JPS61242157A - Method for deciding propriety for reception of radio facsimile - Google Patents

Abstract

PURPOSE:To receive surely FAX signals by deciding at a master station whether the reception of the FAX signals is possible or not according to the presence or absence of a specific frequency signal sent from a master station, the level of a high frequency noise, the input level of a receiver and the working state of a facsimile receiver respectively. CONSTITUTION:The station identifying signal, e.g., the tone signal of a specific frequency sent from a master station is extracted by a station identifying signal detector 10 through an antenna 15 of a slave station, a transmission/reception switch 14, a receiving part 7 and a demodulator 8. While the reception level D, a high frequency noise delivered from a noise detecting part 9, e.g., the level B of an engine cutter, the state C of a FAX device 5, etc. are applied to a logical circuit 11. For instance, if the levels A-D are all equal to 1, the device 5 is started for feed of originals. At the same time, an answer signal showing the reception-enable state of FAX signals is delivered to the master station from an answer signal generating part 12 via a transmitting part 13. Thus it is decided by the slave station itself whether the reception of FAX signals is possible or not. The result of this decision is informed to the master station. Thus the FAX signals can be received from the master station with higher assuredness.

Description

[Detailed Description of the Invention] [Summary] When a facsimile signal (hereinafter abbreviated as FAX signal) is transmitted from a master station to a slave station using a mobile radio line, the slave station determines whether or not there is a station identification signal from the master station. , low frequency noise level, receiver input level, and FAX receiver status.
By determining whether the signal can be received or not and sending it to the master station, the FAX signal can be received more reliably.

[Industrial application field]

The present invention relates to a method for determining whether or not a wireless FAX can be received, which is used when transmitting a FAX signal using a mobile radio line in the VHF or υHP band, for example.

In recent years, image signal transmission has become widespread, but most of this is between fixed stations where line quality is stable, for example. However, as requests for data and image transmission services using mobile radio in the VHF band or UHF band are beginning to arise, it is necessary to be able to receive FAX signals more reliably.

[Conventional technology]

FAX signals are transmitted between fixed stations with stable line quality, and this has rarely been done on mobile radio lines using, for example, the 150 MHz band or the 400 Mllz band.

[Problem that the invention seeks to solve]

In general, mobile radio slave stations move freely and may be located, for example, in the shadow of a large building, in a tunnel, or near a source of high-frequency noise. For this reason, the incoming electric field of the slave station fluctuates or the signal-to-noise ratio deteriorates, and the line quality cannot always be said to be in a good state. For this reason, even if a FAX signal is sent from the master station to the slave station, it may become impossible to receive the signal and the image may disappear midway through, or the signal may not be received at all.

Therefore, in order to receive FAX signals more reliably, the slave station determines whether or not it is in a state where it can receive FAX signals, and sends this information to the master station. Just send a fax signal.

Therefore, there is a problem in that a method for measuring whether wireless FAX reception is possible or not is required.

[Means for solving problems]

The problem with this is whether the slave station is able to receive the facsimile signal depending on the presence or absence of a specific frequency signal from the master station, the peak detected high-frequency noise level, the receiver input level, and the operating status of the facsimile receiver. This problem is solved by the method of determining whether or not wireless FAX reception is possible according to the present invention.

[Effect]

The present invention provides information on whether or not there is a station identification signal from the master station in the slave station;
By determining whether or not it is possible to receive the FAX signal sent from the master station in consideration of the high frequency noise level, receiver input level, and FAX receiver status, and notifying the master station if it is possible to receive the FAX signal, Enabled to receive signals more reliably.

〔Example〕

FIG. 2 shows a configuration diagram of a wireless FAX system.

In the figure, in order to send a FAX signal from the master station to slave stations A and B, it is necessary to know whether slave stations A and B are in a state where they can receive the FAX signal.

Therefore, a station identification signal is sent to the slave station A from the transmitter/receiver section l. Slave station A determines the detection status of this signal and the FAX device 4.
When it is determined that the device is in a state where it can receive from the state etc., a response signal is sent from the transmitting/receiving section 3 to the master station.

Next, the same thing is done for slave station B.

After receiving the response signals from slave stations A and B, the master station
A FAX signal is sent using the X device 2, and the slave station receives it.

FIG. 1 shows a block diagram of an embodiment of the present invention, which is a method for determining whether wireless FAX reception is possible.

In the figure, the station identification signal (for example, a tone signal of a specific frequency) from the master station is transmitted to the antenna 15 of the slave station. Transmission/reception switch 14
．． Receiving section 7. The signal passes through the demodulator 8 and is extracted by the station identification signal detection unit IO. Also, the reception level is D.

The level B of high frequency noise (for example, an engine cutter) output from the noise detection section 9, the state Bc of the FAX machine 5, etc. are added to the logic circuit 11.

For example, if A-B-C-D are all 1, FAX machine 5
The response signal generating section 12
A response signal indicating that the FAX signal can be received is sent to the master station via the transmitter 13.

In addition, A is when the station identification signal is detected. I B is when the high frequency noise is below the specified level. IC is when the FAX machine is ready. ID is when the reception level is above a certain value. FAX signals can be reliably received. However, in reality, even if D is a little low, reception is possible as long as B is close to 1, but the above-mentioned strictest condition can be relaxed by conducting various experiments.

Although impulsive high-frequency noise has little effect on the reception level indication, this item is included because it reduces the signal-to-noise ratio of the FAX signal. Then, this value is subjected to peak value detection to obtain the peak value, and if the value is below a predetermined level, it is set to 1.

Thereby, the FAX signal from the master station can be received more reliably.

〔Effect of the invention〕

As explained in detail above, the slave station itself determines whether it is capable of receiving FAX signals and notifies the master station of the result, making it possible to more reliably receive FAX signals from the master station. .

[Brief explanation of drawings]

Figure 1 is a block diagram of an embodiment of the present invention, and Figure 2 is a block diagram of an embodiment of the present invention.
A configuration diagram of an IFAX system is shown. In the figure, 1.3 is a transmitting/receiving section, 2.4.5 is a FAX device, 7 is a receiving section, 8 is a demodulating section, 9 is a noise detecting section, 10 is a station identification signal detecting section, 11 is a logic circuit, and 12 is a The response signal generator is shown. -I- Station Master station Slave station doorless rAX system 1≦2 lectures (Figure $ 2 Figure

Claims (1)

[Claims] When a facsimile signal is transmitted from a master station to a slave station over a mobile radio line, the slave station detects the presence or absence of a station identification signal from the master station, the high-frequency noise level detected as the peak value, and the receiver. 1. A wireless facsimile reception capability determination method, characterized in that it is determined whether or not the facsimile signal can be received based on an input level and an operating state of a facsimile receiver.