Method for indicating a communicating duration of an office line in a keyphone system

There is disclosed a method capable of indicating a communicating duration on a displaying means (LCD) of a key-phone upon a communication via the public telephone office line in a key-phone system. The method includes the steps of: a first process for driving a communicating duration starting timer and informing that communication is started; second process for initializing a buffer storing a communicating duration and driving the communicating duration increasing timer; third proces for driving said communicating duration increasing timer and then checking if it is in a state of a public telephone office line reserving, and terminating in a state of accumuating the communicating duration to a buffer; fourth process for producing present communicating duration data and transmitting the data to a key-phone; and fifth process for increasing a count value of communicating duration storing buffer, driving the communication increasing timer, and advancing to said third process.

BACKGROUND OF THE INVENTION 
The present invention relates to a key-phone system, and in particular to a 
method capable of indicating a communicating duration on a display of a 
key-phone subset upon a public telephone office line transmission. 
In a conventional key-phone system, when a user of a key-phone subset is 
communicating through a public telephone office line, he or she could not 
know correctly the calling time of the public telephone office line. 
Further, in a key-phone system having a particular function, even though 
it is possible to know the calling time of the public telephone office 
line, it has only been possible to confirm through a printer connected to 
the system after the communication. Therefore, in a state during the 
communication, since a communicator is not able to detect how long the 
communicating duration of the public telephone office line is elapsed, 
application of the public telephone office efficiently carried out. 
OBJECT OF THE INVENTION 
Therefore, it is an object of the present invention to provide a method 
capable of indicating a communicating duration of time by method of a 
displaying means (LCD) of a key-phone upon a communication via the public 
telephone office line in a key-phone system.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Hereinafter, the present invention will be described in detail. FIG. 1 is a 
block diagram illustrating a system for carrying out the invention, which 
includes: a central processing unit (CPU) 10 for controlling and 
processing a key-phone system; a ROM 20 for storing a program code of the 
system, a RAM 30 storing temporarily the data used in the system; a 
key-phone subscriber circuit 40 for executing an interface function of 
key-phone 2 which is mentioned hereinbelow and said central processing 
unit 10; key LED, LCD (liquid crystal display) and the like being 
attached, and a key-phone 2 which is a terminal device controlled by said 
central processing unit 10. In a configuration of said FIG. 1, the 
configuration of switching circuit, public telephone office line circuit, 
tone generating circuit and the like utilized for constructing a 
communication path are omitted, and only a part of the configuration for 
carrying out the present invention is illustrated. 
FIG. 2 is a block diagram illustrating an entire program configuration of a 
preferred embodiment, according to the present invention, which includes: 
a timer processing program 100 for checking a timer by every 100 ms when 
the timer is being driven, and transmitting a message whose time is 
already elapsed 100 ms to an after-mentioning exchanging program 400; an 
O/S program 200 for controlling a program of entire key-phone system; a 
signal processing program 300 for changing data through key-phone 2 and 
key-phone subscriber circuit 40; an exchanging program 400 for executing a 
communication time duration indication by executing a real exchanging 
operation. 
FIG. 3 is a flow chart to indicate communicating duration of time in a 
state of the public telephone office line sending according to the 
invention, which includes: a first process for checking whether or not it 
is a start of communication of the public telephone office line 
transmission, when it is a start of a public telephone office line 
transmission, driving a communication start timing timer, informing of a 
communication start timing, and then terminating; a second process for 
checking whether or not it is an input signal of a communication start 
timer when it is not a public telephone office line sending at said first 
process, when a driving signal of a communication start signal timer is 
inputted, initializing a communication time storing buffer, and driving a 
communication time increasing timer; a third process for checking whether 
or not it is a public telephone office line reserving state after 
executing said second process, when it is a public telephone office line 
reserving state, not transmitting the communication time data in a state 
accumulated with communication time, and then terminating; a fourth 
process for generating the communication time data when it is in public 
telephone office line communication state at said third process, and 
transmitting the data to the key-phone; and a fifth process for checking 
whether or not it is a driving signal input of a communication time 
increasing timer when it is not a driving signal input of a communication 
time start timer at said second process, storing a commuication increasing 
time value when a driving signal of a communication time increasing timer 
is being inputted, after driving a communication time increasing timer, 
and advancing to said third process. 
FIG. 4 is a flow chart of a communication increasing time value generation 
of the fourth process in FIG. 3, which includes: a first process for 
checking whether or not one minute is passed after increasing a buffer for 
storing "seconds", and if not, then terminating; a second process for 
increasing a minute storing buffer after initializing a second storing 
buffer when one minute is passed at said first process; and a third 
process for checking whether or not 100 minutes have passed after 
executing said second process, and terminating after initializing a minute 
storing buffer only when 100 minutes are elasped. 
FIG. 5 is a flow chart of a communication time data generation of third 
process in FIG. 3, which includes: a first process for checking whether or 
not it is in conference communication. When it is in conference 
communication, terminating with ignoring a communication time indicating 
data; a second process for checking whether or not the side subscriber is 
a key-phone when it is in conference communication at said first process, 
when it is not, terminating and disregarding the communication time 
indicating data; and a third process for storing a communication time 
value into ASCII value when it is a key-phone at said second process and 
then storing to a send queue, and terminating. 
The present invention will be described in detail according to 
above-described configuration with reference to FIGS. 1 to 5. 
The central processing unit 10 executes data exchange and transmits and 
receives various kinds of signals and voices with a key-phone 2 that is a 
terminal equipment through a key-phone subscriber circuit 40. When a 
public telephone office line sending communication is started from said 
key-phone 2, the central processing unit 10 recognizes this through a 
corresponding port, after driving the timer and storing this into 
predetermined buffer of RAM 30, producing data for indicating a 
communication time per predetermined time, and transmitting to the 
key-phone subset 2. 
In this invention, communication time indicating data generated per one 
second is rendered to transmit to the key-phone subset 2, and key-phone 
subset 2 is terminal to which is attached a display such as a LCD. When a 
public telephone office line sending communication is carried out through 
said key-phone subset 2, the flowing steps of this invention for 
indicating a communication time proceed as follows,: 
When any of the key-phone subset 2 is hooked off when dialing a public 
telephone office line (local call, long distance trunk call, overseas 
call, etc.), at a step A1, the central processing unit 10 receives a 
dialing digit produced from corresponding key-phone subset 2 through a 
key-phone subscriber circuit 40 and a not shown DTMF receiver, and checks 
whether or not it has completed the public telephone office line dialing. 
When the public telephone office line dialing is completed at said step A1, 
the central processing unit 10 advances to a step A2 and checks whether or 
not it is a public telephone office line sending communication start; when 
there is a response from a called party subscriber through a not shown 
public telephone office line circuit, it has to form a communication path 
through a switching circuit, and it is treated as a communication start 
from this time. At this stage when it is a start of sending communication 
at said step A2, at a step A3, a corresponding message is registered into 
a timer message queue TMSGQ for driving a communicating duration start 
indication timer T-DURSTR, setting a driving start flag and then 
terminating the process. 
At this point, the system follows the processes, when it is not a sending 
communication start, of checking whether it is an input of communication 
duration indicating start timer T-DURSTR informing the public telephone 
office line communication start at a step A4, when it is a communicating 
duration indicating start timer input, advancing to a step A5, intializing 
a communicating duration storing buffers CALL DUR 0 and 1 of subscriber 
table (dynamic line control block: DLCB) contained in RAM 30, and at a 
step A6, driving a communicating duration increasing timer (timer duration 
increment: T-DURINC). 
Each subscriber ends up having a suscriber table DLCB with a table storing 
all states of key-phone subscribers in above-description, therefore, there 
is a communicating duration storing buffer for storing the public 
telephone office line communicating duration within said subscriber table 
DLCB, and here, first communicating duration storing buffer 1 (call 
duration 1) stores "minutes", and secondly, communicating duration storing 
buffer 0 (call duration 0) stores "seconds". If said communicating 
duration increasing timer (T-DURINC) is driven upon increasing the 
communication duration by one second, the duration is decreased from timer 
program 100 in every 100 ms, and when duration becomes 0, timer value 
becomes passed over again to the exchange program 400 by a system control 
program 200. 
After executing said step A6, at a step A7, checking whether or not it is a 
public telephone office line reserving state and, when it is a reserving 
state, terminating without transmitting data with respect to the 
communicating duration of corresponding key-phone subset 2. That is to 
say, though the data with respect to communicating duration of the public 
telephone office line sending communicating keeps being accumulated upon 
the public telephone office line reserving state, the data, however, are 
not transmitted to the corresponding key-phone. When it is released from 
the public telephone office line reserving state, the communicating 
duration data accumulated during that time is transmitted to the key-phone 
together therewith. Therefore when it is not the public telephone office 
line reserving state at said step A7, at a step A8, as shown in FIG. 5, 
the communication duration indicating data is produced and transmitted to 
the corresponding key-phone 2. 
The central processing unit 10 first checks at a step C1 whether or not a 
corresponding subscriber is in a conference communication and, when it is 
in a conference communication, terminates without transmitting the 
communicating duration indicating data to the corresponding subscriber 
side, and when it is not in a conference communication advances to a step 
C2, and checks whether the other party subscriber is a key-phone 
subscriber. At said step C2 also, when the other party subscriber is not a 
key-phone subscriber but a general telephone subscriber, terminates 
without transmitting the communication duration indicating data. 
Thereafter, when a subscriber of the other party is a key-phone subscriber 
and is not in a state of conference communication, at a step C3, a display 
position value of the key-phone subset 2 is stored to a buffer of RAM 30 
used in an exchange program temporarily (call pressing temporary buffer 0: 
CP-TEMP 0), at a step C4, "second" unit data are stored with ASCII code 
value to a next buffer of said buffer (CP-TEMP 0), and at a step C5, it 
stores data ":", at a step C6, stores "minute" unit data with ASCII value, 
at a step C7, stores said buffer (CP-TEMP 0) value to a send queue SEND Q 
of RAM 30 so as to transmit to a corresponding key-phone subset 2 at a 
signal processing program 300, and then terminates the process. 
Said send queue SEND Q is the queue for storing the data which is sending 
to the key-phone subset, the data stored in a send queue SEND Q are 
transmitted to the key-phone subset by a signal process program 300 
executed every 10 ms, and it is displayed at a LCD display with a present 
public telephone office line communicating duration. 
At said step A4, when a communicating duration indicating timer (T-DURSTR) 
is not inputted, at a step A9, it checks whether or not the communicating 
duration increasing timer (T-DURINC) is inputted, when it is not, 
terminates the process, and when the communicating duration increasing 
timer (T-DURINC) is inputted, advances to a step A10 to execute the steps 
as shown in FIG. 4. 
Firstly, since the communicating duration increasing timer is driven at 
every second, in a step B1, it increases a value of "second" storing 
buffer (CALL DUR 0) by one, and at a step B2, checks whether or not said 
second storing buffer value has reached 60 second, i.e., one minute, when 
it has not reached one minute (60 second), completes the process and 
terminates. At said step B2, when it is elapsed one minute, at a step B3, 
it initializes a "second" storing buffer (CALL DUR 0) to 0, subsequentialy 
increases a "minute" storing buffer (CALL DUR 1) at a step B4, at a step 
B5 checks whether or not 100 minutes is elapsed through "minute" storing 
buffer, when it is not, terminating the process, when 100 minutes are 
elapsed, advances to a step B6 to initialize "minute" storing buffer (CALL 
DUR 1) to 0, and then terminates the process. 
Thus, after executing the step A10 and increasing the communicating 
duration, advancing to a step A11, it drives the communicating duration 
increasing timer (T-DURINC) for the next state, and then advances to a 
step A7, as described above, checking whether or not the public telephone 
office line reserving state is present. 
The present invention is a method capable of indicating a communicating 
duration through the display means LCD of corresponding key-phone subset 2 
when any of the key-phone subscribers is carrying out a public telephone 
office line sending communication, according to its operation. Firstly, 
when a public telephone office line sending communication is started, the 
key-phone system drives a communicating duration indication starting timer 
and initializes "second" and "minute" storing buffer for representing the 
communicating duration, and then drives the communicating duration 
increasing timer. 
When the communicating duration increasing timer is operated, it increases 
the communicating duration value, outputs to the corresponding key-phone 
subset and displays it on the display means LCD of the corresponding 
key-phone subset 2. When a public telephone office line reserving state is 
occurred, it increases the communicating duration value and even 
accumulates it to the duration storing buffer, hence, the corresponding 
communicating duration data is not transmitted to the corresponding 
key-phone. When the public telephone office line reserving state is 
released, it operates so as to transmit the data which has been 
accumulated so far to the corresponding key-phone. 
As described above, when it is carried out that a public telephone office 
line sending from a key-phone system, it displays the communicating 
duration through a LCD display of the corresponding key-phone, so that a 
user can easily acknowledge communicating duration of the public telephone 
office line. Further, since the public telephone office line communication 
can be controlled with a pertinent duration based upon the invention, it 
is economical. More convenient and efficient public telephone office line 
utilization can be obtained, therefore, there is an advantage of providing 
a communication service with excellent quality. 
The foregoing description shows only a preferred embodiment of the present 
invention. Various modifications are apparent to those skilled in the art 
without departing from the scope of the present invention which is only 
limited by the appended claims. Therefore, the embodiment shown and 
described is only illustrative, not restrictive.