JP2725684B2 - Door-to-door receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention aims to propose a door-to-door receiver capable of improving the accuracy of information transmission with respect to a door-to-door receiver for a municipal emergency management radio system. Identification code extracting means for extracting a broadcast frequency identification code included; identification code storage means for storing the latest broadcast frequency identification code in a broadcast signal from a master station extracted by the identification code extraction means; Comparing means for comparing the broadcast number identification code in the answer back signal transmitted from the outdoor receiver extracted by the identification code extraction means to the master station with the identification code stored in the identification code storage means; Display control means for controlling the display in accordance with the comparison result.

[Industrial applications]

The present invention relates to a municipal disaster prevention administration wireless system fixed system door-to-door receiver.

The municipal disaster prevention administrative radio system fixed system is composed of a master station installed in the city hall, town hall or village office, an outdoor receiver installed outdoors, and a door-to-door receiver provided for each household, and transmits information related to disasters. Its main purpose is to quickly communicate to the people in the area.

[Conventional technology]

Of these, for the outdoor receiver, the reception state is good because the antenna is provided on an outdoor telephone pole or the like, and it has a transmission function and notifies the master station of the reception state as an answer back signal, so that retransmission etc. The information can be reliably transmitted by the means described above.

On the other hand, in a door-to-door receiver, reception is performed by a rod antenna or the like provided indoors, and there is usually no transmission function.

[Problems to be solved by the invention]

Therefore, depending on the installation position or the situation around the antenna, the reception state may be deteriorated and the speaker may not be opened. Also in this case, there is no answer back function, so that the master station side cannot grasp the situation, and there is a problem that information transmission becomes uncertain.

Accordingly, an object of the present invention is to propose a door-to-door receiver capable of improving the above points and improving the accuracy of information transmission.

[Means for solving the problem]

FIG. 1 is a diagram specifically showing the principle configuration of a door-to-door receiver according to the present invention, and is a diagram showing the configuration of the entire municipal disaster prevention administrative radio system.

A code for identifying the number of broadcasts, for example, an additional number of the number of broadcasts, is added to the broadcast signal transmitted from the master station 10 to the outdoor receiver 20 and the door-to-door receiver 30. Outdoor receiver 20
The answer back signal returned from the master station 10 to the master station 10 also has the same broadcast frequency identification code as that sent from the master station 10. The identification code extracting means 31 belonging to the door-to-door receiver 30 extracts this identification code from the signal received by the door-to-door receiver 30. In this case, if not only the broadcast signal from the master station 10 but also the answer back signal transmitted from the outdoor receiver 20 to the master station 10 is received, the identification code is also extracted from the answer back signal. The identification code storage means 32 stores the latest identification code included in the extracted broadcast signal from the master station 10. The comparing means 33 compares the stored latest identification code with the identification code extracted from the answer back signal,
The display control means 34 performs control such that the display 35 is turned on, for example, when there is a mismatch between the two according to the result.

In addition, since a tuning signal is added to a broadcast signal to selectively broadcast to a specific slave station, this tuning signal is also added to the answer-back signal, and the identification code extracting means 31 outputs the tuning signal. It is preferable to configure only those corresponding to the own station number.

If there are a plurality of outdoor receivers 20, each outdoor receiver 20
Returns answerback signals in a predetermined time slot in order, so that those signals that can be received are targeted.

(Operation)

When the same broadcast can be received at the outdoor receiver 20 and cannot be received at the door-to-door receiver 30, a mismatch occurs in the comparing means 33, and a corresponding display is made on the display 35. Therefore, the listener can identify it, and can obtain information by calling the department where the master station is installed or listening to a neighbor.

〔Example〕

FIG. 2 shows the broadcast signal from the master station to the slave station to which the broadcast serial number is added (column (1)), the tuning signal and the answer back signal from the outdoor station to the master station to which the broadcast serial number is added. FIG.

Among them, the frame synchronization signal a, the bit synchronization signal b,
A channel selection signal c, a control signal d such as a speaker open signal, a broadcast signal f, an end signal g, a local station ID number h, and a broadcast result i are included in a transmission frame in a general system of this type. Therefore, detailed description is omitted. Of these, the broadcast signal f is transmitted as an analog audible signal, but the rest is a digital signal. Therefore, the broadcast station number e newly added to the signal in column (1) and the tuning signal j and the broadcast additional number k added to the signal in column (2) should be added to the area of the digital signal in the form of a digital signal. Is preferred.

FIG. 3 is a block diagram showing an example of a door-to-door receiver configured based on the present invention.

The receiving unit 301 tunes and amplifies a signal of a specific frequency in the radio wave received by the antenna 300, detects the signal, and outputs the signal. The switch 302 detects the detected signal as an audible analog signal (second signal).
The switch 302 is turned on only during a certain period shown in FIG.
The audible signal that has passed through the
Ring 04. The microcomputer 310 decodes the digital signal included in the detected signal, and when it is determined that the frame is transmitted to itself, the control signal (second signal)
The switch 302 is turned on during a period from the signal d) to the end signal (FIG. 2g).

The configuration described so far is also provided in a conventional door-to-door receiver. Each time the microcomputer 310 receives a broadcast signal from the master station to the slave station (column (1) in FIG. 2), the microcomputer 310 extracts a broadcast additional number e included therein and obtains a predetermined address of its own memory. To store the latest broadcast serial number that is always received. When an answer back signal from the outdoor station to the master station is received, a tuning signal j included in the answer back signal is checked, and if it is a number corresponding to the number of the own station, a broadcast additional number k is extracted, and the stored broadcast additional number k is extracted. If the numbers do not match, the LED 350 is turned on.

〔The invention's effect〕

Even if the reception status at the door-to-door receiver is bad for some reason and the signal cannot be received, if the answer back from the outdoor reception station can be received, the display is turned on, the broadcast omission can be known, and the reliability of information transmission can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a principle configuration of the present invention, FIG. 2 is a diagram showing an example of a format of a transmission frame according to the present invention, and FIG. 3 is a diagram showing an example of a door-to-door receiver according to the present invention. In the figure, 30 ... door-to-door receiver, 31 ... identification code extraction means, 32 ... identification code storage means, 33 ... comparison means, 34 ... display control means, 35 ... display, 350 ... LED .

Claims (1)

(57) [Claims] 1. A door-to-door receiver (30) of a wireless system comprising a master station, an outdoor receiver, and a door-to-door receiver, comprising: an identification code extracting means for extracting a broadcast frequency identification code included in a received signal. 31); an identification code storage means (32) for storing the latest broadcast number identification code in the broadcast signal from the master station extracted by the identification code extraction means (31); Comparison means (33) for comparing the broadcast number identification code in the answer back signal transmitted from the outdoor receiver to the master station extracted by (31) to the master station and the identification code stored in the identification code storage means (32); And a display control means (34) for controlling the display (35) according to the comparison result of the comparison means (33).