JP3205311B2 - Communication method and communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication method and a communication apparatus for performing communication by transmitting light using infrared rays or the like.

[0002]

2. Description of the Related Art Infrared communication is one type of communication that performs communication by transmitting light. IrDA standard (Infrared) is one of the infrared communication standards having a handshake procedure.
In dataassociation, the infrared output is defined in the standard to ensure a certain fixed reference value. That is, IrDA ver 1.0 standard: 40 mW / sr is secured IrDA ver 1.1 standard: 100 mW / sr is secured IrDA ver 1.2 standard: 3.6 mW / sr is secured.

In the method of driving the infrared output device, an external load resistor is used, or an LED (light emitting diode) driver is driven at a constant current.
Infrared output is fixed.

[0004] In the IrDA standard, which is one of the above standards, the output value of infrared light during communication is a constant value. However, considering that communication is possible with a smaller output when the communication distance is shorter, wasteful power is consumed when the communication distance is shorter.

As a technique for controlling the output in such communication, Japanese Patent Laid-Open No. 7-66780 and Japanese Patent Laid-Open No.
There is a technique disclosed in Japanese Patent Publication No. 0-336109. The former is referred to as Prior Art 1 and the latter is referred to as Prior Art 2. In the prior art 1, the output power of the primary station is first set to a maximum value, and then the output power is alternately reduced and increased. In the prior art 2, the output power of the primary station is first set to the maximum value, and then reduced. In this way, these prior arts 1 and 2 make the output of the primary station variable and change the output in accordance with the communication distance. By performing communication with the minimum output required for communication, the power consumption is reduced. The increase in power is suppressed.

A station that first searches for a communication partner, that is, a station that requests establishment of communication, and that sends out a station discovery command (XID command) is referred to as a primary station. A station that accepts the communication request and transmits a station discovery response (XID response) to the station discovery command is referred to as a secondary station.

[0007]

As described above, in the prior art 1, the output power of the primary station is first set to a maximum value, and then the output power is alternately decreased and increased. The output power is first maximized and then reduced. Further, in any of the above-described prior arts, the output power of the primary station is always kept at the maximum value so that the secondary station cannot be found. Therefore, the prior art 1
2 has a problem that the power consumption of the primary station increases during the station finding process.

[0008]

According to a first aspect of the present invention, there is provided a communication method for performing communication between a primary station and a secondary station by transmitting light, and performing communication between the primary station and the secondary station. In the communication method of making the output variable, the output of the station finding command output from the primary station is increased from an initial value until a response from the secondary station is received, and the station finding command is output. .

According to a sixth aspect of the present invention, there is provided a communication apparatus for performing communication by transmitting light to and from a partner station and making the output to the partner station variable, a station finding command for finding the partner station. And output power setting means for increasing the output of the station finding command from the output means from an initial value until a response from the partner station is received.

According to the configuration of claim 1 or 6, the output is increased rather than decreased. Therefore, if the communication becomes possible during the increase of the output at the start of the communication, it is not necessary to increase the output to the maximum value. Therefore, an increase in power consumption can be suppressed accordingly.

Further, in the above-mentioned prior arts 1 and 2, the output power of the primary station (communication device) is always kept at the maximum value until the secondary station (counter station) cannot be found as described above. On the other hand, according to the configuration of the present invention, the process of increasing the output power of the primary station (communication device) from the initial value is repeated so as to discover the secondary station (the other station) while the secondary station (the partner station) cannot be found. become. Therefore, an increase in power consumption can be further suppressed.

[0012] The communication method according to claim 1, wherein the secondary station
If there is a response from, then again to the initial value output from the station discovery command, while increasing the output until there is a response from the secondary station outputs the station discovery command, it
If there is a response from the secondary station, the output of the station discovery command at that time, characterized by setting as the output power from the primary station to the secondary station has respect.

[0013] The communication device of claim 6, the other station
If there is a response from, the output power setting means, and again to the initial value output from the station discovery command increases the output until there is a response from the other station, to which
If there is a response from the other station Te, the output of the station discovery command at that time, is characterized by setting the output power to the other station.

According to the configuration of claim 1 or claim 6 , the output of the station finding command at that time is output from the primary station (communication device) to the secondary station in response to a response from the secondary station (counter station). After setting the output power to the station (the partner station), the output of the station discovery command is set again to the initial value, and the station discovery command is increased while there is a response from the secondary station (the partner station). Output, and if there is a response from the secondary station (partner station), the output of the above station discovery command at that time is set as output power from the primary station (communication device) to the secondary station (partner station). .

Therefore, after setting the output of the station finding command as the output power from the primary station (communication device),
When at least one of the next station (communication device) or the secondary station (partner station) moves to a location closer to the previous station, or the angle is set so that the light-emitting part and light-receiving part between the two stations correctly face the other party. When the communication environment changes, as in the case of a change, it is detected that sufficient communication is possible with an output power smaller than the one previously adopted as the set value, and the output power can be employed. Conversely, even when the distance is large or the angle deviation is severe, it is detected that communication is possible if the output power is increased as compared with the setting value, and the output power is set. It can be adopted as a value. Therefore, even if the communication environment such as the distance or the angle between the two stations changes, it is possible to reliably find the minimum communicable output power.

Also, preferably, in a communication method in which communication is performed between the primary station and the secondary station by optical transmission and the output of the secondary station is made variable, station detection output from the primary station is performed. The output of the station discovery response output from the secondary station in response to the command is increased from the initial value until there is a response from the primary station to this station discovery response, and the station discovery response is output. Response
The output of the station discovery response at that time is set as output power from the secondary station to the primary station.

[0017] Preferably, in a communication device which communicates with a partner station by light transmission and makes the output to the partner station variable, a station discovery command output from the partner station is provided. Output means for outputting a response, and increasing the output of the station discovery response from the output means from the initial value until there is a response from the partner station to this station discovery response, and if there is a response from the partner station,
Output power setting means for setting the output of the station discovery response at that time as output power to the partner station.

With the above arrangement, the output is increased rather than decreased. Therefore, if communication becomes possible during the increase in the output of the station discovery response at the start of communication, it is not necessary to increase the output of the station discovery response to the maximum value. Therefore, an increase in power consumption can be suppressed accordingly.

Preferably, in addition to the above-described configuration,
After setting the output of the station discovery response at that time according to the response from the primary station as the output power from the secondary station to the primary station, the output of the station discovery response is again set to the initial value, The station finding response is output while increasing the output until there is a response from the primary station to the station finding response. If there is a response from the primary station, the output of the station finding response at that time is set to 2 1 from next station
Set as output power to the next station.

Preferably, in addition to the above-described configuration,
After setting the output of the station discovery response at that time according to the response from the partner station as output power to the partner station, the output power setting means sets the output of the station discovery response to the initial value again. The output is increased until there is a response from the partner station to this station discovery response. If there is a response from the partner station, the output of the station discovery response at that time is set as output power to the partner station.

With the above configuration, the primary station (the partner station)
After setting the output of the station discovery response at that time as the output power from the secondary station (communication device) to the primary station (partner station) in response to the response from The station discovery response is output while increasing the value until there is a response from the primary station (partner station). If there is a response from the primary station (partner station), the station discovery response at that time is output. Is set as the output power from the secondary station (communication device) to the primary station (partner station).

Therefore, the output of the station discovery response is set to 2
After setting as output power from the next station (communication device),
When at least one of the secondary station (communication device) or the primary station (partner station) moves to a location closer than before, or the angle so that the light emitting part and light receiving part between both stations correctly face the other party. When the communication environment changes, as in the case where the communication power has changed, it is detected that sufficient communication is possible with an output power smaller than the one previously used as the set value, and the output power can be used. Conversely, even when the distance is large or the angle deviation is severe, it is detected that communication is possible if the output power is increased as compared with the setting value, and the output power is set. It can be adopted as a value. Therefore, even if the communication environment such as the distance and angle between both stations changes,
It is possible to find the minimum output power at which communication is possible.

The communication method according to the second aspect is the communication method according to the first aspect.
In addition to the configuration described above, the primary station has a set output power
To the secondary station together with the setting values required for communication,
The secondary station must set the output power accordingly.
Features. The communication device according to claim 7 is the communication device according to claim 6.
In addition to the configuration described in
Inform the partner station together with the required settings and send it to the partner station.
The output power is set based on the
I have. The communication method according to claim 3 is the communication method according to claim 1 or 2.
In addition to the configuration described above, the frequency of retransmission of data sent from the primary station to the secondary station is investigated, and when the frequency exceeds a reference value, the output from the primary station is output from the current value. It is characterized by increasing the output.

[0024] The communication device according to claim 8 is the communication device according to claim 6 or
Has retransmission investigating means for investigating the frequency of retransmission of data to be sent to the other station in addition to the configuration described in 7, and the output power setting means when the frequency exceeds a reference value.
However, it is characterized in that the output to the partner station is increased from the current value and output.

According to the configuration of claim 3 or 8, the output is increased, not decreased. Therefore, if communication with a low retransmission frequency becomes possible in the middle of an increase in output when a retransmission occurs, it is not necessary to increase the output to the maximum value. Therefore, an increase in power consumption can be suppressed accordingly.

Also, for example, by examining the number of retransmission requests per unit time from the secondary station (the other station),
If it is detected that the retransmission frequency exceeds the reference value,
The output from the next station (communication device) is increased from the current value and output. Therefore, if retransmission occurs frequently, the output level from the primary station (communication device) increases, so that the deterioration of the communication state is eliminated, and the state can be shifted to the communication state with a low retransmission frequency. Therefore, even after the communication power is set to the minimum power at which communication can be performed and the communication state deteriorates due to movement during communication and retransmission frequently occurs, communication can be favorably continued.

A communication method according to a fourth aspect is characterized in that, in addition to the configuration of the third aspect, the above-mentioned investigation is performed periodically.

[0028] According to a ninth aspect of the present invention, in addition to the configuration of the eighth aspect, the retransmission investigation means periodically performs the investigation.

With the above configuration, the above-mentioned investigation is performed periodically. Therefore, it is continually investigated whether retransmissions occur frequently. Therefore, in addition to the effect of the configuration of claim 3 or claim 8, it is possible to quickly respond to a situation where frequent retransmission occurs, improve the communication state, and thereby quickly complete the communication.

In the communication method according to the fifth aspect, in addition to the configuration of the third aspect, the above-described investigation is not performed until the primary station receives the retransmission request, and the above-described investigation is performed when the primary station receives the retransmission request. It is characterized by starting.

According to a tenth aspect of the present invention, in addition to the configuration of the eighth aspect, the retransmission investigation unit does not perform the investigation until a retransmission request is received, and starts the investigation when a retransmission request is received. It is characterized by:

According to the above configuration, the above-described investigation is not performed until the primary station (communication device) receives the retransmission request, and the above-described investigation is started when the primary station (communication device) receives the retransmission request. Therefore, the above investigation is not performed frequently, and the above investigation is started only when a retransmission request actually occurs. Therefore, in addition to the effect of the configuration of claim 3 or claim 8, it is possible to suppress an increase in power consumption for the survey, unlike the case of performing the survey continuously.

Preferably, in addition to any one of the above configurations, each output level of the primary station (communication device) is set to a maximum value of (1/2 ⁿ ) ² (n = 1, 2, 3,. ..).

With the above configuration, each output level is set to (1/2 ⁿ ) ² (n = 1, 2, 3,...) Of the maximum value, that is, 1/4, 1 of the maximum value (P). / 16, 1/64, 1/256,
... is set. From this, if the distance between the two stations is 1/2, 1/4, 1/8, 1/16, ... of the specified distance (L), the output level becomes the maximum value P 1/4, 1/16,
1/64, 1/256, ... means that communication is sufficient.

Therefore, the closer the stations are, the closer the distances ((1/8) L and (1/16) L) corresponding to the adjacent output levels (for example, (1/64) P and (1/256) P) are. The difference between them decreases rapidly. In other words, in a situation where both stations are close,
The communicable output level changes finely according to a slight movement. Therefore, when both stations are close to each other, only one or both stations are slightly moved so that the primary station (communication device) and the secondary station (partner station) come closer to each other, and the output level is lowered by one step. However, it is possible to establish a state in which communication is sufficiently possible. Therefore, in addition to the effects of any of the above configurations, the power consumption of the primary station (communication device) can be significantly reduced by only slightly reducing the distance between the two stations.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] An embodiment of the present invention will be described with reference to FIGS.
It is as follows. The communication device according to the present embodiment has I
Two-way communication is performed between two stations using infrared spatial transmission in accordance with the rDA standard. FIG. 1 shows the configuration of a communication device used in each station. As shown in the figure, this communication device is a communication application 1 as software.
01, a protocol driver (communication protocol program) 102, and a device driver (communication controller driving program) 103. As hardware, a communication controller 104, an infrared device (output means) 10
Five. The infrared device 105 is constituted by a PD (photodiode) or an LED (light emitting diode).

The above software is stored in a memory (not shown). In addition, the memory stores an upper limit value of a retransmission frequency described later. Communication controller 1
04 is a C / C such as a microcomputer capable of executing the above software.
It is composed of PU. The software and the communication controller 104 constitute output power setting means, retransmission investigation means, and output level setting means. That is, the output power setting means, the retransmission investigation means, and the output level setting means are
And a functional module constituted by the above-mentioned software which is a computer program operated thereby.

The communication protocol indicates a communication procedure, which is a procedure until communication is established (handshake), a method for coping with an error, a means for ending communication, and a standard for data transfer method. Is included in it.

The protocol driver 102 issues a command to the device driver 103 in accordance with a communication procedure so as to respond to a request for communication start, end, and data transfer from the communication application 101. Device driver 1
Reference numeral 03 denotes software for controlling devices, which scans registers and memories of the communication controller 104 and controls the communication controller 104 in response to a request from the protocol driver 102. Communication controller 104
Controls the infrared device 105, and performs modulation / demodulation of a signal, storage of data in a memory corresponding to a request from the device driver 103, and the like. The communication controller 104 has a timer function described later.

FIG. 2 shows one of the infrared communication standards, I.
In the rDA standard, an outline of a procedure until communication is established is shown. When the communication is established, it indicates that the data of a file such as an image or a document can be transferred. The primary station is a station that first searches for a communication partner, that is, a station that requests establishment of communication, and is a station that sends out a station discovery command (XID command). The secondary station is a station that accepts the communication request, and is a station that sends out a station discovery response (XID response) to the station discovery command. Therefore, in the following description, the primary station
The secondary station corresponds to the communication device described in claims 6 and 7, and the secondary station corresponds to the partner station described in claims 6 and 7. Further, the communication device described in claims 8 to 10 is basically described as a primary station, but may be applied to a secondary station.

Communication data (command) from primary station to secondary station
Is called a command, and conversely, communication data (command) from the secondary station to the primary station in response to the command is called a response. The XID command is a station discovery command, which is a command for searching for a station that can be a secondary station within a communicable distance from the primary station. SlotNumber indicates the number of the command being sent. X which is a station discovery command
The secondary station that has received the ID command returns an XID response, which is a station discovery response, and performs a process of notifying the primary station of its own station. The primary station sends out a station discovery command according to the prescribed number, and the last command SlotNumber is 25.
6, indicating that this is the last command.

Subsequently, the primary station informs the secondary station of the setting values required for communication, such as the communication speed and the size of the communication data, using an SNRM command. The secondary station receiving the command compares the set value with its own station and notifies the primary station of an acceptable set value using a UA response.

The details are as follows.
That is, according to the IrDA standard, the number of transmitted XID command packets from the primary station can be selected from 1, 6, 8, and 15 packets. For example, when eight XID command packets are transmitted as shown in FIG. 2, the SlotNumber is set to 1 for each of the first to seventh packets.
, And the last eighth packet has a SlotNumber of 256, which indicates that this is the last packet.
Notify the next station.

Then, after transmitting the last packet, about 50
After the time of 0 ms elapses, transmission of the first to eighth data is repeated. The transmission interval between packets is 70 ms.

The secondary station does not necessarily return an XID response immediately upon receiving the XID command, but returns an XID response after receiving a packet having an arbitrary (random value) SlotNumber. For example, 8
When packets are sent one by one, the secondary station can arbitrarily determine whether to return an XID response after receiving the first packet or return an XID response after receiving the eighth packet. As an example, FIG. 2 illustrates a case where an XID response is returned after receiving the third packet.

In the present embodiment, the XID
Although the command is being transmitted, all of the packets are transmitted with the same infrared output. That is, when transmitting eight XID commands at a time, all eight packets are transmitted with the same infrared output. If this 8
If the infrared output is different between each packet, for example, when the secondary station returns an XID response after receiving the first packet, and when the secondary station returns an XID response after receiving the third packet, This is because the output settings will be changed. The details will be described later.

Through the above procedure, a communication line has been established between the primary station and the secondary station, and communication is established.

In the present communication apparatus, as described above, the prescribed power (P) at a unit solid angle is determined in order to communicate with the prescribed distance (L) based on the above-mentioned IrDA standard. Have been. In this communication device, the output level of the primary station is equal to the specified power P.
It is variable by being graded to several levels with the maximum value. In the present embodiment, the output power of the secondary station has the maximum value of P as in the case of the primary station, and can be graded to several levels as in the case of the primary station.

FIG. 7 shows an example of a configuration and a control method for controlling infrared output in the communication apparatus according to the present embodiment. The device driver 701 issues a request to the communication controller 702 to change the infrared output. The communication controller 702 includes an UP terminal 704 and a DOWN terminal 7 attached to the infrared device 705.
In response to the request for changing the infrared output, a single pulse signal is output. When the single pulse signal is output to the UP terminal 704, the infrared output becomes 1
Step up. Conversely, the single pulse signal is converted to DOWN
When output to terminal 703, the infrared output is reduced by one step. In this way, the infrared output is controlled.

In order to grade the output to several levels, a known configuration can be adopted. That is, a plurality of resistors can be connected in series and obtained by resistance division. For example, a configuration disclosed in JP-A-7-66780, JP-A-10-336109, or the like can be employed.

Next, with reference to FIG. 3, a procedure for setting an output in the primary station in a process until communication is established will be described. In the present embodiment, first, a station discovery command is output to perform a search for a secondary station. Then, further, the output power from the primary station is optimized.

First, in step S301, the communication controller 104 of the primary station
Communication is started in response to a request from 01. In S302, a flag SecondaryExistFlag indicating whether or not the partner station has already been discovered is initialized to FALSE. Here, FALSE indicates that it has not been discovered, and TRUE indicates that it has already been discovered. In S303, PowerLevel indicating the level (stage) of the infrared output value is initialized to 1. Powe
rLevel indicates that the smaller the value is, the smaller the output level is. A value of 1 indicates that the infrared output is the minimum, and an actual physical infrared output value is assigned to each level. I have.

In S304, several XID commands as station finding commands are transmitted. In S305, it is checked whether there is an XID response from the partner station, that is, whether the partner station is found. If not found,
This means that the other station does not exist or the infrared output of the primary station is supplied to the primary station infrared device 105 to such an extent that the other station cannot receive the XID command. Therefore, in S312, the level of the infrared output of the infrared device 105 of the primary station is increased by one level. In S313, it is checked whether or not the PowerLevel has exceeded the specified power P, which is the upper limit value of the infrared output. If not, the same processing is performed from S304. If the power level has reached the specified power P, the power level is initialized again in S30.
The same processing is performed from No. 3.

If an XID response is received from the partner station in S305, that is, if the partner station is found, the level of the infrared output at that time is adopted as the output power. Thereby, the search processing is completed.

As described above, in the present embodiment, the output of the station finding command is increased, not decreased.
Therefore, if communication becomes possible while the output is increasing, it is not necessary to increase the output to the maximum value. Therefore, an increase in power consumption can be suppressed accordingly.

Further, in the present embodiment, when a partner station is found in S305, the above SecondaryExistFlag is determined in S306 as to whether the partner station has been found for the first time or whether the partner station has been found once before. Use and judge. That is, when the partner station is found for the first time, SecondaryExistFlag is set to FALSE, and 1
There is a possibility that the partner station has reached the communicable distance while the next station is performing the search processing for finding the station while increasing the infrared output level PowerLevel. In this case, PowerLevel
Is not the minimum output level at which communication is possible. Therefore, the PowerLevel is again returned to the initial output level of 1, and the same processing is performed from S303. In this case, in S311, the SecondaryExistFlag is set to TR.
The fact that the partner station has been found once is stored as the UE. In step S305, there is a station discovery response from the partner station. When the processing proceeds to step S306, since the partner station has been discovered before at this point, the PowerLevel at this time is set to the minimum infrared output level at which communication is possible. It will represent. Then, the process proceeds to S307, and the infrared output corresponding to the output level is applied as the actual output. Thus, the optimization processing is completed.

Subsequently, in S308, the above-mentioned command SNRM is sent to the secondary station. In the present embodiment, this command SNRM is transmitted from the own station (primary station) to the partner station.
Contains a set value representing the infrared output level being applied. In S309, it is determined whether a UA response from the secondary station has been received, and if it has been received, communication is established in S310. If not received, the same processing is performed from S308.

Next, with reference to FIG. 4, a procedure for setting an output in the secondary station in a process until communication is established will be described. In S401, the secondary station is in a state in which it is ready to accept a communication establishment request. S402
In, PowerLevel is set to the upper limit. As a result, the station discovery response (XID
Response) can always be received by the primary station. In S403, a station discovery command (X
ID command), and in S404, an arbitrary Sl
After receiving the XID command indicating the otNumber-th, an XID response is transmitted. As a result, the primary station can recognize that the secondary station is within a communication distance of the secondary station.

Subsequently, in the present embodiment, S40
At 5, the secondary station determines whether a command SNRM including the above-mentioned set value indicating the infrared output level has been received from the primary station. If received, the infrared output level is adopted in S406, and an infrared output corresponding to the level is applied. If not received, S403
And the same process is performed. A UA response is sent in S407, and communication is established in S408. In this way, the output at the secondary station is set.

Next, referring to FIG. 5, in the primary station,
A procedure for determining the optimum output after establishing the communication will be described. This processing is for maintaining good communication by adjusting the output when retransmission frequently occurs. Here, retransmission (in a broad sense) means that, when communication data is corrupted due to an error during communication, the data receiving side sends the same data back to the transmitting station by sending the same data to the transmitting station. It refers to a process of requesting retransmission (retransmission request) or a process of actually retransmitting data from the transmission source station (retransmission in a narrow sense). Here, unless otherwise specified, retransmission in the broad sense is simply referred to as retransmission.

In step S501, communication has been established. In S502, the communication controller 1 of the primary station
The timer in 04 is reset (initialized). continue,
In step S503, a timer is set, and the timer expires after a certain period of time. Communication processing is performed in S504. If the timer has not expired in S505, the communication processing in S504 is continued.

If the timer has expired in step S505, the communication controller 104 checks in step S506 the number of retransmissions that occurred per unit time.
Investigate retransmission frequency. That is, the number of retransmissions that occurred during the time from when the timer was set to when it expired may be counted, and the number may be divided by this time. Then, it is determined whether or not the obtained retransmission frequency exceeds a certain reference value.

The number of retransmissions to be counted includes the number of retransmission requests and the number of retransmissions in a narrow sense as described above. The frequency of retransmission of data that could not be transmitted correctly due to a communication error is shown. What is necessary is just a thing and it is not limited to these.

The fact that the level of noise relative to the signal level increases due to the low infrared output, resulting in an error, is considered to be the cause of the large number of retransmissions. Therefore, if the retransmission frequency exceeds the reference value in S506, the infrared output level is increased by one step in S507. In step S508, it is determined whether the output exceeds the upper limit (specified power P). If the output exceeds the upper limit, the output is set to the upper limit in step S509. Thus, 1 after communication is established
The optimum output at the next station is determined. After that, S510
In step (2), the remote station (secondary station) is notified of the changed infrared output level (PowerLevel), and the same processing is repeated from step S502.

In S506, if the retransmission frequency does not exceed the reference value, the same processing is repeated from S502.

In this embodiment, the retransmission frequency check is periodically performed as shown in S502 to S506. That is, as soon as the timer expires, the timer is reset and set again to start counting, thereby continuously and continuously examining the retransmission frequency. Therefore, it is possible to quickly respond to a situation in which retransmission frequently occurs, improve the communication state, and thereby quickly complete the communication.

When the retransmission frequency is equal to or higher than the reference value and the output power of the current primary station has reached the maximum level, the output power cannot be increased any more. Therefore, a warning sound or warning display
Primary station display (not shown) or audio output (not shown)
It can also be output from. In addition, a warning output can be sent from the communication application 101 to higher application software (not shown), and the computer can perform a warning process. Accordingly, it is possible to easily understand that the communication environment is such that the user cannot sufficiently reduce the retransmission frequency even if the output is increased to the maximum power.

Next, referring to FIG. 6, in the secondary station,
A procedure for determining the optimum output after establishing the communication will be described. In step S601, communication has been established. S
In 602, communication processing is performed, and in S603,
The communication controller 104 of the secondary station determines whether or not the infrared output level (PowerLevel) (see S510 in FIG. 5) has been received from the primary station.
02 is continued. If received, S6
In step 04, the same processing is performed from S602 by applying the infrared output level applied by the primary station.

Note that the secondary station may perform the same processing as the primary station. In other words, the frequency of retransmission requests from the secondary station is checked by the primary station and the output of the primary station is increased according to the result. The station may investigate and increase the output of the secondary station according to the result.

As an example of the combination of the primary station and the secondary station in the communication apparatus according to the present embodiment, for example, a cellular phone or other portable information equipment is used as a primary station and a personal computer (hereinafter referred to as a personal computer). ) And telephones including mobile phones and the like are defined as secondary stations. The digital camera is the primary station, and the personal computer is the secondary station. However, the present invention is not limited thereto, and devices that perform two-way communication using optical transmission may be used. Also, these devices are generally
Both can be primary and secondary stations, and
Either may be the primary station or the secondary station.

The output level of the primary station is set to (1/2 ⁿ ) ² (n = 1, 2,
3,...). That is, for example, if n is 1 to 4, each output level of the primary station is 1/4, 1/16, 1/6 of the maximum value (the specified power P).
4, 1/256. From this, if the distance between the two stations is 1/2, 1/4, 1/8, 1/16 of the specified distance L, the output level becomes 1/4, 1 of the maximum value (P), respectively. / 16, 1/64, 1/256 means that communication is sufficient.

In this case, the closer the two stations are, the closer the distances ((1/8) L and (1/8) L corresponding to the adjacent output levels (for example, (1/64) P and (1/256) P) are. 16) The difference between L) decreases rapidly. In other words, in a situation where the two stations are close to each other, the communicable output level slightly changes according to a slight movement. Therefore, when the two stations are close to each other, only one or both stations are slightly moved so that the primary station and the secondary station are close to each other, and a state in which communication can be sufficiently performed even at an output level one step lower. be able to. That is, for example, of both stations, the device side that is easy to move,
Only a slight movement in the direction approaching the device side where movement is difficult is sufficient. Therefore, the power consumption of the primary station can be significantly reduced by only slightly reducing the distance between the two stations.

As for the primary station and the secondary station, for example, a communication device that is easily movable such as a portable terminal device is a primary station (a side that sends an XID command), and a stationary personal computer or the like. The fixed device that is difficult to move as described above may be the secondary station (the side that sends the XID response). In this case, to bring both stations closer to each other, 1
The next station may be moved to the secondary station.

On the other hand, such a fixed device is
The secondary station may be a communication device that is the next station and that is easily movable such as a portable terminal device. For example, on a fixed personal computer (primary station), upper-level software such as a word processor or spreadsheet software is executed, and the software activates infrared communication software and executes itself. Is set to the data receiving state. Then, an XID command is sent to the portable terminal device which is the secondary station, and the portable terminal device requests the portable terminal device to transmit data to itself (the above-mentioned high-level software, that is, the personal computer). The mobile terminal device transmits the XID response and, upon receiving the request, transmits data to the personal computer. In this case, in order to bring both stations closer to each other, set the secondary station to 1
It may be moved to the next station.

Further, by modifying the present embodiment, the output setting process at the time of establishing communication is configured by replacing the primary station with the secondary station as shown in (1) and (2) below. You can also.

(1) Instead of increasing the output of the XID command output from the primary station, the XI output from the secondary station in response to the XID command output from the primary station
The XID response is output while increasing the output of the D response from the initial value until there is a response from the primary station to the XID response. Then, if there is a response from the primary station, the output of the XID response at that time can be set as the output power from the secondary station to the primary station.

With this configuration, the output of the secondary station is
Because it will increase rather than decrease,
When communication becomes possible during the increase of the output of the XID response at the start of communication, it is not necessary to increase the output of the XID response to the maximum value. therefore,
Accordingly, an increase in power consumption can be suppressed.

(2) In addition to the configuration of the above (1), the XI at that time in response to the response from the primary station as described above
After setting the output of the D response as the output power from the secondary station to the primary station, the output of the XID response is set to the initial value again, and the output is increased until there is a response from the primary station to this XID response. While outputting the XID response, if there is a response from the primary station, the output of the XID response at that time is set as the output power from the secondary station to the primary station.

With this configuration, after setting the output of the XID response as the output power from the secondary station,
Communication such as when at least one of the next station and the secondary station moves closer to the previous station, or when the angle changes so that the light emitting unit and light receiving unit between the two stations face each other correctly. If the environment changes, it is detected that sufficient communication is possible with an output power smaller than that previously adopted as the set value, and that output power can be employed. Conversely, even when the distance is large or the angle deviation is severe, it is detected that communication is possible if the output power is increased as compared with the setting value, and the output power is set. It can be adopted as a value. Therefore, even if the communication environment such as the distance or the angle between the two stations changes, it is possible to reliably find the minimum communicable output power.

As a specific procedure of the output setting in the above configurations (1) and (2), this processing is performed on the secondary station side in the above description with reference to FIG. 3, while FIG. 4 is used. In the above description, this processing may be performed on the primary station side. In this case, in the above description with reference to FIG.
04 and S305, respectively, sending a station discovery response,
In step S30, the inspection is replaced with an inspection for the presence / absence of a response (XR) from the partner station (primary station) to the station discovery response.
8 and S309, respectively, sending an arbitrary command (referred to as PC) including the optimum PowerLevel to the partner station,
It may be replaced with a check as to whether a response (PR) to the command PC from the next station) is received. On the other hand, in the above description with reference to FIG.
Set PowerLevel to the upper limit and send a station discovery command. Also, S403, S404, S405, S
407, receiving a station discovery response from the secondary station, transmitting any reply XR to the station discovery response, checking whether the command PC has been received from the secondary station, and transmitting the response PR, respectively. Can be replaced with

[Second Embodiment] The following will describe another embodiment of the present invention with reference to FIGS. For convenience of explanation, members having the same functions as the members shown in the drawings of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The present embodiment is basically the same as the first embodiment. In the present embodiment, as a countermeasure for a case where retransmission frequently occurs, processing is performed according to the flowchart of FIG. 8 unlike FIG. 5 described above. That is, first, communication is established in S801. Then, communication processing is performed in S802. Here, when the primary station receives a retransmission request from the secondary station in S803, the communication controller 104 of the primary station resets the timer in S804. And S80
5 to S808, S503 to S5 in FIG.
As in 06, the retransmission frequency is checked. If the retransmission frequency is equal to or less than the reference value in step S808, the process returns to the communication process in step S802 without returning to the timer resetting process, unlike the example of FIG. Then, in S803, whether or not a retransmission request has been received is monitored again.

Similarly, even if the retransmission frequency exceeds the reference value in S808, the processing of S809 to S812 corresponding to S507 to S510 is performed and the destination station (2
After sending the PowerLevel to the (next station), unlike FIG.
Returning to the communication process of 802, in S803, the presence / absence of the reception of the retransmission request is monitored again.

As described above, in the present embodiment, the above investigation is not performed until the primary station receives the retransmission request, and the above investigation is started when the primary station receives the retransmission request. Therefore, the above investigation is not performed frequently, and the above investigation is started only when a retransmission request actually occurs.
Therefore, it is possible to suppress an increase in power consumption for the survey, unlike the case where the survey is performed continuously.

The communication method according to the present invention may be configured as follows. That is, the communication method according to the present invention can be configured such that, in the infrared space transmission communication method having the handshake procedure, the infrared output of the station finding command is changed and transmitted. According to the above method, the power consumption can be reduced by setting the minimum communicable infrared output.

Further, in the communication method according to the present invention, in the above-mentioned configuration, the infrared output of the station finding command may be gradually increased from a small output.
According to the above method, it is possible to reduce power consumption during a process of obtaining an optimal infrared output.

In the communication method according to the present invention, the infrared output may be increased until there is a response from the communication partner in the above configuration. According to the above method, a minimum communicable infrared output value can be obtained.

Further, according to the communication method of the present invention, in the above configuration, when there is a response from a communication partner, that is, when a partner station is found, the processing of the above configuration is performed again from the first infrared output. can do. According to the above method, it is possible to find the minimum communicable infrared output value for the partner station that has reached the communicable position during the transmission of the station finding command.

Further, in the communication method according to the present invention, in the above configuration, when a set value such as a communication speed used for communication is transmitted to a partner station, an infrared output value can be transmitted. According to the above method, the other station uses the same infrared output value, so that the useless power consumed by the other station can be reduced.

The communication method according to the present invention is an infrared space transmission communication method having a handshake procedure.
It is possible to adopt a configuration in which the infrared output value of the own station is changed in accordance with the infrared output value adopted by the partner station. According to the above method, by using the same infrared output value as that of the partner station to which the optimum infrared output value is applied, it is possible to reduce unnecessary power consumed by the own station.

Further, the communication method according to the present invention, in the infrared space transmission communication method having a retransmission procedure, may be configured such that after establishing communication, communication data is transmitted by changing the infrared output. According to the above method, it is possible to set an output corresponding to a change in environment or a change in distance during communication.

Further, in the communication method according to the present invention, in the above-described configuration, the configuration may be such that the infrared output is periodically optimized. According to the above method, it is possible to set an output corresponding to a change in environment or a change in distance during communication.

Further, in the communication method according to the present invention, in the above-mentioned configuration, the output can be optimized when the number of retransmission requests exceeds a certain reference value per unit time. According to the above method, it is possible to prevent communication from being interrupted due to a change in environment or a change in distance during communication.

Further, in the communication method according to the present invention, in the above configuration, when the infrared output value is changed, the infrared output value can be transmitted to the partner station. According to the above method, the other station uses the same infrared output value, so that the useless power consumed by the other station can be reduced.

Further, the communication method according to the present invention may be arranged such that, in the above configuration, the infrared output value of the own station is changed in accordance with the infrared output value adopted by the partner station. According to the above method, by using the same infrared output value as that of the partner station to which the optimum infrared output value is applied, it is possible to reduce unnecessary power consumed by the own station.

[0096]

As described above, the communication method according to the first aspect of the present invention performs communication by transmitting light between the primary station and the secondary station, and varies the output of the primary station. In this communication method, the output of the station discovery command output from the primary station is increased from the initial value until a response is received from the secondary station, and the station discovery command is output.

A communication device according to a sixth aspect of the present invention communicates with a partner station by transmitting light and has a variable output to the partner station. Output means for outputting a station finding command, and outputting the station finding command from the output means from an initial value,
Output power setting means for increasing the response power until there is a response from the partner station.

Therefore, there is an effect that an increase in power consumption can be suppressed.

[0099] Also, The communication method according to claim 1, secondary
If there is a response from the station, then again to the initial value output from the station discovery command, while increasing the output until there is a response from the secondary station outputs the station discovery command, its
In response to this, if there is a response from the secondary station, the output of the station discovery command at that time is set as output power from the primary station to the secondary station.

[0100] The communication apparatus according to claim 6, opponent
If there is a response from the station, the output power setting means sets the output of the station finding command to the initial value again, and increases the output until there is a response from the partner station .
Then, if there is a response from the partner station, the output of the station discovery command at that time is set as output power to the partner station.

Therefore, even if the communication environment such as the distance or the angle between the two stations changes, an effect that the minimum output power capable of performing communication can be reliably found.

The communication method according to the second aspect is the communication method according to the first aspect.
In addition to the configuration described above, the primary station has a set output power
To the secondary station together with the setting values required for communication,
The secondary station sets the output power based on it
is there. A communication device according to a seventh aspect is the communication device according to the sixth aspect.
In addition to configuration, the set output power is required for communication
Notify the partner station with the set value, and the partner station
In this configuration, the output power is set. According to a third aspect of the present invention, there is provided a communication method according to the first or second aspect.
Then, the frequency of retransmission of data sent from the primary station to the secondary station is investigated, and when the frequency exceeds a reference value, the output from the primary station is increased from the current value and output. Is the way.

[0103] The communication device of claim 8, wherein
In addition to the configuration described in item 6 or 7, a retransmission investigation means for investigating the frequency of retransmission of data to be transmitted to the partner station is provided.
The output power when the frequency exceeds a reference value.
The configuration is such that the setting means increases the output to the partner station from the current value and outputs the result.

Therefore, there is an effect that an increase in power consumption can be suppressed.

Further, even after the communication power is set to the minimum power at which communication can be performed, even if the communication state deteriorates due to movement during communication and retransmission frequently occurs, communication can be satisfactorily continued. .

A communication method according to a fourth aspect is a method in which the above-mentioned investigation is periodically performed in addition to the configuration of the third aspect.

Further, the communication apparatus according to the ninth aspect is configured such that, in addition to the configuration of the eighth aspect, the retransmission investigation unit periodically performs the investigation.

Therefore, in addition to the effect of the configuration of claim 3 or 8, the communication state can be improved promptly in response to a situation where frequent retransmission occurs, and the communication can be completed quickly. This has the effect.

According to a fifth aspect of the present invention, in addition to the configuration of the third aspect, the above investigation is not performed until the primary station receives the retransmission request, and the above investigation is performed when the primary station receives the retransmission request. Is the way to start.

According to a tenth aspect of the present invention, in addition to the configuration of the eighth aspect, in addition to the configuration of the eighth aspect, the retransmission investigation unit does not perform the inspection until a retransmission request is received, and performs the inspection when a retransmission request is received. This is the configuration for starting.

Therefore, in addition to the effect of the configuration of claim 3 or 8, there is an effect that it is possible to suppress an increase in power consumption for the investigation, unlike the case of performing the investigation continuously.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a configuration example of a communication device according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a procedure until communication in infrared space transmission is established.

FIG. 3 is a flowchart showing station discovery and output control processing performed by a primary station in the configuration of FIG. 1;

FIG. 4 is a flowchart showing a station discovery and output control process performed by a secondary station in the configuration of FIG. 1;

FIG. 5 is a flowchart showing an output control process after communication establishment performed by the primary station in the configuration of FIG. 1;

FIG. 6 is a flowchart showing an output control process after communication is established in a secondary station in the configuration of FIG. 1;

FIG. 7 is a block diagram showing a state of output control of an infrared device in the configuration of FIG. 1;

FIG. 8 illustrates another example of the configuration of the communication device according to the present invention.
9 is a flowchart illustrating an output control process performed after communication is established in a next station.

[Explanation of symbols]

Reference Signs List 101 communication application 102 protocol driver 103 device driver 104 communication controller (output power setting means, retransmission investigation means, output level setting means) 105 infrared device (output means) 701 device driver 702 communication controller (output power setting means, retransmission investigation means, Output level setting means) 703 DOWN terminal 704 UP terminal 705 Infrared device (output means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-172409 (JP, A) JP-A-1-261935 (JP, A) JP-A-2-42833 (JP, A) JP-A-9-209 93198 (JP, A) JP-A-11-17613 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 10/00-10/28 H04J 14/00-14/08 H04L 12/28 H04L 12/44

Claims (10)

(57) [Claims] 1. A communication method for performing communication by transmitting light between a primary station and a secondary station and making the output of the primary station variable, comprising: outputting an output of a station discovery command output from the primary station. , from the initial value, while increasing until there is a response from the secondary station outputs the station discovery command, if there is a response from the secondary station, the output of the station discovery command
Is set to the initial value again, and there is a response from the secondary station.
Output the above station discovery command while increasing the output up to
And if there is a response from the secondary station,
Output of station search command from primary station to secondary station
A communication method characterized by setting as power . 2. The primary station transmits a set output power to the primary station.
Notify the secondary station with the set values required for communication.
The communication method according to claim 1, wherein the setting of the output power is based on the setting . 3. The frequency of retransmission of data sent from the primary station to the secondary station is investigated. If the frequency exceeds a reference value, the output from the primary station is increased from the current value. The communication method according to claim 1 , wherein the data is output. 4. The communication method according to claim 3, wherein said checking is performed periodically. 5. The communication method according to claim 3, wherein the investigation is not performed until the primary station receives the retransmission request, and the investigation is started when the primary station receives the retransmission request. 6. A communication device which communicates with a partner station by light transmission and varies output to the partner station, an output means for outputting a station discovery command for discovering the partner station, The output of the station finding command from the output means is increased from the initial value until there is a response from the partner station, and if there is a response from the partner station , the output of the station finding command is repeated again.
Set the output to the initial value and output until there is a response from the partner station.
And if there is a response from the partner station,
Output of the above station discovery command at the time of
A communication device comprising: output power setting means for setting as power . 7. The set output power is required for communication.
Notify the partner station with the set value, and the partner station
The communication device according to claim 6, wherein the output power is set by setting . 8. An apparatus according to claim 8, further comprising: retransmission checking means for checking the frequency of retransmission of data to be transmitted to the other station, and when the frequency exceeds a reference value, said output power setting means.
8. The communication device according to claim 6 , wherein the stage increases the output to the partner station from the current value and outputs the increased value. 9. The communication apparatus according to claim 8, wherein said retransmission investigation means performs said investigation periodically. 10. The communication apparatus according to claim 8, wherein said retransmission investigation means does not perform said investigation until a retransmission request is received, and starts said investigation when a retransmission request is received.