JP2001197144A - Radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the communication of high reliability and high throughput by determining a packet size and the number of times of continuous packet transmission corresponding to fluctuation in the state of a radio channel. SOLUTION: A received radio wave is demodulated by a receiver 12 and an electric field strength is measured. On the basis of the header contents of this demodulated signal, a header analyzing/telegraphic message reconstituting device 13 prepares and outputs receiving data. Besides, the ID of the transmitting source is extracted and it is stored in a packet size/continuous transmission time storage device 15. On the basis of the received electric field strength inputted from the receiver 12, a sample/analytic device 14 determines the suitable size and the number of times of continuous transmission for a packet to be transmitted to the transmitting source and stores them in the storage device 15. When transmitting data are inputted, while referring to the packet size and the number of times of continuous transmission in the storage device 15, a transmitting signal preparing device 17 prepares a continuously transmitting telegraphic message and sends it through a transmitter 18 and an antenna 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a radio communication control system and a radio communication control system for performing data communication using packets.

[0002]

2. Description of the Related Art In recent years, the mainstream of communication has been shifting from telephone (voice) to data. This is due to the rapid increase in demand for multimedia communication with the rapid spread of the Internet, the rapid spread of the use of portable information terminals, and the fact that mobile phones send and receive e-mails, not just voice communications. Or as a mobile terminal for obtaining various information.

Further, a LAN (Local Are) in a company or the like is used.
a Network) is also expected to shift to a wireless LAN due to the complicated wiring work involved in cable connection. As described above, in a network society that will further develop in the future, the mainstream of communication will shift from telephone to data and from wired to wireless, and the importance of wireless data communication will further increase in the future. .

[0004] As a conventional wireless communication system, a method is known in which transmission data is divided into packets and these are continuously transmitted in order to improve reliability. In this conventional method, the packet size and the number of continuous transmissions are determined based on a communication environment (speed and magnitude of electric field strength fluctuation on a line) which is assumed in advance, and they are fixed. Met.

[0005]

In the above-mentioned conventional wireless communication system, the environment in which the system is actually used is:
If the environment is worse than the environment assumed in advance, there has been a problem that packet transmission errors increase. Conversely, when used in an environment that is better than the assumed environment, there has been a problem that the throughput (communication speed) is reduced due to useless continuous transmission.

Incidentally, in packet communication in a wireless communication network, an average random error rate is assumed based on the electric field strength of a received radio wave, and an error occurrence interval is calculated from the error rate. Japanese Patent Application Laid-Open No. 11-205216 discloses an invention that enables variable-length packet communication with higher throughput by selecting a packet size in real time.

However, the present invention provides the following (1) to
(5) is fundamentally different from this known technique. (1) The above-mentioned known technique implicitly assumes that the speed of the fluctuation of the received electric field strength is unique (constant) (for example, see (Equation 2) and FIG. 5). No premise is required. (2) In the above-described known technique, only the packet size is changed according to the error occurrence situation. However, the present invention changes not only the packet size but also the number of consecutive transmissions of the packet. (3) The above-mentioned known technology is based on ARQ (Automatic Repeat R).
equest) and the like, but the present invention does not require error control by such a retransmission protocol. (4) In the above-mentioned known technique, an “average random error rate” is assumed from the measured electric field strength, and the packet size is determined based on the “average random error rate”. In this case, in order to assume an average random error rate, the value of the electric field strength may be one (average value or median value). (5) The above-mentioned known technique is mainly intended to cope with the occurrence of a random error in a wireless channel, and cannot cope with a burst-like error. In actual wireless communication, the occurrence of an error has a burst-like property rather than a random property. This burst error is important in data communication.

[0008] In communication, reliability is an important parameter in addition to throughput. Although these two parameters have a trade-off relationship with each other,
In the above-mentioned known technology, only the throughput is improved, so that it is necessary to use a retransmission protocol such as ARQ in order to guarantee reliability. In contrast, in the present invention,
As described above, since not only the packet size but also the number of consecutive transmissions of the packet are changed, it is possible to ensure reliability without using a retransmission protocol. Therefore,
The present invention is also applicable to applications that require higher reliability in wireless communication, such as data transmission, which cannot be handled by the above-described known technology.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a radio device which can optimize throughput while ensuring high reliability even in various environments. It is another object of the present invention to provide a wireless device that can cope with burst errors and is suitable for data communication.

[0010]

According to a first aspect of the present invention, there is provided a radio apparatus which samples a field intensity of a received signal, and transmits a transmission packet based on a parameter defining a radio channel state obtained from the sampled data. And a transmitting unit that divides transmission data into packet sizes of the size determined by the packet size determining unit and continuously transmits the packet data.

[0011] The packet size determining means of the wireless device according to the first aspect of the present invention determines the state of the wireless line based on the above-mentioned parameters. For example, when the state of the wireless line is poor, the size of the transmission packet is reduced. Conversely, when the condition of the wireless line is good, the size of the transmission packet is increased.

As described above, the radio device according to the first aspect of the present invention grasps the state of the radio channel based on the above parameters and changes the size of the transmission packet according to the change in the status of the radio channel. Thus, highly reliable wireless communication with little packet loss is realized.

A wireless device according to a second aspect of the present invention samples the electric field strength of a received signal, and determines the number of consecutive packet transmissions based on a parameter defining a state of a wireless channel obtained from the sampled data. It is characterized by comprising a number of continuous transmissions determining means, and a transmitting means for dividing transmission data into packets and storing the packets in the number of consecutive transmissions determined by the number of continuous transmissions determining means.

In the second aspect of the present invention, the number-of-times-of-consecutive-transmissions determining means of the radio device determines the state of the radio line based on the above parameters. Increase the number of transmissions. This realizes highly reliable wireless communication even when the state of the wireless line is poor and the possibility of packet loss is high.

[0015] Further, the means for determining the number of continuous transmissions of the wireless device according to the second aspect of the present invention determines the state of the wireless line based on the above parameters. ) To reduce the number of continuous feeds. This improves the throughput (transmission efficiency) when the state of the wireless line is good.

A wireless device according to a third aspect of the present invention samples the electric field strength of a received signal and, based on parameters defining the state of a wireless line obtained from the sampled data, determines the size of the transmission packet and the packet (message). ), The transmission data is divided into packets and stored in packets based on the packet size and the number of consecutive transmissions determined by the sample / analysis means for determining the number of consecutive transmissions. And a transmitting means for continuously transmitting the number of times.

A sample of the wireless device according to the third embodiment of the present invention
The analyzing means has the function of the packet size determining means of the wireless device according to the first aspect of the present invention and the function of the continuous transmission count determining means of the wireless device according to the second aspect of the present invention. The transmission means of the wireless device according to the third aspect is the first aspect of the present invention described above.
Since the wireless communication device has the functions of the transmitting means of the wireless device of the aspect and the transmitting means of the wireless device of the second aspect, the wireless communication having both high reliability and high throughput can be performed according to the state of the wireless line. Can be realized.

In the wireless device according to the first, second, or third aspect of the present invention, the parameters defining the state of the wireless channel obtained from the sampling data include, for example, at least the median value of the received electric field strength, Includes the frequency with which the field strength falls below the threshold and the average time during which the received field strength falls below the threshold.

In such a configuration, the packet size determining means of the wireless device according to the first aspect of the present invention or the sample / analyzing means of the wireless device according to the third aspect of the present invention provides, for example, the time when the received electric field strength falls below the threshold value. If it is short, but the frequency of the received electric field strength falling below the threshold value is high, the size of the transmission packet is reduced. If the received field strength does not fall below the threshold and the average value of the received field strength is sufficiently high, the size of the transmission packet is increased.

Further, the means for determining the number of continuous transmissions of the wireless device according to the second aspect of the present invention or the sample / analyzing means of the wireless device according to the third aspect of the present invention may be arranged, for example, when the average value of the received electric field intensity is small When the frequency of the electric field strength falls below the threshold value is high, the number of consecutive transmissions of the packet (telegram) is increased. This realizes highly reliable wireless communication even when the state of the wireless line is poor and the possibility of packet loss is high.

Further, the means for determining the number of continuous transmissions of the wireless device according to the second aspect of the present invention or the sample / analyzing means for the wireless device according to the third aspect of the present invention, for example, ensures that the received electric field intensity does not fall below the threshold value. In addition, when the average value of the received electric field strength is sufficiently high, the number of consecutive transmissions of the packet (telegram) is reduced.
This improves the throughput (transmission efficiency) when the state of the wireless line is good.

The packet size determining means of the wireless device according to the first aspect of the present invention or the sample / analyzing means of the wireless device according to the third aspect of the present invention determines, for example, the size of a packet transmitted to each of the other wireless devices. Update according to the state of the wireless line at the time of communication. Thus, the size of the transmission packet can be appropriately set by following the change in the state of the wireless channel in real time.

According to the second aspect of the present invention, the means for determining the number of continuous transmissions of the wireless device or the sample / analyzing means for the wireless device according to the third aspect provides the number of consecutive transmissions of the packet (telegram) to be transmitted to each of the other wireless devices. Is updated according to the state of the wireless line at the time of actual communication. Thus, the number of consecutive packet transmissions can be appropriately set while following a change in the state of the wireless line in real time.

The packet size determining means of the wireless device according to the first aspect of the present invention or the sample / analyzing means of the wireless device according to the third aspect of the present invention, for example, performs test communication on the size of a packet to be transmitted to each of the other wireless devices. Sometimes fixedly determined. This eliminates the need to update the packet size during normal communication, thereby simplifying the protocol control unit mounted on the wireless device.

According to the second aspect of the present invention, the means for determining the number of continuous transmissions of the wireless device or the sample / analyzing means of the wireless device of the third aspect transmits the packet (telegram) at the time of transmission to each of the other wireless devices. The number of transmissions is fixedly determined during test communication. This eliminates the need to update the number of continuous transmissions during normal communication, thereby simplifying the protocol control unit mounted on the wireless device.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a system configuration of a wireless device according to an embodiment of the present invention. The wireless device of the present embodiment transmits and receives data wirelessly using packets. A wireless communication system can be constructed using the wireless device of the present embodiment.

The antenna 10 receives a radio wave (reception signal), outputs the radio wave to the receiver 12, and sends out a radio frequency band transmission signal input from the transmitter 18 as a radio wave.

The antenna 10, the receiver 12, and the transmitter 1
8, a changeover switch 11 is provided.
By operating the changeover switch 11, reception and transmission of radio waves are switched.

The receiver 12 generates a demodulated signal from the input received signal and measures the electric field strength of the received radio wave (received electric field strength). Then, the receiver 12 outputs the demodulated signal to the header analysis / telegram reconstruction device 13 and outputs the received electric field strength to the sample / analysis device 14 in an analog manner.

The header analysis / telegram reconstruction device 13 reads the packet length and the number of continuous transmissions from the header of the demodulated signal (packet), reconstructs the data as appropriate, and outputs the reconstructed reception data. . Further, the local station ID (the number of the transmission source wireless device) extracted from the header is written in the packet size / continuous transmission count storage device 15 as the local station ID of the local device. The format of the demodulated signal (packet) will be described later.

The sample / analyzer 14 samples the received electric field strength, which is an analog signal input from the receiver 12, and measures the median value of the sample data, the frequency below the threshold, and the average time below the threshold, The size of the packet to be transmitted and the number of continuous transmissions are determined based on these three measurement data and parameters related to the reliability of wireless communication. Then, the packet size and the number of continuous transmissions are stored in the packet size / number of continuous transmissions storage device 15.

Packet size / number of consecutive transmissions storage device 15
Is composed of a semiconductor memory such as a RAM, an external storage device, or the like. The packet size and the number of consecutive transmissions are determined for each identifier (No.) of the communication partner in the form of a table 20 shown in FIG. And individually memorize them.

As shown in FIG. 2, each entry of the table 20 stores items of “radio device number”, “packet size”, and “number of consecutive transmissions”. As described above, the wireless device No. The packet size and the number of consecutive transmissions are stored by the header analysis / telegram reconstruction device 13 and the sample / analysis device 14, respectively.

When the transmission data is input, the transmission signal generation device 17 then receives the identifier (N
o. ) Is read out, and using the identifier as a key, the size and the number of consecutive transmissions of the packet to be transmitted to the transmission destination wireless device are read out from the packet size / number of consecutive transmissions storage device 15.
Then, based on the read information, the transmission data is divided into packets by a procedure as shown in FIG. 3 to create a continuous transmission telegram.

Here, a procedure for generating a continuous transmission telegram from the transmission data input by the transmission signal generation device 17 will be described with reference to FIG. The transmission signal creation device 17 is configured as shown in FIG.
Based on the packet size read from the packet size / number of consecutive transmissions storage device 15, the transmission data shown in (a) has n pieces of information (n is an arbitrary positive integer) as shown in FIG. Part 1, information part 2,. . . , Information section n. Information part 1, information part 2,. . . , Information part n have the same size and are determined in consideration of the header size of the packet.

Next, as shown in FIG. 3 (c), the transmission signal creation device 17 performs the above-mentioned information section 1, information section 2,. . . , Information part n, header 1, header 2,. . . Header n is added, and packet 1, packet 2,. . . Create a packet n. These packets 1,
Packet 2,. . . Each size of the packet n is equal to the packet size read from the packet size / continuous transmission count storage device 15.

Subsequently, as shown in FIG. 3C, the transmission signal creation device 17 performs the above-mentioned n packets 1, packets 2,. . . The packet n is connected to form a continuous transmission message (continuous transmission message 1, continuous transmission message 2,..., Continuous transmission message N), and the continuous transmission message 1, continuous transmission message 2,. . . , Consecutively transmitted messages N in order, to the transmitter 18.

The continuously transmitted message 1, the continuously transmitted message 2,. . . , And the continuous transmission telegram N have the same contents except for the header part of each packet, and the value of N is equal to the number of consecutive transmissions read from the packet size / continuous transmission number storage device 15.

The transmitter 18 modulates the continuous transmission telegram input from the transmission signal generator 17 into a signal in a radio frequency band.
The signal is amplified and transmitted to the outside via the changeover switch 11 and the antenna 10.

FIG. 4 shows the packet i (i) shown in FIG.
2 is a diagram showing a detailed data structure of a header of (= 1 to n). FIG. As shown in FIG. 4, the header of the packet i is composed of “synchronization signal”, “ID (identifier)”, “continuously transmitted information”, and “packet information”.

The synchronizing signal is composed of a "bit synchronizing signal" and a "frame synchronizing signal", and is used for establishing bit synchronization and frame synchronization, respectively. ID is "own station I
D "and" the partner station ID ". The own station ID is the ID (radio device number) of the transmission source wireless communication device, and the partner station ID
Is the ID (wireless device number) of the wireless device of the transmission destination.

The continuous transmission information includes “continuous transmission No.” and “total number of consecutive transmissions”. Continuous delivery No. Are consecutively transmitted messages 1, consecutively transmitted messages 2,. . . , Is an identifier for identifying the continuous transmission telegram N. The total number of consecutive transmissions is equal to the number of consecutive transmissions. The wireless device on the receiving side can know the number of messages transmitted continuously based on the total number of continuous transmissions.

The packet information includes "packet No."
It consists of “packet size” and “total number of packets”.
Packet No. Are packet 1, packet 2,. . . ,
This is an identifier for identifying the packet N. The packet size is information indicating the size of the packet i (i = 1 to n). The total number of packets is information indicating the total number of packets included in one continuous transmission telegram.

Next, the operation of the wireless device of FIG.
This will be described with reference to the flowcharts of FIGS. FIG. 5 is a flowchart illustrating the operation of the wireless device at the time of reception.

First, a received signal is received by the antenna 10 and input to the receiver 12 via the changeover switch 11. Then, the receiver 12 demodulates the received signal, and outputs the demodulated signal to the header analysis / telegram reconstruction device 13 (step S11).

The header analysis / message reconstructing device 13 reconstructs the message based on the contents of the header of the input demodulated signal (packet) as described above and outputs it as received data (step S12). , S13).

The header analysis / message reconstructing device 13
Extracts the local station ID from the header of the demodulated signal (packet) and stores it as the ID (radio device number) of the wireless device of the transmission destination of the local device, that is, the packet ID and the number of consecutive transmissions as the partner station ID. It is stored in the entry of the device 15 (steps S12, S14).

The receiver 12 outputs the electric field strength of the received signal (received electric field strength) to the sample / analyzer 14. The sample / analyzer 14 samples the received electric field strength (analog signal) (step S1).
5) Subsequently, based on the sampling result, sample data analysis for calculating the median of the received electric field intensity, the frequency at which the received electric field intensity is below the threshold value, and the average time during which the received electric field intensity is below the threshold value by the above-described method. Perform (Step S1
6).

Next, the sample / analyzer 14 calculates the size of the packet to be transmitted and the number of consecutive transmissions based on the above three information obtained in step S16, the reliability parameters, and the like (step S17). Packet size and
It is stored in the entry of the continuous transmission count storage device 15 (step S14).

When the data of the packet size / number of consecutive transmissions storage device 15 is updated only at the time of the test communication when the wireless device is installed, the processing of steps S14 to S17 is performed only at the time of the test communication. , During normal reception,
Only the processing of steps S11 to S13, that is, the reconstruction of the received data (telegram) is performed.

Next, the operation of the wireless device of FIG. 1 when transmitting a transmission signal will be described with reference to the flowchart of FIG. When the transmission data is input, the transmission signal creation device 17 acquires the partner station ID from the input (step S21),
Using the partner station ID as a key, the packet size and the number of consecutive transmissions of the destination wireless device having the partner station ID stored in the packet size / number of consecutive transmissions storage device 15 are referred to (step S22).

Then, based on the packet size and the number of continuous transmissions referred to above, the transmission signal generation device 17 generates the number of consecutively transmitted messages according to the procedure shown in FIG. Output to the device 18 (step S23).

FIG. 7 is a diagram showing an example of the temporal variation of the electric field strength of the received signal received by the wireless device of FIG. In the figure, the horizontal axis represents time [sec], and the vertical axis represents received electric field strength [dBm]. Further, in the case of the figure, the threshold 50 of the received electric field strength is set to 110 [dBm].

In the case where the received field strength 60 fluctuates with time as shown in FIG. 7, if the value of the received field strength 60 of a part of a received packet falls below the threshold value 50, the packet is discarded. Is done. In the case of FIG. 7, the time is “10 sec”, “60 sec”, and “95 sec”
, The reception electric field strength 60 is lower than the threshold value 50. At this time, the packet A having a long packet length is discarded because the reception electric field strength 60 is lower than the threshold value 50 near both ends. On the other hand, packet B having a short packet length is
In any part, the reception electric field strength 60 is equal to the threshold 50.
, So it is received normally.

From this, it can be seen that shortening the packet length (decreasing the packet size) is advantageous for improving the reliability of communication. Next, FIG.
FIG. 4 is a diagram for explaining a problem when a message is transmitted without being divided into packets.

In FIGS. 7A and 7B, shaded portions 70 and 80 indicate portions where the received electric field intensity is lower than the threshold value. As shown in FIG. 9A, if the message is continuously transmitted without being divided into packets, the reception electric field strength of each of the first message and the next message transmitted continuously is lower than the threshold value in the shaded portions 70 and 80. , Any message is discarded and transmission fails.

On the other hand, as shown in FIG. 6B, when a message is divided into three packets, ie, packet 1, packet 2 and packet 3, and transmitted continuously, the packet is transmitted in the first message transmission. 1 is a part of the time zone of the shaded portion 70, so that packet 1 is discarded, but packet 2
And packet 3 are normally received. If the next message is sent continuously, the head of packet 2 is shaded 8
Since this corresponds to the time zone of 0, packet 2 is discarded, but packets 1 and 3 are normally received. As a result, in the wireless device on the receiving side, as shown in FIG.
By reconstructing (reconstructing) the message, packet 1,
Packet 2 and packet 3 can be correctly received, and the transmission of the message is successful.

As described above, it can be seen that the probability of successful transmission of a message increases by dividing the message into packets and successively transmitting the packets. Also, when trying to transmit a message of the same length, the smaller the packet size, the greater the overhead due to the transmission of the packet header,
Furthermore, since the total number of packets to be transmitted increases, the throughput (transmission efficiency) decreases.

Based on the above assumptions, when the average time during which the received electric field strength is below the threshold is short is high, the packet size is reduced to reduce the packet loss caused by fluctuations in the communication quality of the radio line. Can be further reduced (the possibility of recovering a lost packet can be increased by continuous transmission). When the median value of the received electric field strength is small or when the frequency of the received electric field strength is below the threshold value is high, it is considered that the state of the wireless line is bad. In such a case, the communication reliability is improved by increasing the number of continuous transmissions. If the received electric field strength does not fall below the threshold (or the frequency of dropping is very small) and the median of the received electric field strength is sufficiently high, it is considered that the state of the radio line is good. Therefore, in such a case, the transmission efficiency is improved by increasing the packet size and reducing the number of continuous transmissions.

In step S17 of the flowchart of FIG. 5, the packet size and the number of continuous transmissions are determined using the above as basic guidelines. By the way, the packet size and the number of continuous transmissions when the wireless device of FIG.
Before operating the wireless communication system, it may be determined by test communication. For example, if it can be determined that the statistical characteristics of the wireless line do not change when observed for a sufficiently long time compared to the communication time, the packet size and the number of continuous transmissions are determined by test communication, and after the system is activated,
By using them as fixed values, the protocol can be simplified.

According to the wireless device of the present embodiment described above, since a retransmission protocol is not required, design becomes easy. In addition, the wireless device of the present embodiment ensures the reliability of communication quality by variably controlling the number of consecutive transmissions of packets in accordance with the state of the wireless channel instead of using the retransmission protocol. Therefore, the wireless device of the present embodiment is applicable to various applications that require reliability.

In the above-described embodiment, the median value of the reception electric field strength, the frequency at which the reception electric field strength falls below the threshold, and the reception Although the average time during which the electric field strength is below the threshold is used, the present invention is not limited to these parameters, and it is also possible to use parameters that define the state of other wireless circuits. Needless to say. . Also,
Instead of the median value of the received electric field strength, an average value of the received electric field strength may be used.

[0063]

As described above, according to the present invention, the received electric field strength is sampled, and based on the analysis result of the sample data, the packet size and the number of consecutive transmissions of the packet are adjusted, and the data is transmitted. Since transmission is performed, wireless communication having high reliability and high throughput can be realized. Further, since the present invention monitors the fluctuation state of the wireless line while sampling the received electric field strength, it is possible to cope with the occurrence of a burst-like error in the wireless line and use the wireless line. High reliability can be ensured in data communication. For this reason, the present invention is suitable for a field in which reliability of data transmission is emphasized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a system configuration of a wireless device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a data structure of information stored in a packet size / number of consecutive transmissions storage device.

FIG. 3 is a diagram illustrating a procedure for dividing transmission data into packets and continuously transmitting the packets in the present embodiment.

FIG. 4 is a diagram illustrating a detailed data structure of a packet header according to the present embodiment.

FIG. 5 is a flowchart illustrating an operation of the wireless device according to the embodiment at the time of reception.

FIG. 6 is a flowchart illustrating an operation of the wireless device of the present embodiment during transmission.

FIG. 7 is a diagram illustrating a relationship between a temporal variation of a reception electric field strength and a packet size.

FIG. 8 divides a message into packets, rather than a message transmission;
It is a figure explaining the advantage of carrying out continuous feeding.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Antenna 11 Changeover switch 12 Receiver 13 Header analysis / telegram reconstruction device 14 Sample / analysis device 15 Packet size / continuous transmission number storage device 17 Transmission signal creation device 18 Transmitter 20 Packet size / continuous transmission number storage device 50 Received electric field strength threshold 60 Received electric field strength 70, 80 Part where received electric field strength is below the threshold

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Susumu Kato 1-1-1, Tanabe-shinden, Kawasaki-ku, Kawasaki-shi, Kanagawa F-term in Fuji Electric Co., Ltd. (reference) 5K034 AA05 EE03 HH63

Claims (8)

[Claims] 1. A method for sampling the electric field strength of a received signal,
Packet size determining means for determining a size of a transmission packet based on a parameter defining a state of a wireless line obtained from the sampling data; and dividing the transmission data into packet sizes of the size determined by the packet size determining means. And a transmitting means for continuously transmitting the radio signal. 2. The method according to claim 1, wherein the electric field strength of the received signal is sampled,
Continuous transmission frequency determining means for determining the number of consecutive transmissions of a packet based on a parameter defining a state of a wireless line obtained from the sampling data; dividing transmission data into packets and storing the packet in the continuous transmission A transmitting means for continuously transmitting the number of continuous transmissions determined by the number-of-times determining means. 3. Sampling the electric field strength of the received signal,
Sample / analysis means for determining the size of a transmission packet and the number of times of continuous transmission of packets based on parameters defining the state of the radio channel obtained from the sampling data; A transmission unit that divides transmission data into packets based on the number of times of transmission, stores the packets in a packet, and continuously transmits the packet by the number of times of continuous transmission. 4. A parameter defining a state of a wireless channel obtained from the sampling data includes at least:
4. The wireless device according to claim 1, further comprising a central value of the received electric field intensity, a frequency at which the received electric field intensity is below the threshold value, and an average time during which the received electric field intensity is below the threshold value. 5. The packet size determining means or the sample / analyzing means updates a packet size when communicating with each of the other wireless devices in accordance with an actual communication line state. The wireless device according to claim 1, wherein 6. The continuous transmission count determining means or the sample / analysis means sets a continuous transmission count of a packet when communicating with each of the other wireless devices to a state of a wireless line at the time of actual communication. 4. The method according to claim 2, wherein the information is updated accordingly.
The described radio. 7. The test apparatus according to claim 1, wherein said packet size determining means or said sample / analyzing means determines a packet size for communication with each of the other wireless devices at the time of test communication. 3. The wireless device according to 3. 8. The method according to claim 1, wherein the number of consecutive transmissions or the sample / analysis unit determines the number of consecutive transmissions of a packet when communicating with each of the other wireless devices at the time of test communication. The wireless device according to claim 2.