 |
Description  |
|
|
BACKGROUND OF THE INVENTION
This invention relates to an integrated services digital network
(hereinbelow called simply ISDN) system, in which data communication is
effected among media equipments through an ISDN, and in particular to
multimedia equipments and a method for connecting the multimedia
equipments, by which in each of the multimedia equipments connected to the
ISDN, among media devices (input/output devices) within the relevant
multimedia equipment or kinds of the media devices (or kinds of media)
one, for which connection is demanded, is identified and connected to the
ISDN.
In a system, in which a plurality of media equipments (media terminals and
a host computer) are connected with an ISDN through subscriptor lines and
data communication is effected among media terminals through the ISDN, it
is possible to transmit data by using 2 to 24 lines of B channel by means
of one subscriptor line. Consequently, since it is possible to transmit
multimedia data, i.e. image data for facsimile, sound data, and other
ordinary data, through one subscriptor line, in the case where a plurality
of media terminals are connected with the relevant subscriptor line, it is
necessary for each of the media terminals to receive data, while judging
whether the data on the subscriptor line are for the own media terminal or
not.
As a method for identifying the media terminals, for which connection is
demanded, among a plurality of media terminals connected with the relevant
subscriptor line, there is known a method, by which a sub-address in an
ISDN number is used, as indicated e.g. in JP-A-No. 61-214837 and
Recommendation of CCITT, E. 164.
However, according to the techniques stated above, although it was possible
to identify the media terminals connected with the same subscriptor line,
it was not possible to identify one, for which connection is demanded,
among a plurality of media devices, or the kind of the media devices (or
the kind of media such as image, sound, graphic, etc.), for which
connection is demanded, in the case where the relevant terminal is a
multimedia terminal having a plurality of media devices (e.g. facsimile
device, telephone, etc).
SUMMARY OF THE INVENTION
An object of this invention is to provide as ISDN system and a method for
connecting multimedia equipments, by which, in the ISDN system, in the
case where media equipments connected with the ISDN are multimedia
equipments each having a plurality of media devices, the media device or
the kind of media devices (or kind of media), for which connection is
demanded, in a multimedia equipment stated above is identified and
connected with the ISDN.
In order to achieve this object, according to this invention, when data
communication is effected between multimedia equipments (terminal having a
plurality of media devices or a host computer having plural media devices)
through the ISDN, the equipments are connected with each other by a
procedure according to the protocol of the ISDN and in this case an ISDN
number is transmitted and received between the relevant equipments,
whereby a sub-address (address which an user of the ISDN can utilize
freely) in it includes an identification mark indicating the media device
or the kind of media devices (or kind of media) in addition to the mark
identifying the terminal of the destination of the communication, which
has been utilized heretofore. By transmitting these marks from one
multimedia equipment to the other multimedia equipment, in the other
equipment a media device corresponding to the media device or the media
indicated by the identification mark is connected with the ISDN.
According to this invention, in each of the multimedia equipments there are
set a first identification indicating the own multimedia equipment and
second identification marks indicating media devices or kinds of media
devices (or kinds of media) in the relevant equipment. At the same time,
together with the first identification mark indicating the other
multimedia equipment, with which the data communication is to be effected,
the second identification marks indicating media devices in this equipment
or kinds of media devices (or kinds of media) are previously set and
stored as a data base. In this state, in the case where from one
multimedia equipment to a media device, e.g. a facsimile device in another
multimedia equipment, facsimile data are transmitted, the one multimedia
equipment searches the second identification mark of the facsimile device
together with the first identification mark of the other multimedia
equipment from the data base and inputs them in the sub-address of the
ISDN number. Then they are transmitted to the subscriptor line according
to the protocol of the ISDN. At this time the other multimedia equipment
judges whether it is a connection demand to the other multimedia equipment
by using the first identification mark in the subaddress transmitted from
the one multimedia equipment, and when it judges that it is a connection
demand, it is possible to identify the media device, i.e. the facsimile
device, for which connection is demanded, by using the second
identification mark. Consequently it is possible to begin the data
communication by connecting the facsimile device stated above with the
ISDN through the multimedia equipment.
In addition, in the case where the second identification mark indicates a
kind of media devices (or a kind of media), for example in the case where
there are a plurality of facsimile devices, when the second identification
mark indicates simply to be a facsimile device or facsimile data, the
other multimedia equipment selects automatically or manually one facsimile
device among the facsimile devices and executes a connection process to
the ISDN.
In this way, according to this invention, since it is possible to identify
the media device or the kind thereof, for which connection is demanded, at
the establishment of the connection of the media device with the ISDN by
using the sub-address in the ISDN number, the access process in the
system, where multimedia equipments are connected with the ISDN, can be
effected with efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the outline of the construction of
the ISDN system, to which this invention is applied;
FIG. 2 is a scheme showing the construction of the principal part of a
typical embodiment of the ISDN according to this invention;
FIG. 3 indicates an example of the ISDN number transmitted and received
between multimedia terminals in the embodiment indicated in FIG. 2;
FIG. 4 indicates the process of the connection between multimedia terminals
according to this invention;
FIG. 5 is a flow chart showing the process of the connection in the
communication control device on the transmitter side;
FIG. 6 is a flow chart showing the process of the connection in the
communication control device on the receiver side; and
FIGS. 7 and 8 show examples of the address table in the data file in
modified examples of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinbelow typical embodiments of this invention will be explained.
FIG. 1 is a scheme illustrating the whole construction of the ISDN system,
to which this invention is applied. In the figure, reference numeral 1
represents an ISDN, in which a plurality of (here e.g. 3) digital service
units (hereinbelow called simply DSU) 3a, 3b, 3c, . . . are connected with
each other through an ISDN switch board 4. Terminals and multimedia
terminals are connected with each of the DSUs 3a, 3b, 3c through a
subscriptor lines 6a, 6b, 6c. Here it is supposed, for example, that a
terminal 2A.sub.2 and a multimedia terminal 2A.sub.1 are connected with a
line 6a; a terminal 2B.sub.2 and a multimedia terminal 2B.sub.1 are
connected with a line 6b; terminals 2C.sub.2, 2C.sub.3 and a multimedia
terminal 2C.sub.1 are connected with a line 6c. As indicated in the
figure, each of the multimedia terminals is provided with e.g. usual data
terminals (e.g. a display device having an input key board), sound data
terminals (e.g. a telephone device), facsimile devices, which are
facsimile data terminals, etc.
Further, in order to identify the plurality of terminals connected with a
subscriptor line, the addresses of the terminals 2A.sub.1 and 2A.sub.2 on
the subscriptor line 6a are defined e.g. as X and Y, respectively.
Furthermore the address of the terminal 2B.sub.1 on the line 6b is defined
e.g. as Z. a, b and c are addresses of the data terminal equipments (DTE)
for identifying unambiguously the lines 6a, 6b, 6c to be connected in the
ISDN system.
FIG. 2 is a scheme illustrating the construction of the principal part of
an embodiment of the ISDN system according to this invention. Here this
invention will be explained, taking a case where data communication is
executed between the multimedia terminals 2A.sub.1 and 2B.sub.1 as an
example. Therefore the terminals other than the terminals 2A.sub.1 and
2B.sub.1 are omitted in the figure.
The terminal 2A.sub.1 is provided e.g. with a display device 23a having an
input device (e.g. an input key board) 24a, a telephone device 25a, two
facsimile devices (FAX-I) 22a.sub.1 and (FAX-II) 22a.sub.2, a data file
14a and a communication control device 21a. Similarly the terminal
2B.sub.1 is provided e.g. with a data file 14b and a communication control
device 21b in addition to a display device 23b having an input device 24b
and a facsimile device 22b as an input/output device (media device). Each
of the data files 14a and 14b includes a table 30a, 30b storing the
address of the own terminal and the addresses of the media devices within
the own terminal and at the same time holds an address table 32a, 32b
storing the address of the terminal, with which communication is to be
executed, and the addresses of the media devices within the relevant
terminal to be communicated as a data base. That is, a data base 14b
includes a table 30b storing the address Z of the terminal name 2B.sub.1
of the own terminal, the address b of the corresponding DTE and the
addresses (omitted) of the media devices within the own terminal and a
table 32b holding the address Y of the terminal name 2A.sub.1 of the
terminal 2A.sub.1, with which communication is to be executed, the address
a of the corresponding DTE and the names as well as the addresses
.circle.A , .circle.B , .circle.C and .circle.D of the media devices
within the terminal 2A.sub.1.
On the other hand the data base 14a of the terminal 2A.sub.1 is provided
also with a table 30a storing the address of the own terminal, etc. and a
table 32a storing the address of the terminal 2B.sub.1, with which
communication is to be executed, etc.
Consequently each data base has the number of tables, which is equal to the
number of communication destinations.
Each of the communication control devices 21a, 21b reads out the address of
a terminal with which communication is to be executed and the address of a
media device of the communication destination thereof from the data base
in the own terminal; puts them in the connection demanding signal; and
sends them to the ISDN according to the procedure of the ISDN protocol, or
judges whether the terminal, which is to be connected, is the own terminal
or not on the basis of the ISDN number in the connection demanding signal
received from the ISDN; searches the media device, which is to be
connected, from the data file, in the case where the signal is for the own
terminal; and executes the connection process for the media device, which
has been searched according to the procedure of the ISDN protocol.
The data in each of the data file can be set arbitrarily by a user of the
ISDN system. For example it is possible to set it so that the name of the
media device represented by .circle.A , which is a device of the terminal
2A.sub.1, is a display; the address .circle.B is a telephone; the
address .circle.C is FAX-I; and the address .circle.D is FAX-II.
Such a data setting may be effected through the input devices 24a, 24b in
each of the terminals before the beginning of the data communication or by
setting data of the own terminal and the destination terminals all
together at a terminal and sending necessary data to the destination
terminals to store them.
FIG. 3 is a scheme illustrating the structure of an ISDN number in the
connection demanding signal transmitted and received between terminals,
when the terminals are connected through the ISDN. The example indicated
in FIG. 3 shows an ISDN number, in the case where connection is made from
the terminal 2B.sub.1 to the device FAX-II in the terminal 2A.sub.1. As it
can be seen from the figure, the ISDN number consists of an international
ISDN number and a sub-address. The international ISDN number includes the
DTE address (here a) of the terminal of the destination, which is to be
connected and the sub-address includes an terminal identification address,
i.e. the address Y of the terminal 2A.sub.1 of the destination, and a
media device address; i.e. the address .circle.D of the media device,
which is the object to be connected, in the terminal 2A.sub.1 of the
destination. In the figure, a mark * is a delimitter indicating a pause
between addresses, etc.
Further a user can set freely the structure of the sub-address in the ISDN
address. The pause between the sub-address and the international ISDN
address is indicated by "*" and the data succeeding the first * may be
data for identifying the name of the media device and the data succeeding
the second * may be data for identifying the terminal on the relevant
subscriptor line.
Next the connection procedure will be explained, referring to FIGS. 4 to 6
for the case where data are transmitted from a media device in one
multimedia terminal to a media device in another multimedia terminal, e.g.
from the facsimile device 22b in the multimedia terminal 2B.sub.1 to the
facsimile device (FAX-II) 22a.sub.1 in the multimedia terminal 2A.sub.1.
FIG. 4 is a scheme illustrating the connection procedure between multimedia
terminals according to this invention, which is a control sequence
indicating the communication procedure among a terminal--an ISDN--a
terminal. FIGS. 5 and 6 are flow charts indicating the connection
processes by the communication control device in the terminal on the
transmitter side and the terminal on the receiver side, respectively.
At first the user operates the input device 24b to input information to be
transmitted, which is formed by means of the facsimile device 22b in the
multimedia terminal 2B.sub.2, in the communication control device 21b. At
the same time he makes the display device 23b display data in the data
file 14b, among which data he inputs the terminal name 2A.sub.1 of the
destination (FIG. 5, Step 100). He makes the display device display the
kinds of the media device related to the terminal name 2A.sub.1, among
which he selects a media device of the destination (in this case the
device FAX-II 22a.sub.2) (Step 102).
Then the addresses of the inputted terminal name 2A.sub.1 and the selected
media device FAX-II are read out from the Table 32B in the data file 14b.
That is, the address a of the DTE and the address Y of the terminal
2A.sub.1 are read out from the address table of the terminal name 2A.sub.1
and at the same time the address .circle.D of the facsimile device
FAX-II in the terminal 2A.sub.1 is read out (Step 104).
In this way, as indicated in FIG. 3, the structure of the ISDN number is so
formed that international ISDN number=a, terminal identification address
on the subscriptor line 6a=Y, and address of the media device= .circle.D ,
and a connection request signal is transmitted by the terminal 2B.sub.1 to
the ISDN 1 (Step 106 in FIG. 5, Process 106 in FIG. 4).
When the ISDN receives the connection demanding signal, it returns an
acceptance of transmission to the terminal 2B.sub.1 (Process 108 in FIG.
4) and at the same time identifies the subscriptor line 6a, which is to be
connected, from the international ISDN number and sends a reception signal
to the line 6a (Process 110). This reception signal includes the ISDN
number.
The communication control device 21a of the terminal 2A.sub.1 receives the
reception signal and reads out the terminal identification address Y in
the sub-address. Then it judges whether the address is the identification
address of the own terminal or not, referring to the table 32a (Step 120
in FIG. 6). In this case, since it is the identification address of the
own terminal, the connection procedure is continued. In the case where it
is not the identification address of the own address, the connection
procedure is terminated.
Next, the communication control device 21a of the terminal 2A.sub.1 stores
the sub-address in the reception signal and at the same time returns an
acceptance of reception to the ISDN (Process 121). The acceptance of the
reception is sent to the terminal 2B.sub.1 through the ISDN (Process 122).
Further the communication control device of the terminal 2A.sub.1 refers
to the table 32b for the media device address .circle.D in the
sub-address and identifies that the media device, which is to be
connected, is FAX-II (Step 122).
Consequently the facsimile device FAX-II 22a.sub.2 is connected with the
line 6a through the communication control device 21a (Step 124).
Subsequently the communication control device 21a reads out the own
sub-address from the table 30a, which is added to the response signal and
sent to the ISDN 1 (Process 124). The response signal arrives at the
terminal 2B.sub.1 through the ISDN.
In this way the facsimile devices 22b and 22a.sub.2 are connected with each
other through the ISDN and facsimile data are transmitted and received
therebetween (Process 126, Step 126).
Further the connection of the facsimile device with the line 6b may be
effected also in the processing flow (Steps 100 to 106) indicated in FIG.
5 and still further the acceptance of reception (Process 122) indicated in
FIG. 4 may be effected also by responding to the response signal (Process
125).
Although, in the above embodiment, the connection procedure has been
explained between multimedia terminals, one of them may be a media
terminal having only one media device, while the other is a multimedia
terminal.
Although, in the above embodiment, the connection procedure has been
executed by specifying the media device, which is to be connected with the
ISDN, it may be executed by specifying the kind of media devices or the
kind of media.
In the case where the kind of media devices is specified, e.g. display,
telephone, facsimile device, etc. may be enumerated as the kind of media
devices. In this case each of the tables indicated in FIG. 2 may be
constructed as indicated in FIG. 7.
Consequently, in the case where it is required to connect the terminal
2B.sub.1 with eather one of the facsimile devices FAX-I and FAX-II in the
terminal 2A.sub.1, the terminal 2B.sub.1 adopts a media device kind
address for the media device address in the ISDN number indicated in FIG.
3, sets .circle.C for the relevant address and sends it to the ISDN. In
the terminal 2A.sub.1 it can be known from the media device kind address
.circle.C in the ISDN number that the connection object is the facsimile
device, and thus it is sufficient to connect one of FAX-I and FAX-II,
which is not busy or arbitrary one, in the case where none of them is
busy, with the ISDN.
On the other hand, in the case where the kind of media is specified, e.g.
facsimile data (corresponding to a facsimile device), sound data
(corresponding to a telephone device), image data, character data, graphic
data, etc. may be enumerated as the kind of media. In this case each of
the tables 30a and 32b indicated in FIG. 2 is constructed as indicated in
FIG. 8.
In this case also, similarly to that described above, the terminal 2B.sub.1
adopts a media kind address for the media device address in the
sub-address and sets .circle.C for the relevant address. In the terminal
2A.sub.1 the connection procedure is executed by connecting selectively
one of the two facsimile devices, responding to the address .circle.C .
Further, although, in the above embodiment, explanation has been made for
the case where the multimedia equipment connected with the ISDN is a
multimedia terminal, this invention can be applied also to a host computer
having a plurality of media devices.
Still further, although in the above addresses consisting of alphabetical
letters have been used as identification marks in the sub-address, any
mark such as numerals, etc. may be used, if it can be identified.
According to this invention, since it is possible to identify the media
device, which is to be connected, at establishing the connection in each
of the multimedia equipment by using the ISDN number in the received data,
an effect can be obtained that the communication processing efficiency is
increased in a structure, where a plurality of multimedia equipments are
connected with an ISDN.
* * * * *
|
|
 |
|
 |
Description |
|
