JPH0750872B2 - Wireless data relay system - Google Patents

Description

The present invention relates to a wireless data relay system for performing optical wireless communication between a center terminal and a data terminal.

(Prior Art) Various types of cards such as prepaid cards and vending machines for selling goods and providing services by currency are known. For example, when the card settlement information or the monetary information from the vending machine is requested to the control device (collection / distribution device) having a so-called aggregation function at a predetermined time interval or when the control device requests. , Transmitted. There are the following problems when the transmission is performed by wire communication.

(1) In vending machines for game machines and the like, the installation position is frequently changed and the vending machine itself is replaced. It is necessary to redo the wiring for wired communication every time such a change or replacement is made, and the work for that is troublesome.

(2) In order to install wiring for wired communication, it may be necessary to make a hole in a wall on which a vending machine or a control device is attached.

(3) If the vending machine is a floor-standing type, wiring for communication may be exposed on the floor surface, which may cause a wire breakage accident.

In order to solve such a problem, there is a system in which data transmission is performed by optical wireless communication. Figure 5 shows
It is an external view of an actual usage state of such a system.
In FIG. 5, a plurality of automatic vending machines (automatic ticket vending machines) 5, 5, ... Are fitted in a wall 3 between a floor 1 and a ceiling 2. Each vending machine 5 has a coin slot 6 and a card slot 7
And an article take-out port 8. Furthermore, each vending machine 5
Has a light receiver 11 and a light emitter 12 for performing optical wireless communication with a collecting and delivering device (control device) 13 attached to the ceiling 2. Then, for example, the communication between the vending machines 5, 5, ... And the collection and distribution device 13 is performed as follows. That is, the collection / delivery device 13 transmits a transmission command including an address code designating one of the plurality of vending machines 5, 5, ... To the vending machines 5, 5 ,. Each vending machine 5,5, ...
Receives the transmission command at the light receivers 11, 11, .... Of the vending machines 5, 5, ..., The vending machine 5 that has determined that the received signal is addressed to itself sends data such as sales from the light emitter 12 to the concentrator / delivery device 13. The above operation is repeated for all vending machines 5, 5, ....

However, even in the data communication by optical wireless shown in FIG. 5, when the purchaser stands between the vending machines 5, 5, ... And the collection and distribution device 13, the communication path is blocked, and the communication is often performed. It was sometimes interrupted. In order to avoid this, it is conceivable to dispose a large number of light receivers 11 and light emitters 12 on the outer peripheral surface of the vending machine 5, for example, the front surface. However, it is difficult to reliably prevent the above interruption.

(Problems to be Solved by the Invention) As described above, a wired communication system has a problem associated with wiring, and an optical wireless system has a problem that communication is interrupted.

The present invention has been made in view of the above, and its purpose is to:
It is an object of the present invention to provide a wireless data relay system in which communication is unlikely to be interrupted.

[Structure of Invention]

(Means for Solving the Problem) A first wireless data relay system of the present invention is an optical wireless communication system for performing optical wireless communication between at least one center terminal and a plurality of data terminals. The data terminal converts the data of its own to be transmitted from an electric signal into an optical signal and outputs it to the space, and the data terminal receives the optical signal that the self and other data terminals output from the light transmitter to the space. And a light receiver for converting to an electric signal, and a light emitter for converting the electric signal converted by the light receiver into an optical signal again and outputting it to the space toward the center terminal,
The same data is transmitted from the plurality of data terminals to the center terminal through a plurality of different paths by optical wireless communication.

In a second wireless data relay system of the present invention, in the first optical wireless communication system, the center terminal transmits a control signal for controlling a carrier of the optical signal output from the light emitter in each of the data terminals. The data terminal is provided with a light emitter for outputting to the space as an optical signal, and each of the data terminals receives the optical signal as the control signal and converts the optical signal into an electric signal, and the electric signal converted by the receiver. And a fixed carrier output means for outputting the carrier as a carrier whose frequency and phase correspond to the control signal.

(Operation) In the first and second wireless data relay systems of the present invention, the data held by a certain data terminal is sent from the plurality of data terminals to the center terminal through a plurality of different routes. Therefore, even if, for example, one of the above paths is blocked by some shield, communication is performed by the other paths. Therefore, the communication is surely performed. Further, in the second wireless data relay system of the present invention, the control signal from the center terminal locks the frequency and phase of the carrier for communication from the plurality of data terminals to the center terminal. That is, the carriers of the plurality of data terminals match each other. Therefore, when optical signals from a plurality of data terminals reach the center terminal, no cancellation or beat occurs.

(Embodiment) FIG. 1 is an overall appearance plan view showing the concept of one embodiment of the present invention. On the floor 20, two wall plates 21 and 22 stand in parallel with each other with a constant space. A plurality of vending machines 23, 23, ... Are instructed to be fitted into the front wall plate 21. Each vending machine 23 sells and rents tickets and goods by using various cards and coins. On the front of each vending machine 23, a light emitting device 28 and a receiver of a concentrating device (control device) 24 are provided.
Receiver 26 and light emitter for optical wireless communication with 29
27 are exposed. In addition, each vending machine
On the back surface of 23, a light transmitter 31 and a light receiver 32 are provided in an exposed state. As the light transmitter 31 on the back side, the one of the vending machine 23 (the central vending machine 23 in FIG. 1) designated by the collecting and distributing device 24 operates to emit an optical signal. The optical signal is received by the receiver 32 of the vending machine 23 itself and other vending machines.

The system thus arranged simply operates as follows. That is, the collection / delivery device 24 is used for all vending machines
A transmission command signal is output toward. During this signal,
Includes addresses of vending machines that wish to collect various data such as card monetary payment information and inventory information. Further, as will be described later, all the vending machines 23, 23 ...
Outputs a local signal (control signal) for matching the frequency and phase of the carrier output from.
The transmission command signal and the local signal are received by the receivers 26, 26, of all the vending machines 23, 23, ...
Received by ... Each vending machine 23 decodes the address in the received signal. The vending machine 23 designated by that address is the central one in FIG. The central vending machine 23 outputs the above various data from the light transmitter 31 on the back surface. This data is reflected by the inner surface of the wall plate 22 and the receivers of self and other vending machines 23, 23, ...
Received by 32, 32, ... After that, all the vending machines 23, 23, ... Output various data received by the light receivers 32, 32, ... To the collecting and distributing apparatus 24 from the light emitters 27, 27 ,. That is, all the vending machines 23, 23, ... Output the same data to the collecting and distributing apparatus 24 all at once via different routes. Therefore, as can be seen from FIG. 1, even if there is a shield 34 such as a person between the designated central vending machine 23 and the collecting and distributing apparatus 24, communication is surely performed by another path. Further, the carrier of data output from the light emitters 27, 27, ... Has the same frequency and phase based on the local signal from the above-mentioned concentrator / distributor 24. Therefore, even if the optical signals (data) from the plurality of vending machines 23, 23, ... arrive at the receiver 29 of the collection and distribution apparatus 24, there is no canceling operation or beat generation, and it is assumed that the reception level is sufficient. Definitely received.

FIG. 2 shows the details of the internal circuit of the vending machine 23. The input signal S from the light emitter 28 of the collecting and distributing apparatus 24 is received by the receiver 26 and sent to the terminal 36 and the PLL 37. The terminal 36 decodes the address in the input signal S. When the decoded address is its own, various data such as sales information stored in the internal memory is sent to the FSK modulator 38 at the next stage. The FSK modulator 38 FSK-modulates the internally generated carrier F1 with the above-described various data to generate an FSK-modulated wave.
This FSK modulated wave is output from the light transmitter 31 in the next stage as an optical signal without any time delay. As shown in FIG. 2, this output is received by the light receiver 32 of its own, and is also received by the light receivers 32, 32 ... Of other vending machines 23, 23. The photodetector 32 converts the received optical signal into an electrical signal and outputs it to the BP of the next stage.
Passed to F (F ₁ ) 39. The BPF 39 removes the unnecessary band and adds the signal of the frequency F ₁ to the mixer 40. A local signal of a frequency (F ₁ + F ₂ ) from the PLL (F ₁ + F ₂ ) 37 is applied to the mixer 40. That is, to the PLL 37, the signal from the receiver 26, that is, the unmodulated carrier (F ₁ + F ₂ ) from the concentrating / distributing device is added as described above. Therefore,
The PLL 37 outputs a local signal whose frequency and phase match the non-modulated carrier. This is the same for any of the vending machines 23, 23, .... Therefore, if you look at each vending machine 23, 23 ... Mutually, each PLL 37, 37 ...
It means that the frequency and the phase of the local signals output from ... coincide with each other. Now, the mixer 40 outputs an FSK modulated wave whose carrier frequency is converted from F ₁ to F ₂ . The FSK modulated wave is added to the light emitter 27 after the unnecessary band is removed by the BPF (F ₂ ) 42 in the next stage. A control signal for determining whether or not light emission from the carrier sense 41 is permitted is added to this light emitter. That is, as briefly described above, the output of the BPF (F ₁ ) 39 is added to the carrier sense 41. In this carrier sense 41, whether the received level of the received signal is equal to or higher than the level within a good signal quality range. Determine whether or not. When the carrier sense 41 determines that the level is equal to or higher than the above level, the carrier sense 41 outputs a permission signal to the light emitter 27 to permit light emission. As a result, the light emitter 27 outputs an optical signal having a relatively good signal quality without a time delay. Looking at this for each vending machine 23,23, ..., each vending machine 23,23, ...
From the light emitters 27, 27, ..., Optical signals having the same carrier frequency and phase are output. This allows
There is no risk that the optical signals from the light emitters 27, 27, ... Of the vending machines 23, 23, ... Will cancel each other out or that beats will occur. Therefore, the optical data from each of the vending machines 23, 23, ... Is ideally added and amplified in the collection and distribution device 24.

FIG. 3 shows transmission / reception of various signals described above, that is, the light emitting device 28 of the collecting / delivering device 24 → the receiver 26 of the vending machine 23, the vending machine.
23 light transmitter 31 → vending machine 23 light receiver 32, vending machine 23
7 shows the timing of transmission / reception of various signals from the light emitter 27 to the receiver 29 of the collection / distribution device 24.

In the embodiment of FIG. 1, in each vending machine 23,
Although the light-transmitting and light-receiving devices 31 and 32 are provided on the back surface thereof, the same effect can be obtained by providing the light-receiving devices 31 and 32 on the front surface thereof and reflecting or scattering the light on an existing wall surface.

In the embodiment shown in FIG. 1, the case where one collecting / delivering device 24 is provided has been described. However, when many vending machines 23 are installed, as shown in FIG. Devices 24 (1), 24 (2), ... Can also be provided. For example, the collection / delivery device 24 (1), 24 (2), ...
It is assumed that 3 (3) is specified. Similar to the case of FIG. 1,
Signals are sent and received on the back, for example, vending machines 23
It is assumed that (1) to 23 (5) output optical signals from the front light emitters 27, 27 .... Assuming that the directivity of each of the light emitters 27, 27, ... Is shown in FIG. 4, the data from the vending machine 23 (3) is eventually received by the two collecting and delivering devices 24 (1), 24 (2). To be done. In this way, the collection / delivery devices 24 (1), 24
If a plurality of (2), ...
The path between (1), 24 (2), ... And the vending machines 23, 23 ,. Therefore, the communication path can be secured and the optical communication can be performed more reliably.

In addition, for example, when outputting the data of the vending machine 23 (3) from only the light emitting device 27 of the vending machine 23 (3),
Collection and distribution devices 24, 24, at narrow intervals as shown by the chain line in FIG.
... must be provided. On the other hand, according to the embodiment of the present invention, it is possible to reduce the number of collecting and delivering apparatuses.

〔The invention's effect〕

According to the first and second systems of the present invention, since one data is transmitted through a plurality of different routes, even if a certain route is blocked, the communication is performed on another route. Can be performed without interruption.

According to the second system of the present invention, the carrier frequencies and phases of the optical signals sent from the plurality of data terminals to the center terminal are fixed according to the control signals sent from the center terminal to the respective data terminals so as to match each other. Can
Proper communication can be performed by preventing the optical signals reaching the center terminal from a plurality of data terminals from canceling each other or causing a beat.

[Brief description of drawings]

FIG. 1 is a general plan view showing an outline of an embodiment of the present invention, FIG. 2 is a detailed view showing an example of an internal circuit of the vending machine, and FIG. 3 is a diagram showing signals in the system of FIG. FIG. 4 is a timing diagram showing transmission / reception timing, FIG. 4 is an overall plan view of a different embodiment of the present invention, and FIG. 5 is a perspective explanatory view of a conventional system. 23 …… automatic vending machine (data terminal), 24 …… collection and distribution device (center terminal), 26 …… receiver, 27 …… light emitter, 28…
… Light emitter, 29 …… receiver, 31 …… light transmitter, 32 …… light receiver, 37 …… PLL (fixed carrier output means).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keishi Ushijima 1-26-5 Toranomon, Minato-ku, Tokyo NTT Data Communications Corp. (72) Inventor Takaaki Takeda 1-chome Toranomon, Minato-ku, Tokyo No. 26-5 NTT Data Communications Co., Ltd. (72) Inventor Kazutoshi Hirohashi 3-12 Moriya-cho, Kanagawa-ku, Yokohama, Kanagawa Japan Victor Company of Japan (72) Inventor Yoshiki Iwasaki, Kanagawa 3-12 Moriya-cho, Kanagawa-ku, Yokohama Victor Company of Japan, Ltd. (72) Inventor Shunichi Shichijo 3-12 Moriya-cho, Kanagawa-ku, Yokohama, Kanagawa Japan Victor Company of Japan, Ltd. (56) Reference JP 1 -176127 (JP, A) JP-A-2-43889 (JP, A)

Claims (2)

[Claims] 1. An optical wireless communication system for performing optical wireless communication between at least one center terminal and a plurality of data terminals, wherein each of the data terminals transmits its own data from an electrical signal to an optical signal. A light transmitter that converts it into a signal and outputs it to the space,
A light receiver that receives the optical signal output from the light transmitter to the space by itself and another data terminal and converts it into an electrical signal,
A light emitter that converts the electric signal converted by the light receiver into an optical signal again and outputs the light signal to the space toward the center terminal, and outputs the same data from the plurality of data terminals to the center terminal through a plurality of different paths. A wireless data relay system that transmits by optical wireless. 2. The center terminal includes a light emitter that outputs a control signal for controlling a carrier of the optical signal output from the light emitter in each of the data terminals to the space as an optical signal. A receiver for receiving an optical signal as the control signal and converting the optical signal into an electric signal, and a fixed device for outputting the carrier as a signal whose frequency and phase correspond to the control signal based on the electric signal converted by the receiver The wireless data relay system according to claim 1, further comprising carrier output means.