JPH0865250A - Optical repeater using infrared rays and line network provided with optical repeater and terminal - Google Patents

Abstract

PURPOSE: To provide the low-priced line network with less interference by transmitting a signal between the faced optical repeaters while using the rectilinear propagation light of infrared rays, and defining one of faced optical repeaters as an access point to form the line network. CONSTITUTION: Concerning the optical repeater for transmitting the signal with a terminal while using the diffused light of infrared rays, the signal is transmitted by using rectilinearly propagating light 50 of infrared rays between faced optical repeaters 41 and 51 and using rectilinearly propagating light 40 of infrared rays between an access point 11 and the optical repeater 41. Besides, one of faced optical repeaters 41 and 51 is composed of the access point 11 to form the line network. Therefore, since tandem connection using the rectilinearly propagating light is enabled by the infrared repeaters 41 and 51, even when the infrared rays whose arrival distance is not so long are used, the line network can be easily constructed over a wide range without any special signal cable. Further, since the rectilinearly propagating light of infrared rays is utilized, interference with the diffused light of the circuit network is not caused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical repeater using infrared rays and a line network including the optical repeater and a terminal.

[0002]

2. Description of the Related Art A local area network system configured by connecting various computers distributed in a relatively narrow area such as the same site by wire is commonly called a LAN. Even if the building is on the same site, it is LA
If there is a desire to form N, it is natural that the wiring work becomes complicated.

Therefore, a "wireless LAN" using radio waves in the microwave band has been put into practical use, and a LAN in the frequency band of 2.4 GHz has been approved for use in Japan based on the Radio Law. However, a wireless LAN based on this frequency is likely to be interfered with by electromagnetic noise in connection with a device that uses an approximate frequency. Therefore, research has been started on using infrared rays other than microwaves as wireless. Infrared LAN.

Since the infrared LAN has a strong straight-line property of infrared rays, in many places such as offices and factories, the infrared rays do not wrap around, so that communication is often impossible. For this reason, infrared rays are reflected by the walls and ceiling of buildings, and signals are transmitted as far as possible. The infrared diffusion method using reflection has a relatively short reach of about 10 to 30 m, and when the ceiling is high and the floor area is large like a factory, the reflected infrared rays are attenuated and good signal transmission is achieved. Can not. Therefore, the arrangement of access points as relay stations shown in FIG. 7 in cells has been studied and is well known.

In FIG. 7, the LAN line 10 is a wired LAN, and the host computer is not shown. The access point 11 includes a LAN configuration line 10 and a user terminal 13,
14, points to connection points with. Therefore, the access point 11 is provided with an infrared diffuser antenna 11A to emit infrared diffused light 12 toward the terminal. At the same time this antenna 1
1A also means to receive radiated light from the terminals 13, 14 ,. Similarly, the antennas 13A and 14A of the terminal
Receives infrared diffused light between each terminal and the access point 11, and emits infrared rays from the terminal to the access point.

In FIG. 7, access points 21 and 31 are shown.
Is connected in parallel with the access point 11 to the LAN line 10 as shown. The access points 21 and 31 arranged in a cell shape can communicate with the terminals 23, 24, 33 and 34 by the infrared diffused lights 22 and 32, similarly to the access point 11. Therefore, the terminals 23, 24, ..., 33, 34, ... are not limited to terminals whose positions are fixed, and may be of a type that moves within a range where diffused light reaches. In Fig. 7, infrared diffused light enables effective communication between the terminal and access point.
It is an infrared wireless LAN as a whole.

[0007]

An LA having the structure shown in FIG.
In N, since the access points 21 and 31 are installed, the apparatus itself is expensive, and when forming a wireless LAN in a wide area, it is necessary to install a large number of access points, which makes the system very expensive. In the case of a large building such as a factory, a large amount of "cables" are required to connect the access points, and it becomes more and more complicated to form a LAN including adjacent buildings.

The object of the present invention is to remedy the above-mentioned drawbacks, to form a wireless LAN using a minimum number of access points, and also to use an optical repeater for transmitting signals. It is to provide a line network using infrared rays that is inexpensive and has less interference by combining the above.

[0009]

FIG. 1 is a diagram showing the principle configuration of the invention described in claims 1 and 2. In FIG. 1, the LAN configuration line 10 is, for example, an access point 11
To form a wired LAN. The access point 11 is equipped with a diffused light antenna 11A and an infrared rectilinear antenna 11D. The optical repeaters 41 and 51 include diffused light antennas 41A and 51A and a straight light antenna 41.
D, 41E, 51E, 51D.

Further, diffused light antennas 11A, 41A, 5
Infrared diffused light 12, 42, 52 is emitted from 1A,
In addition, the communication signal light from the terminal described later is received. Terminal 1
3, 14, ..., 43, 44, ..., 53, 54, ... communicate with the access point 11 and the optical repeaters 41, 51 via communication antennas 13A, 14A, ..., respectively.

In an optical repeater for transmitting a signal to and from a terminal using infrared diffused light, the invention according to claim 1 is
Infrared straight light 50 is used between the optical repeaters 41 and 51 facing each other, and infrared straight light 40 is used between the access point 11 and the optical repeater 41 to transmit a signal.

According to a second aspect of the present invention, one of the optical repeaters facing each other has an access point 11 forming a line network.
It consists of. According to the third aspect of the invention, the terminal that transmits a signal via the optical repeater is configured to be roamable via another optical repeater.

According to a fourth aspect of the present invention, a multiplexing line is formed between the optical repeaters facing each other by the infrared light traveling straight. In the invention described in claim 5, a loop line is formed, and in the invention described in claim 6, a line by tree-type connection is formed for the lower station.

According to a seventh aspect of the present invention, the optical repeater is configured to operate by being supplied with power from the solar cell.

[0015]

The optical repeater 4 has the above-mentioned structure according to claim 1.
An infrared straight light 50 is connected between 1 and 51. By using a larger number of optical repeaters 41 and 51, a large number of terminals can be incorporated in the line network.

If one of the optical repeaters 51 is considered as the access point 11 according to the configuration of the second aspect, it is possible to connect to the wired LAN. With the configuration according to the third aspect, a certain terminal can roam and communicate with a terminal via another optical repeater.

Further, in the inventions according to claims 4, 5, and 6, since lines can be multiplexed, looped, or tree-type connected, communication between terminals can be made safer and more reliable in a wireless state. Can communicate.

[0018]

FIG. 2 is a diagram showing the configuration of an embodiment of the invention described in claims 1 and 3. In FIG. 2, the optical repeater is generally designated as 41. Signal processing circuit 41
In the present invention, the minimum number of constituent elements is as follows: That is, the microprocessor 41
1, a communication path selection unit 412 and a roaming processing unit 413. More specifically, the communication path selection unit 412.
The presence of the microprocessor 411 is indispensable as the configuration of the roaming processing unit 413, but is separated for the sake of easy understanding of the operation description. Therefore, if the function of the microprocessor 411 is further improved and a processing operation unit is added, it is possible to execute other processing operations.

Next, in FIG. 2, the infrared diffused light antenna 41A and the infrared straight light antennas 41D and 41E are provided with a reception antenna and a transmission antenna, respectively. Since the signal processing is performed electrically in the optical repeater, the optical repeater incorporates an optical → electrical converter, an electrical → optical converter, and an electric signal amplifier. Light-to-electricity converters are 421, 422, 4
23, and the electric-to-optical converters are 431, 432, 43.
3 and the amplifiers are shown as 441, 442, 443.

Now, an optical repeater or an access point (not shown) facing each other with the infrared rectilinear antenna 41D
When the infrared straight-ahead light from is received, the route selecting unit 412 of the signal processing unit 410 selects a route for transmitting the signal. As a result, when it is determined that the signal should be transmitted to the terminal belonging to the self optical repeater, it is determined that the signal is transmitted via the diffused light antenna 41A and should be transmitted to the adjacent optical repeater. Then, the antenna for straight light 41
Send via E.

In addition, the terminal belonging to another optical repeater is movable, and the terminal deviates from the diffusion range of the diffused light antenna of the other optical repeater, and the diffused light range of the self optical repeater. When the microprocessor 411 determines that it has come in, the roaming processing unit 413 performs a predetermined operation to execute route selection and the like as if the other terminal were its own terminal. When the terminal returns to the range of the old optical repeater, the self-optical repeater becomes incapable of processing, and the subsequent problems do not occur.

Next, the optical repeater shown in FIG.
The connection line between the antenna 1 and each of the antennas 41A, 41D, and 41E may be a little long. Therefore, the main body of the optical repeater can be mounted inside or outside the wall of the building, inside or outside the door, or below or above the ceiling of the room, and each antenna can be mounted on the opposite side. Therefore, if the infrared rectilinear light antennas are installed in a place where they can be seen from each other, it is not necessary to look through the optical repeater bodies.

FIG. 3 is a diagram showing a configuration of an embodiment of the invention described in claims 2 and 4. In FIG. 3, the access point 11, the optical repeaters 41 and 51, and the antennas attached to them are almost the same as those in FIGS. The duplicated portion 60 indicates that the basic operation unit of the optical repeater shown in FIGS. 1 and 2 is similarly installed. Therefore, it is naturally possible to further overlap the range shown as the doubled portion 60 to form a triple structure. In FIG. 3, illustration of terminals belonging to each optical repeater is omitted.

The component of the duplicated portion 60 has a communication capacity of 2 if it transmits a signal different from the operation signal of the conventional optical repeater.
Double. Large-capacity communication can be facilitated by adding a direct part, excluding the building where the device is installed. Alternatively, if the duplicated portion 60 is prepared as a standby device for the conventional portion, the straight traveling light of the conventional optical repeater may be temporarily blocked,
Even if the device goes down, automatic backup operation is possible.

FIG. 4 is a diagram showing the construction of an embodiment of the invention described in claim 5. In FIG. In FIG. 4, the illustration of the terminals belonging to each repeater is partially omitted. Like the other optical repeaters, the access point 11 is configured to allow bidirectional transmission and reception. The transmitting device of the access point 11 is always used only in one direction and is used as a backup in the other direction. Further, the receiving device of the access point 11 is set so that it can always receive signals from two directions. Optical repeaters 71, 82, 91 are provided following the optical repeaters 41, 51, and are arranged so that they can mutually transmit and receive by infrared light. Then, in FIG. 4, the optical repeater 91 located near the access point 11 has an antenna arranged so as to enable straight-line optical communication with the access point 11.

The terminal belonging to the optical repeater is always placed in the receiving state and calls the access point when it becomes necessary to transmit. As the operation of FIG. 4, the access point 1
For the transmission of 1, from the target terminal to the transmission data A
It waits for a CK (normal connection) reply, and if it does not come, it changes the transmission direction and waits for an ACK. If the same data is returned for the transmitted data, it can be discarded.

As the reception of the access point, the reception from two directions is possible. The reception states are compared, and the data in the better state is sent to the next stage for processing. At that time, other data is discarded as extra data.

The optical repeater passes the received data through and transmits it to the optical repeater on the opposite side, except when the data addressed to the terminal to which it belongs arrives. Since the above operation is performed, the loop-shaped transmission line always has a backup communication line. If the communication via the location becomes impossible due to a failure or the like, the access point determines as described above and changes the transmission direction to the opposite direction. By this means, communication can be automatically continued with any terminal to which the optical repeater belongs, unless two different faults occur simultaneously in the loop transmission line.

FIG. 5 is a diagram showing the construction of an embodiment for the invention of claim 6. In FIG. In FIG. 5, access point 1
1 includes two sets of transmission equipment and two sets of reception equipment including an antenna so as to enable transmission / reception in two directions as in the case of the loop transmission line shown in FIG. Since the communication is performed as the connection shown by the solid line, the circuit network has a tree structure. Then, the access point AP transmits a synchronization signal to all terminals via the all-optical repeater at regular time intervals in order to synchronize the entire line network.

The optical repeater is provided with the synchronous data receiving / judging means and the priority judging means, and waits for the priority shown by the circled numbers in FIG. 5A. In FIG. 5A, the solid line shows a normal connection route, and the dotted line shows a backup route changed as described later. FIG. 5B is shown in FIG.
A part of A is re-posted to show that the access point indicated as AP and the optical repeater of the priority order are disconnected. Figure 5
C indicates that the backup route connecting the two is reconfigured when the state of FIG. 5B occurs.

Now, referring to FIG. 5A, access point A
P sends a synchronization signal to all terminals at intervals of 50 msec, for example, and the terminals and the optical repeaters constantly receive and monitor the synchronization signal. The optical repeaters have a set priority,
When it detects that the synchronization signal does not arrive for a certain period of time, the lower optical repeater cuts off the straight-line optical transmission / reception with the higher-order optical repeater, and establishes a straight-line optical transmission / reception communication path with the same priority. To do. For example, in FIG. 5B, when a failure occurs with the AP, a backup route connecting the APs is configured as shown by the dotted line in FIG. 5C.

The optical repeaters which are subordinate to the tree structure may connect the scheduled backup route when the loss of the synchronizing signal is detected, but all the subordinate optical repeaters are below the faulty optical repeater. Backup processing will be performed. Therefore, the priorities are set and the backup process is configured so that the process with the lower priority is processed only when the synchronization signal is detected that many times.
Therefore, the optical repeater of the priority order performs the backup process immediately after the loss of the synchronization signal once, and the optical repeater of the priority order operates to perform the backup process when the loss of the synchronization signal is detected three times.

As the signal processing circuit described with reference to FIG. 2, the addition of the operation relating to the synchronization signal and the priority does not cause a large burden on the microprocessor.

Next, FIG. 6 is a diagram showing the configuration of an embodiment for the invention described in claim 7. In FIG. In FIG. 6, the solar cell refers to a power supply source that supplies the power required for the main body of the optical repeater 41. In addition, parts and elements denoted by the same reference numerals as those in FIGS. 1 to 5 refer to the same things and operate similarly.

In the infrared optical repeater network shown in FIG. 5, it is necessary to install the optical repeater within the line-of-sight range of the infrared light traveling straight. Therefore, it is necessary to consider the power supply line for supplying power to the optical repeater. did not become. Due to the laying of the power supply line, the installation location of the optical repeater was limited, and the characteristics of the line network due to infrared rays may be adversely affected, but according to the present invention, the solar cell is provided at a predetermined location. The optical repeater to be fed from it can be installed in the place with the best characteristics in the construction of the network. Therefore, it is not necessary to lay a new cable for both the signal line and the power line, and it is possible to construct a line network with good characteristics.

[0036]

As described above, according to the present invention, since the tandem connection using the straight light (infrared light having a strong directivity) can be made by the infrared repeater, the infrared light whose reach distance is not so long is used. Even in a very wide range,
A circuit network can be easily constructed without a special signal cable. Communication between terminals can be easily roamed and is extremely effective. Further, since the infrared straight-ahead light is used, there is no interference as compared with a line network simply using diffused light.

Further, if the power is supplied by the solar cell, it is possible to construct a new circuit network without any new laying work of the cable including the power supply line. Therefore, even if the optical repeater has the minimum necessary configuration, it is possible to perform good communication, so that the line network can be constructed at low cost. Further, since a multiplexed line network, loop line network, and tree type line network can be easily constructed, in that case, a safer and more reliable communication line network is provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle configuration of the present invention.

FIG. 2 is a diagram showing a configuration of an embodiment of the invention described in claims 1 and 3;

FIG. 3 is a diagram showing a configuration of an embodiment of the invention described in claims 2 and 4;

FIG. 4 is a diagram showing a configuration of an embodiment of the invention described in claim 5;

FIG. 5 is a diagram showing a configuration of an embodiment of the invention described in claim 6;

FIG. 6 is a diagram showing the configuration of an embodiment of the invention as set forth in claim 7;

FIG. 7 is a diagram showing a configuration of an infrared LAN as a conventional technique.

[Explanation of symbols]

10 Wired LAN Constitution Line 11 Access Point 11A, 41A, 51A Diffusing Antenna 12, 42, 52 Infrared Diffused Light 13, 14, 43, 44, 53, 54 Terminal 11D, 41D, 41E, 51E, 51D Directional Antenna 40, 50 Infrared straight light 41,51 Optical repeater

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04L 12/28 H04L 11/00 310 B

Claims (7)

[Claims] 1. An optical repeater for transmitting a signal to and from a terminal by using infrared diffused light, characterized in that a signal is transmitted between the opposing optical repeaters by using infrared straight-ahead light. Optical repeater used. 2. A line network using an optical repeater and a terminal, wherein one of the opposed optical repeaters according to claim 1 is an access point forming a line network. 3. A terminal for transmitting a signal via an optical repeater,
A line network including the optical repeater and the terminal according to claim 1 or 2, which is configured to be roamable via another optical repeater. 4. A line network including an optical repeater and a terminal according to claim 1 or 2, characterized in that a multiplexed line is formed between the optical repeaters facing each other by using an infrared straight light. 5. A line network including an optical repeater and a terminal according to claim 2, wherein a signal is transmitted between the optical repeaters by using an infrared straight-ahead light to form a loop line as a whole. 6. A signal is transmitted between the optical repeaters by using an infrared straight-ahead light, and a tree-type connection line is constructed for the optical repeaters sequentially distant from the access point or the closest optical repeater. A line network including the optical repeater and the terminal according to claim 2. 7. The optical repeater according to claim 1 or 2, wherein the optical repeater operates by power supply from a solar cell.