JPH0340535A - Isdn terminal equipment connecting system - Google Patents

Abstract

PURPOSE:To connect a transmission line between a network terminating equipment and an ISDN terminal equipment similarly to a wired line even in the case of using the line as a wireless line by allowing the ISDN terminal equipment to decide whether control channel information included in control information is the same as control channel information sent from the self-terminal or not. CONSTITUTION:The ISDN terminal equipment 1 to originate a call detects that the output of a delay circuit 9 is an antenna signal and sends transmission signal from a spread spectrum type transmitter 3. Then, the equipment 1 monitors the output of a comparing/detecting circuit 11, and only when the output coincides with the signal sent from the self equipment, continuously transmits the succeeding data. If both the signals are different, the transmission is stopped and waited until an antenna signal is received again, so that the generation of a collision due to the simultaneous calling or the like of plural ISDN terminal equipments 1, 2 can be prevented. Thereby the transmission line between the network terminating equipment 3 and the ISDN terminal equipments 1, 2 can be connected equivalently to the wired line even when it is used as a wireless line.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an I5DN fl terminal device connection system, and specifically relates to an ISDN terminal device in which the transmission path between a network termination device and an ISDN terminal device is a wireless line. Regarding the connection method.

[Conventional technology]

Conventionally, as a connection method between a network termination device and an ISDN terminal device, various methods that assume a wired line as a transmission path have been proposed and put into practical use. However, there is no particular connection method established when the transmission path is a wireless line. Furthermore, it is impossible to apply the various methods that are currently being proposed that assume wired lines as transmission paths to wireless lines, and it is especially difficult to apply them to wireless lines, especially when it comes to collisions such as when calls are made between ISDN terminals. Measures are necessary.

[Problem that the invention seeks to solve]

The above-mentioned conventional ISDN terminal device connection system has the problem that there is no particular connection system established when the transmission path is a wireless line, and there is no suitable connection system.

An object of the present invention is to provide an ISDN terminal device connection system that allows a connection equivalent to a wired line even if the transmission path between a network termination device and an ISDN terminal device is a wireless line.

[Means for solving problems]

The ISDN terminal device connection method of the present invention uses a wireless line as a transmission path between a network termination device and one or more ISDN terminal devices, and the network termination device has a function of extracting control channel information included in a received signal. and a phase modulation method or frequency modulation method transmitter having a function of including the extracted control channel information in the control information to be transmitted, and the I SDN terminal device A comparison detection circuit that determines whether control channel information included in the control information received from the network terminal device, such as a modulation method receiver and a spread spectrum transmitter, is the same as the control channel information transmitted by itself. Configured with the necessary features.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

The I SDN terminal device 1 and the I SDN terminal device 2 are
Spread spectrum transmitters 3 and 4, a phase modulation or frequency modulation receiver 5.6, a data control section 7.8 that controls operation as a data terminal device, and a spread spectrum transmitter 3.4, respectively. A delay circuit 9.10 extracts the control channel information sent by itself from the transmitted signal, delays it for a certain period of time, and outputs it, and a phase modulation type or frequency modulation type receiver 5.6 extracts control channel information from the received signal of the receiver 5.6. Comparison and detection circuits 11 and 12 are provided for comparing the output of the output delay circuit 9 and the output of the delay circuit 9 and 10 to determine whether or not the received information is the same as the control channel information transmitted by itself.

The network terminal device 13 includes a spread spectrum receiver 14 having a function of extracting control channel information included in the received signal.
, a phase modulation type or frequency modulation type transmitter 15 having a function of including the extracted control channel information in the control information sent to the ISDN terminal devices 1 and 2, and a network device that controls the operation as a network terminal device. A termination control section 16 is provided.

Next, the operation will be explained.

The ISDN terminal device 1 that is about to make a call now sends out a transmission signal from the spread spectrum transmitter 3 after detecting that the output of the delay circuit 9 is a blank line signal. After that, the output of the comparison detection circuit 11 is monitored, and only when it matches the signal sent by itself, continues to transmit the next data,
If there is a mismatch, transmission is stopped and waits until a blank line signal is received again. This makes it possible to avoid collisions caused by ISDN terminals making simultaneous calls, etc.

Next, verification of the signals sent by itself will be explained with reference to FIG. 2.

FIG. 2 is a signal sequence diagram showing the transmission and reception of signals between the network termination device 13 and the ISDN terminal devices 1 and 2. In FIG.

All I SDN terminal equipment's SUBEC I-LE spreading method transmitters have a cyclic pseudo-random sequence pattern generation circuit having the same generating polynomial, and are synchronized with the signal reception of the idle signal 17 from the network termination equipment. The time point is set as reference 18, and each I
The system is such that control channel information 21 is transmitted with a time difference of 19.20 determined for each SDN terminal device.

The spread spectrum receiver of the network termination equipment is an ISDN
It has a pattern generation circuit for a cyclic pseudo-random sequence having the same generating polynomial as the transmitter of the terminal device, and synchronization is performed by transmitting control channel information 21 from the network terminal device and then synchronizing it with the control channel information 21 transmitted by the I5DN terminal device. , demodulation is performed with a time difference of 19.20 determined for each ISDN terminal device described above, based on the loop delay time 22 until reception. The network terminal device periodically changes the time difference until it sequentially demodulates the signal until it detects the transmission from each ISDN terminal device, fixes the time difference when it detects the signal, and then
Continuously decode and receive signals from the DN terminal equipment.

The transmission signal from the network terminal equipment includes control channel information 21 received from the ISDN terminal equipment as return information. In FIG. 2, the control channel information 21 of the ISDN terminal device 1 is shown as AI, A2°A3, and the control channel information 21 of the ISDN terminal device 2 is shown as B1. When all ISDN terminal devices are not transmitting, this return information is a blank line signal 17.

In this way, by checking the control channel information 21 prefixed to the transmission signal of the network terminal device 13, each ISD
N terminal devices can detect simultaneous calls.

〔Effect of the invention〕

As explained above, the present invention provides a network termination device and an ISD.
Even if the transmission path with the N terminal device is a wireless line, it has the effect that a connection equivalent to a wired line is possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a signal sequence diagram showing the transmission and reception of signals between the network termination device 13 and the ISDN terminal devices 1 and 2. In FIG. 1.2...I SDN terminal device, 3,4...
...Spread spectrum transmitter, 5.6...
Phase modulation type or frequency modulation type receiver, 7.8...
...Data control unit, 9, 10...Delay circuit, 11.12...Comparison detection circuit, 13...
... Network termination device, 14 ... Spread spectrum receiver, 15 ... Phase modulation method or frequency modulation method transmitter, 16 ... Network termination control unit, 17.
...Blank signal, 18...Standard, 1920
......Time difference, 21...Control channel information, 22...Loop delay time.

Claims (1)

[Claims] In the ISDN terminal device connection method, the transmission path between the network terminating device and one or more ISDN terminal devices is a wireless line, and the network terminating device has a function of extracting control channel information contained in a received signal.A spread spectrum method is used. receiver and
The ISDN terminal device includes a phase modulation type or frequency modulation type transmitter having a function of including the extracted control channel information in the control information to be transmitted, and the ISDN terminal device includes a phase modulation type or frequency modulation type receiver and a spread spectrum type transmitter. and a comparison detection circuit that determines whether the control channel information included in the control information received from the network termination device is the same as the control channel information transmitted by the ISDN terminal. Device connection method.