Note: Descriptions are shown in the official language in which they were submitted.
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i TITLE OF THE INVENTION
2 "SYSTEM AND METHOD FOR HANDLING A CALL IN
DIFFERENT MODES ACCORDING TO STORED DATA"
4 BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates generally to telephone switching
7 systems when operating in response to an incoming call, and more
s specifically to a system and method of handling an incoming call in
different modes respectively specified by users of a group sharing a same
directory number.
Description of the Related Art
12 A conventional method of restricting an incoming call relies on
13 the directory number of a calling station or a password entered by a
calling station. Specifically, when calls from a particular source are
~5 denied access to a particular destination, the directory number of the
particular source or a password specified by the particular destination
are stored in a switching system and compared with a directory number
sent from a remote switching office or a password entered by a calling
station. If they match, a connection is established. Otherwise, the
2o incoming call is rejected. Such a method is described in a number of
2~ Japanese Laid-Open Patent Applications 58-66455, 4-70046, 5-68097
22 and 6-86352. According to another prior art method, described in
23 Japanese Laid-Open Patent Application 4-27258; when a calling station
24 encounters a busy condition of a called station, the switching system
25 allows the calling station to store a password that specifies a particular
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call handling service. When the called station becomes idle, the
2 switching system proceeds to perform a switching operation according
3 to the stored mode.
4 In business and home environments, a single directory number is
often shared by a number of users which form an organisational group.
G Users sharing the same directory number are individual in respect of
their availability to answer an incoming call depending on their work
s locations and other reasons. Thus, an attempt by a calling party often
9 results in a fruitless effort when a called station is idle but a desired
o person is not available. Additionally, users who are currently available
~ to answer an incoming call would feel responsible to respond to an
12 unanswered call and have the trouble of interrupting their work to
~3 answer the call. This represents an inefficient work practice. The
14 number of such unsuccessful and inefficient calls is substantial. As a
result, there exists a need to reduce the number of such events.
i ~ SUMMARY OF THE INVENTION
n7 It is therefore an object of the present invention to provide a
I8 system and method of reducing unsuccessful call attempts.
m According to a first aspect of the present invention, there is
2o provided a telephone switching system comprising a switching network
2~ having a plurality of ports for terminating user stations, and a processor
22 for controlling the switching network in response to a call from a calling
23 station for establishing a connection across a pair of ports in the
24 switching network according to a directory number received from the
calling station. A user table is provided, which is associated with a
~
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particular port of the switching network, the user table having a
2 plurality of entries respectively associated with a plurality of users
3 sharing the particular port, each of the entries storing a user private
4 number identifying each one of the users and service information
specifying one of a plurality of call processing modes. The processor is
6 responsive to a user private number received from the calling station for
7 establishing a connection in the switching network according to the
s service information stored in one of the user table entries in which a
9 coincidence is detected between the received user private number and
~o the stored user private number.
According to a second aspect, the present invention provides a
~2 method of handling a call from a calling station. The method comprises
~3 the steps of (a) creating a user table associated with a particular one of
a
14 plurality of ports of a switching network, the user table having a
~5 plurality of entries respectively associated with users of a group sharing
~ the particular port, (b) receiving a command signal from a user of the
7 group and setting received instructions in one of the plurality of entries,
~s the instructions including a user private number identifying each one of
19 the users and service information specifying one of a plurality of call
2o processing modes, (c) receiving a directory number from a calling
21 station, and (d) receiving a private number from the calling station and
22 establishing a connection in the switching network according to the
23 service information stored in one of the user table entries in which a
24 coincidence is detected between the received user private number and
25 the stored user private number.
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i BRIEF DESCRIPTION OF THE DRAWINGS
2 The present invention will be described in further detail with
3 reference to the accompanying drawings, in which:
4 Fig. 1 is a block diagram of a telephone switching system
according to a first embodiment of the present invention, which is
G particularly useful for business environment;
Fig. 2 is a flowchart of the operation of the processor of Fig. 1 in
s response to an incoming call destined for a group of users whose private
9 information are registered in a user table;
o Fig. 3 is a block diagram of a telephone switching system
~ according to a second embodiment of the present invention which is
i2 particularly useful for household applications;
~3 Fig. 4 is a flowchart of the operation of the processor of Fig. 3 in
~4 response to an incoming call destined for a group of family members
~5 whose private information are registered in a user table; and
Fig. 5 is a block diagram of the second embodiment which shows
7 user states during a night-time.
is DETAILED DESCRIPTION
Referring now to Fig. 1, there is shown a telephone switching
2o system according to one embodiment of the present invention, which is
2~ useful for business environment. The switching system, as indicated by
22 numeral 10, generally includes a line interface 11, a switching network
23 12, a processor 13 and a memory 14. To the line interface 11 are
24 terminated a plurality of user stations, or telephone sets, 20 to 22 which
25 represent call originating telephones and user stations 30 to 32 which
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represent call terminating telephones. All user stations are connected via
2 the interface 11 to corresponding input ports of the switching network
3 12. A signaling message, such as directory number information, from
4 each user station is transmitted via the line interface 11 to the processor
13; where the message is analyzed using information stored in the
G memory 14 to determine an output port. Processor 13 establishes a
7 switched connection across the switching network 12 from the input
s port of the calling user station to the determined output port.
9 According to the present invention, a plurality of message storage
o devices are connected to the output ports of the switching network 12.
~ These message storage devices include a voice command device 15, an
~2 absence message storage device 16, and one or more voice mail boxes 17.
~3 Additionally, a user-associated table 18 is defined in the memory
14 14 for the user station 30, for example, having a directory number "XX-
~5 YYYY". The user table 18 for user station 30 is referenced by the
G processor 13 when the processor receives an incoming call destined for
17 the user station 30.
is When the processor 13 receives an incoming call for the user
19 station 30, it proceeds to establish a connection to the voice command
2o device 15 after transmitting a short duration of ring-back tone to the
2~ calling station. Then, the voice command device 15 sends a voice
22 command requesting the calling user to dial one of the user private
23 numbers.
24 User table 18 has a plurality of entries (rows) respectively
25 associated with users of a group that share the same directory number, or
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a particular port of the switching network 12. Each entry is assigned to
2 each user of the group to store particular service information of the user.
3 Each user table entry is divided into a plurality of fields for respectively
4 storing a user private number (UPN), a user state indicating whether the
associated user is available for answering a call, a service identifier for
G indicating one of a plurality of predetermined services, and a directory
number which is used when an incoming call is forwarded. Service
s identifiers and directory numbers are referenced only when the
corresponding user state field contains a binary "0" which indicates that
o the associated user is not available to answer a call. If the user is
i ~ available to answer a call, a binary "1 " is stored in the user state
field of
~2 the table 18, and the processor 13 sends a ringing signal to the called
13 station as will be described in detail later.
4 Assume that there are six users in a group that share the user
~ 5 station 30, respectively identified by user private numbers "01 " through
G "06". Assume that the telephone sets 31 and 32 are located in separate
7 rooms of the same premises of the user station 30 and respectively
8 assigned directory numbers "XX-WWWW" and "XX-ZZZZ" to which
9 incoming calls may be forwarded.
2o A service identifier "11" indicates that the associated user is in a
2~ separate room and that incoming calls be forwarded to the station
22 indicated in the corresponding directory number field.
23 A service identifier "12" indicates that the associated user is
24 absent and that the user desires that the absence message storage device
25 16 be operated to send a prerecorded announcement to the calling
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1 station.
2 A service identifier "13" is one that indicates that the user leaves a
3 message as a voice mail which is stored in one of the voice mail boxes 17.
4 The directory number field of each entry not only stores a directory
number of other telephone, but also a mail box number to specify one of
G the mail boxes.
7 All users of the group are requested to enter desired data into the
s corresponding entries of the user table 18 and update the stored data
9 whenever there is a change in their user state.
o When the processor 13 receives an incoming call destined for the
~ user station 30, it proceeds to operate according to a flowchart shown in
~2 Fig. 2 by establishing a connection in the switching system 12 from the
~3 input port of the calling station to the voice command device 15 (step
t4 201). Processor 13 checks to see if a user private number is entered
~5 within a specified period of time (step 202). If the decision is
~ affirmative at step 202, the processor 13 searches through the user table
17 18 and determines if the same user private number is stored in the user
I8 table 18 (step 203). If this is the case, the decision at step 204 is
9 affirmative and the routine proceeds to step 205 to check to see if the
2o user state of the current entry is "1" or "0".
2i If the user state is "1 ", the routine proceeds from step 205 to step
22 206 to connect the calling station to the user station of the dialled
23 directory number and sends a ringing signal to the called station, while
24 returning a ring-back tone to the calling station. Processor 13 then
25 checks to see if the called station goes off-hook (step 207). When an off-
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hook condition is detected (step 207), the processor 13 starts charging the
2 calling station (step 208) and terminates the routine.
3 If the user state is "0", indicating that the associated user is not
4 available to answer the incoming call, the routine proceeds from step
205 to step 209 to read a corresponding service identifier from the user
G table 18 and proceeds to one of steps 210, 211 and 212 according to the
read service identifier.
s If the service identifier is "11 ", indicating that an incoming call
be forwarded to a specified station, the routine proceeds to step 210 to
~o connect the calling station to the user station specified in the directory
~ number field of the table 18 and sends a ringing signal to the specified
12 station, while returning a ring-back tone to the calling station. Then,
~ 3 the routine proceeds to steps 207 and 208 to start charging the calling
4 station when it goes off-hook.
~ 5 If the service identifier is " 12 ", indicating that an absence
G announcement be returned to the calling station, the routine proceeds to
7 step 211 to connect the calling station to the absence message storage
1s device 16 and proceeds from step 212 to step 208 to start charging the
19 calling station.
2o If the service identifier is "13", indicating that there is a voice
2~ mail for the calling station, the routine proceeds to step 212 to connect
22 the calling station to a voice mail box identified by the mail box number
23 given in the directory number field of the user's entry. The routine
24 proceeds from step 212 to step 208 to start charging the calling station.
25 If the decision at step 202 or 204 is negative, it is determined that
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the request for connection to the dialled user station be rejected and the
2 processor 13 sends back a busy tone to the calling station and terminates
3 the routine.
4 If the user at station 20 places a call by dialling digits "XX-
YYYY", the processor 13 connects it to the voice command device 15
G prompting the calling user to enter a user private number. If UPN = 02
is entered, the processor 13 looks up the user state field corresponding to
s UPN = 02. Since the user state is "1 ", a connection 33 is established in
9 the switching network 12 between the stations 20 and 30 and a ringing
o signal is sent to the called station 30, while returning a ring-back tone to
~ 1 the calling station 20, and starts a charging operation when the called
12 station answers the call.
~3 If the user at station 21 places a call to the same user station, the
~4 calling user is also prompted to enter a user private number. If UPN =
O1 is entered, the processor 13 looks up the user state field corresponding
G to UPN = 01. Since the user state is "0" and the service identifier is
17 "12", the processor establishes a connection 34 in the switching network
~s 12 between the station 21 and the absence message storage device 16, and
9 starts a charging operation.
2o If the user at station 22 places a call to the same user station 30,
21 the calling user is also prompted to enter a user private number. If UPN
22 = 03 is entered, the processor 13 looks up the user state field
23 corresponding to UPN = 03. Since the user state is "0" and the service
24 identifier is "11 ", the processor establishes a connection 35 in the
switching network 12 between the station 22 and the station 31
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identified by the directory number "XX-WW\X1VU" and sends a ringing
2 signal to the called station, returns a ring-back to the calling station and
3 starts a charging operation when the called station goes off-hook.
4 Accordingly, the processor 13 references the user table 18 in
response to the arrival of an incoming call for the user station 30 and
G connects the call according to a user private number entered by the
7 calling party. The incoming call is thus answered in a specific manner
s according to the contents of the entry of the user private number. When
any user of the telephone 30 changes his or her work location, the user
io updates the corresponding entry of the user table 18.
If the telephone switching system 10 is an ISDN switching office
~2 and user telephones are privately assigned ISDN sub-addresses, the
~3 processor 13 can provide individual call-handling services to family
~4 members, as shown in Fig. 3. In this modification, the memory 14
defines a user table 19 having entries for members (father, mother, son
1~ and daughter) of a family, for example. Each entry of the user table 19
m additionally includes a sub-address/directory-number field in which the
8 sub-address of a nearby telephone or a mail box number is stored.
19 User private numbers "O1", "02", "03" and "04" are assigned
2o respectively to father, mother, son and daughter and stored in the
2~ respective entries of the table 19. A three-bed room house is illustrated.
22 Telephone sets 41 and 42 with respective sub-addresses SA=11 and
23 SA=12 are installed in the living room 51 and the kitchen, respectively,
24 and other telephones 43, 44 and 45 (with SA=21, SA22 and SA=23) are
in the bed rooms 53, 54 and 55, respectively. All telephone stations are
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1 connected to an ISDN terminal adapter 50.
2 Assume that, in the daytime, the father and daughter are in the
3 living room 51 and the mother in the kitchen 52, as shown in Fig. 3, and
4 the son is out, leaving his voice message in a voice mail box 17.
Therefore, user state "1" is registered in the entries of the father, the
6 mother and the daughter and user state "0" in the entry of the son, and
7 sub-address "11" is stored in the entries of USP = 01 and USP = 04, sub-
s address "12" in the entry of USP = 02, and a mail box number in the
9 entry of USP = 03.
o The operation of the processor 13 proceeds according to a
1 ~ flowchart shown in Fig. 4. This flowchart differs from that of Fig. 2 by
12 the inclusion of steps 401 and 402 between steps 205 and 207.
13 If it is determined, at step 205, that the user state of an entry
4 corresponding to the entered user private number is "1 ", the processor 13
~5 reads a sub-address from that entry at step 401. The read sub-address is
m then transmitted, at step 402, to the terminal adapter 50 of the dialed
m directory number and a connection is established in the switching
Is network between the calling station and the port identified by the
9 directory number received from the calling station. Terminal adapter
20 50 decodes the received address and sends a ringing signal to the
2~ telephone of the sub-address. When the called telephone goes off-hook
22 (step 207), the processor 13 starts charging the called telephone (step
23 208).
24 If a calling telephone 40 places a call to the father, the calling
25 party sends dialing information DN = XX-YYYY and then enters a
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UPN = O1 when the calling party is prompted by the voice command
2 device 15 (step 202). Since user state "1" is stored in the entry of UPN =
3 O1, the processor 13 proceeds through steps 203, 204 and 205 to step 401.
4 Thus, sub-address SA = 11 is detected (step 401) and sent to the terminal
adapter 50 (step 402) to alert the telephone 41 in the living room 51.
6 If all the family members go to bed in the night-time as illustrated
in Fig. 5, the user table 19 is updated to reflect their current locations.
s The user state fields of all entries are set equal to "1" and the sub-
address
9 fields of the parents are set to SA = 21 and those of the son and daughter
o are set to SA = 22 and SA = 23, respectively.
Under this condition, if the telephone 40 places a call to the
~2 father, the calling party uses the same dialing information and the same
~3 user private number as those used in the daytime call. Processor 13
14 detects the sub-address SA = 21 in the UPN = 01 entry and sends it to the
~ 5 terminal adapter 50 to alert the telephone 43 in the bed room 53.
