout of the display 17 to its default di~play of 000.00 wh~n depr2sssd. If the reset button 27 is not depressed t it will continue ~o add to the cost of the pr~ious call,~allowing ~or computation of the total ~: amount of ~uccessive calls made by a single u~er.

Th~ CPU control board 9 iB conn~cted to a ~tatic 15~ ra~dom access ~e~ory (RAM) 31 which i~ prot~cted by a ; : back up battery 33 to prevent loss of stored information in~:the event o~a power outage. The memory 31 stores ; bil~ling~rate :or services to be provided, such a~ local and~long di~tance rate charges, incoming and outgoing 2~0~ p~echargec, tariff:~,~ mark-ups and th~ like as well as a~counting in~ormation for ~ervices provided.

A ~tack of, for example, four ~emory locations ar~pr w ided by the:memory 31 for storing accounting inf~rmation. TAese:four memory locations include: 1) 2;5~: tota~1 a~ount accumulated sincP the last system reset, i:.e~O,~the s~m of~all the current periodæ, 2) last current : period, 3) curr~nt:period, i.e., this is the current period ~ince` period reset ~sum of all current ri~es for a given working shift), and 4~ total for the current ride 30 ~:which includes the sum of all charges since the counter reset, the current ride being defined as the total displayed on the display.

:

WO~2J19~66 PCTJUS92~02802 -31- ZL~ 3 ~ S ~

Thus~ the a~counting information stored ~y the internal m~mory 31 in~ludes the total amount of money charged by the arrangement ll since its last internal reset, which is don~, for example, via the portable c~mputer connected to port 25 or from the hand-set 21 using special commands. This allows the owner of the autonomous pay telephone arrang~ment 11 to have an exact total of the money collect~d by the driver of, for example a taxi or bus, a~ ~he end of 2ach shift.
~oreQver, the total a~ount stored in the memory 3~ is proteated from unauthorized resetting by using appropriate security passwords.

The various pa.sword levels permit the authorized u~er to ha~e access to read data,-change data or perfor~ optionæ. According to the specific level of the pa~sword provided, the u~er will be able to change pa~swords, ch~nge tari~, precharges and charges, assign or unassign a particular autonomous pay telephone arranl~ement 11 to a particular transceiver 19 80 that the 20~ rangement will work only with its assigned transceiver , : to~ preYen~ un~uthoriz~d use, reset the system, examine : money account accumulation, program mark-ups and perform pr~grammable options as pr~vided.

: Options which can be provided by suîtably Z5~programming the CPU~control board 9 include inc~ming call :enable which will enable or disenable incoming call~ as he operator deems necessary. In thi~ regard, i~ the I : incoming ca~l feature of the arran~ement 11 has been ~:~disenabled, the transceiver 19 will be turned off upon :: ~ 30 r~ceipt of an unauthorized incoming call. Further optisns include charge call enable which will enable or ~ disenable the money charge for incoming calls if the : `

WO92/1~K~ PCT~US92/02802 21~'a$1 -32- ~

incoming call enable has been activatedO In this r~gard9 a pu~h to charge b~tton (29) is provided which enables the incoming call charg if the operator n~eds to screen the incoming calls before deciding whether or not to charge his customer.

Additionally, the arrangement ll can be programmed t~ allow the operator to input a total of, for example, lO no charge nu~b~rs, outgoing only, ~uch as for example, emergency telephone numbers or work ralated ~0 t~l~phone~num~er~ ~dditionalIy, call re~triatîon can be provided to restrict lo al, long-distance, international, operatQd as isted calls or calls by the central office identification or NNX aode. The country of operator's dialing plan can al~o be preprogrammed ~o ~hat the arrangemen~ ~1 can be taken ~rom country to country to opsrate locally. In this:regard, local and long distance ra~e:tableo are downloaded fro~ the ext.rnal co~put~r via port:2S ~o ~ha~ the arrangement ll will accurately aal~uIate charges accvrding to the local rate table 0 ~conf:iguration. Also included in the billing scheme is a ro~ing fee which can be altered to conform to the area'~
r~ami~g requir~ents.

he CPU ontrol board 9 is also preferable progr3m~ed ~o that~the arrangement ll cons~antly ~erifies 25~ma~ory circuits t~ certify normal operation. Any ~alfunct:ion~de~ected will cause the unit to cease to ~:~ opera~e and a malfunction message w~ll appear at the : hand set. ' ~ :
::
~ Thus, in~the preferred embodiment, the ::
arrangement ll is a software controlled, full feature m~ile phone add on which includPs a metering davice for worldwide use which shows, in local currency, the amount , ~, :~ :
: ~

WO 92/lg~66 PCr~US92/02802 -33~ 2~ ~8'~

of money due to the owner or operator of the autonomous pay t~lephone arrangement for callE; ~ade from 1:he mobile phone 13 attached to the arrangement ii. It is designed to meter calls whic:h may be local, longdistanc~, 5 international, incoming or outgoing.

This equipment allows the owners and u ers of mobile telephones, suc:h as for example, cellular t~lephones, to monitor the ~:o~;t of calls placed or received, in a real t~e basisO ~he owner or uE;er does 10 not have to wait until the call i8 completed or until the bill comes in a mvnth later ~o f ind out how much the cost of the call wa~.

The ~rrangement 11 i8 easy to use and requires ~; no driYer interference or as~istance. In the ca~e of a 15 taxi, 1:he hand6et i8 installed in the back of the front eat to allow ~asy acc~s~; by the pas enger~ A s~cond hand-~et can al~:o be installed n~ o the pas~:enger ;~ at . ~rhe need sati~f ied by the autonomous pay t~lephone arrangement 11 i8 the ability to communicate at all 0 tim¢~. The pa~eng~r who arrives at th~: airport and wan~ to Gall the office or the person:who is late to an appoint~ent can use th~ autonomou~ pay telephone arr ng~m~nt to càll ahead. Also, ~he person:who rent~ a : Gar and n~ads to ma~e a call can also use thi~ unit if so :
~ 5 proYid~d by ~h~ r~ntal~company.

; Th~ particular problem that the autonamou~ pay telephone 11 overcomes is the method of metering the call and providing an indic~tion of how much is owed immediately. Thi~ is particularly important to the taxi driver who may never see the rider again. Money is collected in cash, another advantage to the taxi owner W~g~ K6 P~T/VS9~/0~802 2 1 0 8 5 8 ~ ~34~

and can be u~ed by anyone that rides a taxi and has the required cash on hand 80 a~ to eliminate the need for credit cards or a particular debit or calling card.

By being able to control the tariffs, i.e., charges, ~he taxi owner or pay telephone owner provider can e~tablish the de~ired mark-up without ha~ing to depend on othersu Further, the static memory 31 provides ~or a method of maintaining accounting information ~hat ~et~ the particular n~eds for auditing taxi ride money coll~cted related t~ the use of the autonomous pay telephone arrang~ment 11.

In the cas~ of rental cars, the use of the autonomous pay telephon~ arrangement ll permits immediate ~iGing o~ c~ ~ade on a real-time basis. Thi~ is ;: 15 advantag~ous :to th~ person renting the car ince such calls are nor~ally made at a premium and by knowing how much h~ has been charged prior to returning the call there will be no dispu~es relating to the rental billo : : :
:`: In:opera~ion, to generate an outgoing call, the tel ~ one n~mber is dial2d from the hand-set 21, and the 8end button 29 is depre sed to generate a ~end signal.
herea~ert ~he autonomous pay ~elephone arrangem~n~ 11 valida~es the number~and assign~ the appropriate rate eharge in accordance with charge data stored in the 25~ memory 31. Rfter confirmation that the call has been an wered, in accordance with the unigu2 and novel call answer supervision method to be descri~ed in detail : hereinafter, the autonomous pay telephone arrangement 11 starts to send the:charges to the di~play 17 until the c~lled party or thé calling party ends the call. The number called, the time and date, total charge and other , , WOg2/1gO66 PCT/U~92/0~802 3 ~

d~sired parameters are saved in the memory 31 for reference in ~ memory updating process conducted upon completion of the outgoing call.

When the autonomous pay telephone arrangement 11 det~cts an incoming call, the CPU control board 9 refers to the ~emory 31 to determine if incoming ca}ls are allowed. If incoming calls are ~ot allowed, the autonomous pay telephone arrangement ll turns off the tran~ceiver 19~ Ho~ever, if incoming calls are permitted, the arrange~ent ll waits until the call is answered and thereafter, immediately starts to charge for the call upon an~wering or al~ernatively, when a pu~h to charge button 29 is depressed, so that the operator of the autono~ous pay telephone arrangement can determina if 15: char~ or ~he call ~hould be accessed. As with outgoin~ call~, ~pon completion of each of the inco~ing ~, c~ll , to~al charges for each of the incoming call$ are al80 sav~d ~or ~urth~r reference during a memory updating process conducted~upon completion of the incoming càll.

20~ he~autonomous pay telephone arrangement can be pro~ided options for operation with any type of full duplex conventional:and trunked radios, and radio telepho~e transceiv rs including cellular transceivers compatible with ~he cellular format such a~: ~MPS, NNT
25: 450, ~MT 900,~ TACS, ETACS as well as with options for interpreting the tariffing signals, in the aase of ~ome NM~ æystems and in E-TACS systems, normally sent by the : mobile telephone switch (MTX) applying the corresponding call rate charge.: In this regard, the AMPS cellular protocol does not con emplate any signalling from the MTX
to the cellular telephone for either answer ~uper~ision or tariffing purposes. Due to ~his, the answer WOg2/190~ P~T/US92/02802 21~8~
supervision method of the present invention is preferrPd for use with the autonomous pay telephone. In the case of NMT protocol, it contemplates in its specification the possibility of incorporating a known answer supervision and tariffing scheme called ~l, Ql which utilizes Fast Frequency Shift Key (FFSK~. However, in most countries, this feature i8 not activated and the NMT ~ystem i~ ~hus the same as the AMPS as discussed above. The TACS
systems do not employ such a siynalling scheme. The 10 ~-TACS system~ e~loy an wer supervision and tariffing signàling to the mobi1e:unit as a ~tandard feature.

: Thus, when th MTX ~ends an answer ~upervision signal and/or tariffing ~ignal(s), then the answer supervision of the present invention i~ no' r~quired and the;standard means for de~ecting these answer supervision signal and/or tarif~ing:signal(s) is employed. The : : autonomou~ pay te1ephone of the pr~sent invention would hen d~t~ct such~ignals from the MTX and either comm~nce the~tari~fing based on a preset tariff table tif only 2Q ~answer supervision signaling is sen~) or interpret the tar~iff~ signals and ~pply the appropriate mark-up for thie : on-line~charge display (if tariff signals are sent).

Obviously, numerous modifications and variations o~f~:the~ present invention are possible in light of the 25~ above teachings. It i th~refore to be understood that within the scope~o~ the appended claims, the invention ~ay be practi ed otherwise than ~s specifically describe ~: above.

.

Claims (21)

Claims

1. A method for providing call answer supervision to determine if a call placed to a given telephone number has been answered by a called party at the given telephone number, the method comprising the steps of:
transmitting a tone of a given frequency on a transmit line of a telephone;
monitoring a receive line of the telephone to determine if the tone is received back on the receive line;
simultaneously monitoring the transmit and receive lines to determine the presence of other audio activity; and determining that the placed call has been answered if at least one of the following conditions occurs:
1) the tone of the given frequency is received back on the receive line; and 2) audio activity having a non-repetitive cadence is present on both the transmit and receive lines of the telephone.

2. A method according to Claim 1, wherein the tone has a frequency of about 2,100 Hz.

3. An apparatus for providing call answer supervision to determine if a call placed to a given telephone number has been answered by a called party at the given telephone number, the apparatus comprising:

tone generating means for transmitting a tone of a given frequency on a transmit line of a telephone;

tone detection means for monitoring a receive line of the telephone and for determining if the tone is received back on the receive line;

audio activity detection means for simultaneously monitoring the transmit and receive lines for the presence of other audio activity; and answer confirmation means for determining that the placed call has been answered if at least one of the following conditions occurs:

1) the tone of the given frequency is detected as received back on the receive line by the tone deflecting means; and 2) audio activity having a non-repetitive cadence is detected on both the transmit and receive lines of the telephone by the cadence determining means.

4. An arrangement adapted to be connected to a mobile full duplex radio including handset means for placing and receiving a telephone call and transceiver means coupled to said handset means via a communication line for processing calls placed and received by said handset means, for providing a mobile autonomous pay telephone, comprising:

a memory for storing charge information including at least outgoing call rate information for setting a rate to be charged, per unit of time, for an outgoing call to a given telephone number;

charging determining means adapted to be coupled to said communication line for receiving the telephone given number and for determining a charge for the call based on at least the rate to be charged for the outgoing call placed to the given number from at least the outgoing call rate information stored in the memory;

metering means for accessing, in real-time, as a call progresses, the charge for the call as determined by the charge determining means utilizing at least the outgoing call rate information; and display means for displaying, in real-time as the call progresses, charges accessed by the metering means for the call placed to the given telephone number.

5. An arrangement according to Claim 4, further comprising a call answer supervision means for determining when a call has been answered by a called party.

6. An arrangement according to Claim 5, wherein the metering means includes means for accessing the charges for the call only if the call answer supervision means determines that the call has been answered by the called party.

7. An arrangement according to Claim 5, wherein the call answer supervision means comprises:

tone generating means for transmitting a tone of a given frequency on a transmit line of a telephone;

tone detection means for monitoring a receive line of the telephone and for determining if the tone is received back on the receive line;

audio activity detection means for simultaneously monitoring the transmit and receive lines for the presence of other audio activity;

cadence determining means for determining if the other audio activity, present on at least one of the transmit and receive lines, has a repetitive cadence;
and answer confirmation means for determining that the placed call has been answered if at least one of the following conditions occurs:

1) the tone of the given frequency is detected as received back on the receive line by the tone detecting means; and 2) audio activity having a non-repetitive cadence is detected both on the transmit and receive lines of the telephone by the cadence determining means.

8. An arrangement according to Claim 7, wherein the cadence determining means comprises detection means for detecting a repetitive cadence on the receive line to indicate that the call is being processed and for detecting a nonrepetitive cadence in both the transmit and receive lines to confirm that the call has been answered.

9. An arrangement according to Claim 4, further comprising accounting means for storing, in the memory, accounting information including at least a total charge accessed by the metering means for each completed telephone call.

10. An arrangement according to Claim 9, further comprising an output port means for outputting the accounting information, from the memory, including the total charge accessed by the metering means for each completed telephone call.

11. An arrangement according to Claim 10, wherein the accounting means includes means for storing the total charges assessed by the metering means for each completed telephone call for a given period of time.

12. An arrangement according to Claim 4, further comprising input port means for inputting, to the memory, the charge information for storage in the memory.

13. An arrangement according to Claim 4, further comprising interface means for interfacing the arrangement with a mobile telephone.

14. An arrangement according to Claim 4, wherein the charge information stored in the memory further includes at least an incoming call rate for setting charges to be accessed for incoming calls received and wherein the charging determining further includes means for determining the rate to be charge for a received incoming call from the incoming call rate information stored in the memory.

15. An arrangement according to Claim 14, wherein the charge information stored in the memory further includes tariff information for tariffs to be charged for at least one of outgoing and incoming telephone calls and mark-up information for accessing a mark-up for the outgoing and incoming call rate and wherein the charge determining means further determines the charge for a completed telephone call based on the tariff information and the mark-up information.

16. An arrangement according to Claim 4, wherein the display means is an light emitting diode display.

17. An arrangement according to Claim 4, further including a reset means for resetting the display means.

18. An arrangement according to Claim 4, wherein the memory means is a random access memory.

19. An arrangement according to Claim 17, further comprising a back-up battery for maintain the charge information and accounting information in the memory in the event of a power outage.

20. An arrangement according to Claim 4, further comprising means for supplying power to the arrangement from a 12 volt battery.

21. A mobile autonomous pay telephone set including:
mobile full duplex radio means for communicating with a distant party via radio waves, comprising, handset means for placing and receiving a telephone call, and transceiver means coupled to said handset means via a communication line for processing calls placed and received by said handset means;

a memory for storing charge information including at least outgoing call rate information for setting a rate to be charged, per unit of time, for an outgoing call to a given telephone number;

charging determining means coupled to said communication line for receiving the telephone given number and for determining a charge for the call based on at least the rate to be charged for the outgoing call placed to the given number from at least the outgoing call rate information stored in the memory;

metering means for accessing, in real-time, as a call progresses, the charge for the call as determined by the charge determining means utilizing at least the outgoing call rate information, and display means for displaying, in real-time as the call progresses, charges accessed by the metering means for the call placed to the given telephone number.