JP2003198416A - Communication system, communication equipment, communication method, program and recording medium therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide communication equipment and a communication method for improving the stability of the throughput of a communication system and to provide a program for such communication equipment and a recording medium therefor. <P>SOLUTION: As a transmission system of a transmitting part 103 and a modulation part 105, an encoding rate or modulation/demodulation system is selected by a transmission system selection part 111 and a communication is performed by this transmission system. In response to a request Smr from an application, the storage areas of a transmitting memory 101 and a receiving memory 107 are assigned and when receiving data, the average throughput of received data written in the storage area is measured. The transmission system is newly selected according to the measured value. A period to measure the throughput is set according to the transmission system selected at present and the size of the assigned storage area and since a measuring interval can be prolonged as the storage area becomes large, for example, the transmission system is not frequently changed, and the throughput can be stabilized. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system, a communication device, a communication method, and a program and its recording medium, and, for example, a communication system, a communication device, which can change a transmission method according to a communication situation, The present invention relates to a communication method, a program and its recording medium.

[0002]

2. Description of the Related Art Currently, TDMA (time division multipl)
PDC (personal digital) based on ex access technology
cellular) PHS (personal handy phone system)
Such as mobile phones and CDMA (code division multiplex
Communication devices such as mobile phones and wireless LANs based on access technology that use various wireless technologies to communicate audio and video are on the market.

On the other hand, with the recent improvement in frequency utilization efficiency of broadcasting and mobile communication, orthogonal frequency division multiplexing (orthogona) is one of the communication systems resistant to multipath interference.
Technical development of a multi-carrier system called l frequency division multiplexing (OFDM system) has become popular.

The OFDM system is a system in which a plurality of carriers (hereinafter, subcarriers) orthogonal to each other are arranged at a predetermined frequency interval in one transmission band, and data is dispersed and modulated on each subcarrier and transmitted. Is. That is, in the transmitting device, the transmission data arranged in time series is arranged on the virtual frequency axis, and the transmission data is allocated to each subcarrier. Then, the signals are orthogonally transformed into a multi-carrier signal having a predetermined frequency interval by inverse fast Fourier transform or the like and transmitted. Further, in the receiving device, the received multi-carrier signal is arranged in time series by the conversion reverse to that at the time of transmission, and received data is obtained.

In communication using the OFDM system, modulation such as QPSK is performed as the primary modulation, and inverse Fourier transform is further performed as the secondary modulation. This inverse Fourier transform averages the bit sequences arranged on the subcarriers on the time axis, so the OFDM method has the great advantage of being strong against interference by interference waves such as fading, shadowing, and multipath. have. In this way, an OFDM communication system has been proposed that realizes seamless communication that is not limited to indoors or outdoors by utilizing the ability to cope with various radio wave propagation environments.

[0006]

By the way, since the data error rate of the wireless communication device is significantly inferior to the data error rate of the wired communication device, an image compressed and encoded by, for example, the MPEG system is used. An unacceptable error is likely to occur in an application that reproduces a data stream in real time. As a result, for example, block distortion and frame dropping occur when reproducing video data, and sound interruption occurs when reproducing audio data. In order to reduce such unacceptable errors, communication schemes with high frequency utilization efficiency, such as the above-mentioned OFDM scheme, are beginning to be used in wireless communication.

In practice, however, even if the data error rate is improved by using the OFDM method, in the wireless communication, an error more than the wired communication is generated in most cases due to the influence of the radio wave propagation environment as described above. Is.

[0008] In the communication standard of the OFDM system using the 5 GHz band, which has recently been attracting attention as a frequency band of an indoor wireless LAN, IEEE 802.11a and HiperLAN
(Standard name in Japan is HiSWAN), Wireless 139
There are 4 etc. Taking such an OFDM communication device as an example, in the frequency band of 5 GHz band, the reception power of subcarriers is likely to become non-uniform due to the influence of various indoor multipaths and fading. A phenomenon occurs in which the received power of the book subcarriers is significantly reduced. Correct data can be corrected in the Viterbi decoder if only one or two subcarriers are lost, but in the case of a poor radio wave propagation environment in which the number of missing subcarriers is larger, The data assigned to the subcarriers will be lost at all. Further, if some subcarriers out of only 52 subcarriers are lost in one OFDM symbol, the throughput of the entire system is considerably reduced.

As described above, no matter how much modulation efficiency or coding rate is used for data transmission / reception, throughput may be significantly reduced in an environment where radio wave propagation is poor, while modulation may be performed. In some cases, the throughput can be improved as a result by changing the method or the coding rate.

Therefore, there has been considered a method of establishing a communication system which is hardly influenced by the radio wave propagation environment by appropriately changing the combination of a plurality of existing modulation methods and coding rates. For example, IEEE 802.11a and Hipe
In rLAN and wireless 1394, a function called fallback or rate adaptation is used to select one or more optimal types from combinations of a plurality of modulation methods and coding rates according to the radio wave propagation environment. Throughput is being improved.

In order to realize such a function, in the conventional technique, the radio wave propagation environment is mainly inferred based on the information in a layer relatively close to the physical layer, and the modulation method and the coding rate are changed based on the analogy result. It is carried out. For example, RSSI
(Receive signal strength indication) and PER (pac
Ket error rate), BER (bit error rate), delay spread, frequency characteristics, and other physical layer level measurement results are used to infer the radio wave propagation environment between transmission and reception, and the modulation method and coding rate are changed accordingly. is doing.

However, an application that actually uses data rarely directly handles transmitted / received data, and normally transfers data to / from a communication destination via a cache memory. Therefore,
The data transmission rate that enables communication at the application level does not require a control as high as the data transmission rate controlled according to the radio wave propagation environment inferred from the measurement result at the physical layer level as in the conventional technology. . This is because the application actually receives the data from the cache memory, and even if the throughput fluctuates in a short period according to the radio wave propagation environment, the influence of the fluctuation is averaged over time.

Nevertheless, in the prior art, since the data rate is changed every moment according to the measurement result at the physical layer level, there is a problem that unnecessary fallback is performed at the application level. . Stable data transmission is impaired when such useless fallback is performed, and therefore, a problem may occur in an application that requires constant throughput, such as an application that processes transmitted image data in real time. is there. Further, since the data transmission rate is frequently controlled, there is a problem that the power consumption increases due to the power required for this control.

The present invention has been made in view of the above circumstances, and an object thereof is stability of throughput without performing unnecessary control of a transmission system for an application using data transmitted and received via a cache memory. A communication device, a communication method, and a program in such a communication device and a recording medium thereof can be provided.

[0015]

In order to achieve the above object, a communication system according to a first aspect of the present invention performs communication using a transmission method selected from a plurality of predetermined transmission methods. A communication system having a first communication device and a second communication device, wherein the first communication device is a storage unit capable of storing received data, and the storage device is capable of storing the received data according to an input allocation request. Storage area allocating means for allocating a storage area of the received data in the storage means, and received data processing means for writing the received data in the storage area allocated by the storage area allocating means,
Throughput measuring means for measuring the average throughput of received data written in the storage means for each set measurement period, and the throughput based on the size of the allocated storage area and the selected transmission method. Measurement period setting means for setting the measurement period of the measuring means, and transmission method selection for newly selecting the transmission method used for receiving data from the plurality of transmission methods according to the throughput measurement result in the throughput measuring means. Means, and transmission method notifying means for notifying the second communication device of the transmission method selected by the transmission method selection means, the second communication device being notified from the first communication device. The data is transmitted using the transmission method.

According to the communication system of the first aspect of the present invention, in the first communication device, the storage area of the received data in the storage means is stored in the storage means in response to an allocation request input from, for example, an application. Assignment is made. The received data is written in the allocated storage area, and the average throughput of the received data written in the storage means is measured for each set measurement period. The measurement period of the throughput is set by the measurement period setting means based on the size of the allocated storage area and the selected transmission method. Then, according to the measurement result of the throughput, a transmission method used for receiving data is newly selected from the plurality of transmission methods, and the first communication device notifies the second communication device. In the second communication device, data is transmitted using the transmission method notified by the first communication device.

A communication system according to a second aspect of the present invention includes a first communication device and a second communication device that perform communication using a transmission method selected from a plurality of predetermined transmission methods. In a communication system having the above, the first communication device allocates a storage area capable of storing received data and a storage area of the received data in the storage means in response to an input allocation request. Storage area allocating means, reception data processing means for writing the reception data in the storage area allocated by the storage area allocating means, and first information for extracting information requesting the start of detection of the reception data amount from the reception data The information extraction means and the detection of the amount of received data written in the storage means are started from the time when the detection start request information is extracted, and the detection is started from the detection start time. Received data amount notifying means for notifying the second communication device of the information of the reference received data amount when the received data amount reaches the reference received data amount according to the size of the allocated storage area. The second communication device includes a detection start request notification means for notifying the first communication device of the detection start request information,
Second information extracting means for extracting the reference received data amount information from the received data, and the elapsed time from the transmission time point of the detection start request information to the reception time point of the reference received data amount information is measured and measured. Throughput measuring means for measuring the throughput based on the elapsed time and the reference received data amount information, according to the measurement result of the throughput in the throughput measuring means, the transmission method used for data transmission, the plurality of transmission methods And a transmission method selecting means for newly selecting from the inside.

According to the communication system of the second aspect of the present invention, in the first communication device, in the storage area of the received data in the storage means, in response to an allocation request input from, for example, an application or the like. Allocation is performed, and the received data is written in the allocated storage area. When the second communication device notifies the first communication device of information requesting the start of detection of the amount of received data, the detection start request information is sent to the first information in the first communication device. From the time of extraction by the extraction means, detection of the amount of received data written in the allocated storage area of the storage means is started. Then, at the time when the received data amount from this detection start time reaches the reference received data amount according to the size of the allocated storage area, the reference received data amount information is
The first communication device notifies the second communication device. In the throughput measuring means of the second communication device, the elapsed time from the time of transmitting the detection start request information to the time of extracting the reference received data amount information is measured, and the measured elapsed time and the received reference reception are measured. Throughput is measured based on the data amount information. In the transmission method selection means, a transmission method used for data transmission is newly selected from the plurality of transmission methods according to the throughput measurement result of the throughput measurement means.

A communication system according to a third aspect of the present invention includes a first communication device and a second communication device that perform communication using a transmission method selected from a plurality of predetermined transmission methods. In the communication system, the first communication device includes a storage unit capable of storing received data, and a storage for allocating a storage area for the received data in the storage unit in response to an input allocation request. Area allocation means, reception data processing means for writing the reception data in the storage area allocated by the storage area allocation means, and reception data amount written in the storage means
Throughput measuring means for measuring the time required to reach the reference received data amount according to the size of the allocated storage area, and measuring the throughput based on the measured time and the reference received data amount, A transmission method selection unit that newly selects a transmission method used for receiving data from the plurality of transmission methods according to the throughput measurement result in the throughput measurement unit, and a transmission method selected by the transmission method selection unit. And a transmission method notifying means for notifying the second communication device,
The communication device transmits the data using the transmission method notified from the first communication device.

According to the communication system of the third aspect of the present invention, in the first communication device, the storage area for storing the received data in the storage means is provided in response to an allocation request input from, for example, an application. It is allocated and the received data is written in the allocated storage area. Also, the amount of received data written in the storage means, the time until the amount of received data reaches a reference received data amount according to the size of the assigned storage area is measured,
Based on the measured time and the reference received data amount,
Throughput is measured. According to the measured throughput, a transmission method used for receiving data is newly selected from the plurality of transmission methods, and the first communication device notifies the second communication device. In the second communication device, the notified transmission method is used for data transmission.

A communication device according to a fourth aspect of the present invention is a communication device having a transmitting means and a receiving means for transmitting and receiving data using a transmission method selected from a plurality of predetermined transmission methods. And a storage means capable of storing the reception data of the reception means, and an input allocation request,
Storage area allocating means for allocating a storage area for the received data in the storage means, received data processing means for writing the received data in the storage area allocated by the storage area allocating means, and for each set measurement period , Setting the measurement period of the throughput measuring means based on the throughput measuring means for measuring the average throughput of the received data written in the storing means, and the size of the allocated storage area and the selected transmission method. The transmission method used by either one or both of the transmission means and the reception means is newly selected from among the plurality of transmission methods according to the measurement period setting means and the throughput measurement result in the throughput measurement means. And a transmission method selection means for performing the same.

According to the communication device of the fourth aspect of the present invention, in the storage area allocating means, for example, in response to an allocation request input from an application or the like,
The storage area of the received data in the storage means is allocated. The reception data received by the receiving means is written in the storage area allocated by the storage area allocating means by the reception data processing means. Further, the throughput measurement period is set in the measurement period setting means based on the size of the allocated storage area and the selected transmission method, and is written in the storage means for each set measurement period. The average throughput of received data is measured by the throughput measuring means. In the transmission method selection means, a transmission method used by either or both of the transmission means and the reception means is newly selected from the plurality of transmission methods in accordance with the throughput measurement result.

Further, the transmission method information notifying means for transmitting the information of the transmission method selected by the transmission method selecting means to the communication destination from the transmitting means, and the information of the transmission method included in the reception data. Information transmitting means for extracting data, the transmitting means transmits data using a transmission method according to the information of the transmission method extracted by the information extracting means, and the receiving means selects the transmission method. Data may be received using the transmission method selected by the means.

A communication device according to a fifth aspect of the present invention is a communication device having a transmitting means and a receiving means for transmitting and receiving data using a transmission method selected from a plurality of predetermined transmission methods. And a storage means capable of storing the reception data of the reception means, and an input allocation request,
A storage area allocating means for allocating a storage area for the received data in the storage means, a received data processing means for writing the received data in the storage area allocated by the storage area allocating means, and a detection start of the received data amount. The detection start requesting means for transmitting the requested information from the transmitting means to the communication destination, the first information extracting means for extracting the detection start requesting information from the received data, and the detection start requesting information are extracted. From the time when the amount of received data written in the storage means is detected, and when the amount of received data from the detection start time reaches the reference amount of received data according to the size of the allocated storage area, A received data amount information notifying unit for transmitting the information of the reference received data amount from the transmitting unit to a communication destination, Second information extracting means for extracting the reference received data amount information from the received data, and the elapsed time from the transmission time point of the detection start request information to the reception time point of the reference received data amount information is measured and detected. Throughput measuring means for measuring the throughput based on the progress measurement and the reference received data amount information, and used by either or both of the transmitting means and the receiving means depending on the measurement result of the throughput in the throughput measuring means. And a transmission method selecting means for newly selecting a transmission method from the plurality of transmission methods.

A communication device according to a sixth aspect of the present invention is a communication device having a transmitting means and a receiving means for transmitting and receiving data using a transmission method selected from a plurality of predetermined transmission methods. And a storage means capable of storing the reception data of the reception means, and an input allocation request,
Storage area allocating means for allocating a storage area for the received data in the storage means, reception data processing means for writing the reception data in the storage area allocated by the storage area allocating means, and reception written in the storage means Throughput measurement for measuring the time until the data amount reaches a reference received data amount according to the size of the allocated storage area, and measuring the throughput based on the measured time and the reference received data amount Means and a transmission method selection for newly selecting a transmission method to be used by either one or both of the transmitting means and the receiving means in accordance with the throughput measurement result of the throughput measuring means. And means.

Further, the transmission method information notifying means for transmitting the information of the transmission method selected by the transmission method selecting means from the transmitting means to the communication destination, and the information of the transmission method included in the reception data. Information transmitting means for extracting data, the transmitting means transmits data using a transmission method according to the information of the transmission method extracted by the information extracting means, and the receiving means selects the transmission method. Data may be received using the transmission method selected by the means.

A communication method according to a seventh aspect of the present invention is a communication method for performing communication using a transmission method selected from a plurality of predetermined transmission methods, and receiving data according to an allocation request. Allocating a storage area in the storage device, based on the size of the allocated storage area and the selected transmission method, sets the throughput measurement period, and writes the received data in the allocated storage area, The average throughput of the received data written in the storage area is measured for each of the set measurement periods, and the transmission method used for communication is newly selected from the plurality of transmission methods according to the result of the throughput measurement. select.

A communication method according to an eighth aspect of the present invention uses a transmission method selected from a plurality of predetermined transmission methods to perform communication between a first communication device and a second communication device. In the communication method, the first communication device allocates a storage area in the storage device for the received data in response to the allocation request, and determines the size of the allocated storage area and the selected transmission method. Based on this, a throughput measurement period is set, the received data from the second communication device is written in the assigned storage area, and the average of the received data written in the storage area is set for each set measurement period. The effective throughput is measured, a transmission method used for receiving data is newly selected from the plurality of transmission methods according to the result of the throughput measurement, and the selected transmission method is transmitted to the second communication device. Notifies the selected transmission method, the second communication device, using the transmission method notified from the first communication apparatus performs data transmission to the first communication device.

A communication method according to a ninth aspect of the present invention uses a transmission method selected from a plurality of predetermined transmission methods to perform communication between a first communication device and a second communication device. In the communication method, the first communication device allocates a storage area in the storage device for received data in response to an allocation request, and the second communication device starts detection of the amount of received data. The requested information is transmitted to the second communication device, the first communication device writes the received data from the second communication device in the allocated storage area, and the received data is received from the received data. The information for requesting the detection start of the amount is extracted, and from the time when the detection start request information is extracted, the detection of the received data amount written in the storage device is started, and the received data amount from the detection start time is ,the above When the reference received data amount corresponding to the size of the allocated storage area is reached, the reference received data amount is notified to the second communication device, and the second communication device starts the detection. From the time when the request information is transmitted, the elapsed time from the time when the reference received data amount is notified is measured, and the throughput is measured based on the measured elapsed time and the notified reference received data amount, and A transmission method used for data transmission to the first communication device is newly selected from the plurality of transmission methods according to the throughput measurement result.

A communication method according to the tenth aspect of the present invention is
A communication method for performing communication using a transmission method selected from a plurality of predetermined transmission methods, wherein a storage area in a storage device for received data is allocated in response to an allocation request, and the storage area is allocated. While writing the received data to, the amount of received data written to the storage device, the time until reaching the reference received data amount according to the size of the allocated storage area is measured, and the measured time and Throughput is measured based on the reference received data amount, and a transmission method used for communication is newly selected from the plurality of transmission methods according to the result of the throughput measurement.

A communication method according to the eleventh aspect of the present invention is
A communication method for performing communication between a first communication device and a second communication device using a transmission method selected from a plurality of predetermined transmission methods, wherein the first communication device comprises: In response to the allocation request, a storage area in the storage device for the received data is allocated, and the received data from the second communication device is written in the allocated storage area,
The amount of received data written in the storage device measures the time until it reaches a reference received data amount according to the size of the allocated storage area, and based on the measured time and the reference received data amount. Throughput is measured according to the throughput measurement result, a transmission method used for receiving data is newly selected from the plurality of transmission methods, and the selected transmission method is notified to the second communication device. Then, the second communication device transmits data to the first communication device using the transmission method notified from the first communication device.

According to a twelfth aspect of the present invention, there is provided a storage device for storing received data in response to an allocation request to a communication device which communicates using a transmission method selected from a plurality of predetermined transmission methods. Allocating a storage area in step 1, a step of setting a throughput measurement period based on the size of the allocated storage area and the selected transmission method, and writing the received data in the allocated storage area. , A step of measuring an average throughput of received data written in the storage area for each of the set measurement periods, and used for either or both of data transmission and reception, depending on the result of the throughput measurement. And a step of newly selecting a transmission method from the plurality of transmission methods.

A program according to a thirteenth aspect of the present invention is a storage device for storing received data in response to an allocation request to a communication device which communicates using a transmission method selected from a plurality of predetermined transmission methods. In the step of allocating a storage area in step, based on the size of the allocated storage area and the selected transmission method, the step of setting the throughput measurement period, and the allocated storage area,
In addition to writing the reception data from the second communication device, measuring the average throughput of the reception data written in the storage area for each of the set measurement periods, and according to the result of the throughput measurement, A step of newly selecting a transmission method used for receiving data from the plurality of transmission methods, a step of notifying the source of the received data of the selected transmission method, and a transmission method selected by a communication destination Is notified,
And a step of setting the transmission method used for data transmission to the communication destination to the notified transmission method.

A program according to a fourteenth aspect of the present invention is a storage device for storing received data in response to an allocation request to a communication device which communicates using a transmission method selected from a plurality of predetermined transmission methods. Allocating a storage area in, the step of writing the received data in the allocated storage area, extracting information requesting the start of detection of the amount of received data from the received data, and the detection start request information. When extracted, the detection of the amount of received data written in the storage device is started from the extraction time point, and the received data amount from the detection start time point depends on the size of the allocated storage area. When the reference received data amount is reached, a step of notifying the reference received data amount to the sender of the received data is included. And a step of transmitting the detection start request information to a communication destination, and measuring an elapsed time from the time when the detection start request information is transmitted to the time when the reference reception data amount is notified from the communication destination, A step of measuring the throughput based on the measured elapsed time and the notified reference received data amount, and a transmission method used for data transmission to the communication destination according to the measurement result of the throughput, And a transmission step including a step of newly selecting from the transmission methods.

According to a fifteenth aspect of the present invention, a program stores a received data storage device in response to an allocation request to a communication device that communicates using a transmission method selected from a plurality of predetermined transmission methods. And a step of allocating a storage area in the step of writing the received data into the allocated storage area, and the amount of received data written in the storage device is a reference received data according to the size of the allocated storage area. Measuring the time until reaching the amount, and measuring the throughput based on the measured time and the reference received data amount; and, depending on the result of the throughput measurement, the transmission method used for communication is the plurality of transmissions. And a step of newly selecting from the methods.

A program according to a sixteenth aspect of the present invention is a storage device for storing received data in response to an allocation request to a communication device that communicates using a transmission method selected from a plurality of predetermined transmission methods. And a step of allocating a storage area in the step of writing the received data into the allocated storage area, and the amount of received data written in the storage device is a reference received data according to the size of the allocated storage area. Measuring the time to reach the amount, the step of measuring the throughput based on the measured time and the reference received data amount, depending on the result of the throughput measurement, the transmission method used for data reception of the plurality of A step of newly selecting from the transmission methods and a step of notifying the source of the received data of the selected transmission method , When the transmission scheme selected in the communication destination is notified, the transmission scheme to be used for data transmission to the communication destination, to execute processing comprising the steps of setting to the notified transmission method.

Other objects and features of the present invention will become apparent from the more detailed description based on the embodiments of the present invention described later and the accompanying drawings.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION Three embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 is a schematic block diagram showing a configuration example of a communication apparatus according to a first embodiment of the present invention. In FIG. 1, reference numeral 101 denotes a transmission memory, reference numeral 1
Reference numeral 02 is a transmission data processing unit, reference numeral 103 is a transmission unit, reference numeral 104 is an antenna switch, reference numeral 105 is a receiving unit, reference numeral 106 is a reception data processing unit, reference numeral 107 is a receiving memory, and reference numeral 108 is a storage. Reference numeral 109 indicates a measurement period setting unit, reference numeral 110 indicates a throughput measuring unit, and reference numeral 111 indicates a transmission system selecting unit.

The transmission memory 101 temporarily stores the transmission data DT supplied from an application that performs data communication using the communication device 1001.

The transmission data processing unit 102 reads the transmission data DT accumulated in the transmission memory 101 by the application from the storage area designated by the storage area allocating unit 108 and outputs it to the transmission unit 103.

For example, as in processing in the MAC (media access control) layer, JPEG (joint photograp)
hic coding experts group) method and MPEG (moving pic)
JBIG (joint bi-level image coding exper)
reversible image coded data such as the ts group) method, or various data other than image data is transmitted to the transmission memory 101.
Then, a packet-type transmission information bit sequence to which a device address of a destination and a transmission source, an ECC (error correcting code) and the like are added is generated. Before the data processing in the transmission data processing unit 102,
When error detection / correction processing using ECC such as Reed-Solomon code or turbo code is performed, the transmission data processing unit 102 does not have to perform error detection / correction processing.

The transmitting section 103 is a block for transmitting data using the transmission method selected by the transmission method selecting section 111 from a plurality of predetermined transmission methods. In the configuration example of FIG. 1, convolutional coding is performed. 1031, interleaver 1032, modulator 1033, IFF
T (inverse fast fourier transform) section 1034, D
A / A 1035, an RF (radio frequency) unit 1036, and a transmission control unit 1037. Note that the configuration example of FIG. 1 is for generating a transmission signal of the OFDM system, but the configuration of the transmitting unit 103 is not limited to this ODFM system and is arbitrary, for example, generating a transmission signal of the TDMA system or the CDMA system. It may be configured.

The convolutional encoder 1031 expands the inter-sequence distance for the transmission information bit sequence generated in the transmission data processing section, and generates a transmission encoded bit sequence. For the coding rate of the convolutional coding, one specified by the transmission control unit 1037 is used from a plurality of types (for example, 1/2, 2/3, 3/4, 7/8, etc.).

Interleaver 1032 disperses the bit sequence by performing a predetermined rearrangement process on the transmission coded bit sequence generated in convolutional encoder 1031.

The modulator 1033 has an interleaver 103.
In the transmission coded bit sequence rearranged in 2, the preamble (Preambl
e) Insert a signal and then perform primary modulation on this bit sequence. The first-order modulation method includes a plurality of types of modulation methods, for example, BPSK (binary phase shift key).
ing), QPSK (quadrature phase shift keying),
16QAM (16 quadrature amplitude modulation),
Among 64QAM, 128QAM, 256QAM, etc., the one designated by the transmission control unit 1037 is used.

IFFT section 1034 performs an inverse fast Fourier transform as a secondary modulation on the transmission symbol stream modulated by modulating section 1033, and further performs windowing processing. As a result, a transmission sequence averaged on the time axis is generated from the transmission symbol stream virtually arranged on the frequency axis.

The D / A converter 1035 includes an IFFT unit 10
The transmission sequence generated at 34 is converted from a digital signal to an analog signal. The RF unit 1036 performs high-frequency signal processing such as filtering and frequency conversion on the transmission signal converted into an analog signal by the D / A converter 1035, and supplies it to the antenna switching unit 104.

The transmission control unit 1037 controls the transmission timing in the transmission unit 103 in accordance with a control signal from a system control unit (not shown), and the convolutional code in accordance with the transmission system designated by the transmission system selection unit 111. The coding rate in the demultiplexer 1031 and the modulation method in the modulator 1033 are designated.

The antenna switching unit 104 responds to a control signal from a system control unit (not shown), and the transmitting unit 103.
Or the received signal from the receiving unit 105 is switched and supplied to the common antenna.

The receiving section 105 is a block for receiving data using the transmission method selected by the transmission method selecting section 111 from a plurality of predetermined transmission methods. In the configuration example of FIG. 1, the RF section 1051 is used. , A / D converter 1052,
FFT section 1053, demodulator 1054, de-interleaver 1055, Viterbi decoder 105
6. It has a reception control unit 1057. Note that the configuration example of FIG. 1 is configured to receive an OFDM system signal in accordance with the transmission unit 103, but the configuration of the reception unit 105 is ODF.
The method is not limited to the M method and may be arbitrary, and may be configured to receive a signal of the TDMA method or the CDMA method, for example.

The RF unit 1051 is the antenna switching unit 1
The received signal from 04 is subjected to high frequency signal processing such as filtering and frequency conversion. A / D converter 1052
Converts the received signal, which has been subjected to high-frequency signal processing in the RF unit 1051, from an analog signal to a digital signal,
Generate a reception sequence.

The FFT section 1053 has the A / D converter 105.
Data breaks and frame breaks to be subjected to Fourier transform are detected from the reception sequence generated in 2 and fast Fourier transform of the reception sequence is performed in synchronization with the detection timing.

Demodulation section 1054 demodulates the reception sequence Fourier-transformed in FFT section 1053,
Generate a received symbol stream. The demodulation method used for demodulation is the reception control unit 1057 of the plurality of predetermined demodulation methods corresponding to the plurality of modulation methods in the modulator 1033.
The one specified by is used.

The de-interleaver 1055 includes the demodulation unit 1
The bit sequence dispersed in the reception symbol stream generated in 054 is rearranged to generate a reception encoded bit sequence. The Viterbi decoder 1056 decodes the reception coded bit sequence generated by the de-interleaver 1055 to generate a reception information bit sequence.
The algorithm used for decoding is the convolutional encoder 10
Of the plurality of predetermined decoding algorithms corresponding to the plurality of coding rates in 31, the one designated by the reception control unit 1057 is used.

The reception control unit 1057 controls the reception timing in the reception unit 105 according to a control signal from a system control unit (not shown), and also demodulators according to the transmission system specified by the transmission system selection unit 111. 105
The demodulation method in 4 and the decoding algorithm in the Viterbi decoder are designated.

The reception data processing unit 106 includes a reception memory 107 allocated by the storage area allocation unit 108.
The reception data output from the reception unit 105 is written in the storage area of the above, and the throughput measurement unit 110 is notified of the data writing in the reception memory 107. For example, in the case where received data including packet format data to which an address for identifying a communication source or destination of data is added is received as in the processing in the MAC layer, the destination included in the packet is received. , And extracts packets that match its own device address. When ECC is added at the transmission source, the error detection / correction process may be performed.

The reception memory 107 temporarily stores the reception data DR processed by the reception data processing unit until it is read by the application.

The storage area allocating unit 108 allocates a storage area for transmission / reception data in the transmission memory 101 and the reception memory 106 in response to a memory allocation request Smr from an application. In addition, the measurement period setting unit 109 is notified of the information on the size of the allocated storage area.

The measurement period setting unit 109 determines the throughput based on the information S108 on the size of the storage area allocated to the application being communicated and the information S111 on the transmission method selected by the transmission method selection unit 111. The measurement period of the throughput in the measurement unit 110 is set. For example, by referring to a data table (not shown) that stores the transmission method and the corresponding ideal throughput value in association with each other, the ideal throughput value corresponding to the selected transmission method is obtained, and the ideal throughput value and the size of the storage area are calculated. The throughput measurement period is set according to the ratio. If the ideal throughput value is 54 Mbps and the size of the storage area allocated to the application is 54 Mbps.
In the case of t, the storage area becomes full in about 1 second.
In this case, for example, the measurement period can be set to about 1 second so that the measurement result of the throughput measuring unit 110 does not greatly change in response to the change in throughput in a short time.

The throughput measuring unit 110 counts the number of data written in the received data memory 107 in response to the data write notification from the received data processing unit 106,
Using the count value, the average throughput of the reception data written in the reception memory 106 is measured for each measurement period set by the measurement period setting unit 109. The throughput measurement value is obtained, for example, by detecting the amount of reception data written in the reception memory 107 for each measurement period set by the measurement period setting unit 109, and according to the ratio between the detected reception data amount and the measurement period. You may ask. Alternatively, it may be obtained according to the average value of a plurality of throughput measurement results in the measurement period set by the measurement period setting unit 109.

The transmission method selection unit 111, in accordance with the throughput measurement result of the throughput measurement unit 110,
The transmission method used in the transmission unit 103 and the reception unit 105 is selected from a plurality of predetermined transmission methods, and the selected transmission method is designated to the transmission unit 103 and the reception unit 105.
For example, it is determined which of the plurality of throughput ranges respectively corresponding to the plurality of transmission schemes the throughput measured by the throughput measuring unit 110 is included, and the determined throughput range and the selected transmission scheme are associated with each other. A new transmission method may be selected according to the result of comparison with the throughput range. Thereby, for example, when the throughput range including the measured throughput is lower than the throughput range corresponding to the selected transmission method, it is expected that the throughput is reduced due to interference such as interference waves. Therefore, switching to another transmission method is performed in order to increase throughput. Further, in this case, from the plurality of transmission methods ranked corresponding to the above-mentioned each throughput range, the rank of the transmission method corresponding to the throughput range including the measured throughput, and the rank of the selected transmission method. The transmission method may be newly selected according to the rank difference.
Thus, for example, the transmission method can be changed on condition that the rank of the transmission method obtained from the measured throughput is several ranks apart from the rank of the currently selected transmission method. It can be suppressed from being changed.

Here, the transmitting and receiving operations of transmitting apparatus 1001 of FIG. 1 having the above configuration will be explained.
At the time of data transmission, the transmission data DT supplied from the application is temporarily stored in the storage area of the transmission memory 101 designated by the storage area allocation unit 108, and is transmitted in synchronization with the transmission timing of the transmission unit 103. The data is sequentially read by the processing unit 102. The transmission data DT read by the transmission processing unit 102 is converted into, for example, a transmission information bit sequence in a packet format, and the transmission unit 103
Is supplied to. This transmission data is transmitted by the transmission method selection unit 11
The signal is converted into a transmission signal according to the transmission method selected in 1, and is transmitted from the antenna via the antenna switching unit 104.

According to the transmission section 103 having the configuration shown in FIG.
The transmission information bit sequence generated in the transmission data processing unit is encoded by the convolutional encoder 1031 at a coding rate according to the transmission scheme specified by the transmission scheme selection unit 111. This transmission coded bit sequence is rearranged in the interleaver 1032, then a preamble signal is added, and the modulator 1033 uses a modulation method according to the transmission method specified by the transmission method selection unit 111. Primary modulation is performed. The transmission symbol stream that has been first-order modulated is further subjected to IFFT section 1034.
Inverse Fourier transform and windowing are performed as the secondary modulation at, and converted into an analog signal at the D / A converter 1035. Then, high-frequency signal processing such as filtering and frequency conversion is performed in the RF unit 1036,
It is supplied to the antenna switching unit 104.

At the time of data reception, the signal received by the antenna passes through the antenna switching unit 104 and then the receiving unit 1.
The data is input to the reception data processing unit 106 and is converted into reception data according to the transmission method specified by the transmission method selection unit 111. The received data is written in the storage area of the receiving memory 107 allocated to the application receiving the data by the received data processing unit 106. In the case where the received data is packetized together with, for example, an address and an ECC for identifying the source / destination device, in the received data processing unit 106,
A packet having an address that matches its own device is extracted, and after being subjected to processing such as error detection / correction, it is written to the reception memory 107. The reception data DR stored in the memory 107 is read by a system control unit (not shown) and passed to an application which is receiving the data and other applications.

Further, according to the receiving unit 105 having the configuration shown in FIG. 1, the signal received by the antenna is input to the RF unit 1 via the antenna switching unit 104 and subjected to high frequency signal processing such as filtering and frequency conversion. Then, the A / D converter 1052 converts the analog signal into a digital reception sequence. Next, in FFT section 1053,
Data breaks and frame breaks to be subjected to Fourier transform are detected from the reception sequence, and fast Fourier transform of the reception sequence is performed in synchronization with the detection timing. The Fourier-transformed received sequence is demodulated by the demodulator 1054.
The deinterleaver 1055 is demodulated using a demodulation method corresponding to the transmission method specified by the transmission method selection unit 111.
In, the rearrangement of the bit sequence is performed. Further, in the Viterbi decoder 1066, decoding is performed using a decoding algorithm corresponding to the transmission method specified by the transmission method selection unit 111, and converted into a reception information bit sequence.

Next, the operation of changing the transmission method in the communication device 1001 of FIG. 1 will be described with reference to the flowchart of FIG. FIG. 2 shows the communication device 1001 shown in FIG.
5 is a flowchart for explaining the operation of changing the transmission method in FIG.

Step ST101: Storage areas in the transmission memory 101 and the reception memory 107 are allocated in response to a request Smr from an application or the like. Step ST102: The throughput measurement period S109 is set based on the size of the storage area of the reception memory 107 allocated to the application in step ST101 and the information S111 on the transmission method currently selected by the transmission method selection unit 111.

Step ST103: Reception memory 107 assigned to the application receiving the data
The reception data DR processed by the reception data processing unit 106 is sequentially written in the storage area of. In addition, the number of received data written in the reception memory 107 is counted in response to the data write notification from the received data processing unit 106, and the average throughput is measured for each set measurement period using this count value. To be done.

Step ST104: The transmission method used in the transmission section 103 and the reception section 105 is selected from a plurality of predetermined transmission methods in accordance with the throughput measurement result in the throughput measurement section 110.

Step ST105: Step ST104
It is determined whether or not the transmission method selected in step 1 is different from the currently selected transmission method. If they do not match, the process proceeds to step ST106, and if they match, step ST106 is skipped and step ST106
The processing shifts to 107. Step ST106: The currently selected transmission method is changed, and the transmission method selected in step ST104 is used as a new transmission method in the transmitting unit 103 and the receiving unit 1.
Specified for 05.

Step ST107: For example, when the application for receiving data is switched, or when the type of data processed by the application being received is changed from small-capacity audio data to large-capacity image data. At, it is determined whether or not the allocation of the storage area in which the received data is written changes.
If a change occurs, the process moves to step ST108. If there is no change, the process is returned to step ST103, and the processes after the throughput measurement are repeated again. Step ST108: A storage area in which the received data is written is newly allocated. After that, the process is returned to step ST102 again, the throughput measurement period is reset according to the size of the newly allocated storage area, and then the processes after the throughput measurement are repeated again.

As described above, in the communication device 1001 shown in FIG. 1, the reception memory 107 used by the application.
Depending on the size of the storage area and the selected transmission method,
A throughput measurement period is set as a criterion for determining whether to change the transmission method.

FIG. 3 is a diagram showing an example of the measurement result in the throughput measuring unit 110, in which the vertical axis represents throughput and the horizontal axis represents time. FIG. 3A shows the throughput measurement result when the measurement period is set to 20 msec, and FIG. 3B shows the throughput measurement result when the measurement period is set to 1 sec. As can be seen by comparing FIG. 3A and FIG. 3B, the fluctuation range of the measurement result greatly differs depending on the throughput measurement period. In the example of FIG. 3A, the measured value fluctuates up to 20 Mbps, whereas in FIG.
In the example of B, the fluctuation is suppressed to less than 5 Mbps.

When the throughput measurement result of FIG. 3A is input to the transmission method selection unit 111, the transmission method is rapidly changed according to the change of the measurement result, and accordingly, the throughput also greatly changes. For example, if the measurement result of the throughput temporarily drops according to the radio wave propagation environment, and if the measurement period is short, the throughput measurement result changes in response to this change, and the transmission method is changed to compensate for this. As a result, the throughput increases sharply. Further, when the temporary change in the radio wave propagation environment is restored, the transmission method becomes inappropriate for this environment, and the throughput drops sharply. Such a fluctuation in throughput is 20 m
It is considered that the transmission rate is controlled so that the throughput becomes constant on the scale of about sec.

On the other hand, when the throughput measurement result of FIG. 3B is input to the transmission method selection unit 111, the measurement result is stable, so that the transmission method is not frequently changed and a stable throughput is obtained. Even if the actual throughput changes rapidly in a short time according to the radio wave propagation environment, it is temporally averaged according to the length of the measurement period, so that the fluctuation of the throughput measurement result is suppressed. In this case, 1se
It is considered that the transmission rate is controlled so that the throughput is constant on a scale of about c.

The reception memory 107 for accumulating the reception data alleviates the influence of the fluctuation of the throughput and enables the application to process the reception data at a constant rate. In consideration of such a function of the reception memory, As long as the received data accumulated in the allocated storage area is completely exhausted and the processing in the receiving-side application is not stopped, the throughput fluctuation is allowed. In other words, the reception memory 107
As long as the accumulated data of No. is exhausted, the operation of the application will not be hindered even if the transmission method is not changed at a high speed to increase the transmission rate.

From this point of view, it is necessary to switch the transmission system at a high speed as shown in FIG. 3A when a small storage capacity of received data is allocated to a relatively large throughput. in this case,
The transmission method is changed at a high speed so that a high throughput can be obtained in order to prevent the reception memory from running out of the reception data that rapidly decreases. In addition, when the reception data storage area of a sufficient size is allocated, as shown in FIG. 3B, even if the measurement period of the throughput measurement is lengthened to some extent, the data is not exhausted from the reception memory, and furthermore, Stable throughput can be obtained as compared with the case where the transmission method is changed at high speed.

Therefore, the communication device 1001 shown in FIG.
As shown in the figure, depending on the size of the storage area where the received data is accumulated and the ideal throughput value corresponding to the selected transmission method, a throughput measurement period that is long enough to prevent the received data from being exhausted from the receiving memory. By setting and measuring the average throughput and reselecting the transmission method for each measurement period to control the transmission rate slowly, the throughput required by the application can be achieved without changing the transmission method faster than necessary. It can be stably obtained. As a result, it is possible to perform communication suitable for an application that requires stable throughput, such as a case of reproducing an image data stream in real time while receiving it. Moreover, since the transmission method is not wastefully controlled, the power consumption can be reduced.

In the above description, an example in which the transmission method selection section 111 sets both the transmission methods of the transmission section 103 and the reception section 105 has been shown, but the present invention is not limited to this example and the transmission section 103 or The transmission method of only one of the receiving units 105 may be set.

Next, another configuration example of the first embodiment of the present invention will be described. FIG. 4 is a schematic block diagram showing another configuration example of the communication device according to the first embodiment of the present invention. The same reference numerals in FIG. 4 and FIG. 1 indicate the same components. Further, in FIG. 4, reference numeral 112 indicates a transmission method notification unit, and reference numeral 113 indicates an information extraction unit.

The transmission method notification unit 112 supplies the transmission method information selected by the transmission method selection unit 111 to the transmission data processing unit 102, causes the transmission data processing unit 102 to process the information, and sends it from the transmission unit 103 to the communication destination. Send it. The information extraction unit 113 extracts the above-mentioned transmission method information included in the received data from the communication destination, and supplies it to the transmission unit 103. The transmission unit 103 generates a transmission signal using a transmission method according to the transmission method information extracted by the information extraction unit 113. The receiving unit 105 receives data using the transmission method selected by the transmission method selecting unit 111.

The communication device 10 of FIG. 4 having the above-mentioned configuration.
The operation of changing the transmission method in the communication system configured by 01 'will be described for each function of the receiving side and the transmitting side with reference to the flowcharts of FIGS. 5 and 6, respectively. FIG. 5 is a flowchart for explaining a transmission method selection and notification operation in the communication device 1001 ′ on the receiving side.

Step ST201: Storage areas in the transmission memory 101 and the reception memory 107 are allocated in response to a request Smr from an application or the like. Step ST202: The throughput measurement period S109 is set based on the size of the storage area of the reception memory 107 allocated to the application in step ST201 and the information S111 on the transmission method currently selected by the transmission method selection unit 111.

Step ST203: Reception memory 107 assigned to the application receiving the data
The reception data DR processed by the reception data processing unit 106 is sequentially written in the storage area of. In addition, the number of received data written in the reception memory 107 is counted in response to the data write notification from the received data processing unit 106, and the average throughput is measured for each set measurement period using this count value. To be done.

Step ST204: The transmission method used in the transmission section 103 and the reception section 105 is selected from a plurality of predetermined transmission methods according to the throughput measurement result in the throughput measurement section 110. The selected transmission method is designated as the transmission method of the receiving unit 105.

Step ST205: Step ST204
The information of the transmission method selected in (1) is output from the antenna as a transmission signal and notified to the communication destination.

Step ST206: It is determined whether or not there is a change in the allocation of the storage area in which the received data is written. If a change occurs, the process moves to step ST207. If there is no change, step ST20
The processing is returned to 3, and the processing after the throughput measurement is repeated again. Step ST207: A storage area in which the received data is written is newly allocated. After that, the process is returned to step ST201 again, the throughput measurement period is reset according to the size of the newly allocated storage area, and the processes after the throughput measurement are repeated again.

FIG. 6 is a flow chart for explaining the operation of selecting and changing the transmission method in the communication device 1001 'on the transmitting side. Step ST208: Information extraction section 113 extracts the information about the transmission method included in the received data. Step ST209: It is determined whether or not the information on the transmission method extracted in step ST208 is different from the currently selected transmission method. If they are different, the process moves to step ST210. If they match, the process of step ST210 is skipped and the information extraction process of step ST208 is repeated. Step ST210: The currently selected transmission method is changed, and the transmission method according to the transmission method information extracted in step ST208 is the transmission section 1 as a new transmission method.
03 and the receiving unit 105.

FIG. 7 is a diagram for explaining the operation of changing the transmission method in the communication system having the two communication devices shown in FIG. 7, reference numeral 1001a ′ indicates a communication device on the transmitting side having the same configuration as that of the communication device 1001 ′ in FIG. 4, and reference numeral 100b ′ indicates the communication device 10 in FIG.
The communication device on the receiving side having the same configuration as that of 01 'is shown.

First, data is transmitted from the communication device 1001a 'on the transmitting side to the communication device 1001b' on the receiving side. Further, at this time, the communication device 1001 on the receiving side
In b ′, the processes of steps ST201 to ST203 described above are executed to measure the average throughput in the set measurement period (FIG. 7A).

Based on this throughput measurement result, the transmission method to be set in the transmission section 103 of the communication apparatus 1001a 'on the transmission side is selected by the transmission method selection section 111 of the communication apparatus 1001b' on the reception side, and the transmission method on the transmission side is selected. Communication device 1
001a 'is notified. The transmission method in the transmission unit 103 of the communication device 1001a ′ is set according to the notified transmission method information (FIG. 7B).

As described above, according to the communication system shown in FIG. 7, the size of the storage area used by the application for data reception and the transmission method being selected are set in the same manner as in the transmitting device 1001 shown in FIG. The throughput measurement interval is set appropriately based on the corresponding ideal throughput value, and the transmission method is selected according to the measurement result, so the application can request it without changing the transmission method faster than necessary. Throughput can be stably obtained. In addition, since the transmission method in the transmission unit on the transmission side is selected between the two communication devices by using the throughput measured on the reception side, it is practically more effective than the single communication device 1001 shown in FIG. The transmission method in the transmitter can be selected based on the measured value close to the throughput, and more stable throughput can be obtained.

In the transmission method selection unit 111, at least a transmission method different from the transmission method selected according to the measurement result of the throughput measurement unit 110 during a predetermined percentage of the set measurement period S109 (a period of several%, for example). 1
According to the result of comparing the throughput measurement values of the data received by the plurality of transmission methods, for example, the transmission method with the highest throughput value,
It may be selected as a new transmission method. This allows
The transmission method selection unit 111 does not need to have a data table of a throughput range (not shown) that is referred to when determining which throughput range the throughput measurement value falls within, and the configuration can be simplified.

<Second Embodiment> Next, a second embodiment of the present invention will be described. Communication device 1001 described above
In the communication device 1001 ′, the throughput measurement period used as a criterion for selecting a transmission method depends on the size of the storage area in which the received data is accumulated and the ideal throughput value in the currently selected transmission method. Is set. In the second embodiment described below, such setting of the throughput measurement period is not performed, and the information of the received data amount written in the receiving memory of the communication destination and the elapsed time until the received data amount is reached are set. Based on that, the throughput of its own transmission data is measured.

FIG. 8 is a schematic block diagram showing a configuration example of a communication device according to the second embodiment of the present invention. Figure 8
1 and the same reference numerals in FIG. 1 indicate the same components. Also, FIG.
In the above, reference numeral 114 is a detection start requesting unit, and reference numeral 115 is
Is a first information extraction unit, reference numeral 116 is a received data amount notification unit, reference numeral 117 is a second information extraction unit, reference numeral 110a.
Indicates a throughput measuring unit, respectively.

The detection start requesting unit 114 generates information requesting the start of detection of the amount of received data, and the transmission data processing unit 1
No. 02 is processed and processed as transmission data, and is transmitted from the transmission unit 103 to the communication destination. In addition, the transmission of the detection start request information is performed by the throughput measuring unit 110a.
To notify. The first information extraction unit 115 extracts the above detection start request information included in the received data from the communication destination, and outputs this to the received data amount notification unit 116.

The received data amount notification unit 116 receives the received data written in the reception memory 107 in response to the data write notification of the received data processing unit 106 from the time when the detection start request information is extracted by the first information extraction unit 115. Is counted, and the amount of received data is detected. Then, when the received data amount from the detection start time reaches the reference received data amount according to the size of the storage area allocated in the storage area allocation unit 108, the reference received data amount information is transmitted. Processing unit 102
To be processed as transmission data and transmitted from the transmission unit 103 to the communication destination. The reference received data amount is set, for example, according to a predetermined ratio (50% or the like) to the size of the allocated storage area.

The second information extraction unit 117 extracts the above-mentioned reference received data amount information contained in the received data from the communication destination and outputs it to the throughput measuring unit 110a. The throughput measuring unit 110a measures the elapsed time from the time when the detection start requesting unit 114 notifies the transmission of the detection start requesting information to the time when the second information extracting unit 117 extracts the reference received data amount information. The throughput is measured based on the measured elapsed time and the reference received data amount information.

The communication device 10 of FIG. 8 having the above-mentioned configuration
The operation of changing the transmission method in the communication system configured by 02 will be described for each function of the reception side and the transmission side with reference to the flowcharts of FIGS. 9 and 10, respectively. FIG. 9 is a flowchart for explaining the operation of detecting and notifying the amount of received data in the communication device 1002 on the receiving side.

Step ST301: Storage areas in the transmission memory 101 and the reception memory 107 are allocated in response to a request Smr from an application or the like.

Step ST302: The detection start request information included in the received data from the communication destination is extracted by the first information extracting section 115. Step ST303: When the reception start request information is not included in the received data, the information extraction processing of step ST302 is continued, and when it is included, step ST3
The processing shifts to 04.

Step ST304: From the time when the detection start request information is extracted, the number of received data written in the receiving memory 107 is counted in response to the data write notification of the received data processing unit 106, and the received data amount is detected. To be done. Step ST305: It is determined whether or not the detected received data amount has reached a reference received data amount according to the size of the storage area allocated by the storage area allocation unit 108. If not reached, step ST30
The received data amount detection process of No. 4 is continued, and when it reaches, the process proceeds to step ST306.

Step ST306: Information for notifying the time when the received data amount reaches the reference received data amount and the value of the reference received data amount is supplied to the transmission data processing unit 102 and transmitted to the communication destination. To be done.

Step ST307: It is determined whether or not there is a change in the allocation of the storage area in which the received data is written. If a change occurs, the process moves to step ST308. If there is no change, step ST30
The processing is returned to 2, and the subsequent processing from the extraction of the detection start request information is repeated again. Step ST308: A storage area in which the received data is written is newly allocated. After this, the process is returned to step ST302 again, and the processes after the extraction of the detection start request information are repeated again.

FIG. 10 is a flow chart for explaining the throughput measurement and transmission method selection operation in the communication apparatus 1002 on the transmission side.

Step ST309: The above-mentioned detection start request information S15 for requesting the start of detection of the amount of received data is generated in the detection start request unit 114 and transmitted to the communication destination. Further, the transmission timing of the detection start request information is notified to the throughput measuring unit 110a, and the time measurement is started.

Step ST310: The above-mentioned reference received data amount information contained in the received data from the communication destination is the second
Information is extracted by the information extraction unit 117.

Step ST311: If the received data does not include the reference received data amount information, step S31
The information extraction process of T310 is continued, and if included, the process proceeds to step ST312.

Step ST312: Step ST309
From the time when the detection start request information is transmitted in step S
The elapsed time up to the time of receiving the reference received data amount information at T11 is measured. Step ST313: The throughput of transmission data is measured based on the elapsed time detected in step ST312 and the reference received data amount information received in step ST311.

Step ST314: Step ST313
According to the throughput measurement result in
3 and the transmission method used in the receiving unit 105 are
It is selected from a plurality of predetermined transmission methods.

Step ST315: Step ST314
It is determined whether or not the transmission method selected in step 1 is different from the currently selected transmission method. If they are different, the process proceeds to step ST316, and if they match, step ST316 is skipped and step ST316 is executed.
The processing is returned to 309. Step ST316: The currently selected transmission method is changed, and the transmission method selected in step ST314 is newly designated for the transmission section 103 and the reception section 105.

FIG. 11 is a diagram for explaining the operation of changing the transmission method in the communication system having two communication devices shown in FIG. In FIG. 11, reference numeral 1002a indicates a communication device on the transmitting side having the same configuration as that in FIG. 8, and reference numeral 1002b indicates a communication device on the receiving side having the same configuration as in FIG.

First, the transmission side communication device 1002a transmits the reception data amount detection start request information to the reception side communication device 1002b. At this time, time measurement is started in the communication device 1002a on the transmission side (FIG. 11A).

When the receiving side communication device 1002b receives the detection start request information, the sending side communication device 1002b receives the detection start request information.
2a is transmitted to the communication device 1002b on the receiving side, and detection of the amount of received data written in the receiving memory 107 is started (FIG. 11B).

It is determined whether or not the received data amount detected by the communication device 1002b on the receiving side has reached the reference received data amount according to the size of the storage area allocated in the storage area allocation unit 108. When this is reached, the reference reception data amount information is transmitted from the communication device 1002b on the reception side to the communication device 1002a on the transmission side. In response to this, the communication device 1002a on the transmission side
In, the elapsed time from the time of transmitting the detection start request information to the time of receiving the reference received data amount information is measured,
The throughput of the transmission data is measured based on the measured elapsed time and the received reference reception data amount information. Then, the transmission method is selected according to the measured throughput (FIG. 11C).

As described above, according to the communication system shown in FIG. 11, the reference received data amount is set according to the size of the storage area used by the application for data reception, and the received data amount in the communication device on the receiving side is set. The throughput is measured on the basis of the elapsed time until the amount reaches the reference received data amount and the value of the reference received data amount. Then, the transmission method in the transmission unit of the transmission-side communication device is selected according to the measurement result of the throughput. As a result, since the throughput is measured according to the size of the storage area of the received data in the communication device on the receiving side, the throughput required by the application can be stably obtained without changing the transmission method faster than necessary. be able to. Further, the throughput is measured from the amount of received data of the receiving communication device and the elapsed time, and the transmission method in the transmitting unit of the transmitting communication device is selected according to the measurement result. Compared with, the transmission method in the transmitter can be selected based on the measured value close to the substantial throughput, and more stable throughput can be obtained. Furthermore, the communication device 10 shown in FIG.
Since it is not necessary to continuously measure the throughput as in No. 01, the processing can be simplified.

<Third Embodiment> Next, a third embodiment of the present invention will be described. Communication device 1002 described above
In the above, the block for detecting the amount of received data and the block for calculating the throughput by measuring the time to reach the amount of received data are divided into the communication device on the receiving side and the communication device on the transmitting side. However, in the third embodiment described below, a block that detects the amount of received data and measures the time thereof to measure the throughput is arranged in a single communication device.

FIG. 12 is a schematic block diagram showing a configuration example of a communication device according to the third embodiment of the present invention. 12 and FIG. 1 indicate the same constituent elements. Also,
In FIG. 12, reference numeral 110b indicates a throughput measuring unit.

The throughput measurement amount 110b counts the number of reception data written in the reception memory 107 in response to the data write notification of the reception data processing unit 106, and thereby detects the reception data amount. Then, the time until the amount of the received data reaches the reference received data amount according to the size of the storage area allocated in the storage area allocation unit 108 is measured, and the measured time and the reference received data amount are Throughput is measured based on.

FIG. 13 shows a communication device 1003 shown in FIG.
5 is a flowchart for explaining the operation of changing the transmission method in FIG.

Step ST401: Time measurement is started at the time of starting the detection of the amount of received data written in the receiving memory 107. Step ST402: The throughput measuring unit 110b counts the number of received data written in the receiving memory 107 in response to the data write notification of the received data processing unit 106, thereby detecting the received data amount. Step ST403: It is determined whether or not the detected received data amount has reached a reference received data amount according to the size of the storage area allocated by the storage area allocation unit 108. If not reached, step ST40
The received data amount detection process of No. 2 is continued, and when it reaches, the process proceeds to step ST404.

Step ST404: Step ST401
The elapsed time from the start of detection of the amount of received data in is measured. Step ST405: Throughput is measured based on the elapsed time measured in step ST404 and the reference received data amount.

Step ST406: Step ST405
According to the throughput measurement result in
3 and the transmission method used in the receiving unit 105 are
It is selected from a plurality of predetermined transmission methods.

Step ST407: Step ST406
It is determined whether or not the transmission method selected in step 1 is different from the currently selected transmission method. If they are different, the process proceeds to step ST408, and if they match, step ST408 is skipped and step ST408 is skipped.
The processing is returned to 409. Step ST408: The currently selected transmission method is changed, and the transmission method selected in step ST406 is used as a new transmission method in the transmitting unit 103 and the receiving unit 1.
Specified for 05.

Step ST409: It is determined whether or not there is a change in the allocation of the storage area in which the received data is written. If a change occurs, the process moves to step ST410. If there is no change, step ST40
The process is returned to 1, and the reception data amount is detected again with the start of the time measurement. Step ST410: A storage area in which the received data is written is newly allocated. After this, step S
The process is returned to T401, and the reception data amount is detected again with the start of the time measurement.

As described above, according to the communication device 1003 shown in FIG. 12, the reference received data amount is set according to the size of the storage area used by the application for data reception, and the received data amount is set to this reference received data amount. Throughput is measured based on the elapsed time until reaching the amount and the value of the reference received data amount. Then, the transmission method is selected according to the measurement result of the throughput. This allows
Since the throughput is measured according to the size of the storage area of the received data used by the application, the throughput required by the application can be stably obtained without changing the transmission method faster than necessary. Further, unlike the communication device 1001 shown in FIG. 1, it is not necessary to continuously measure the throughput, so that the process can be simplified.

In the above description, an example in which the transmission method selection section 111 sets both transmission methods of the transmission section 103 and the reception section 105 has been shown, but the present invention is not limited to this example, and the transmission section 103 or The transmission method of only one of the receiving units 105 may be set.

Next, another configuration example of the third embodiment of the present invention will be described. In the configuration example described below, similarly to the communication device 1001 ′ shown in FIG. 4, the communication device on the reception side performs throughput measurement and the selection of the transmission method, and the communication device on the transmission side is notified from the reception side. The transmission method of the transmission unit is set according to the transmission method information.

FIG. 14 is a schematic block diagram showing another configuration example of the communication device according to the third embodiment of the present invention. The same reference numerals in FIG. 14, FIG. 12 and FIG. 4 indicate the same components.

Of the operation of changing the transmission method in the communication system configured by the communication device 1003 'shown in FIG. 14, the function of the receiving side will be described with reference to the flowchart of FIG. Note that the function of the transmission side that sets the transmission method of the transmission unit according to the notified transmission method is the same as the content described with reference to the flowchart of FIG. 6, and therefore the description is omitted here.

FIG. 15 is a flow chart for explaining the transmission system selection and notification operation in the communication device 1003 'on the receiving side.

Step ST501: At the start of detection of the amount of received data written in the receiving memory 107, time measurement is started. Step ST502: The throughput measuring unit 110b counts the number of received data written in the receiving memory 107 in response to the data write notification of the received data processing unit 106, thereby detecting the received data amount. Step ST503: It is determined whether or not the detected received data amount has reached a reference received data amount according to the size of the storage area allocated by the storage area allocation unit 108. If not reached, step ST50
The received data amount detection process of No. 2 is continued, and when it reaches, the process proceeds to step ST504.

Step ST504: Step ST401
The elapsed time from the start of detection of the amount of received data in is measured. Step ST505: Throughput is measured based on the elapsed time measured in step ST504 and the reference received data amount.

Step ST506: Step ST405
According to the throughput measurement result in
3 and the transmission method used in the receiving unit 105 are
It is selected from a plurality of predetermined transmission methods.

Step ST507: Step ST506
The information of the transmission method selected in (1) is output from the antenna as a transmission signal and notified to the communication destination.

Step ST508: It is determined whether or not there is a change in the allocation of the storage area in which the received data is written. If a change occurs, the process moves to step ST509. If there is no change, step ST50
The processing is returned to 1, and the reception data amount is detected again with the start of the time measurement. Step ST509: A storage area in which the received data is written is newly allocated. After this, the process is returned to step ST501 again, and the detection of the amount of received data is performed again with the start of the time measurement.

As described above, according to the communication device 1003 'shown in FIG. 14, in the communication device on the receiving side, the reference reception data amount is set according to the size of the storage area used by the application for data reception, The throughput of the received data is measured based on the elapsed time until the received data amount reaches the reference received data amount and the value of the reference received data amount. Then, the transmission method is selected according to the measurement result of the throughput. The information on the selected transmission method is notified from the communication device on the reception side to the communication device on the transmission side, and the transmission system in the transmission section of the communication device on the transmission side is set accordingly. Therefore, similarly to the communication device 1003 shown in FIG. 12, since the throughput measurement is performed according to the size of the storage area of the received data used by the application, the application can be executed without changing the transmission method faster than necessary. The required throughput can be stably obtained. Further, since the transmission method in the transmission unit of the transmission side communication device is selected according to the throughput measurement result in the reception side communication device, it is possible to select the transmission system in the transmission unit based on the measured value close to the actual throughput. It is possible to obtain more stable throughput.

The present invention is not limited to the above-described first to third embodiments, and various modifications can be made. For example,
A part or all of the configuration of the communication device described above may be replaced with a processing device such as a DSP that executes a process in accordance with a program including a part or all of the procedures of the flowcharts referred to in the description of each embodiment. good.

Also, as the selectable transmission method, the example in which the modulation method and the coding rate are selectable is given in the above description, but the present invention is not limited to this example, and various other transmission methods can be selected. You can

Further, in the above-mentioned embodiment, a wireless communication device is mainly described as an example, but the present invention is not limited to this example, and the present invention can be applied to a wired communication device.

[0141]

As described above, according to the present invention, it is possible to improve the stability of throughput without performing unnecessary control of a transmission method for an application that uses data transmitted and received via a cache memory.

[Brief description of drawings]

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

FIG. 2 is a flowchart for explaining a changing operation of a transmission method in the communication device shown in FIG.

FIG. 3 is a diagram showing an example of a measurement result in a throughput measuring unit.

FIG. 4 is a schematic block diagram showing another configuration example of the communication device according to the first embodiment of the present invention.

5 is a flowchart for explaining a transmission method selection and notification operation when the communication device shown in FIG. 4 is a data receiving side.

FIG. 6 is a flowchart for explaining a transmission method selection and change operation when the communication device shown in FIG. 4 is a data transmission side.

FIG. 7 is a diagram for explaining a change operation of a transmission method in a communication system having two communication devices shown in FIG.

FIG. 8 is a schematic block diagram showing a configuration example of a communication device according to a second embodiment of the present invention.

9 is a flowchart for explaining a detection and notification operation of a received data amount when the communication device shown in FIG. 8 is a data receiving side.

10 is a flowchart for explaining a throughput measurement and a transmission system selection operation when the communication device shown in FIG. 8 is a data transmission side.

FIG. 11 is a diagram for explaining the operation of changing the transmission method in the communication system including the two communication devices shown in FIG.

FIG. 12 is a schematic block diagram showing a configuration example of a communication device according to a third embodiment of the present invention.

13 is a flowchart for explaining a transmission system changing operation in the communication device shown in FIG.

FIG. 14 is a schematic block diagram showing another configuration example of the communication device according to the third embodiment of the present invention.

FIG. 15 is a flowchart for explaining a transmission method selection and notification operation when the communication device shown in FIG. 14 is a data receiving side.

[Explanation of symbols]

101 ... Transmission memory, 102 ... Transmission data processing unit, 10
3 ... Transmission unit, 1031 ... Convolutional encoder, 1032 ...
Interleaver, 1033 ... Modulator, 1034 ... IFF
T section, 1035 ... D / A, 1036 ... RF section, 1037
... transmission control units 1037, 104 ... antenna switching device,
105 ... Receiving unit, 1051 ... RF unit, 1052 ... A / D
Converter, 1053 ... FFT section, 1054 ... Demodulator, 10
55 ... De-interleaver, 1056 ... Viterbi decoder, 1057 ... Reception control section, 106 ... Reception data processing section, 107 ... Reception memory, 108 ... Storage area allocating section, 109 ... Measurement period setting section, 110, 110a, 11
0b ... Throughput measuring section, 111 ... Transmission method selecting section,
112 ... Transmission method notification unit, 113 ... Information extraction unit, 114
... Detection start requesting unit, 115 ... First information extracting unit, 116
... reception data amount notification unit 117 ... second information extraction unit.

Continued front page    F-term (reference) 5K011 EA00 FA00 GA06 JA01 KA13                 5K014 AA01 BA10 FA11 HA10                 5K022 DD01 DD23 DD33                 5K033 AA01 DA17 EA06                 5K067 AA02 BB04 BB21 CC01 DD51                       EE02 EE12 HH23 HH25

Claims (36)

[Claims] 1. A communication system, comprising a first communication device and a second communication device, for performing communication using a transmission method selected from a plurality of predetermined transmission methods, comprising: The communication device includes: storage means capable of storing received data; storage area allocating means for allocating a storage area of the received data in the storage means in response to an input allocation request; and the storage area allocating means. Received data processing means for writing the received data in the allocated storage area, throughput measuring means for measuring an average throughput of the received data written in the storage means for each set measurement period, and the allocated data Measurement period setting means for setting the measurement period of the throughput measuring means based on the size of the storage area and the selected transmission method. According to the throughput measurement result of the throughput measuring means, a transmission method selecting means for newly selecting a transmission method used for receiving data from the plurality of transmission methods, and a transmission method selecting means selected by the transmission method selecting means. Transmission method,
A communication system, comprising: a transmission method notifying unit for notifying the second communication apparatus, wherein the second communication apparatus transmits data using the transmission method notified by the first communication apparatus. 2. A first communication device and a second communication device, which perform communication using a transmission method selected from a plurality of predetermined transmission methods.
A communication system including the communication device according to claim 1, wherein the first communication device stores the received data in the storage unit according to an input allocation request, and a storage unit capable of storing the received data. Storage area allocating means for allocating areas, reception data processing means for writing the reception data in the storage areas allocated by the storage area allocating means, and information for requesting the start of detection of the reception data amount from the reception data. First information extraction means for extracting, and detection of the amount of received data written in the storage means is started from the time when the detection start request information is extracted, and the received data amount from the detection start time is When the reference received data amount corresponding to the size of the allocated storage area is reached, the reference received data amount information is used as the second information. The second communication device includes a received data amount notifying unit that notifies the communication device, and the second communication device notifies the first communication device of the detection start request information, and the reference reception from the received data. Second information extracting means for extracting data amount information, and an elapsed time from the transmission time point of the detection start request information to the reception time point of the reference reception data amount information, and the measured elapsed time and the reference reception time. Throughput measuring means for measuring the throughput based on the data amount information, and a transmission method used for transmitting data is newly selected from the plurality of transmission methods according to the throughput measurement result by the throughput measuring means. A communication system including a transmission system selecting means. 3. A first communication device and a second communication device, which perform communication using a transmission method selected from a plurality of predetermined transmission methods.
The communication device including the communication device according to claim 1, wherein the first communication device includes a storage unit capable of storing reception data, and a storage area for storing the reception data in the storage unit according to an input allocation request. A storage area allocating means for allocating the received data, a received data processing means for writing the received data in the storage area allocated by the storage area allocating means, and a received data amount written in the storage means for the allocated storage area Of the throughput in the above-mentioned throughput measuring means, which measures the time required to reach the reference received data amount according to the size of, and measures the throughput based on the measured time and the reference received data amount. Depending on the measurement result, the transmission method used to receive the data may be one of the above transmission methods. A transmission mode selecting means for selecting a new, a transmission scheme that is selected in the transmission mode selecting means,
A communication system, comprising: a transmission method notifying unit for notifying the second communication apparatus, wherein the second communication apparatus transmits data using the transmission method notified by the first communication apparatus. 4. A communication device having a transmitting means and a receiving means for transmitting and receiving data using a transmission method selected from a plurality of predetermined transmission methods, capable of storing received data of the receiving means. Storage means, a storage area allocating means for allocating a storage area of the received data in the storage means in response to an input allocation request, and the received data in the storage area allocated by the storage area allocating means. Received data processing means for writing, throughput measuring means for measuring an average throughput of received data written in the storage means for each set measurement period, size of the allocated storage area and selected transmission method And a measurement period setting means for setting the measurement period of the throughput measuring means based on And a transmission method selection means for newly selecting a transmission method used by either or both of the transmission means and the reception means according to the measurement result of the throughput in the measurement means. Communication device. 5. The measurement period setting means sets the measurement period according to a ratio between a predetermined ideal throughput value corresponding to the selected transmission method and the size of the allocated storage area. Item 4. The communication device according to item 4. 6. The transmission method selection means determines which of a plurality of throughput ranges respectively corresponding to the plurality of transmission methods the throughput measured by the throughput measurement means is included in, and the determined throughput is determined. The communication device according to claim 5, wherein a transmission method is newly selected according to a result of comparison between the range and a throughput range corresponding to the selected transmission method. 7. The transmission method selecting means selects a transmission method rank corresponding to a throughput range including the measured throughput from a plurality of transmission methods ranked corresponding to the predetermined throughput range. The communication device according to claim 6, wherein the transmission method is newly selected in accordance with a rank difference from the rank of the selected transmission method. 8. The throughput measuring means detects the amount of received data written in the storage means for each of the set measuring periods, and according to the ratio between the detected received data amount and the measuring period. The communication device according to claim 4, wherein an average throughput of the received data is measured. 9. The communication device according to claim 4, wherein the throughput measuring unit measures an average throughput of the received data according to an average value of a plurality of throughput measurement results in the set measurement period. . 10. Transmission method information notifying means for transmitting information on the transmission method selected by the transmission method selecting means from the transmitting means to a communication destination, and information on the transmission method included in the received data. Information transmitting means for extracting, the transmitting means transmits data using a transmission method according to the information of the transmission method extracted by the information extracting means, and the receiving means selects the transmission method. The communication device according to claim 4, wherein data is received using a transmission method selected by the means. 11. The transmission method selection means selects at least one other transmission method different from the transmission method selected according to the measurement result of the throughput measurement means during a predetermined ratio period of the set measurement period. The communication device according to claim 10, wherein a transmission method is newly selected in accordance with a result of selection and comparison of throughput measurement values of data received by the plurality of transmission methods. 12. The transmitting means modulates transmission data by a modulation method selected from a plurality of predetermined modulation methods, and the receiving means modulates data selected from a plurality of modulation methods. The communication device according to claim 4, wherein transmission data is demodulated by a demodulation method corresponding to the method. 13. The transmitting means performs convolutional coding of transmission data at a coding rate selected from a plurality of predetermined coding rates, and the receiving means selects from among the plurality of coding rates. The communication device according to claim 4, wherein the convolutional coded data is decoded using a decoding algorithm corresponding to the selected coding rate. 14. A communication device having a transmitting means and a receiving means for transmitting and receiving data using a transmission method selected from a plurality of predetermined transmission methods, wherein the reception data of the receiving means can be stored. Storage means, a storage area allocating means for allocating a storage area of the received data in the storage means in response to an input allocation request, and the received data in the storage area allocated by the storage area allocating means. A reception data processing means to be written, a detection start request means for transmitting information requesting the start of detection of the received data amount from the transmission means to a communication destination, and a first for extracting the detection start request information from the reception data And the amount of received data written in the storage means from the time when the detection start request information is extracted, At the time when the received data amount from the detection start time reaches the reference received data amount according to the size of the allocated storage area, the reference received data amount information is addressed from the transmission means to the communication destination. Receiving means for transmitting the received data amount information, second information extracting means for extracting the reference received data amount information from the received data, and receiving the reference received data amount information from the time when the detection start request information is sent. Throughput measuring means for measuring the elapsed time up to the point of time, and measuring the throughput based on the detected elapsed measurement and the reference received data amount information, and the transmitting means according to the throughput measurement result in the throughput measuring means. Alternatively, a transmission method used by either or both of the receiving means is newly selected from the plurality of transmission methods. Communication device and a transmission method selection means. 15. The transmission method selection means determines which of a plurality of throughput ranges respectively corresponding to the plurality of transmission methods the throughput measured by the throughput measurement means is included in, and the determined throughput is determined. The communication device according to claim 14, wherein a transmission method is newly selected according to a result of comparison between the range and the throughput range corresponding to the selected transmission method. 16. The transmission method selection means selects a transmission method rank corresponding to a throughput range including the measured throughput from a plurality of transmission methods ranked corresponding to the predetermined throughput range. The communication device according to claim 15, wherein the transmission method is newly selected according to a rank difference from the rank of the selected transmission method. 17. The transmitting means modulates transmission data by a modulation method selected from a plurality of predetermined modulation methods, and the receiving means modulates data selected from a plurality of modulation methods. The communication device according to claim 14, wherein transmission data is demodulated by a demodulation method corresponding to the method. 18. The transmission means performs convolutional coding of transmission data at a coding rate selected from a plurality of predetermined coding rates, and the receiving means selects from a plurality of coding rates. The communication device according to claim 14, wherein the convolutional coded data is decoded using a decoding algorithm corresponding to the selected coding rate. 19. A communication device having a transmission means and a reception means for transmitting and receiving data using a transmission method selected from a plurality of predetermined transmission methods, wherein the reception data of the reception means can be stored. Storage means, a storage area allocating means for allocating a storage area of the received data in the storage means in response to an input allocation request, and the received data in the storage area allocated by the storage area allocating means. The received data processing means to be written, and the amount of received data written to the storage means are measured until the reference received data amount corresponding to the size of the allocated storage area is measured, and the measured time and the above Throughput measuring means for measuring the throughput based on the reference received data amount, and the throughput in the throughput measuring means. Depending on the measurement result of Putto, a transmission scheme to be used in either or both of the transmission means or the reception means, a communication device having a transmission mode selecting means for selecting new from the plurality of transmission schemes. 20. The transmission method selection means determines which of a plurality of throughput ranges respectively corresponding to the plurality of transmission methods the throughput measured by the throughput measurement means, and the determined throughput. The communication device according to claim 19, wherein a transmission method is newly selected according to a result of comparison between the range and the throughput range corresponding to the selected transmission method. 21. Transmission method information notifying means for transmitting information on the transmission method selected by the transmission method selecting means from the transmitting means to a communication destination, and information on the transmission method included in the received data. Information transmitting means for extracting, the transmitting means transmits data using a transmission method according to the information of the transmission method extracted by the information extracting means, and the receiving means selects the transmission method. 20. The communication device according to claim 19, wherein data is received using a transmission method selected by the means. 22. A communication method for performing communication using a transmission method selected from a plurality of predetermined transmission methods, wherein a storage area in a storage device for receiving data is allocated in response to an allocation request, Based on the size of the allocated storage area and the selected transmission method, a throughput measurement period is set, the received data is written in the allocated storage region, and the storage area is set for each set measurement period. A communication method in which an average throughput of received data written in is measured, and a transmission method used for communication is newly selected from the plurality of transmission methods according to the result of the throughput measurement. 23. A communication method for performing communication between a first communication device and a second communication device using a transmission method selected from a plurality of predetermined transmission methods, the method comprising: The communication device allocates a storage area in the storage device for the received data in response to the allocation request, and sets a throughput measurement period based on the size of the allocated storage area and the selected transmission method, The received data from the second communication device is written in the allocated storage area, and the average throughput of the received data written in the storage area is measured for each of the set measurement periods. According to the result, a transmission method used for receiving data is newly selected from the plurality of transmission methods, and the selected transmission method is notified to the second communication device, Serial second communication apparatus, by using the transmission method notified from the first communication device,
A communication method for transmitting data to the first communication device. 24. A communication method for performing communication between a first communication device and a second communication device using a transmission method selected from a plurality of predetermined transmission methods, the method comprising: The communication device allocates a storage area in the storage device for the received data in response to the allocation request, and the second communication device sends information requesting the start of detection of the received data amount to the second communication device. Then, the first communication device writes the received data from the second communication device in the allocated storage area, and from the received data,
The information requesting the detection start of the reception data amount is extracted, and the detection of the reception data amount written to the storage device is started from the time when the detection start request information is extracted, and the reception data is detected from the detection start time. When the amount reaches the reference received data amount according to the size of the allocated storage area, the reference received data amount is set to the second received data amount.
To the communication device, and the second communication device measures an elapsed time from the time when the detection start request information is transmitted to the time when the reference received data amount is notified,
Throughput is measured based on the measured elapsed time and the notified reference received data amount, and a plurality of transmission methods are used for data transmission to the first communication device according to the measurement result of the throughput. A communication method that is newly selected from among the above transmission methods. 25. A communication method for performing communication using a transmission method selected from a plurality of predetermined transmission methods, wherein a storage area of a storage device for receiving data is allocated in response to an allocation request, While writing the received data in the allocated storage area, the amount of received data written in the storage device is
The time required to reach the reference received data amount according to the size of the allocated storage area is measured, the throughput is measured based on the measured time and the reference received data amount, and the result of the throughput measurement A communication method for newly selecting a transmission method used for communication from the plurality of transmission methods according to the above. 26. A communication method for performing communication between a first communication device and a second communication device using a transmission method selected from a plurality of predetermined transmission methods, the method comprising: Communication device allocates a storage area of the received data in the storage device in response to the allocation request, writes the received data from the second communication device in the allocated storage region, and writes the received data in the storage device. The time required for the received data amount to reach the reference received data amount according to the size of the allocated storage area is measured, and the throughput is measured based on the measured time and the reference received data amount. According to the result of the throughput measurement, a transmission method used for receiving data is newly selected from the plurality of transmission methods, and the selected transmission method is transmitted to the second communication device. Notified, the second communication device, using the transmission method notified from the first communication device,
A communication method for transmitting data to the first communication device. 27. A step of allocating a storage area in a storage device for receiving data in response to an allocation request to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, A step of setting a throughput measurement period based on the size of the allocated storage area and the selected transmission method; and writing the received data in the allocated storage area, and for each of the set measurement periods, A step of measuring an average throughput of received data written in the storage area, and a transmission method used for either or both of data transmission and reception according to the result of the throughput measurement,
A program for executing a process including a step of newly selecting from the plurality of transmission methods. 28. A step of allocating a storage area in a storage device for receiving data in response to an allocation request to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, Setting a throughput measurement period based on the size of the allocated storage area and the selected transmission method; writing the received data from the second communication device into the allocated storage area; The step of measuring the average throughput of the received data written in the storage area for each set measurement period, and the transmission method used for receiving the data among the plurality of transmission methods according to the result of the throughput measurement. , A step of notifying the sender of the received data of the selected transmission method, and a communication destination A program for executing a process including the step of setting the transmission method used for data transmission to the communication destination to the notified transmission method when the transmission method selected in (1) is notified. 29. A step of allocating a storage area in a storage device for receiving data in response to an allocation request to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, Writing the received data in the allocated storage area and extracting information requesting the start of detection of the received data amount from the received data; and when the detection start request information is extracted, from the extraction time point. At the time when the detection of the amount of received data written in the storage device is started and the amount of received data from the detection start time reaches a reference amount of received data according to the size of the allocated storage area. Communicating the detection start request information, and a receiving step including a step of notifying the sender of the received data of the reference received data amount. And the elapsed time from the time when the detection start request information is transmitted to the time when the reference reception data amount is notified from the communication destination, and the measured elapsed time and the notified reference A step of measuring the throughput based on the amount of received data, and a step of newly selecting, from the plurality of transmission methods, a transmission method used for data transmission to the communication destination in accordance with the measurement result of the throughput. A program that causes a process including a transmission step including a. 30. A step of allocating a storage area in a storage device of received data to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, in response to an allocation request, While writing the received data in the allocated storage area, the amount of received data written in the storage device is
Measuring the time required to reach a reference received data amount according to the size of the allocated storage area, and measuring the throughput based on the measured time and the reference received data amount, and the throughput measurement And a step of newly selecting a transmission method used for communication from the plurality of transmission methods according to the result of (1). 31. A step of allocating a storage area in a storage device for receiving data to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, in response to an allocation request, While writing the received data in the allocated storage area, the amount of received data written in the storage device is
Measuring the time required to reach a reference received data amount according to the size of the allocated storage area, and measuring the throughput based on the measured time and the reference received data amount, and the throughput measurement In accordance with the result of step 1, a step of newly selecting a transmission method used for data reception from the plurality of transmission methods, a step of notifying the source of the received data of the selected transmission method, and a communication destination When notified of the selected transmission method,
A program for executing a process including a step of setting a transmission method used for data transmission to the communication destination to the notified transmission method. 32. A step of allocating a storage area in a storage device for receiving data in response to an allocation request to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, A step of setting a throughput measurement period based on the size of the allocated storage area and the selected transmission method; and writing the received data in the allocated storage area, and for each of the set measurement periods, A step of measuring an average throughput of received data written in the storage area, and a transmission method used for either or both of data transmission and reception according to the result of the throughput measurement,
A recording medium of a program for executing a process including a step of newly selecting from the plurality of transmission methods. 33. A step of allocating a storage area in a storage device for receiving data in response to an allocation request, to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, Setting a throughput measurement period based on the size of the allocated storage area and the selected transmission method; writing the received data from the second communication device into the allocated storage area; The step of measuring the average throughput of the received data written in the storage area for each set measurement period, and the transmission method used for receiving the data among the plurality of transmission methods according to the result of the throughput measurement. , A step of notifying the sender of the received data of the selected transmission method, and a communication destination A recording medium of a program that, when notified of the transmission method selected in step 1, sets a transmission method used for data transmission to the communication destination to the notified transmission method. 34. A step of allocating a storage area in a storage device for receiving data in response to an allocation request, to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, Writing the received data in the allocated storage area and extracting information requesting the start of detection of the received data amount from the received data; and when the detection start request information is extracted, from the extraction time point. At the time when the detection of the amount of received data written in the storage device is started and the amount of received data from the detection start time reaches a reference amount of received data according to the size of the allocated storage area. Communicating the detection start request information, and a receiving step including a step of notifying the sender of the received data of the reference received data amount. And the elapsed time from the time when the detection start request information is transmitted to the time when the reference reception data amount is notified from the communication destination, and the measured elapsed time and the notified reference A step of measuring the throughput based on the amount of received data, and a step of newly selecting, from the plurality of transmission methods, a transmission method used for data transmission to the communication destination in accordance with the measurement result of the throughput. And a recording medium of a program for executing a process including a transmitting step including. 35. A step of allocating a storage area in a storage device of received data to a communication device that communicates using a transmission method selected from a plurality of predetermined transmission methods, in response to an allocation request, While writing the received data in the allocated storage area, the amount of received data written in the storage device is
Measuring the time required to reach a reference received data amount according to the size of the allocated storage area, and measuring the throughput based on the measured time and the reference received data amount, and the throughput measurement A recording medium of a program for executing a process including a step of newly selecting a transmission method used for communication from the plurality of transmission methods in accordance with the result. 36. A step of allocating a storage area in a storage device for receiving data in response to an allocation request to a communication device that performs communication using a transmission method selected from a plurality of predetermined transmission methods, While writing the received data in the allocated storage area, the amount of received data written in the storage device is
Measuring the time required to reach a reference received data amount according to the size of the allocated storage area, and measuring the throughput based on the measured time and the reference received data amount, and the throughput measurement According to the result of step 1, a step of newly selecting a transmission method used for data reception from the plurality of transmission methods, a step of notifying the transmission source of the received data of the selected transmission method, and a communication destination When notified of the selected transmission method,
A recording medium of a program for executing a process including a step of setting a transmission method used for data transmission to the communication destination to the notified transmission method.