JP3052276B2 - ISDN signal relay method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the setting of a communication line between a fixed ISDN network (Integrated Services Digital Network) and another network such as a mobile communication network.
That is, the present invention relates to an ISDN signal relaying method in an ISDN calling / incoming call procedure when a connection delay occurs due to synchronization, interleaving, and outgoing / incoming call processing unique to the network.

[0002]

2. Description of the Related Art In recent years, needs for diversification of mobile communication have been increasing. Conventionally, the mobile communication mode is shifting from a telephone-centered mobile communication mode to a variety of needs including non-telephone communication such as image communication and data communication. An offer is being attempted.

[0003] In a mobile communication system mainly for voice transmission, the transmission quality of radio section signals is significantly inferior to the transmission quality of fixed ISDN. That is, fixed ISDN
Provides a quality of 10 ^-6 or less in bit error rate, whereas the bit error rate for obtaining voice quality allowed in mobile communication is about 10 ^-2 . For this reason, a fixed ISD is used in a mobile communication system mainly for voice transmission.
In order to provide an ISDN service having a signal transmission quality equivalent to N, it is inevitable to apply a quality improvement technique such as an error correction code. Such a method of providing high-quality facsimile communication and modem communication by interposing a function for quality improvement (hereinafter, referred to as a unit) in a mobile radio section has already been put into practical use (Literature, Kamibayashi, Sawai, Nagata, Ishino, "Digital Mobile Communication System: Non-telephone Signal Transmission Service" NTT DoCoMo Technical Journal V
ol. 1, No. 1, pp. 47-49, Jul. 19
93).

[0004] When an ISDN service is provided in a mobile communication system using such a unit, the unit serving as a network-side function is demand-assigned (intervening the unit after a request for ISDN communication is generated by a user). It can be said that the use in ()) is a desirable form from the viewpoint of the efficiency of operation of the unit device. In this case, it is necessary to establish synchronization between the units in the above-described poor transmission quality after the units are allocated and before the B-channel communication can be actually performed, and the time required for the synchronization is required. become. In addition, if interleaving is applied to randomize burst errors occurring in a radio section to extract the performance of an error correction code, a delay time for this is generated. In addition, the normal call originating and terminating procedures defined in ISDN (for the ISDN normal calling and terminating procedures, CCIT
In addition to the T recommendation, in some cases, a procedure specific to a mobile communication system may be required (for details, refer to literature, Yamamoto, Takamura, Uchida, Hirata, "Digital Mobile Communication System: Network Configuration and Signaling"). NTT DoCoMo Technical Journal Vol.1, No.1, pp. 20-2
2, Jul. 1993), and time is needed for these.

For example, as shown in FIG. 2, a mobile terminal 13 is connected to a mobile communication system 11 via a mobile unit 12, and the mobile communication system 11 is connected to a fixed ISDN network 15 via a base station unit 14. A system in which the mobile terminal 13 is connected to the fixed terminal 16 via the mobile communication system 11 and the fixed ISDN network 15 and performs various kinds of communication with each other can be considered.

In such a system, as shown in FIG. 3, when a setup signal (corresponding to a transmission request) 21 is transmitted from a transmission side terminal, for example, a mobile terminal 13, for transmission, the mobile terminal side which has received this signal. The unit 12
The mobile communication system 11 for notifying the tup signal 21 to the receiving side unit, in this example, the base station side unit 14.
Is sent. The base station side unit 14 which has received the signal 22 immediately sends out the setup signal 23 to the fixed terminal 16 which is the receiving terminal. The fixed terminal 16 is
When the tup signal 23 is received, the call proc signal 24, A
A lert signal 25 and a Conn signal 26 corresponding to off-hook are sent to the base station unit 14 (Call
Some terminals do not output the Proc signal 24 because it is optional).

[0007]

Since the Call Proc signal 24 and the Alert signal 25 do not require a response from the network side, the progress of the protocol at the terminating terminal cannot be controlled on the network side. However, as described above, in the wireless section, processing unique to the mobile communication system for synchronization and interleaving between the mobile unit 12 and the base station unit 14, and call origination / termination procedures, that is, the network sets a communication line. Since the delay due to the processing 27 required for performing the operation is inevitable as shown in FIG. 3, the receiving side unit (base station side unit 14) is connected to the receiving side terminal (fixed terminal 1).
6 ) Even when the Conn signal 26 is received, there is no guarantee that the B channel has been established, the line setting process 27 has not been completed, and even if the called terminal 16 goes off-hook,
There is a disadvantage that communication on the B channel cannot be performed immediately. In the worst case, the timer of the receiving terminal 16 from the transmission of the Conn signal 26 to the establishment of the B channel may time out, and the receiving terminal 16 may disconnect the line.

An object of the present invention is to provide an ISDN as described above.
To solve the above-mentioned problem caused by the connection delay caused by the influence of the other network when setting up a communication line via the network and another network, and to perform the B-channel communication immediately when the called terminal goes off-hook. It is an object of the present invention to provide a method for relaying an ISDN transmission / reception signal which enables the following.

[0009]

According to the present invention, the setup signal transmitted from the originating terminal is temporarily stored in another network, and the processing in the other network necessary for relaying the B channel signal is performed. Is completed, a setup signal is sent to the called terminal.

[0010]

With this configuration, B-channel communication can be performed immediately when the receiving terminal goes off-hook. From the receiving side terminal, it looks as if the protocol is proceeding in exactly the same way as a normal outgoing / incoming call procedure.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a case where a communication line is set via a fixed ISDN network and a mobile communication network as another network will be described with reference to FIG. Therefore, the system configuration to which this embodiment is applied is, for example, the same as that shown in FIG. As in the case of FIG.
Sends out a setup signal 21 for transmission, FIG.
A mobile communication system 11 for notifying a setup signal 21 from the mobile unit 12 to the base station as shown in FIG.
Is transmitted to the base station side unit 14. In the base station unit 14, that is, in the mobile communication network, the received notification signal 22, that is, the setup signal, is temporarily stored, and processing 27 for relaying the B channel signal in the mobile communication system 11, that is, the mobile unit 12 and the base station are connected. After the processing specific to the mobile communication system 11 for synchronization and interleaving with the station unit 14 and the calling / calling procedure is completed, the base station unit 14 sends the setup signal 23 to the called terminal, that is, the fixed terminal 16. Send out. Fixed terminal 1
6 receives the setup signal 23, and sends the same incoming call procedure as a normal incoming call procedure, that is, a Call Proc signal 24, an Alert signal 25, and a Conn signal 26 to the base station side unit 14. The base station side unit 14 is C
When the on signal 26 is received, the confirmation signal Conn
Ack signal 28 is returned to fixed terminal 16 and fixed terminal 16
And the mobile terminal 13 can communicate on the B channel.

According to this embodiment, if the fixed terminal 16 goes off-hook, the communication line between the units 12 and 14 is set at that time, so that B-channel communication can be performed immediately. In the above description, the case where the mobile terminal 13 starts is described. However, even when the fixed terminal 16 transmits a signal, the fixed terminal 1 or
The setup signal from 6 to escrowed, Unit 1
The transmission to the mobile terminal 13 may be performed after the setting process of the B channel line between 2 and 14 is completed. In the above, setu
Although the p signal is temporarily stored in the base station side unit, it may be temporarily stored in the mobile unit side. Further, the communication line is set up via the fixed ISDN network and the mobile communication system. However, not only the mobile communication network but also the satellite communication network and other fixed ISDNs are set.
The present invention can be applied to a signal relay in an ISDN calling / incoming call procedure in a system in which a connection delay occurs due to the influence of the connected other network when the line is set by connecting the network to another network.

[0013]

As described above, according to the present invention, the setup signal is temporarily stored in the terminating side network,
Since the setup signal is transmitted to the called terminal after the line setting process of the B channel communication between the DN network and another network is completed, the B channel communication can be performed immediately when the called terminal goes off-hook. From the receiving side terminal, it looks as if the protocol is proceeding in exactly the same way as a normal outgoing / incoming call procedure. It does not happen that the timer of the called terminal times out and the called terminal disconnects the line.

[Brief description of the drawings]

FIG. 1 is a diagram showing a processing procedure in an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a system to which the present invention is directed.

FIG. 3 is a diagram showing a conventional processing procedure and its problems.

──────────────────────────────────────────────────の Continuing on the front page (51) Int.Cl. ⁷ Identification symbol FI H04Q 7/30 (72) Inventor Akira Hiroike 2-10-1 Toranomon, Minato-ku, Tokyo In-company (56) References JP-A-5-68001 (JP, A) JP-A-59-216334 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B ^7/ 24- 7/26 H04M 7/00-7/16 H04Q 7/00-7/38

Claims (3)

(57) [Claims] 1. A when setting the communication line via the fixed ISDN network and other networks, the ISDN signal relaying method in an ISDN incoming and outgoing call procedure for connection delay due to the influence of the other network occurs, the other The setup signal sent from the originating terminal connected to the other network is temporarily stored in the other network, and the setup signal after the processing in the other network for relaying the B channel signal is completed. To the fixed ISDN network
IS, wherein the sending to the receiving-side terminal that is
DN signal relay method. 2. Communication via a fixed ISDN network and another network.
When setting up a line, connection delay due to the effects of other networks
ISDN signal in ISDN originating and terminating call procedure when
In the signal relay method, a message is transmitted from a calling terminal connected to the fixed ISDN network.
The output setup signal is temporarily stored in the other network,
The processing in the other network for relaying the B channel signal is as follows.
After the termination, connect the setup signal to the other network
Characterized by sending to the called terminal
DN signal relay method. (3) The other networks are mobile communication networks.
The ISDN signal relay method according to claim 1 or 2, wherein