CA2235977A1 - Selective call waiting disable service feature for analog telephone equipment - Google Patents

Abstract

A selective call waiting disable (SCWD) service feature allows incoming data transmission over a POTS line to disable the call waiting "tones" which cause data errors and sometimes loss of connections. The originator of the incoming call must be authorized by the called party to prevent unauthorized persons from monopolizing a person's line without some protection. This SCWD feature allows data transmissions for software updates, small business data exchanges and facsimile page data, among others, to be accomplished without call waiting tones corrupting data or causing loss of synchronization and connection. SCWD can even use transmission data availableto the call originator to advise a subsequent caller when the called party's line will be available for other incoming calls.

Description

. CA 0223S977 1998-04-27 SELECTIVE CALL WAITING DISABLE SERVICE FEATURE
FOR ANALOG TELEPHONE EQUIPMENT

Field of the Invention s The invention relates to a method and apparatus for providing telephone service features for analog telephones and more particularly to a method and appaldl~ls for providing a selective call waiting service feature.
Background Call waiting is a well know service feature that gives an analog telephone user o th~e capability of being notified during a current telephone call if a further telephone call is being attempted to the user's number. Referring to telecommunication arrangement 100, as shown in Fig. 1, the calling station 101 attempts a call while the called station 109 is presently in the midst of another call, for example with station 103 or 1 1 1. This call attempt from calling station 101 is transmitted through switch 104, network 106, such as the public switched telecommunications network, to switch 108. Switches 104 and 108 may be any telephone switches of the type that providecall features such as call waiting, such as a 5ESS-2000(~) by Lucent Technologies Incorporated located in Murray Hill, New Jersey.
Connected to switch 108 on a shared analog line are station 109 and data station 1 10. The switch 108 provides the standard call waiting feature for stations 109 and 110. In response to the call attempt from station 101, both the stations 109 and 110 are notified of the dllelllpl~d incoming call by means of a subtle tone that is audible to a human using a handset of station 109, or a similar device. This tone is inlçnt1s~1 to notify the party using station 109 of an incoming call without interrupting the call-in-progress with another party using another station, e.g. 103 or 1 1 1. The non-called party of the call-in-progress is not notified by the tone in the same way that the party using station 109 or 1 10 is notified; however, the blocking by switch 108 of the tone to the non-called party leaves a subtle, often noticeable signal drop out during the conversation.
This standard call waiting service feature is popular because it provides a party using analog telephone station 109 the equivalent of two line service with only one analog line. The main problem to human users is that the notification tones or beeps, which may or may not be distracting during on-going conversations. In some service areas a tone sequence prefix code, for ex~mp!e *70, c,ln be entered by the user of station 109 or 110 before an outgoing telephone call to disable the call waiting service feature; however, there is no similar prefix code sequence to disable call waiting by an incoming call. Additionally, in some areas, the call waiting service feature provider CA 0223~977 1998-04-27 E. Duesing 2-2 2 has not implemented a call waiting disable for the call waiting feature by the user.
Thus, for incoming calls and in some areas all calls cannot have the standard call waiting service feature disabled wilhout completely dropping call waiting as a service feature.
One known approach to disabling the call waiting is taken in U.S. Patent Number 5,359,598 issued to Steagall et al. in a non-POTS setting in which a conference call set-up packet disab]es call waiting at the voice processor of the called party. The purpose of disabling the call waiting in Steagall et al. is the conclusion that a conference call within the special system is a higher priority than any subsequent 0 call. When the conference call is over, the voice processor returns the call waiting feature to its previous active status. This patent focuses on making digital signal tr~n~mi~sion and digital voice processing transparent to the users, so its focus is clearly limited to the disabling of call waiting for voice conference calls.
For incoming data tr~n~mi~sions on an analog line, where users either cannot s disable call waiting or where the service provider does not allow any disabling of call waiting, a tr~n~mi~ion, for example from data station 102 to data station 110, can be cc~rrupted and/or interrupted by the standard call waiting feature. The standard 250 millisecond call waiting tones which are injected into the user's receiving circuit corrupt the frequency shift keying and phase shift keying signals transmitted to the user's data equipment, such as a modem or a facsimile m~hine. Similarly, the 250milli~econd blanking which is mearlt to prevent the other party or parties to a conversation from hearing the call waiting tones corrupts any data from the user's data equipment back to the remote data equipment. Such data corruption caused by the call waiting tones leads to loss of data synchronization and file corruption. If the loss of synchronization becomes so large that recovery is not possible, most modems and facsimile machines will drop the connection completely leading to both a corruption of' data and an interrupted and incornplete data transfer. Both results are veryundesirable.
Sllmmarg of the Invention Briefly stated, in accordance with one aspect of the invention, the foregoing problems are solved by providing a method which includes receiving at a call waiting feature providing switch a call incoming to a subscriber, determining if the selective ca.ll waiting disable feature is active for this subscriber and if it is not active continuing with normal call processing and setting-up the incoming call, otherwise 3s determining if a directory number of this incoming call is on a list of selective call waiting disable directory numbers. If the directory number of the incoming call is not on the list of selective call waiting disable directory numbers the method continues CA 0223~977 1998-04-27 E. Duesing 2-2 3 with normal call processing and sets-up the incoming call, otherwise the method disables call waiting and then continues with normal call processing and sets-up the incoming call.
In accordance with another aspect of the invention, the foregoing problems are s solved by providing a method which includes sending to a call waiting featureproviding switch a call incoming to a selective call waiting disable subscriber having a selective call waiting disable prefix code and an identification code, determining if selective call waiting disable is active and if it is not active continlling with normal call processing and setting-up of the incoming call, otherwise determining if the call o has a prefix code. If the call does not have a prefix code, the method continues with normal call processing and sets-up the incoming call, and if it does have a prefix code, the method determines if an identification number of the incoming call is on a list of selective call waiting disable identification numbers. If the identification number is not on this list of selective call waiting disable identification numbers the method 15 continues with normal call processing and sets-up the incoming call, otherwise the method disables call waiting; and continues with normal call processing and sets-up the incoming call.
Fig. 1 is a block diagram of a prior art telepl-~, ne arrangement for providing standard call waiting features to its .~tt~çhP~l subscribers.
Fig. 2 is a block diagram of a telephone arrangement for providing selective call waiting disable service features according to the present invention to its attached subscribers.
Fig. 3 is a flow diagram of one embodiment of a selective call waiting disable service feature.
Fig. 4 is a flow diagram of a second embodiment of a selective call waiting disable service feature.
Fig. 5 is a flow diagram of a third embodiment of a selective call waiting se-rvice feature.
DetailedD~s~ ;l.lion Referring now to Fig. 2, an arrangement 100' is shown. The primary difference between arrangement 100' and arrangement 100' shown in Fig. 1 are theprogr~mmin~ and hardware changes to telephone switch 108' in order to provide pr,ocessing haldw~e and software to implement a method for providing a new call waiting feature called Selective Cal] Waiting Disable (SCWD).
3s Referring now to Figs. 2 and. 3, a flow diagram of a method 300 according to the present invention is explained. Method 300 starts with step 302 which is thereceipt of an incoming call to a directory number of a subscriber of switch 108' CA 0223~977 1998-04-27 E. Duesing 2-2 4 (shown in Fig. 2). From step 302, lhe incoming call progresses to step 304 where the mLethod determines whether the Selective Call Waiting Disable feature is active, i.e.
the subscriber has chosen this feature for his or her service, for the subscriber corresponding to this directory nurnber. If the subscriber to which the incoming call is directed has the SCWD feature activated, method 300 progresses to step 306 and if the subscriber does not have the SC~I) feature activated, method 300 progresses to default step 310. At step 306 method 300 determines if the directory number ofthe calling station from which the incoming call originated is on a list of directory mlmbers authorized by the subscriber to disable call waiting for the subscriber as 0 pl epaLLdlion for an incoming call to the subscriber. If the directory number of the calling station is on the list of directory numbers authorized to disable call waiting, method 300 progresses to step 308, otherwise the method 300 progresses to default step 310. The method 300 gets the directory number of the calling station from such sources as ANI data field of the incoming call or the ICLID field of the incoming call.
Sl:ep 308 disables the call waiting feature for the subscriber for the duration of the call which is from an authorized directory number and then progresses to default step 310.
Default step 310 is the beginning oi' normal POTS incoming call processing, which is where the incoming call will eventually progress to, if the caller does not hang-up prematurely. Beyond step 310, call processing is as it was previously implemented, 20 which includes resetting any call waLiting after being disabled upon termination of the call. Thus, normal call processing at this point includes resetting from any prefix code disabling or any SCWD disabling upon termination of the call.
Thus, method 300 allows calls from selected stations attached to selected lines having selected directory numbers to a disable call waiting of the subscriber to the 2s feature. It is envisioned that, at least in part, callers authorized to disable call waiting will be computers and f~imile machines attempting, and hopefully succee~ling, atuncorrupted data tr~n~mi.~ions. As mentioned previously, the call waiting 'beep' can caLuse data errors and/or loss of synchronization and a related loss of connection. One such situaLtion is when a call-back arrangement has been made between a user and a 30 dial-up server. When the server calls back, it would be very desirable that a call waiting feature of the user be disabled and therefore non-disruptive of the datatraLnsferred during a call-back data tr~n.cmi~sion session. Similarly, for a non-callback server which periodically dials up various user data stations to upgrade files or to transfer files, it would be similarly desirable that a call waiting feature of the user be 35 disabled and non-disruptive of the data transmitted during a computer origin~te~ data tr:ln~mi.~ion session.

CA 0223~977 1998-04-27 E. Duesing 2-2 5 Referring now to Fig. 4, a method 400 for SCWD according to another aspect oi-'the invention will be described. Method 400 starts with step 402 which is the receipt of an incoming call to a directory number of a subscriber of switch 108'(shown in Fig. 2). From step 402, the incoming call progresses to step 404 where the s method determines whether the Selective Call Waiting Disable feature is active, i.e.
whether the subscriber has chosen this feature for his or her service, for the subscriber corresponding to this directory number. If the subscriber to which the incoming call is directed has the SCWD feature activated, method 400 progresses to step 406 and if the subscriber does not have the SCWD feature activated, method 400 progresses to 0 default step 412. At step 406 method 400 determines if the incoming call contains a prefix code for disabling call waiting. If the incoming call does have such a prefix code, method 400 progresses to step 408, and if the incoming call does not have such a prefix code, method 400 progresses to default step 412. At step 408, method 400 determines if the incoming call contains an identification number which is on a list of identification numbers authorized by the subscriber to disable call waiting for that su.bscriber's stations 109,110 as ple~aldtion for the incoming call. If the identification mlmber, which is provided by the calling station, such as station 102, is on the list of identification numbers authorized to disable call waiting, method 400 progresses to step 410, otherwise the method 400 progresses to default step 412. The identification 20 number, such as a 'personal identification number', is sent by the calling station either as a separate field with the prefix code, or as an additional code. Further, thesubscriber pre-sets with switch 108' the list of identification numbers which he or she au,thorizes to disable call waiting. Step 410 disables the call waiting feature for the subscriber for the duration of the call and then progresses to default step 412. Default 2s step 412 is the beginning of normal POTS incoming call processing, which is where thle incoming call will eventually progress to, if the caller does not hang-up prematurely. Beyond step 412, call processing is as it was previously implemented, which includes resetting any call waiting that had been disabled. Thus, normal call proces~in~ at this point includes resetting from any prefix code disabling or any 30 SCWD disabling upon t~rmin~tion of the call.
Thus, method 400 allows calls from selected stations transmitting both SCWD
prefix codes and authorized identification numbers to a disable call waiting of the subscribers to disable their respective SCWD features. It is envisioned that, at least in part, calling stations, such as station 102, authorized to disable call waiting will be 35 computers attempting, and hopefully succee.ling, at data transmissions as mentioned in regard to method 300. Method 400 is more flexible than method 300 in that thesubscriber is not required to know the directory number of the caller. Instead, the CA 0223~977 1998-04-27 E,. Duesing 2-2 6 subscriber is only required to pre-set an identification number, thus allowing the caller who knows an SCWD prefix code and identification number the flexibility to move between directory numbers and hence locations.
For both methods 300 and 400 when call waiting has been disabled, a s subsequent incoming call attempted during the time period that call waiting is disabled will be routed to some type of 'busy' signal. Normally, this busy signal is the usual slow beep - beep - beep with which users are f~mili~r. Users that subscribe to the standard voice mail feature typically will be routed to an announcement that the line is busy and an aural proln~ting to leave voice mail or try again later at an unspecified o time. The try again later is a hit and miss operation since the caller can only guess when the phone line will be available again.
In another aspect of the invention, method 500 shown in Fig. 5 takes the guess work out of the when-to-try-again question of the caller receiving a busy signal.
Method 500 is especially useful since some data tr~n~mi~ions may be quite long, e.g.
for computer software updates or f~c~imi1e tr~n~miC;c;ions of 50 pages or more.
Method 500 has the capability to advise the subsequent caller, e.g., from station 111, of an expected time when the data tr~ncmi~sion call will be over and the line likely to be available. Method 500 does assume that time pal~llel~ such as start time, estimated length of tr~n.smi.csion and/or estim~ted end of tr~n~mi~ion time are sent to 20 the switch 108' (shown in Fig. 2) by the calling station 102. Such information may be tr;ansmitted in various ways. for example as a field of the prefix code that disables call waiting or as an additional prefix code. This time data can be estim~ted by the tr,~nsmitting station 102 by file size information and historical data transfer rates, and projected time-of-day start of data tr~n~mi.~sion to the station 110. From this time data 25 an estim~ted end of ll~1s~l time is computed and announced to a subsequent caller as part of the method 500. If the calling station sends the start time, data rate and file size data for computer tr~n~mi~.C ions or page data for fAccimile tr~nC;mic;.~ions~ then switch 108' can calculate an estimal:ed end of data tr~n.~mi~C;ion and availability of the line for subsequent incoming calls. Similarly, the calling station that disables call 30 waiting, e.g. station 102, can calculate an estim~tecl end of data tr~n~mi.csion and availability of the line for subsequent incoming calls and transmit that end time to s~;vitch 108', such that switch 108' can announce, i.e. advise, anyone who makes a call attempt during the data tr~n.cmi~sion of a good time to call back.
Specifically, method 500 st~rts with step 502 which is the receipt of an 35 incoming call to a directory number of a subscriber of switch 108' (shown in Fig. 2).
From step 502, the incoming call progresses to step 504 where the method determine whether the SCWD feature is active, i.e. the subscriber has chosen this feature for his CA 0223~977 1998-04-27 E. Duesing 2-2 7 or her service, for the subscriber colTesponding to this directory number. If the subscriber to which the incoming call is directed has the SCWD feature activated, method 500 progresses to step 506 ~md if the subscriber does not have the SCWD
feature activated, method 500 progresses to default step 516. At step 506 method 500 determines if the incoming call contains a prefix code for disabling call waiting. If the incoming call does have such a prefix code, method 500 progresses to step 508, and if thle incoming call does not have such a prefix code, method 500 progresses to default step 516. At step 508, method 500 determines if the incoming call contains an id,entification number which is on a list of identification numbers authorized by the o subscriber to disable call waiting for the subscriber as preparation for the incoming call. If the identification number, which is provided by the calling station, is on the list of identification numbers authorized to disable call waiting, method 500 progresses to step 510, otherwise the method 500 progresses to default step 516. The identification number, such as a 'personal identification number', is sent by the calling station either with the prefix code Ol as a separate field in addition to the prefix code.
Further, the subscriber pre-sets the list of identification numbers which he or she authorizes to disable call waiting. Step 510 disables the call waiting feature for the subscriber for the duration of the ca]l and then progresses to step 512. Step 512 determines if a time field that is either part of the prefix code or is a second prefix 20 code is greater than zero (which me~ms 00:00:00 as a midnight end point would have to be avoided by at least one second more or one second less). If the answer is yes, that means that end of tr~n~mi.c~ion data has been sent by the calling station, and the method 500 progresses to step 514, otherwise method 500 progresses to default step 516. Step 514 processes the end of tr~n.emi~ion data and plepal._s a 'busy' 25 announcement, and then the method 500 progresses to step 516. Step 516 continues with typical call processing except that any announcement made to a subsequent caller while call waiting is disabled by a data transmission providing end of tr~n~mi~sion data will include advice as to when lhe data tr~n.~mis.cion is likely to be over and when the line is likely to be available for incoming calls. Like methods 300 and 400, this 30 call processing by switch 108' includes resetting call waiting, any prefix fields stored in switch 108 ', and clearing any 'busy' signals or messages at the end of the data the incoming call.
Thus, it will now be understood that there has been disclosed a method and apparatus for a selective call waiting disable feature. While the invention has been 35 particularly illustrated and described with reference to preferred embodiments thereof, it ~,vill be understood by those skilled in the art that various changes in forrn, details, and applications. For example, the telephone switch may be sent file transfer duration E. Duesing 2-2 8 data instead of time-of-day data in order to prepare the callback later advice. Further, the local telephone switch could update the end of tr:ln.cmi.~sion time as it isrliimini~h~l It is accordingly intended that the appended claims shall cover all such changes in form, details and applications.

Claims (10)

1. A method comprising the steps of:
a. receiving at a call waiting feature providing switch a call incoming to a subscriber;
b. determining if selective call waiting disable is active for said subscriber and if it is not active jumping to step e, otherwise continuing to step c;
c. determining if a directory number of said incoming call is on a list of selective call waiting disable directory numbers and if it is not on said list of selective call waiting disable directory numbers jumping to step e, otherwise continuing to step d;
d. disabling call waiting; and e. continuing with normal call processing and setting-up of said incoming call.

2. A method according to claim 1, further comprising the step of:
if said incoming call is still underway and said call waiting is disabled, routing a subsequent incoming call to said subscriber to a busy signal.

3. A method according to claim 1, further comprising the step of:
if said incoming call is still underway and said call waiting is disabled, routing a subsequent incoming call to said selective call waiting disable subscriber to an announcement and a voice mail box for recording a message.

4. A method according to claim 1, further comprising the step of:
if said incoming call is completed, enabling call waiting upon termination of said call.

5. A method comprising the steps of:
a. sending to a call waiting feature providing switch a call incoming to a selective call waiting disable subscriber having a selective call waiting disable prefix code and an identification code;
b. determining if a selective call waiting disable feature is active and if it is not active jumping to step f, otherwise continuing to step c;
c. determining if said call has a prefix code and if it does not jumping to step f, otherwise continuing to step d;
d. determining if said identification number of said incoming call is on a list of selective call waiting disable identification numbers and if it is not on said list of selective call waiting disable identification numbers jumping to step f, otherwise continuing to step e;

e. disable call waiting; and f. continuing with normal call processing and setting-up of said incoming call.

6. A method according to claim 5, further comprising the step of:
if said incoming call is still underway and said call waiting is disabled, routing a subsequent incoming call to said subscriber to a busy signal.

7. A method according to claim 5, further comprising the step of:
if said incoming call is still underway and said call waiting is disabled, routing a subsequent incoming call to said selective call waiting disable subscriber to an announcement and a voice mail box for recording a message.

8. A method according to claim 5, further comprising the step of:
if said incoming call is completed, enabling call waiting upon termination of said call.

9. The method according to claim 5, further comprising the steps of:
transmitting end of transmission data to said switch as a part of said incoming call to provide advice to a subsequent caller who calls in while call waiting isdisabled; and advising a subsequent caller that calls in while call waiting is disabled when to when to try again.

10. An apparatus comprising:
means for receiving at a call waiting feature providing switch a call incoming to a subscriber;
means for determining if selective call waiting disable is active for said subscriber and if it is not active continuing with normal call processing, otherwise presenting a directory number of the calling station for a determination; and means for determining if the directory number of said incoming call is on a list of selective call waiting disable directory numbers and if it is not on said list of selective call waiting disable directory numbers continuing with normal call processing otherwise disabling call waiting; and then continuing with normal call processing and setting-up of said incoming call.