Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2108223 ~
1 FIELD OF THE lNV~N'l'lON
2 This inv~ntion relates to telephony and in
3 particular to a method of directing telephone calls to a
4 subscriber who has left the vicinity of his telephone
set.
6 BACKGROUND TO THE lNv~NllON
7 Telephone switching systems typically have the
8 capability of rerouting incoming calls to a telephone
9 set to another location designated by a subscriber, this
capability being referred to as call forwarding. A
11 telephone number of a line at a location where the
12 subscriber expects to be is registered, and when an
13 inc. i ng call is received to the subscriber's line, the
14 line to which calls are to be transferred i5 rung in
place of the called line. It is possible, however, that
16 the subscriber has not yet reached that location, has
17 left that location, or has changed his mind as to being
18 in that location. In that case the telephone line to
19 which calls are transferred will be rung, and the
subscriber can miss the transferred call.
21 In case the subscriber is uncertain exactly
22 where he will be, he can establish a hunt group. All
23 calls to his line then ring all telephone lines of the
24 hunt group. With the subscriber expecting to be located
25 adjacent one of the telephone lines designated in the
26 hunt group at some time, he expects to be able to pick
27 up the call from one of the telephone lines in the
28 group.
29 This procedure, however, causes all telephone
30 lines of the, group to be rung, which is wasteful of
31 ringing current, and can be annoying to other persons
32 within earshot of the many telephones being rung.
33 Indeed, the ringing telephones may induce some other
34 party than the subscriber to answer one OI the ringing
telephones, and this could restrict the ability of the
'~
2 1 ~ 8 2 2 3
1 subscriber to obtain important information from the
2 caller, since for example the person answering the
3 telephone may not see the subscriber and may not give
4 the subscriber a message relating to the call; yet the
caller may expect that the message is to be passed to
6 the subscriber. -~
7 Therefore the use of neither call forwarding ; -
8 nor hunt group ringing is satisfactory to successfully
9 locate and transfer a call to a subscriber who is
roaming from place to place, without knowing ahead of
11 time exactly where he will be and for what period of ''
12 time.
13 SUMMARY OF THE lNV~!;N'l'lON
14 The present invention is a method by which
calls intended for a subscriber can be directed to that
16 subscriber, even though the subsoriber may be roaming
17 from place to place in no defined sequence and for no
18 particular period of time, without ringing all
19 telephones in a hunt group together. Further, the
invention provides for alternatively ringing all
21 telephones in a hunt group at one time according to
22 normal hunt group operation.
23 In accordance with an embodiment of the
24 invention, a method of ringing a telephone subscriber is
comprised of (a) defining a hunt group of teleph~ne
26 lines for a particular telephone line associated with
27 said subscriber, (b) receiving a call to the telephone
28 line from a calling party, (c) seizing and ringing a
Vb '
29 telephone line contained in the group as a result of
receiving the call, (d) timing an interval of answering
31 time, (e) in the event the telephone line is not
32 answered within the interval, releasing and ceasing
33 ringing the telephone line and ringing another telephone
34 lir.e listed in the hunt group, (f~ repeating steps (d)
and (e) until a ringing telephone line has been
- 2108223
1 answered, all telephone lines in the hunt group have
2 been rung ~or the interval, or the calling party has
3 hung up, and (g) in the event a ringing telephone line
4 has been answered, routing the call to the answ~red
telephone line.
6 In accordance with another embodiment, a
7 telephone line of the hunt group is registered, and the
8 registered line is rung first of all those listed in the
9 hunt group. Steps (f) and (g) as described above are
then performed.
11 In accordance with another embodiment, a
12 method of ringing a telephone subscriber is comprised of
13 defining a hunt group of telephone lines for a a
14 telephone line associated with the subscriber, and in
the event of receipt of a telephone call to the
16 subscriber, ringing each telephone line in the hunt
17 group in sequence for a period of time until one
18 telephone line has been answered or until a caller of
19 the received call has hung up.
BRIEF INTRODUCTION TO THE DRAWINGS
21 A better understanding of the invention will
22 be obtained by reference to the description below, in
23 conjunction with the following drawings, in which:
24 Figure l is a block diagram of a telephone
system in which the invention may be used,
26 Figure 2 is a block diagram of the content of
27 a memory used in the telephone system and used in the
28 process of the invention.
29 DETAILED DESCRIPTION OF THE lNV~NllON
Figure l is a block diagram illustrating
31 a telephone switching system, o~ the type described in
32 U.S. patents 4,615,028 issued September 30th, 1986,
33 invented by Conrad Lewis and Gino Totti and 4,616,360
34 issued October 7th, 1986, invented by Conrad Lewis. It ;
~- 21~8223
1 should be understood that other telephone switching
2 systems could be used in place thereof.
3 In the system of Figure l, station sets l such
4 as telephone sets are interconnected with each other and
with trunks 2 via at least one circuit switch 3, ~-
6 telephone lines 4 connected to the station set being
7 switched to circuit switch links via peripheral controls
8 5 which interface the telephone lines and trunks via
9 peripheral inter~ace circuits (PICs) 6. Ringing
generators 7 are connected to the peripheral controls 5
11 in order to provide ringing signals to the telephone ~
12 lines. Random access memories (RAMs) 8 are also ;
13 connected to the peripheral controls 5, which store
14 control signals for operation of the peripheral
controls.
16 A processor (main control) ~0 is connected via
17 a main bus 12 to the circuit switch 3, in order to
18 control it's operation. A message switch 12 is also
19 connected to bus 12 and to peripheral controls 5, to
receive control messages from processor lO and to route
21 them to peripheral control 5, for storage in memories 8
22 or for transmission to telephone lines 4, destined for
23 the station sets l. A system memory 14, connected to bus
24 12, contains control programs and data used by the
processor for controlling tha operation of the system.
26 An operator console 16 is connected to the main bus 12,
27 which is used to configure and test the system when
28 required.
29 In accordance with the present invention, a
hunt group memory 17 is connected to bus 12, for read
31 and write access by processor lO. This memory is used
32 to store hunt group tables. These hunt group tables are
33 used in a particular way. ;
34 In addition, a timer l8 is as~ociated With the
processor lO, for timing ringing intervals.
2~8223
1 Turning now to Figure 2, the details of an the
2 present invention will be described.
3 Using the operator console 17, for example, an
4 operator who has been asked to prepare a hunt group as a
result of a subscriber request prepares a hunt group
6 such as hunt group list 18 with members designated by
7 the subscriber. The hunt group is headed by a pilot
8 number, which can be either a special number looked
9 stored in a table and associated with the subscriber
n~ h~r, or can be the subscriber number itself. The
11 hunt group list will also cont~in the subscriber numbers
12 of the other members of the hunt group, as shown. This
13 list is converted, if necessary, to a hunt group table
14 20, which is headed by the pilot number of the
subscriber, and lists information designating each of
16 the stations (telephone lines and numbers associated
17 therewith) of the other members oP the hunt group.
18 Contained within system memory are station
19 tables 22. ~ach station table retains information used
by the switching system about the characteristics of the
21 station number, for example the classes of ser~ice
22 allocated $o the station number. In a preferred
23 embodiment of the invention, one of the characteristics
24 stored in a station tables 22 corresponding to the hunt
group pilot number (which can be the telephone number of
26 the subscriber who is to be located), is a hunt group
27 option code, as will be described below.
28 Each of the station identifiers stored in the
29 hunt group tables 20 contains a pointer to a particular
station table 22.
31 The system memory 14 contains a table which is
32 looked up as a result of an incoming call, referred to
33 herein as a digit tree table 24. ~his table contains
34 re~erence to the station associated with each incoming
35 telephone number, and in particular a pointer to the ~;
S
2~82~3 ~:
1 station table 22 containing the station characteristic~ ~ -
2 so that the processor can avail itself of the
3 information stored in the station table for a particular
4 incoming call and properly process the call. For
example, incoming dialed digits 5110103 has an entry in
6 digit tree table 24, and a cross-reference to station y.
7 This cross-reference is a pointer to the station table
8 carrying the characteristics of station y.
9 Depending on the characteristics of the
switching system, the seven digit number could have
11 fewer (e.g. four) or more digits which designate the
12 called line.
13 In the present invention, the digit tree
14 replaces the cross-reference to a particular station
table of a particular subscriber for which the hunt
16 group is set up, with reference to a corresponding hunt
17 group table 20. Each of the members of the hunt group
18 in the hunt group table has its own pointer to a
19 particular station table 22.
Thus for an incoming call to a number which is
21 the pilot number, or designates the pilot number of one
22 hunt group table, the pilot number will point from the
23 hunt group to a particular station table. The data
24 relating to that station number is retrieved by the
processor, and is transmitted to the peripheral control
26 for controlling the ringing of stations in the hunt
27 group in accordance with the particular data stor~d in
28 the pointed-to station table.
29 When a subscriber wishes to use the present
invention, he establishes a hunt group of telephone
31 lines at locations where he expects to be from time to
32 time during a desired interval. The operator, or th~
33 person inputting the hunt group list, places an option
34 aode in the ~tation table related to the station number
(which can be the pilot number of the hunt group), which
2108223
1 option code specifies th~t the hunt group ringing should
2 be "continuous". "Continuous~ ringing designates that
3 each telephone line corresponding to the numbers in the
4 hunt group should be seized and rung one at a time,
rather than all at once.
6 Upon receipt of an incoming call to the
7 subscriber's telephone line number, the main processor,
8 accessing the station table for that telephone line
9 (which has the "continuous" option code stored in the
associated station table), recognizes the option code,
11 and as a result seizes only the first listed telephone
12 line in the hunt group, instead of all lines in the hunt
13 group. The processor sends a messaye to the peripheral
14 control to cause a ringing generator to ring the first
listed telephone line, timing the ringing using timer
16 18. If the rung telephone line has not been answered ~
17 during the timed interval, the processor causes release --;
18 o~ the rung telephone line and thus stops ringing it. ;
19 The processor then reads the hunt group table again, and
causes seizure and rinying of the second listed
21 telephone line in the hunt group. Again the timer times
22 the ringing, and if the rung telephone line has not been
23 answered within the timed interval, the processor causes
24 release of the rung telephone line and thus stops
ringing it. The steps are repeated for all telephone
26 lines in the hunt group list, until a telephone has been -
27 answered, or until the calling party has hung up.
28 In case all of the telephones have been rung
29 without any being answered, as long as the calling party
has not hung up, the main processor, recognizing that
31 all of the telephones in the list have been rung, ceases
32 ringing any of them. Alternatively, the entire seguence
33 of ri.nging each line of the list in sequence may be
34 repeated for as many cycles as desired, for a particular
interval, or until a predetermined clock time has bePn
" 21~22~
1 reached, as long as the calling party has not hung up, .
2 The alternative steps described above can allow the
3 subscriber who has not reached any of the telephone
4 lines, or who may be travelling between stations, to
reach a station associated with one of the lines and
6 pick up the call.
7 Thus with each telephone line in the hunt
8 group rung in sequence for a prQdeteL ;ne~ time period
9 (which can be programmed into the main processor
operation programs~, all telephones in the hunt group
11 are not rung at the same time, avoiding the deficiencies
12 of the prior art hunt group ringing mode as described
13 earlier. Indeed, in effect each telPphone in the hunt
14 group is rung in a manner so as to seek the location of ;~
the roaming subscriber. The result is a form of
16 sequential call transfer that is timed per subscriber
17 line, and in case the call transfer is unsuccessful,
18 another line is selected for call transfer. The
19 possibility of locating the subscriber is thus obtained,
with ; n; annoyance to others who may be within
21 earshot o~ other telephone lines of the hunt group, and
22 with minimum possibility of missing the call due to
23 mishap, such as answer by a a child or the like.
24 In accordance with another embodiment, when
the subscriber reaches a line where he expects to stay
26 for a period of time, he can register his location.
27 This can be e~fected by him dialing the operator, and
28 providing his location. The operator can then access
29 the systPm, and keying in control digits and a
designation of the pilot number of the hunt group, or if
31 dif~erent, the base line number of the subscriber. The
32 switching system controller, recognizing the control
33 digits, places a mark against that telephone line in the
34 hunt group table associated with the basQ telephone line
number.
2108223
1 In this ~ase, when there is an incoming call
2 to the base telephone number, the controller detects the
3 mark against the telephone number in the hunt group,
4 where the subscriber is located. The main controller
then seizes and rings that number ~irst, instead of the
6 first number of the hunt group. Assumin~ that the
7 subscriber is still at that location, he will answe~ the
8 ringing telephone. This process makes the transfer of
9 calls very efficient. Only one telephone line in the
hunt group is rung, thus relieving use of the telephone
11 system equipment, and the call is answered with minimum
12 possibility that the caller will hang up before the call
13 is answered, or that the call will be answered by some ~'
14 other party on another telephone listed in the hunt -
group before the call is answered by the subscriber.
16 It should be noted that the hunting option ~"
17 that is stored in the station table associated with any
18 particular subscriber can be changed to "simultaneous",
19 instead of "continuous". In this case, instead of
ringing each telephone in the hunt group in sequence,
21 the controller detects the "simultanPous" option, and it
22 proceeds to ring all telephones in the hunt group
23 simultaneously, in the normal manner of the prior art.
24 The use of the hunt group option allows the
subscriber to select which form of hunting he wishes to
26 use, depending on how he wishes to use the telephone
27 system, and how and when he sxpects to travel between
28 locations.
29 A person skilled in the art understanding this
invention may now design other embodiments using the
31 principles described herein. For example, the method is
32 not restricted to hunt groups using fixed telephone
33 lines, but can be used with hunt groups designating
34 cellular or other wireless telephones.. Thus there is
no restriction that the method be used in association
';'':, ~ ' ' ', , ' '~' ' . ' ' '
3 ~
~ 21Q8223
1 with a PABX, but it may be used in association with
2 general telephone switching systems and networks. All
3 such designs are part of the present invenkion if they .~:
4 fall within the scope of thP claims appended hereto
S
6 .
' ~,'''
' ,:
