JPS63312731A - Radio individual calling system - Google Patents

Abstract

PURPOSE:To clearly recognize the position of a slave station at a master station side by detecting the level of a received answer-back signal and outputting information to be corresponded to the position of the slave station. CONSTITUTION:A master station 1 catches an answer-back signal with an antenna 8, reduces it by a superheterodyne in a receiving part 9, detects it and gives it to a control part 3. In the control part 3, it is A/D converted, whether or not a discriminating code desired to be transmitted is coincident with a returned recognizing code is decided and when they are coincident, an output device 12 displays that a calling is normally executed. A detecting part 10 detects the level of the answer-back signal reduced and converted in the receiving part 9. An output compared by a comparator 11 is given to the control part 3 and the large, the intensity as for middle and small sizes of the electric field intensity of the answer-back signal is decided. According to the result, the output which is near, or middle or far from a slave station 2 is generated and displayed with the output device 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a master station that wirelessly transmits a signal for making an individual call, and a portable mobile station that wirelessly returns an answerback signal to confirm reception of the transmitted signal. This invention relates to a wireless individual paging system consisting of stations.

2. Description of the Related Art In conventional radio paging systems of this type, an identification code is set for each slave station to identify selective calls between multiple slave stations and one master station, and this identification code is applied to a carrier signal. I try to send and receive it by carrying it. That is, first, the transmission signal from the master station to the slave station includes the identification code of the slave station to be called, and after receiving and detecting it at the slave station, it combines the identification code stored in its own station and the transmitted identification code. The identity of the codes is checked, and if they are the same, a ringing alert is issued and an answerback signal is sent back to the master station. If the identification codes are not the same, no sounding operation will be performed and no answerback signal will be returned.

Since the answerback signal includes the identification code, the master station decodes it to confirm that a call has been made! I can recognize it.

Problems to be Solved by the Invention However, as mentioned above, in the conventional wireless individual paging system, from the perspective of the master station, it is only possible to know whether or not the call to the intended slave station has been made normally. Therefore, it was not possible to know the location of the slave station.

Since a slave station can be carried around, for example as a pocket phone, it would be convenient to know whether the person holding the slave station is far from the master station or nearby. This is because it is possible to estimate the amount of time it will take for the person to arrive at a predetermined location after making a call, and to be able to instruct the direction in which the person should move.

Therefore, the purpose of the present invention is to enable the master station to not only confirm a call to a slave station, but also to know the location of the slave station.

Means for Solving Problems In the present invention, a master station transmits a signal for making an individual call, and a portable slave station transmits an answerback signal to confirm reception of the transmitted signal. In a wireless individual paging system, a master station receives an answer bank signal returned from the slave station using an answer back signal receiving antenna provided in the master station, and measures the level of the received answer back signal. The mobile station is configured to detect and output information that corresponds to the detected level and the position of the slave station.

When the level of the answerback signal detected by the active master station is high, information is output that the called slave station is located close to the master station. Conversely, when the level of the answerback signal is low, information indicating that the location is far away is output. This information can be displayed in the form of characters or graphics on a printer or CRT display, for example. In this way, the parent station can clearly grasp the location of the slave station.

Embodiment In FIG. 1 in which the present invention is implemented, (1) is a master station, and (2) is one of a plurality of slave stations that can be called by the master station. The master station (1) includes a control unit (3) consisting of a microcomputer, an input device (4) consisting of a keyboard etc. that provides input data and commands to the cough control unit (3), and output from the control unit (3). A transmitting unit (5) that outputs a transmitted signal formed by modulating a high-frequency signal with an identification signal, a transmitting antenna (6) that radiates the transmitted signal supplied from the transmitting unit (5) as an electromagnetic wave, and a slave station (2). an answerback receiving antenna (8) that receives the answerback signal radiated from the transmitting/receiving antenna (7); a receiving section (9) that performs low frequency conversion and detection of the answerback signal caught by the antenna; and the receiving section. The results processed by the detection unit (10) that detects the level of the answerback signal after low frequency conversion in (9), the comparison unit (11) that compares the detected level with a predetermined value, and the control unit (3) and an output device (12) for outputting and displaying. Output device 7 (12
) is a printer or a CRT display.

Next, the operation of this system will be explained.

First, identification data specifying a desired slave station is input to the control section (3) using the input device (4). The control section (3) reads out the code corresponding to this input data from the memory, converts it from D/A, and supplies it to the transmission section (5).

In the transmitter (5), the identification signal is placed on the high frequency signal by modulating the high frequency signal as a carrier with this analogized identification signal. The transmission signal formed in this way is radiated from the transmission antenna (6), and is transmitted to the slave station (2).
) is received and processed. At this time, the slave station (2) detects the identification signal in the received signal, A/D converts it, compares it with the identification code of its own station stored in memory in advance, and finds a match. If there is, a sound is made to notify the holder of the slave station (2) that there is a call, and an answerback signal is output and radiated from the antenna (7). Note that the answerback signal is a signal obtained by modulating a high frequency signal with an identification signal.

The master station (1) transmits this answerback signal to the antenna (8).
), the receiving section (9) lowers the frequency by superhetero gain, detects the signal, and supplies it to the control section (3). The control unit (3) converts it to AID and determines whether the transmitted identification code and the returned identification code are lost. If they match, it means that the call was successfully made. is displayed on the output device (12).

The answerback signal is attenuated due to various reasons during its wireless transmission, and generally the longer the transmission distance, the lower the signal level. A detection section (10) detects the level of the answerback signal that has been low frequency converted by the reception section (9). Specifically, it is detected by FM detection, envelope detection, synchronous detection, or the like.

This detection output is compared with a plurality of (for example, three) predetermined levels in the next stage comparator (11). The output is given to a control section (3) to determine whether the electric field strength of the answerback signal is large, medium, or small. Accordingly, output information indicating whether the slave station (2) is close, intermediate, or far is generated and displayed on the output device (12).

For example, if this system is used in a building and the master station is on the first floor, although it is not limited thereto, there are substations on the first, second, third,..., nth floors. If the level at which a station exists is tested in advance and stored as data, it becomes possible to display on the output device (12) which floor the person with the called slave station is currently on. In that case,
It is assumed that the comparison unit (11) performs detailed level comparison according to the rank n.

Figure 2 shows the operation flow after receiving the answerback signal in the master station (1). First, in step (#1) the answerback signal is received, and in step (#2) the detection unit (10)
Detects the level of the answerback signal at Next, compare this detection level with the comparison section (11) #3)
Based on the results, the arithmetic unit (3) divides the position of the slave station into three stages ((#4) to (#6)). Finally, this result is displayed on the output device (12) (#7).

In FIG. 1, the control unit (3) is assumed to have a function of processing the comparison result and driving the output device (12), and the input device (4) and output device (12) are simply used to input and output data. Although it is only a display, it is not in this manner,
As shown in Figure 3, the control unit (3) is connected to a personal computer (
13) may be connected to the personal computer (13) so that the display calculations and the like are performed by this personal computer (13). This is effective when the capacity of the control unit (3) is small and cannot process a large amount of data (messages, etc.). still,
Input data is performed using a keyboard (14) attached to a personal computer (13), and output display is performed using an output means (15) of the computer (13).

Next, when using this system not only in one building but also in a premises that spreads horizontally,
In many cases, it is not possible to cover the problem with just one receiving antenna installed on the master station side. Particularly in the case of a slave station of the type in which the transmitting/receiving antenna (7) is built into the housing, the directivity cannot be ignored. In the embodiment shown in FIG. 4, in order to deal with such a case, three answerback signal receiving antennas (8a), (8b), and (8c) are arranged at intervals on the master station (1) side. .

And these antennas (8a) (8b) (8c
) is detected by a separate detector (1
0a) (10b) (10c) are used to detect the level, and comparators (lla), (llb), and (Ilc) are used to individually compare the levels with predetermined values.

The calculation unit (3) calculates the three data and sends it to the slave station (2).
Outputs information that specifies the location of. This information is displayed on an output device (12). Note that the system shown in FIG. 4 may be combined with the configuration shown in FIG. 2.

Although the present invention has been described above with reference to each embodiment, the present invention is not limited to these embodiments, and various changes can be made without departing from the gist of the invention described in the claims. , correction is possible.

Effects of the Invention According to the present invention, there is an effect that it is possible not only to simply confirm a call, but also to know the location of the called slave station on the side of the master station, which is extremely effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a wireless individual paging system according to an embodiment of the present invention, and FIG. 2 is a flowchart of its operation. FIG. 3 is a block diagram showing another embodiment of the present invention, and FIG. 4 is a block diagram of still another embodiment. (1)...Master station, (2)...Slave station, (3)...Control unit. (8)... Answer back signal receiving antenna. (9)...Reception section, (10)...Detection section. (11)... Comparison section, (12)... Output device.

Claims (1)

[Claims] (1) In a wireless individual paging system consisting of a master station that transmits a signal for individual paging and a portable slave station that returns an answerback signal to confirm reception of the transmitted signal, the master station At the side, the answerback signal returned from the slave station is received by an answerback signal receiving antenna provided in the master station, and the level of the received answerback signal is detected, and the position of the slave station is corresponded to the level. A wireless individual paging system is characterized in that it outputs information that has been sent.