Note: Descriptions are shown in the official language in which they were submitted.
2126170
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,
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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
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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:
4 2126170
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
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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
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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
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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.
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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
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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
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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
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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
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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
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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.
