CA2126170A1

CA2126170A1 - Automatic call router

Info

Publication number: CA2126170A1
Application number: CA 2126170
Authority: CA
Inventors: Deborah L. Pinard
Original assignee: Mitel Corp
Current assignee: Microsemi Semiconductor ULC
Priority date: 1994-06-17
Filing date: 1994-06-17
Publication date: 1995-12-18
Also published as: GB2290434A; DE19521853A1; GB9511979D0

Abstract

A method of routing calls, comprised of storing, in association with a subscriber identification (I.D.), a call routing destination number associated with a forwarding time, receiving a call to the subscriber I.D. number, checking the time of the call, and in the event the time of the call is equal to or later than the forwarding time, completing the call to the call routing destination number.

Description

FIELD OF THE INVENTION
This invention relates to the field of telephony, and in particular to a method of call forwarding.
BACKGROUND TO THE INVENTION
Automatic call forwarding is a common feature offered in PABXs and by telephone companies today.
Typically a subscriber dials a prefix number followed by a forwarding number. The first number is an indicator to the telephone system that all future calls to the particular subscriber number dialing the code should be routed to the forwarding number. When the subscriber wants incoming calls to be restored to his normal number, a call forwarding cancelling code, or a forwarding code to the normal subscriber number must be entered.
When a subscriber is often at various locations during the day, such as in an office environment, it is easy to forget to update the call forwarding information stored by the PABX, and as a result, many calls are misrouted, ca~sing annoyance and wasted time of callers.
SUMMARY OF THE INVENTION
The present invention is a method for automatically routing calls wherein the subscriber can advise the telephone system where he will be during intervals during the day or week, and the telephone system automatically checks, for each incoming call, the time of the day and the number to which the call is to be completed, then completes the call to that number.
If no forwarding location or number has been indicated for a particular time interval, the incoming call is completed to the subscriber's normal line.
In order to advise the telephone system where to route calls during certain time intervals, it is preferred that a chart should be presented to the user, e.g. on a display, which is filled in by the user in the manner of a desk calendar or agenda. The user can fill in the time periods with a forwarding number, or preferably with a plain language location (e.g. lunch, meetingl, etc.) wherein the telephone system can look up the telephone line number corresponding to the plain language location previously allocated by the user or stored by the system for global use by all subscribers, and route the call to that number. If nothing is filled into the chart against a particular time interval, the system assumes that the call is to be completed to the subscriber's normal line.
In this manner the subscriber can fill in an agenda for the week, and calls will be automatically routed to the subscriber's location. The subscriber need not be concerned about entering a call forwarding number on a case by case basis, and the system will know automatically where the calls are to be routed to, and when the calls are to be routed to those various numbers including the subscriber's own line number.
Calls can be routed not only to other subscriber lines, but also to voice mail lines and telephone answering machines carrying various messages, pagers, wireless telephones, etc., to suit the needs of the subscribers. This routing can be done automatically as a result of the subscriber simply filling in an agenda with plain language entries on a display associated with his telephone.
In accordance with an embodiment of the invention, a method of routing calls is comprised of storing, in association with a subscriber identification (I.D.), such as a telephone number, name, etc. , a call routing destination number associated with a forwarding time, receiving a call to the subscriber I.D., checking the time of the call, and in the event the time of the 21~6170 ._ call is equal to or later than the forwarding time, completing the call to the call routing destination number.
The forwarding times referred to above are preferred to be time intervals, but can be a single future real time.
In accordance with another embodiment, the method further includes the steps of storing a sequence of call routing destination numbers each associated with a time, and in the event the call to the subscriber I.D.
is equal to or later than one of the times but prior to the beginning of another of the times, completing the call to a call routing destination number associated with the one of said times.
In accordance with another embodiment, the method includes storing the call routing destination numbers in association with destination names, displaying a time chart to a user, filling in the chart with at least one of the destination names at chart locations corresponding to times, looking up the stored destination names associated with the call routing destination numbers and storing the call routing destination numbers in substitution for the names with the times corresponding to the chart locations, and upon receiving the call to the subscriber number, retrieving an associated call routing destination number, and performing the checking and completing steps of the first-noted embodiment to a call routing destination number stored in association with a corresponding time.
BRIEF INTRODUCTION TO THE DRAWINGS
A better understanding of the invention will be obtained by reading the description of the invention below, with reference to the following drawings, in which:

Figu~-e 1 is a block diagram of a system in accordance with the prior art, Figure 2 is a block diagram of an embodiment of a system which can be used to implement the present invention, Figure 3 is a call forwarding chart, Figure 4 is a data entry chart, Figure 5 is a block diagram of another embodiment of a system which can be used to implement the present invention, and Figure 6 is a flow chart used to describe the operation of the system of Figure 5.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 illustrates a typical PABX telephone system in accordance with the prior art, such the one sold by Mitel Corporation as type SX2000, and as described in ~J.S. patents 4,615,028 issued September 30, 1986 and 4,616,360 issued October 7, 1986 and assigned to Mitel Corporation. Basically this system is comprised of a circuit switch 1 for switching calls between lines to telephones 3 and trunks 5 which terminate at line and trunk circuits (not shown) and which are routed to the circuit switch via a peripheral switch 7. Control message signals are switched to the peripheral switch via a message switch 9. Messages are passed between the message switch and a central processing unit (CPU) 11, and between the circuit switch and the CPU via bus 13. Programs for operating the CPU, and data stored during its operation are stored in random access memory (RAM) 15.
When a subscriber wishes to transfer a call, he goes offhook and dials a call transfer code (or depresses a button designating the same), followed by the number to which calls to his subscriber's line number are to be transferred. The call transfer code is s -received by the CPU which stores the following new number in the RAM 15 in a feature table normally looked up by the CPU whenever a call to a subscriber line terminated on the PABX is received. From then on, all calls to that subscriber line are routed to the line number entered by the subscriber.
In the SX2000 system, there is the facility of routing all incoming calls to the PABX to ring a particular single number or group of numbers during night hours, i.e. an automatic night line facility.
This requires that a PABX attendant, operating an attendant station 17 connected to the bus 13, set up the night line facility via the station 17 when the PABX is first installed and programmed.
The above system routes all incoming calls to fixedly designated lines, and cannot route incoming calls to particular subscriber numbers, to other numbers on a randomly chosen and on an as needed basis by various subscribers. The automatic call transfer can only be set up by an attendant station, which is not reasonably usable to obtain the objectives of the present invention.
Figure 2 is a block diagram of an embodiment of a system which may be used to implement the present invention. The elements which are common to the prior art system described with reference to Figure 1 have similar reference numerals.
A correlation table 19 is stored in a memory connected to the bus 13 which is accessible by the CPU
11. The correlation table maintains a correlation of subscriber identifications, an example being referred to below as line numbers 21, against pointers 23 to a forwarding table 25-25N (e.g. forwarding table numbers 5000-509N) .

_ 6 21261 70 Forwarding tables 25 - 25N to which the pointers 23 point are stored in a memory connected to the bus 13 which is accessible by the CPU, one table for each subscriber which has the class of service granting the automatic forwarding facility to which this invention is directed. The forwarding tables maintain a list of times against subscriber line numbers to which calls are to be transferred. Each table is shown in Figure 2 with a table number corresponding to a subscriber PABX local number, e.g. table 5000, table 509N, etc.
A real time clock 22 should also be accessible by the CPU, and is shown connected to the bus 13.
The system may also have various devices to which calls may be routed, each having a number to which calls may be transferred, e.g. voice mail 26, call answering machines 27, wireless handsets 28A in communication with line circuits 28B, pagers 29, wireless personal digital assistants, wireless personal communication devices, etc.
The subscribers who have the class of service granting the automatic forwarding facility preferably have telephones with displays 31 (referred to herein as display phones 31) connected to their subscriber lines.
It should be noted it is intended that telephones as used in this specification means any form of device which can inciude voice communication, and can be for instance telephones with liquid crystal displays, video telephones, computers with handset adjuncts, facsimile machines with handset adjuncts and with displays, etc.
In addition, while connection of these telephones to the telephone switching system is described herein as being via subscriber lines, this invention is not limited thereto, and is intended to include connection via broad _ 7 spectra media, such as a local area network, coaxial cable, wireless link, etc.
When the automatic call forwarding class of service is allocated to a subscriber, the attendant or the CPU 11 enters the subscriber's line number into table 19. This may be done from an attendant's terminal 17, or from a telephone designated to be the equivalent.
It is known to allocate classes of service to individual subscriber lines in a telephone system from a telephone set designated to be the equivalent of an attendant's console, as has been done in the system known as Entrepreneur, sold by Mitel Corporation since the early 1980's.
The CPU then establishes a forwarding table 25 for that subscriber number and enters a pointer to that forwarding table against the subscriber number in table 19. A forwarding table can contain times in at least either of two ways; (a) individual clock times separated by increments (e.g. 1:00 PM, 2:00 PM, 3:00 PM), or tb) individual clock times, with a global increment to be used for each. In the latter case the individual times are entered as needed by the subscriber, e.g. 3:00 PM
(only), the global increment of 1 hour (or any other increment) to be used with the time. Indeed, the tables 25 can be set up with increments or times all of which are settable by the subscriber.
In the preferred embodiment of the invention, a graphical user interface (GUI) form 33 display is generated by CPU 11, or by a processor controlling the peripheral switch 7, or by the subscriber's display phone 31, and is presented to the subscriber on his display phone display. The preferred style of the form is illustrated in Figure 3, and is similar to a weekly desk schedule The first column indicates time, and the first row indicates day of the week. The subscriber .~

need merely enter his location for the indicated interval, in this case shown as hours, but which can be in any convenient increments (which increments may be selectable). For example, in Figure 3 the subscriber has filled in the blank spaces on Monday between 9:00 AM
and 11:00 with the words MEETING1, which indicates that incoming calls should be routed to a number correlated with the words MEETING1 between the hours of 9:00 AM and 11:00 AM.
Also entered into the form is LUNCH between the hours of 12:00 noon and 1:00 PM, each day, extended to

2:00 PM on Friday, and various other entries such as MEETING2, MEETING3, MEETING4, SPECIAL, etc. for other time intervals on other days. Also entered are the letters OH, meaning "off hours", when the subscriber is not available.
It should be noted that rather than entering plain language words on the form 33, the user could have entered a call forwarding number. However the former is preferred, in order that the subscriber need not look up and enter forwarding numbers each time an entry is to be made into the form. If the latter is used (entry of actual numbers) is used, a second form, to be described below, need not be used.
Assuming that plain language words are to be used to control the call forwarding function, a second form which is a call data entry chart 35 is used, as shown in Figure 4. This chart is generated in the same manner as chart 33, and is displayed on the display phone 31 on call by the subscriber. The chart is a table of plain language names against subscriber numbers to which calls are to be transferred. The subscriber fills in the plain language names which he wishes to use, and the sorrelating subscriber line numbers.

-For example, when the subscriber is first given the class of service, he requests from the GUI to present on his display phone a display of chart 35. He then enters the plain language names of the events he expects to use for various transfer events, such as MEETING1, MEETING2, LUNCH, etc., as shown in Figure 4, and the corresponding call transfer subscriber line numbers meant by the event names. This chart 35 can be called up at any time to allow the subscriber to add new event names, to change event names, and to add or change call transfer numbers.
The subscriber then enters a completion indication code or other GUI indication that the data entry function has been completed. The completion signal is sent to whichever processor has controlled the GUI, which either stores the chart data in a local database, or transfers the chart data to CPU 11 via the message switch 9. In the latter case CPU 11 stores the chart data in memory in association with the forwarding table 25 associated with the subscriber's line which had generated the current table data.
The CPU can interpret the plain language words used in table 33 to specific call transfer numbers, using table 35 as a dictionary, and enter the times and call transfer numbers directly into table 25. This can be done quickly and easily if the table 35 data is stored in a memory local to CPU 11. However, instead, if the table 35 data is stored more locally to display phone 31, such as in the phone 31 memory or in memory associated with peripheral switch 7, when a change to the form 33 is made, either the local GUI software program can access table 35, interpret the subscriber number associated with the change, and send that number to the CPU instead of the event name for storage in table 25, or the GUI program can send a message to the _ CPU 11 via peripheral switch 7 and message switch 9 that a change in schedule has occurred, resulting in the CPU
sending a message signal interrogating tables 33 and 35 to either send only the changed information, or to send the entire schedule whereupon the associated table 25 is completely updated by CPU 11 from the information received.
In the above manner, the schedule of a subscriber is stored in an associated table 25, with call transfer numbers, which can be associated with plain language events entered into the schedule form 33, indicated against time intervals in the table 25.
Upon receiving a call to the subscriber, the CPU looks up the called subscriber number 21 in table 19, and finds a pointer to an associated table 25 for that subscriber. CPU 11 then checks the real time clock 22 to obtain the time. It then checks the pointed-to table against the real time. When it finds the real time equal to or later than a particular time entered in table 25, but not equal to or later than the beginning of an immediately later entered time, it checks and retrieves the subscriber number entered in table 25 against the span of time beginning at the particular time, and uses that number to which to complete the incoming call.
In the event there is no number entered against the aforenote~ particular time, the CPU completes the call to the normal subscriber number. It should be noted that the CPU could have filled the blank entries in table 25 wi-th the normal number of the subscriber, and simply used that number as the number to which the call should be completed, merely changing that number when the subscriber enters an event into table 33.
In the event that table 25 merely stores start times for an event as well as a global increment, or if Il -the CPU can assume a global time increment, when the times stored in table 25 are checked against the real time clock time, the transfer number entered against a time is retrieved if the real time is within and immediately following the entered time by the time increment. If the time increment is exceeded, and there is no time entered into table 25 equal to or within the incremental time immediately following the entered time, the CPU should complete the call to the subscriber's normal subscriber's line number, without transfer.
It should be noted that table 33 need not be in weekly diary form, but can be in daily form, monthly form, or in any desirable form. A GUI presentation to the subscriber can be from a commercial program, such as Lotus NotesTM, the data in the desk calendar of which is accessed in the manner described above. Further, the GUI can be supplied via a LAN to plural display phones 31, or from a remote host via a commercial network such as one accessible by computer.
It should also be noted that the number stored in table 23 (and first entered in table 35 if table 35 is used), need not be restricted to a local PABX
subscriber, a.ld can be a number which is out of the PABX. Such a number can be the subscriber's home phone number, the number of a customer, the number of a remote warehouse or other building, etc. Thus, for example, the subscriber can enter HOME in table 33 during a period when he is sick but wishes to receive calls, or during a normally out-of-hours time, and have calls incoming to the local telephone system routed to his home telephone.
Further, the system can route calls to the subscriber's wireless handset, to his pager, to various telephone answering machines, voice mail, etc, shown in Figure 2 connected to the PABX. Some of these devices 12 ~ I ~ Jl ~
-may be accessible via a main switching office to which the PABX is connected, and are accessible by the PABX
routing calls to those numbers, as stored in table 25, via a trunk such as trunk 5.
In the above-described manner, once call transfer information has been entered into the table 33, the telephone switching system automatically routes the calls to the location of the subscriber depending on the time interval indicated in the table, and if there is no entry, routes the calls to the normal subscriber's line.
The system determines not only the start time to perform the call transfer to a particular number, but also the end time, when calls should no longer be transferred to that number. Further, the subscriber can enter his location in plain language, in the usual manner in which desk diaries are used, and he need not use complicated call transfer routines and access codes which are more suitable to the telephone system, rather than to the user, to indicate where calls are to be transferred.
Since the call transfers with respect to time are automatic, the user need not instruct the telephone system when and where call transfer is to be effected, and when it is to be terminated, and thus the possibility of forgetting to cancel call transfer is substantially reduced.
Another form of system on which the present invention may be implemented is described in Canadian patent application 2,123,068 filed May 6, 1994, and which may be depicted in a different form as illustrated in block diagram in Figure 5. In this case the system is implemented in a personal computer 37, to which plural peripheral circuit cards and hardware and software drivers (shown as MVIP) 39 are connected.
Various peripherals such as voice mail 26, answering machine 27, etc. as connected to the system of Figure 2 -~- 13 21 261 70 are shown. As well, for completion, a LAN is shown, to which another personal computer which may have an associated telephone handset is connected.
As described with reference to the aforenoted U.S. patent application, a software user agent 45 which is associated with and deals with the requirements of the subscriber terminal is implemented in the computer 37, and operates as described in the aforenoted patent application, and as desribed below.
Contained in the computer 37 memory 47 are tables conforming to table 33, table 35 if used, and a table 25, which are accessible by user agent 45.
Figure 6 will be used in combination with Figure 5 to illustrate operation of the invention. An incoming call request is received via a peripheral device driver by the personal computer 37, which is transferred to the user agent for the called subscriber's line. The user agent has a representation of each of the user's devices, to which calls may be transferred, e.g. a telephone answering machine 27, a telephone 3, a terminal 31, a wireless handset 28A, a pager 29, etc. These representations can be stored in the table 25 in memory 47, along with alternate number designations 48, resulting from the content of table 35 stored in memory 47. In addition, memory 47 can store user preferences data 49 relating to the aforenoted devices for different situations, such as a ringing cadence or loudspeaking announcement depending on the source of a call.
When the user agent is invoked due to the incoming call to the associated subscriber number, it accesses the desk diary data 33, and 35 if used, (as described with reference to the first embodiment) as well as the user preferences data 49 stored in memory 47, to determine the proper destination of the call for -the time of the call: if it is to be transferred or completed to the normal subscriber's line of the called party. It then causes completion of the call to the proper user's device or alternate number stored in memory 47, in a normal manner as described in the aforenoted patent application.
It should be noted that this invention is not restricted for use in a PABX, but can be used in general switching offices.
A person understanding this invention may now conceive of alternative structures and embodiments or variations of the above. All of those which fall within the scope of the claims appended hereto are considered to be part of the present invention.

Claims

I claim:

1. A method of routing calls, comprising storing, in association with a subscriber identification (I.D.), a call routing destination number associated with a forwarding time, receiving a call to said subscriber I.D., checking the time of the call, and in the event the time of the call is equal to or later than the forwarding time, completing the call to the call routing destination number.

2. A method as defined in claim 1 including the step of storing a sequence of call routing destination numbers each associated with a time, and in the event the call to said subscriber I.D. is equal to or later than one of said times but prior to the beginning of another of said times, completing the call to a call routing destination number associated with said one of said times.

3. A method as defined in claim 2 in which at least one of said call routing destination numbers is said subscriber I.D.

4. A method as defined in claim 2 including storing said call routing destination numbers in association with destination names, displaying a time chart to a user, filling in the chart with at least one of said destination names at chart locations corresponding to times, looking up the stored destination names associated the call routing destination numbers and storing the call routing destination numbers in substitution for the names with the times corresponding to the chart locations and upon receiving said call to said subscriber I.D., retrieving an associated call routing destination number, and performing the checking and completing steps to a call routing destination number stored in association with a corresponding time.

5. A method as defined in claim 2 including storing said call routing destination numbers in association with destination names, displaying a time chart to a user, filling in the chart with at least one of said destination names at chart locations corresponding to times, and upon receiving said call to said subscriber I.D., looking up the stored destination names associated with the times corresponding to the chart locations and retrieving an associated call routing destination number, and performing the checking and completing steps to a call routing destination number stored in association with a destination name.

6. A method as defined in claim 4 in which the stored and displayed times include both clock times and days of the week.

7. A method as defined in claim 6 in which said displayed days of the week is comprised of a full week, and including selectably displaying times and days of plural weeks.

8. A method as defined in claim 4 in which said displayed times are comprised of time intervals, and in which the checking step includes checking whether the time of a received call follows the end of a time interval in association with which a destination name has been entered and completing the call to said subscriber I.D. in the event the time of a received call follows the end of said time interval which is not the beginning of an immediately following time interval in association with which a destination name has been entered.

9. A method as defined in claim 8 in which the stored and displayed times include both clock times and days of the week.

10 . A method as defined in claim 9 in which said displayed days of the week is comprised of a full week, and including selectably displaying times and days of plural weeks.

11. A method as defined in claim 7 in which the displayed days of the week is in the form of a desk calendar.

12 . A method as defined in claim 7 in which the displayed days of the week is in the form of a timetable.

13 . A method as defined in claim 2, in which said subscriber I.D. is within a PABX, and in which one of said call routing destination numbers designates a subscriber's line which is terminated on a system other than the PABX, and including routing said incoming call to the subscriber number in the PABX, via said PABX and an outgoing trunk to said other system whereupon it may be completed to said designated subscriber's line.

14 . A method as defined in claim 2 in which the subscriber I.D. is a subscriber's telephone number.

15. A method as defined in claim 2 in which the subscriber I.D. is a subscriber's line number.