JP2707719B2 - Communication terminal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a communication terminal device suitable for use in, for example, an ISDN terminal.

[Summary of the Invention]

The present invention relates to a communication terminal device suitable for use in, for example, an ISDN terminal, transmits a call setup message including a called number to a signal switching network via a signal channel, and waits for a response message from the signal switching network. After transmitting the information, the communication terminal device transmits a disconnection message to the signal switching network via the signal channel, waits for a release message from the signal switching network, and ends the information transmission. Transmitting a call setup message containing the first called number to the signaling network via the channel to transmit information, and sending a disconnect message corresponding to the first called number to the signaling network via the signaling channel; Immediately after transmitting the call setup message including the second called number via the signaling channel without waiting for the release message corresponding to the first called number. Transmitting information corresponding to the second called number after transmitting to the network and receiving from the signaling network a release message corresponding to the first called number and a response message corresponding to the second called number; Is performed, so-called broadcast communication in which the same information is sequentially transmitted to a large number of receiving terminals can be efficiently performed.

[Conventional technology]

With the development of digital technology, ISDN (Integrated Services Digital Network :) that can digitize and integrate different networks such as telephone, telegraph, circuit switching, and packet switching and provide various services to users with a single subscriber line
Service integrated digital network) has been constructed and started operation.

FIG. 2 shows an example of the ISDN network configuration. In FIG. 2, (1) is an ISDN (hereinafter simply referred to as "network"), and this network (1) is distributed to each telephone station. ISDN
Switch (2A), (2B) B-channel circuit switching network (3) with a communication speed of 64 kbps, communication speed of 384 kbps (HO channel)
And the like, and are connected by a high-speed circuit switching network (4), a packet switching network (5), and a common line signal network (6) for transmitting control signals and the like. The ISDN exchange (2A) has 2
DSU (Digital-data Service Uni) in the user's home (8A) via a subscriber line (7) consisting of a metallic wire
t) (9A) is connected, and DSU (9A) is connected in parallel with this DSU (9A).
B), (9C) ‥‥ are connected. Similarly, DSUs (10A), (10B), (10C)} are connected to the ISDN exchange (2B), and these DSUs (9A), (9B)} and DSU (10A),
(10B) ‥‥ is the network terminating device (NT: Network) of the network (1).
Termination).

In the user's house (8A), a bus line (13) having a transmission line (11) and a reception line (12) and consisting of a 4-wire metallic wire is derived from the DSU (9A), and this bus line (13) Digital telephone (14A), computer (14B), G4 facsimile (14C), terminal adapter (TA: Terminal Adapter) (14D), non-ISDN terminal (15) in parallel with 1: N wiring (bus wiring) It is connected to the. This interface is the smallest basic interface defined in ISDN, and this basic interface is logically composed of two B
Channel (16A), (16B) and one D channel (17)
B channel (16A) and (16B) are 64kb each
Various user information is transmitted bi-directionally at the communication speed of ps,
The D channel (17) bidirectionally transmits call control (transmission, termination, etc.) information mainly for circuit switching and packet switching at a communication speed of 16 kbps. However, since the signals of these (2B + D) channels are physically transmitted in a time-division manner on one bus line, the nominal bit rate including the control bits is 192 kbp.
s.

In addition, it is convenient to classify the communication protocol, which is generally a rule for the exchange of control information between the communication device and the communication network, into several layers in appropriate functional units in order to facilitate expansion of communication functions. One of such classification methods is a seven-layer standard protocol model standardized by the International Organization for Standardization (ISO) as an OSI (Open System Interconnection) reference model. FIG. 4 shows a configuration example in which the ISDN user / network interface is divided into seven layers according to the standard protocol model. In FIG. 4, a terminal device (TE: Ter) such as a digital telephone is shown.
minal Endpoint) (18) and (19) are connected to the network (1) via DSUs (9A) and (10A), respectively, and the terminal device (1
8) is composed of layer (layer) 1 (20A), layer 2 (20B), layer 3 (20C) and layers 4 to 7 (20D), and network (1) is layer 1 (21A), layer 2 (21B). ), Layer 3
(21C) and layers 4 to 7 (21D). Similarly, the terminal device (19) also includes seven layers (22A) to (22D).

Among these seven layers, protocols from layer 1 to layer 3 are defined for the ISDN user / network interface, and layer 1 (physical layer) is used for electrical connection such as pin arrangement for connecting the terminal device to the network. Layer 2 (data link layer) defines procedures for detecting and recovering transmission errors occurring in the communication process, and layer 3 (network layer) defines data between terminal devices via the network. Specifies how to transfer

When the information in layers 1 to 3 is S _{1 to} S ₃ , respectively, the information S _{1 in} layer ₁ is an AMI (Alternate) having a 100% pulse width.
ate Mark Inversion) code. Specifically, a low level “0” is represented by a positive or negative pulse, and a high level “1” is represented without a pulse. Further, information S ₁ is 250μ in one frame of 48 bits (192kbps as shown in FIG. 5
FIG. 5A shows a frame configuration when transmitted from the DSU to the terminal equipment (TE).
FIG. B shows a frame configuration when transmitted from the terminal device to the DSU. In FIG. 5, F is a framing bit, L. is a DC balanced bit, D is a D channel bit, E
Is the D echo channel bit, FA is the auxiliary frame bit,
N is an inverted bit of FA, B1 is a bit string of the first B channel,
B2 is a bit string of the second B channel, A is a bit used for activation, S is a spare bit, and M is a multi-framing bit.

Also, the information S _{1 of} layer 1 has the meaning shown in Table 1.
Classified as INFO signal.

The INFO signal shown in Table 1 is used for activating Layer 1 as described later.

Information S2 used in layer ₂ is a signal of layer 1
S ₁ has a high degree of frame format than the type and content of the main frame of information S ₂ the layer 2 second
These are summarized in the table.

In Table 2, in the information transfer frame (I frame), the user information is transmitted via the B channel, but the I frame for call control and the unnumbered frame (U frame) are respectively transmitted via the D channel. Transmitted. The SABME command of the U frame is used to set the data link between the terminal device and the network side to the multiframe confirmation type operation mode. The multiframe confirmation type operation mode is a number-based information transfer frame in Layer 2. This is an operation mode in which I frames are transmitted in numerical order, and when a transmission error occurs, retransmission is performed for recovery. The DISC command is then used to terminate the multi-frame acknowledged operation mode.

In addition, the call control signal of the D channel of the information S ₃ used in the layer 3 are classified into the following message, each of these messages B channel for realizing circuit switching and packet switching in B channel Used for link setting.

Call setup message Contains caller number, called number, relay network selection information, transmission capability information, etc., and is used for call setup requests.

Call setup acceptance message Used to notify that all call setup information has been accepted.

Response message Used to notify the calling party that the called party has accepted the call.

Disconnect message Used to request disconnection of the connection between terminal devices.

Release message Used for a release request of the information channel or the like after disconnection of the information channel (B channel).

Release completion message Used to notify the release of the information channel.

When transmitting B-channel information from a terminal device (TE) to another terminal device via a network (ISDN) using the above information of layers 1 to 3, the communication between the terminal device on the transmission side and the network is performed. The communication operation between them will be described with reference to FIG. First, in step (101), for example, when the receiver of the terminal device is taken off-hook by the operator, the terminal device transmits a layer 1 <INFO 1> signal (see Table 1) to the network side,
In response, the network returns a layer 1 <INFO 2> signal in step (102). Then, step (10
When the terminal transmits the <INFO 3> signal to the network side in 3), a layer 2 activation display request signal is sent to the network side, and in step (104), the network sends the <INFO 4> signal to the terminal side. The transmission establishes a link of layer 1 and activates layer 2 of the terminal device.

Next, the terminal device receives a layer 3 dial setting request for dialing the called number, which is the number of the called side, and in step (105), sends a layer 2 SABME command (see Table 2) to the network side. In response to this, the network responds by displaying a dial setting display as a notice of dial setting on a circuit system corresponding to layer 3 of the network, and then transmitting a UA command to the terminal device in step (106). As a result, dial setting confirmation indicating that dial setting is possible for the circuit system corresponding to layer 3 of the terminal device is performed, and layer 2 is confirmed.
Is established, the I frame can be transmitted in the multi-frame confirmation type operation mode in the layer 2, and the layer 3 is activated.

Next, in response to the dialing of the called number by the operator, in step (107), the terminal device transmits a layer 3 call setting message including the calling number and the called number to the network side. The call setup message and the like are transmitted in a layer 2 information transfer frame (I frame). Upon completion of the reception of the layer 3 call setup message, the network proceeds to step (108).
Transmits a layer 3 call setting acceptance message to the terminal device. Then, when the called number has a vacancy and the receiving side accepts the call, the network transmits a layer 3 response message to the terminal device side (step (108)), and the layer 3 information transmission on the B channel becomes possible.

Subsequently, after information transmission on the B channel is completed in step (110), for example, when the operator goes on-hook, the terminal device transmits a layer 3 disconnection message to the network side in step (111) and responds to this. When the layer 3 release message is transmitted from the network to the terminal device (step (112)), the terminal device transmits a layer 3 release completion message to the network side (step (113)) and is used. The B channel is released.

Then, in response to a dial release request from a circuit system corresponding to layer 3 of the terminal device, the terminal device performs step (11).
In step 4), a layer 2 DISC command is transmitted to the network side (see Table 2), and the network transmits a UA command to the terminal device (step (115)). To end. Next, step (11)
In 6), the network transmits a layer 1 <INFO 0> signal indicating no signal to the terminal device (step (116)),
In response, the terminal device transmits a layer 1 <INFO 0> signal indicating a no-signal state to the network side in step (117), thereby terminating the communication operation.

In the operation of FIG. 6, steps (105) to (109) and steps (111) to (115) are respectively performed via the D channel for transmitting a call control signal, and the transmission in step (110) is performed for information transmission. Through the B channel.

[Problems to be solved by the invention]

In FIG. 6, there is a case where a terminal device wants to perform a so-called broadcast communication in which the same information is transmitted to many receiving terminal devices via a network. In this case, since the terminal device can normally perform only transmission via one B channel, it is necessary to sequentially transmit information to these many receiving terminals serially via the network.

However, in order to sequentially and serially transmit information to these many receiving terminal devices, the steps (10) in FIG.
It is necessary to repeat 1) to (117) by the number of the receiving terminals, and there is a disadvantage that the transmission time (line occupation time) of the broadcast becomes long.

Further, in ISDN, as shown in FIG. 2, one DSU (9
Since terminal devices (14A) to (14D) are connected to A) in the form of a bus wiring, for example, if each of terminal devices (14A) and (14B) uses one B-channel, The device cannot transmit information using the B channel. In FIG. 6, the transmission of the disconnection message in step (111) is followed by step (117) to the next step (10).
Since it is possible to interrupt another terminal device up to 1), the probability of being interrupted by another terminal device is extremely high when steps (101) to (117) of FIG. 6 are repeated many times. Get higher. Therefore, there is a problem that the time until the end of the broadcast communication becomes longer and the difference between the transmission times to the respective receiving terminals becomes larger.

The present invention has been made in view of the above, and has as its object to enable broadcast to be performed efficiently.

[Means for solving the problem]

For example, as shown in FIG. 1, a communication terminal device according to the present invention transmits a call setup message including a called number to a signal switching network via a signal channel, and waits for a response message from the signal switching network to transmit information. Later transmitting a disconnect message over the signaling channel to the signaling network;
In a communication terminal device configured to wait for a release message from the signal switching network and terminate transmission of information, a call setup message including a first called number is transmitted to the signal switching network via the signal channel. (Step (107 ₁ )) The information is transmitted (Step (110 ₁ )), and immediately after the disconnection message corresponding to the first called number is transmitted to the signal switching network via the signal channel (Step (111)). ₁ )), without transmitting a release message corresponding to the first called number, transmitting a call setup message including the second called number to the signal switching network via this signal channel (step (10)).
7 ₂ )), after receiving a release message corresponding to the first called number and a response message corresponding to the second called number from the signaling network (steps (112 ₁ ) and (10 ₁ ))
9 ₂ )), the information corresponding to the second called number is transmitted (step (110 ₂ )).

[Action]

According to the present invention, a plurality of signal channels for call control are substantially set at the same time for a plurality of receiving terminals, and information transmission from the first receiving terminal to information transmission to the second receiving terminal is performed. Switching time can be shortened.

Further, the time that the other terminal device can interrupt is from the transmission of the disconnection message corresponding to the first called number (step 111 ₁ ) to the transmission of the call setup message including the second called number (step 107 ₂ ). Is reduced, and the probability of being interrupted by another terminal device is greatly reduced.

〔Example〕

Hereinafter, an embodiment of a communication terminal device according to the present invention will be described with reference to FIG. In this example, the present invention is applied to an ISDN terminal device. In FIG. 1, steps corresponding to the steps in FIG. 6 are denoted by the same or similar reference numerals, and detailed description thereof will be omitted.

The terminal device (TE) of this example is similar to the example of FIG.
N) and two B channels for information transmission via DSU and 1
It is assumed that the DSUs are logically and bidirectionally connected by a call control D channel, and that the physical connection between the DSU and the terminal device of the present example is of a bus connection type as in the example of FIG.

The operation in the case where the terminal device of the present example performs the broadcast communication will be described with reference to FIG. 1. The terminal device of the present example uses one B channel and uses n B devices via the network. It is assumed that the same information is sequentially transmitted to (n is an integer of 2 or more) destination terminals. In this case, call control for each receiving terminal is performed using the D channel.

In FIG. 1, steps (101) to (106)
Up to layer 2 of the terminal device and layer 2 of the network
After the link (multi-frame confirmation type operation mode) is set, the terminal device in step (107 ₁ ) performs layer 3 including the first called number (hereinafter referred to as No. ₁ ) designated by the operator. Is transmitted to the network side. Then, the No. 1 call setting acceptance message indicating that all the call setting messages have been accepted is transmitted from the network to the terminal device side (step (108 ₁ )), and the No. 1 terminating terminal cancels the call. After the response message indicating that it has been accepted and off-hook has been transmitted (step (109 ₁ )),
In step (110 ₁ ), the terminal device transmits information to the No. 1 destination terminal via the network using the B channel.

Thereafter, in step (111 ₁ ), the terminal device transmits the No. 1 disconnection message to the network side, and immediately thereafter, in step (10 ₁ ).
In 72), the terminal device transmits a layer 3 call setup message including the second called number (hereinafter referred to as No. ₂ ) designated by the operator to the network side. For example, step (11
When 1 ₁₎ in the terminal device is on-hook, operation of the step (107 ₂₎ is such to dial the next number in the off-hook immediately after the hook. After the transmission of the No. 1 release message from the network side to the terminal device side (step (112 ₁ )) and the transmission of the No. 2 call setup acceptance message (step (108 ₂ )), the step (113) _{In 1} ), the terminal device transmits a No. 1 release completion message to the network, and notifies that the use of the B channel to the No. 1 called terminal has been released. Then, after a response message indicating that the No. 2 called terminal has gone off-hook is transmitted from the network to the terminal device (step (109 ₂ )), the terminal device uses the B channel to transmit the response message via the network. The information is transmitted to the No. 2 receiving terminal device (step (110 ₂ )).

Following the same procedure, in step (110 _n )
After the transmission of the information to the receiving terminal of No. n (the n-th called number) is completed, the terminal device transmits a disconnection message of No. _n to the network side (step (111 _n )). After the network transmits the release message of No.n to the terminal (step (11)
2 _n)), the terminal apparatus transmits a release complete message No.n the network (step (113 _n)), B channel used is released. Subsequently, the multi-frame confirmation type operation mode in the layer 2 is terminated by steps (114) and (115), and the operations of the broadcast of this example are all terminated by steps (116) and (117).

In the above embodiment, steps (112 ₁ ), (10
8 ₂ ) and (113 ₁ ) are steps (113 ₁ ) are steps (112 ₁ )
The order can be changed under the condition that it comes later.

As described above, according to this example, the operations of steps (101) to (106) and steps (114) to (117) need only be performed once to perform broadcast communication to the n receiving terminals. It is. On the other hand, when performing the broadcast communication by repeating the operation of the example of FIG. 6 n times, the operations of steps (101) to (106) and steps (114) to (117) need to be executed n times. According to this example, the switching time of transmission from one receiving terminal to the next receiving terminal is reduced. Therefore, there is an advantage that the time required for communication as a whole is shortened and the communication efficiency is improved.

Further, according to this example, for example, step (110 ₁ ) in FIG.
The other terminal device can interrupt from the step (110 ₂ ) to the transmission of the No. 1 disconnection message (step (11)
1 ₁₎₎ and the transmission of the second call setting message (step (10
7 ₂ )). Therefore, the probability of being interrupted by another terminal device during a broadcast is greatly reduced, so that the time until the end of the broadcast is shortened and the difference between the transmission times to the respective receiving terminals is shortened. There are benefits to be done.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the switching time of the information transmission from the called terminal of a 1st called number to the called terminal of a 2nd called number is shortened, and the probability of being interrupted halfway from another terminal device is reduced. Therefore, there is an advantage that the broadcast can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a broadcast operation of one embodiment of the present invention;
FIG. 2 is a block diagram showing the network configuration of ISDN, and FIG. 3 is ISDN.
FIG. 4 is a diagram showing a hierarchical structure of a user / network interface of ISDN, FIG. 5 is a diagram showing a layer 1 frame structure of the example of FIG. 4, and FIG. FIG. 1 is a diagram showing a conventional communication operation. (1) is an ISDN (network), (9A) is a DSU, (13) is a bus line, and (14A) is a digital telephone.

Claims (1)

(57) [Claims] 1. A method for transmitting a call setup message including a called number to a signaling network via a signaling channel, transmitting information with a response message from the signaling network, and then transmitting the signaling via the signaling channel. A communication terminal device for transmitting a disconnection message to a switching network and terminating the transmission of information after waiting for a release message from said signaling network, comprising: a first called number to said signaling network via said signaling channel; And transmitting a call setup message including the following, and immediately after transmitting a disconnection message corresponding to the first called number to the signal exchange network via the signaling channel, corresponding to the first called number. Without waiting for the release message
A call setup message including the called number of the first party to the signaling network via the signaling channel, and a release message corresponding to the first called number and a response message corresponding to the second called number are exchanged in the signal exchange. A communication terminal device for transmitting information corresponding to the second called number after receiving from a network.