JP3710029B2 - Optical information communication system - Google Patents

Description

[0001]
[Industrial application fields]
  The present invention relates to an information communication system used in a local network system via an access station (satellite device), and improves the reliability of communication between the access station and the terminal, and speeds up the communication. Simplification can be achieved.
[0002]
[Prior art]
  FIG. 1 shows a conventional optical space transmission system. In this type of conventional optical space transmission system, the light emitted from the access station (or satellite, hereinafter referred to as “optical AS”) installed on the ceiling is basically a lot of light sources in order to secure a communication area. So that the light is projected as far as possible below. In such a configuration, reliable data transmission (downlink) becomes impossible from the point of deterioration of transmission efficiency due to dispersion of transmitted optical power and time delay due to multiple optical paths (multipath). Problems such as data interruption are likely to occur. In order to perform communication more efficiently with such a system, it is necessary to align the direction of the uplink as much as possible, and a method as shown in FIG. 2 is adopted. That is, this is a method in which the optical transmission / reception unit on the terminal side is searched until the light receiving power is maximized on the terminal side while the downlink light is always emitted from the optical AS. There is a description of a means for displaying the state when an optimum direction is reached, and this is described in Japanese Patent Application Laid-Open No. 5-191357. This is a one-to-many communication optical axis alignment between a satellite device installed on the ceiling and a transmission / reception device installed on a desk, and a continuous signal transmission that transmits a continuous optical signal at the time of optical axis alignment. Means are provided in the satellite device, and reception state display means for determining the reception level of the optical signal and displaying the reception state of the optical signal in the optical axis adjustment mode is provided in each transmission / reception device. This method has the advantage that it is not necessary to individually set the mode for aligning the optical axis on the transmission / reception device side, and only the direction adjustment needs to be performed on the transmission / reception device side.
[0003]
[Problems to be solved by the invention]
  By the way, a local area network (LAN) is spreading with the spread of personal computers in offices, and all information and data are exchanged via the network. Traditionally, wired cables have been used to connect terminal devices to the network. If the number of terminal devices increases in this way, the number of connected cables will overflow into the office, and the degree of freedom of installation. There is a problem that there is not. Therefore, in order to solve such a problem, a wireless system that does not use a cable is desired because it does not impair the aesthetics and has a high degree of freedom in installation. In particular, a method using light as a transmission medium is superior to a method using radio waves in terms of speeding up, cost reduction, confidentiality, and prevention of influence on the human body. “Optical space transmission system” is basically a system in which satellite devices (optical access stations) installed on the ceiling can communicate regardless of where the terminal devices are on a certain range of desks. The configuration is such that each light emitting element can emit light over 360 degrees (see FIG. 1B), and transmission (downlink) from the satellite device is performed by simultaneously driving these light emitting element groups. This is to ensure a wide communication area and simultaneous promptness. In this case, the optical axis alignment of the downlink is unnecessary, and only the optical axis alignment of the uplink as described here is a problem. However, since light is emitted in the direction of 360 degrees around here, there is a problem of multipath (multi-path interference) from the surrounding environment, for example, the received signal becomes unstable due to irregular reflection of the surrounding environment, and communication is halfway. There is a problem that the reliability of communication is greatly impaired due to repeated retransmission / retransmission in the communication protocol. Further, since sufficient light receiving power for speeding up cannot be secured in the light receiving unit of the terminal, it is inevitably disadvantageous for speeding up. For speeding up, there is a method of narrowing the emission beam of the light emitting element to increase the directivity and increase the transmission efficiency of the optical power, but in order to obtain a uniform light projection state over 360 degrees as described above, many light emitting elements Therefore, problems such as an increase in power consumption, an increase in cost, and generation of heat occur, and the problem of multipath (multi-path interference) is unavoidable. On the other hand, as a method advantageous in speeding up, there is a one-to-one communication method using beam light. In order for a satellite device to perform practical communication with a plurality of terminal devices (including portable devices), One-to-one optical axis alignment with individual terminal devices must be possible in both directions. In particular, in one-to-many communication centering on a ceiling-type access station (satellite device) according to the present invention, the terminal can be manually adjusted, but the access station (satellite device) installed on the ceiling is Alignment with each terminal device located in the center, that is, optical axis alignment is essential, and the optical access station (satellite device) side is excessive because it is equipped with an optical system unit that includes more light emitting elements than the number of terminal devices It is not practical because it becomes a device configuration.
[0004]
  The present invention aims to eliminate such problems, and as a downlink means from the network, it is highly reliable, supports a certain degree of speeding up and secures a transmission / reception area, and is a practical system with a simple configuration. Is to provide. The subject of this invention for that is as follows.
(A) Ensure a highly reliable communication area and enable high speed,
(B) preventing a collision at the time of accessing the optical access station from a terminal device located in a plurality of areas accessing the optical access station;
(C) Stabilize communication between the optical access station and the terminal device;
(D) To equalize access opportunities from each terminal device to the optical access station;
(E) improving communication reliability;
(F) To speed up access to communication opportunities.
[0005]
[Measures taken to solve the problem]
  The means taken to solve the above problems is an optical information communication system that transmits information via light between a plurality of terminal devices installed on a desk and an optical access station connected to a wired LAN configured by wire. Based on the above, it is configured as follows.
[0006]
[Solution 1]
[Solution to Problem (a)]
  The transceiver for transferring data to and from the wired LAN, the optical receiver for receiving the optical signal transmitted from the terminal device side, and the area where the terminal device is installed are divided into two or more, and the divided And an optical transmitter that emits light while rotating the area in an arc.DoAn optical access station, an optical transceiver for transmitting and receiving optical signals to the optical access station, and a transceiver for exchanging data with other terminal devices.DoAnd a terminal device.
[0007]
[Solution 2]
[Solution to Problem (b)] (Corresponding to claim 1)
  In addition to Solution 1, when data is transmitted from the wired LAN to each terminal device via the optical access station (downlink), the data is transmitted from the wired LAN stored in the buffer memory installed in the transceiver. Incoming frame signal (data signal)The first frame signal is projected to the area where the terminal device is installed until the area where the terminal device is installed is rotated once for each divided area, and the second and subsequent frame signals are transmitted. In addition, each frame signal is projected to the area where the terminal device is installed..
[0008]
[Solution 3]
[Solution to Problem (c)]
  In addition to Solution 1 or Solution 2, when uplinking data transmission from each terminal device to the optical access station, an optical link that informs the optical access station that no frame signal is coming from the wired LAN The optical transmission unit of the optical access station projects the pulse signal, and the terminal device that receives the link pulse optical signal transmits the frame signal for uplink, and the frame signal is returned by the optical access station for the next division. Project light sequentially from the area.
[0009]
[Solution 4]
[Solution to Problem (d)]
  In addition to the solution means 3, the frame signal is returned by the optical access station and sequentially projected for one rotation and one divided area from the area where the terminal device that transmitted the frame signal is located.
[0010]
[Solution 5]
[Solution to Problem (e)]
  Solution 1ThruSolution 4EitherIn addition, the number of continuous transmission data frame signals from the terminal device to the optical access station based on the same transmission destination address, or the continuous data frame signals transmitted from the wired LAN based on the same transmission destination address The optical access station detects that the number is at least two and the plurality of data frame signals are continuously projected from the optical access station to the same area.
[0011]
[Solution 6]
[Solution to Problem (d)]
  Solution 1 to Solution 5EitherIn addition to the left rotation of the area lightAroundAlternately and clockwise.
[0012]
[Solution 7]
[Solution to Problem (f)]
  Solution 1 to SolutionOne of 6In addition, the number of divisions is 2n (n ≧ 1, n is an integer), and the number m of divided areas to be projected is an even number (m ≦ n) not exceeding n.
[0013]
[Action]
  The present invention is directed to an optical space transmission system in which a terminal device freely transmits various data from a local area network (LAN) using light as a transmission medium.
[0014]
[Optical space transmission system according to means 1]
  In the optical space transmission system according to Solution 1, the area where the transmission light source for downlink of the optical access station arranged on the ceiling or the like is irradiated with light, that is, the area downlinked from the optical AS to the terminal device side is divided into a plurality of areas. Thus, a downlink signal is transmitted by sequentially projecting the divided areas by rotation. For this purpose, the optical AS includes, in addition to a conventional transceiver for exchanging data, an optical transmission unit that divides a light projection area and an optical reception unit for uplink transmitted from a terminal device. Includes a transceiver for exchanging data transmission with the optical AS and an optical transceiver. By dividing the communication area in this way, the light projecting area can be reduced, the conventional multipath environment can be improved, and the light use efficiency in the light projecting area can be improved.
[0015]
[Optical space transmission system by means 2]
(Corresponding to claim 7)
  In the optical space transmission system according to Solution 2, the downlink data frame signal sent from the LAN is buffered once,The first frame signal of the frame signals is projected to the area where the terminal apparatus is installed until the area where the terminal apparatus is installed is rotated once for each of the divided areas. The frame signal is also projected to the area where the terminal device is installed for each frame signal..
[0016]
[Optical space transmission system according to Solution 3]
  In the optical space transmission system according to Solution 3, when the optical AS informs the terminal device of the situation that the line is free and when a communication request is made from the terminal device that wants to communicate with the optical AS (access from the terminal device to the optical AS). (Right request), the signal is turned back, and light is sequentially projected to each terminal device directly from the next divided area.
[0017]
[Optical space transmission system by means 4]
  In the optical space transmission system according to the solution means 4, the return projection in the optical space transmission system according to the solution means 3 is performed for one rotation and one divided area for all the areas to be communicated.
[0018]
[Optical space transmission system by means 5]
  In the optical space transmission system according to Solution 5, only when the frame signal transmitted from the LAN has the same destination address and is longer than the basic data frame length in communication of the LAN being used, The frames are continuously projected in the same area.
[0019]
[Optical space transmission system according to means 6]
  In the optical space transmission system according to the solution 6, the area light is alternately rotated counterclockwise and clockwise.
[0020]
[Optical space transmission system by means 7]
  The optical space transmission system according to the solution 7 is configured such that the number of divided areas to be communicated is an even number, and the number of divided areas to be projected at one time is a number not exceeding half of the even number. is there.
[0021]
【Example】
  Next, embodiments will be described with reference to the drawings. The embodiments should be understood with reference to the corresponding drawings.
  First, an example implemented in a network system currently in general use will be described mainly using a block diagram. As shown in FIG. 3, the LAN system includes a device connected to a LAN having a communication function and a wired cable that connects a plurality of LAN connection devices to each other. Here, hereinafter, in the configuration block diagram as in this figure, the left side is the ceiling side in the actual office, and the right side is the ground side (desktop). Each LAN connection device performs communication by transmitting a data frame signal via a wired cable. Here, a repeater type hub (Hub, a concentrator) is connected, and each terminal device is adapted to a system connected to this hub by a cable. With this system, a terminal device connected to a hub can communicate with another terminal device connected to the same hub or another terminal device via a network. In the figure, MAU is a communication media access device that corresponds to a transceiver and provides an interface standard (AUI = Attachment Unit Interface) around the transceiver cable, and MDI is an interface portion for direct connection to the communication media. Depends on. Among these configurations, an optical wireless wireless system configuration in which an optical link portion is set by replacing the input / output from the MAU with an E / O portion that converts light into an optical signal or an O / E portion that converts an optical signal into an electrical signal, and To do. At this time, the downlink light is not projected on the assumption of a sufficiently wide area as in the conventional case or an extremely narrow area such as a beam light. An area where reliability and high speed can be achieved is realized.
[0022]
[Example 1]
  An embodiment of the optical space transmission system according to Solution 1 will be described with reference to FIGS. 4 and 5 in an example in which an area to be communicated is divided into six. It is assumed that each terminal device T1 to T5 is in each divided area. At this time, the data frame signal sent from the LAN is first projected through the optical AS for a certain period of time in a certain area T1 (FIG. ( a ) reference). Next, this projection state is rotated to project the adjacent area and downlink to the terminal device T2 (see FIG.4(See (b)). Each terminal device checks whether the destination address of the transmitted data frame signal matches its own address, and if it matches, takes it into its own device, and discards it if it does not match. In order to downlink all the terminal devices existing in this area, rotate at least once,4Last at (d). The downlink light rotates the area light using a scanning optical system as shown in the block diagram of FIG. For example, an optical system using a polygon mirror or a galvanometer mirror can be used as long as it uses the rotation of the reflecting mirror, and a holo scanner using a hologram may be used to realize a scanning function. In any case, the light converted by the E / O unit is scanned by the scanning optical system so as to rotate. Further, when a frame signal is not transmitted from the LAN, an optical link pulse signal as described later is projected.
  The operation flow of the embodiment shown in FIG. 4 is as shown in FIG.
[0023]
An embodiment of an optical space transmission system according to the solution 2 is shown in FIG. Here, it is assumed that the frame signal FT3 addressed to T3 and the frame signal FT5 addressed to T5 are transmitted to the optical AS via the network (FIG.6(See (a)). That is, since these two frame signals are continuous,SolutionIf the optical AS is downlinked as it is as in 1, the time during which light is projected to the T1 area that is not related as the frame transmission destination becomes long, and it takes time until the transmission reaches T3 that is actually the transmission destination. Therefore, first, only the frame signal FT3 addressed to T3 is promptly transmitted to all the divided areas (see FIG.6(See (b), (c), (d)), and then downlink the frame signal FT5 addressed to the next T5 in the same manner (see FIG.6(See (e) and (f)). During this time, these frame signals are buffered by the optical AS and transmitted. On the other hand, in this method, when each terminal device requests transmission from each other terminal device, it becomes possible to know the usage status of the line at a short time interval, and transmission is performed from each terminal device during downlink. In this way, it is possible to reduce the occurrence of transmission frame signal collision that occurs when uplink is performed from each terminal apparatus.
  The operation flow of the embodiment shown in FIG. 6 is as shown in FIG.
[0024]
[Example 2]
  An embodiment of an optical space transmission system according to the solution 3 is shown in FIG. Here, the collision between the terminal devices is prevented in the uplink from each terminal device to the optical AS. When the data frame signal is not transmitted, an optical link pulse signal indicating that the line is free is transmitted from the optical AS to each terminal device. This is also done with rotation split light, and when it comes to an area with T1 (Fig.7(see (a)), T1 detects that the line is free and immediately requests transmission to transmit the frame signal FT1 to the optical AS via the uplink (see FIG.7(See (b)). In this case, although it is described with an arrow in the figure, it may be in a slightly expanded light projection state for easy alignment with the light AS as described above. Thereafter, the area light rotates to the next area, and at the same time, the frame signal FT1 is transmitted by the optical AS.FoldReturn and flood. The terminal device T2 can detect that the line is being used by receiving the frame signal FT1 (see FIG.7(See (c)). Similarly, as the area light rotates, other terminal devices can detect that the line is being used (Fig.7(See (d)). If each terminal device wants to request transmission, it can wait for one rotation and transmit (uplink) after confirming that the signal received at that time is a link pulse signal. In this embodiment, T1 is again applicable (see FIG.7(See (e)).
  The operation flow of the embodiment shown in FIG. 7 is as shown in FIG.
[0025]
[Example 3]
  An embodiment of the optical space transmission system according to the solution 4 is shown in FIG. In the case of the embodiment shown in FIG. 7 (the embodiment of the optical space transmission system by the solution means 3), T1 can obtain the right to request transmission and transmit (uplink) again before other terminal devices. For example, it is effective for a system that wants to give the access right to the network most preferentially to T1, but there is a problem when it is desired to give an equal access opportunity to each terminal device. Here, the time for transmitting the frame signal transmitted from the terminal device by the area light from the optical AS is set not to one rotation but to one rotation plus one divided area (that is, until returning to the original position). (Figure8(See (a), (b)). Then, since the frame transmission ends in the area where T1 is located, T1 detects that the line is in use, so it cannot request transmission again, and is actually possible. It becomes T2 in the next area to receive the optical link pulse (Figure8(See (c) and (d)), and the access priority shifts to T2. And when T2 is uplinked,FoldReturned (Figure8(See (e)). In this way, a system with an equal access opportunity is realized because the priority is cycled from T1-> T2-> T3-> T4-> T5.
  The operation flow of the embodiment shown in FIG. 8 is as shown in FIG.
[0026]
[Example 4]
  An embodiment of an optical space transmission system according to the solution 5 is shown in FIG. This is not a frame-by-frame downlink, but if the destination addresses assigned to the beginning of a plurality of data frame signals sent continuously are the same, the frame signals for the same address are consecutive. Projecting and communicating in one area. Now, it is assumed that two frames F1T2 and F2T2 are sent from the network with the terminal device T2 as a transmission destination (see FIG.9(see (a)), once buffered in the optical AS, F1T2 is first downlinked, and then F2T2 is downlinked to T1 (see FIG.9(See (b)). Here, since T1 is not the transmission destination, the frame is discarded. In the next area, T2 similarly receives F1T2 and subsequently receives F2T2 and incorporates it into its own device (see FIG.9(See (c)). And the next is done in the same way (Fig.9(See (d)). After one round, an optical link pulse is emitted again. Such a system, for example, when it is desired to realize continuous data transmission of moving image data, etc., even if the data must be divided into a plurality of frames and transmitted with data longer than the minimum frame format length for transmitting the network. Data can be received without interruption on the side.
  The operation flow of the embodiment shown in FIG. 9 is as shown in FIG. 14 which is the same as the operation flow of the embodiment shown in FIG.
[0027]
[Example 5]
  An embodiment of an optical space transmission system according to the solution 6 is shown in FIG. In this method, an optical link pulse that is sent when there is no frame signal on the network line is first rotated clockwise from an area with T1 (see FIG.10(Refer to (a)), after sequentially transmitting to each area and making one round (Figure10(See (b)), this time rotating around the opposite (Fig.10(See (c) and (d)). By alternately rotating the left and right in this way, the priority order for the terminal devices of T1 and T5 here to grasp the line usage status during one round changes, so the access opportunity when uplinking Can be set fairly without depending on the position of the terminal device.
  The operation flow of the embodiment shown in FIG. 10 is as shown in FIG.
[0028]
[Example 6]
  Finally, an embodiment of the optical space transmission system by the solution means 7 is shown in FIGS. In this case, since the divided areas to be projected are to be rotated, two or more areas are simultaneously projected and rotated using optical symmetry. In this case, since transmission is performed to two or more areas at the same time, the time for completing transmission to all terminals can be shortened, and higher speed can be achieved than in the case of one. First, the number of divisions is an even number. The number of areas to be projected simultaneously is set to be less than half of the number to be divided. Figure11In the case of (a), the figure is divided into 6 parts, and when there are two areas that project simultaneously,11In the case of (b), there are 12 areas, and the number of areas to be simultaneously projected is 4. Such a configuration using symmetry can be realized with a simple optical path splitting optical system and a rotating system as shown in FIG. 12, for example. However, S is a light source, L is a lens system, HM is a half mirror, and M is a mirror.
[0029]
【effect】
  In the optical information communication system using the space optical transmission system according to Solution 1, the downlink signal is transmitted so as to divide and rotate the downlink area from the optical AS to the terminal device side. A reliable data transmission access system is ensured.
  In the optical information communication system using the space optical transmission system according to Solution 2, the downlink data frame signal sent from the LAN is buffered once,Of the frame signals, the first frame signal is projected to the area where the terminal device is installed until the area where the terminal device is installed is rotated once for each divided area. The signal also projects the area where the terminal device is installed for each frame signal.Therefore, there are few signal collisions and the reliability of the communication system can be improved. (Inventions according to claims 1 and 7)
  In the optical information communication system using the optical space transmission system according to Solution 3, since the collision of signals at the time of access from each terminal device to the optical AS is prevented, the reliability of the communication system can be improved. (Inventions according to Claims 2 and 8)
  In the optical information communication system using the optical space transmission system according to Solution 4 or Solution 6, since a certain terminal apparatus is not preferentially accessed, an equal communication system without bias is realized. be able to. (Inventions according to claim 3, claim 5, claim 9 and claim 11)
  The optical information communication system using the optical space transmission system according to the solution 5 is a system capable of high-quality data transmission because the terminal side continuously receives data longer than a frame unit. . (Inventions according to claims 4 and 10)
  In the optical information communication system using the optical space transmission system according to the solution means 7, the area to be divided can be used for optical symmetry, so that the transmission speed in the communication system according to the solution means 1 can be increased. Simplification can be achieved. (Inventions according to claims 6 and 12)
[Brief description of the drawings]
FIG. 1A is a schematic diagram of a conventional optical space transmission system, and FIG. 1B is a schematic diagram of a satellite device of the optical space transmission system.
FIG. 2 is a schematic diagram of another conventional optical space transmission system.
3A is a conceptual diagram of a LAN system, and FIG. 3B is a conceptual diagram of an optical space transmission system in the LAN system.
4A to 4D are schematic views of an embodiment of an optical space transmission system according to Solution 1; FIG.
FIG. 5 is a schematic diagram of a light projecting and rotating device in the optical space transmission system of FIG. 4;
FIGS. 6A to 6F are schematic views of an embodiment of an optical space transmission system according to the solving means 2;
FIGS. 7A to 7E are schematic views of an embodiment of an optical space transmission system according to solution means 3; FIG.
FIGS. 8A to 8E are schematic views of an embodiment of an optical space transmission system according to solution means 4; FIG.
FIGS. 9A to 9E are schematic views of an embodiment of an optical space transmission system according to the solving means 5; FIG.
FIGS. 10A to 10D are schematic views of an embodiment of an optical space transmission system according to solution means 6; FIG.
11A is a schematic diagram of an embodiment of an optical space transmission system according to the solving means 7, and FIG. 11B is another embodiment of the transmission system.
FIG. 12 is a schematic view of a light projecting and rotating device used in the embodiment of FIGS. 11A and 11B and realized by a simple optical path division type optical system and a rotating system.
FIG. 13 is an operation flowchart of the embodiment of FIG. 4;
14 is an operation flowchart of the embodiment of FIGS. 6 and 9. FIG.
15 is an operation flowchart of the embodiment of FIG.
16 is an operation flowchart of the embodiment of FIG.
FIG. 17 is an operation flowchart of the embodiment of FIG. 10;

Claims (13)

A plurality of terminal devices to be installed on a desk, met optical information communication system for performing via the optical transfer information between optical access stations connected to a wired LAN constituted by wire,
The transceiver for transferring data to and from the wired LAN, the optical receiver for receiving the optical signal transmitted from the terminal device side, and the area where the terminal device is installed are divided into two or more, and the divided and optical access station for chromatic and optical transmission unit that projects while rotating the area in an arc,
In an optical information communication system comprising: an optical transmission / reception unit that transmits and receives an optical signal to and from the optical access station; and a terminal device that includes a transceiver that exchanges data with other terminal devices.
The first of the frame signals sent from the wired LAN stored in the buffer memory installed in the transceiver when data is transmitted from the wired LAN to the terminal devices via the optical access station. For each divided area, the area where the terminal device is installed is projected to the area where the terminal device is installed, and the second and subsequent frame signals are also transmitted for each frame signal. An optical information communication system, wherein light is projected to an area where the terminal device is installed . When uplinking data transmission from each terminal device to the optical access station, the optical transmission unit of the optical access station sends an optical link pulse signal that informs the optical access station that no frame signal is coming from the wired LAN. The terminal device that transmits the light and receives the link pulse optical signal transmits an uplink frame signal, returns the frame signal at the optical access station, and sequentially projects light from the next divided area. The optical information communication system according to claim 1 . 3. The optical signal according to claim 2 , wherein the frame signal is turned back by an optical access station and sequentially projected for one rotation and one divided area from the area where the terminal device that transmitted the frame signal is located. Information communication system. The number of continuous transmission data frame signals from the terminal device based on the same destination address to the optical access station, or the number of continuous data frame signals transmitted from the wired LAN based on the same destination address is at least But detects that at least two in the optical access station, the claims 1 to 3, characterized in that projecting light to the plurality of data frames signals continuously from the optical access stations in the same area Any one of the optical information communication systems. 5. The optical information communication system according to claim 1, wherein the rotation of the area light is alternately performed counterclockwise and clockwise. The number of divisions is 2n (n ≧ 1, n is an integer), and the number m of divided areas to be projected is an even number not exceeding n (m ≦ n). The optical information communication system according to any one of claims 5 . An optical information communication method for transmitting information via light between a plurality of terminal devices installed on a desk and an optical access station connected to a wired LAN configured by wire,
Sending and receiving data between the wired LAN and the transceiver of the optical access station,
The optical transmission unit of the optical access station divides the area where the terminal device is installed into two or more, and projects the light while rotating the divided area in an arc shape,
In an optical information communication method in which an optical signal is transmitted to and received from the optical access station by the optical transceiver of the terminal device, and data is exchanged with other terminal devices by the transceiver of the terminal device.
The first of the frame signals sent from the wired LAN stored in the buffer memory installed in the transceiver when data is transmitted from the wired LAN to the terminal devices via the optical access station. For each divided area, the area where the terminal device is installed is projected to the area where the terminal device is installed, and the second and subsequent frame signals are also transmitted for each frame signal. An optical information communication method comprising projecting light to an area where the terminal device is installed . When uplinking data transmission from each terminal device to the optical access station, the optical transmission unit of the optical access station sends an optical link pulse signal that informs the optical access station that no frame signal is coming from the wired LAN. The terminal device that transmits the light and receives the link pulse optical signal transmits an uplink frame signal, returns the frame signal at the optical access station, and sequentially projects light from the next divided area. The optical information communication method according to claim 7 . 9. The optical information according to claim 8 , wherein the frame signal is turned back by an optical access station and sequentially projected for one rotation and one divided area from the area where the terminal device that transmitted the frame signal is located. Communication method. The number of continuous transmission data frame signals from the terminal device based on the same destination address to the optical access station, or the number of continuous data frame signals transmitted from the wired LAN based on the same destination address is at least However, the optical access station detects that the number is two or more, and continuously projects the plurality of data frame signals from the optical access station to the same area . Any optical information communication method. 11. The optical information communication method according to claim 7, wherein the rotation of the area light is alternately performed counterclockwise and clockwise. The division number of 2n (n ≧ 1, n is an integer), and the claims 7 to the number of divided areas m of projected light, characterized by an even number not exceeding n (m ≦ n) 11. The optical information communication method according to any one of 11 above . A recording medium storing the software of the optical information communication method according to claim 7 .

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