KR20090090985A - Radio communication apparatus, radio communication method, and storage medium recording program - Google Patents

Abstract

A wireless communication apparatus, a wireless communication method and a recording media recording a program are provided to measure the communications quality of the radio channel with the memory device and set up the communications parameter according to the communications quality. A communication quality measuring unit(1e) measures the communications quality of a wireless channel to a memory device. The communications quality measuring portion measures the received signal strength indication of the electric wave transmitted from the memory device. A communication parameter determining unit(1g) determines communication parameter when wirelessly communicating with the memory device. According to the received signal strength indication which the communications part of determining parameter is measured by the communications quality measuring portion, the communications parameter is determined.

Description

Wireless communication device and storage medium for storing wireless communication method and program {RADIO COMMUNICATION APPARATUS, RADIO COMMUNICATION METHOD, AND STORAGE MEDIUM RECORDING PROGRAM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission / reception control technology of a wireless communication device, and more particularly to a transmission / reception control technology of a reader / writer device that communicates with a wireless tag (hereinafter, simply referred to as a tag).

Recently, RFID (Radio Frequency Identification), a non-contact recognition technology using radio waves, has been used in various fields. In particular, the 950MHz band RFID, which is characterized by a longer communication distance than the conventional RFID system is attracting attention and is rapidly spreading.

In addition, wireless tags of passive type (battery-free) equipped with a large capacity memory are beginning to be released from domestic and foreign wireless tag manufacturers, and are expected to be spread in the future.

Conventionally, the communication between a reader / writer device and a wireless tag is centered on very short data communication such as ID (Identification) information, and the amount of one-time communication data is about a hundred tens of bits.

However, with the increase in the capacity of the wireless tag memory, the amount of communication data is expected to increase from tens of kilos to hundreds of kilobits.

Since the response wave of the passive type wireless tag is very weak and is susceptible to communication environments such as the distance from the reader / writer, it is always fast and stable regardless of the communication environment with an increase in the amount of communication data in the future. Establishing a way to communicate is a new challenge.

In order to solve this problem, Patent Literature 1 measures the communication time between the reader / writer device and the wireless tag and the number of retries upon communication failure as information indicating an indicator of the stability of communication, and informs the user. As such, a method is disclosed that enables a user to set optimal parameters.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2007-94890

According to the system disclosed in Patent Document 1, the reader / writer device communicates with a wireless tag by receiving an operation instruction from an external control device or the like.

At this time, the communication processing time and the number of command retries at the time of communication failure are acquired as a stability parameter indicating the stability of the communication, and this stability parameter is added to the communication result data and output.

This allows the user to grasp the situation or change in communication stability and set communication parameters according to the communication environment, based on indicators such as long and short periods of communication processing time and refreshments in the number of communication retries. have.

However, in an actual system operation environment, the communication environment changes from time to time due to the movement of radio tags, multipath, or the like.

Therefore, in order to realize high speed and stable communication regardless of the communication environment, it is necessary to grasp the communication environment at the time of communication in real time and optimize the communication parameters.

In the system disclosed in Patent Document 1, since the user adjusts the communication parameters based on the stability parameters including the communication processing time and the number of retries, the communication parameters are optimized in real time in response to changes in the communication environment. There was a problem that it was difficult.

The main object of the present invention is to realize a radio communication apparatus or the like capable of coping with the change of the communication environment in real time and continuing stable communication.

A wireless communication apparatus according to the present invention is a wireless communication apparatus that performs wireless communication with a memory device having a wireless communication function, comprising: a communication quality measuring unit for measuring a communication quality of a wireless communication path with the memory device, and the communication quality measurement And a communication parameter determining unit for determining a communication parameter in wireless communication with the memory device according to the communication quality measured by the unit.

In the wireless communication device according to the present invention, the communication quality measuring unit measures the received radio wave intensity of the radio wave transmitted from the memory device, and the communication parameter determining unit is configured according to the received radio wave intensity measured by the communication quality measuring unit. It is characterized by determining a communication parameter.

In the radio communication apparatus according to the present invention, the communication parameter determining unit determines the data length of the communication data performing radio communication with the memory device as the communication parameter according to the communication quality measured by the communication quality measuring unit. It is characterized by.

In the radio communication apparatus according to the present invention, the communication parameter determining unit increases the data length of the communication data as the communication quality measured by the communication quality measuring unit is higher.

In the radio communication apparatus according to the present invention, the communication parameter determining unit retries communication when the radio communication with the memory device fails as the communication parameter according to the communication quality measured by the communication quality measuring unit. The upper limit of the number of times is determined.

In the radio communication apparatus according to the present invention, the communication parameter determining unit decreases the upper limit of the number of communication retry attempts as the communication quality measured by the communication quality measuring unit is higher.

In the radio communication apparatus according to the present invention, the radio communication apparatus includes a communication parameter storing communication parameter information in which a communication quality level is displayed in a plurality of stages, and the communication parameter and the condition for changing the communication parameter are displayed for each communication quality level. It further has an information storage part, The said communication parameter determination part extracts from the said communication parameter information the communication parameter of the communication quality level corresponding to the communication quality measured by the said communication quality measuring part, and the condition for changing a communication parameter, and the present state. It is determined whether or not the extracted change condition is satisfied, and when the current state matches the changed condition, communication parameters other than the extracted communication parameters are used.

In the radio communication apparatus according to the present invention, the communication parameter information storage unit stores communication parameter information indicating the number of consecutive successes of radio communication as a condition for changing the communication parameter, and the communication parameter determination unit is wireless with the memory device. The number of successes succeeding in communication is counted, and it is determined whether the counted number is equal to or greater than the successive success number indicated in the extracted change condition, and when the counted number is equal to or greater than the successive success number, the communication quality corresponding to the extracted communication parameter. And a communication parameter corresponding to a communication quality level higher than the level.

In the radio communication apparatus according to the present invention, the communication parameter information storage unit stores communication parameter information indicating the number of consecutive failures of radio communication as a condition for changing the communication parameter, and the communication parameter determination unit wirelessly communicates with the memory device. The number of times of successive failures in communication is counted, and it is determined whether the counted number is equal to or greater than the number of consecutive failures indicated in the extracted change condition, and when the counted number is equal to or more than the continuous failure number, the communication quality corresponding to the extracted communication parameter. And a communication parameter corresponding to a communication quality level lower than the level.

In the radio communication apparatus according to the present invention, the radio communication apparatus receives read data read from the radio tag apparatus from the radio tag apparatus by radio communication, and the communication parameter determining unit is configured by the communication quality measuring unit. According to the measured communication quality, the data length of the read data is determined as the communication parameter.

In the radio communication apparatus according to the present invention, the radio communication apparatus transmits recording data recorded on the radio tag apparatus to the radio tag apparatus by radio communication, and the communication parameter determining unit is configured by the communication quality measuring unit. According to the measured communication quality, the data length of the recording data is determined as the communication parameter.

In a wireless communication method according to the present invention, there is provided a communication quality measuring step of measuring, by a computer performing wireless communication with a memory device having a wireless communication function, a communication quality of a wireless communication path with the memory device; And a communication parameter determining step of determining a communication parameter in wireless communication with the memory device according to the communication quality measured by the communication quality measuring step.

A storage medium according to the present invention includes a communication quality measurement process for measuring a communication quality of a wireless communication path with the memory device to a computer that performs wireless communication with a memory device having a wireless communication function, and the communication quality measurement process. According to the measured communication quality, a communication parameter determination process of determining a communication parameter in wireless communication with the memory device is characterized in that it is executed.

According to the present invention, by measuring the communication quality of the wireless communication path with the memory device and setting the optimum communication parameters in accordance with the communication quality, it is always estimated in real time to change the communication environment, depending on the change of the communication environment It is possible to realize high speed and stable communication.

Hereinafter, two embodiments of the radio communication apparatus according to the present invention are shown. In addition, the Example shown below is a part of Example concerning this invention, and the technical scope of this invention is not limited only to a following Example.

In the following embodiments, the reader / writer apparatus mainly estimates the communication environment by measuring the propagation intensity of the response wave from the radio tag and analyzing the intensity.

The reader / writer device automatically optimizes communication parameters in accordance with the communication environment, thereby enabling communication in real time in response to changes in the communication environment.

In addition, it is possible to realize high speed and stable communication at all times without being influenced by changes in the communication environment.

Here, the memory configuration of the radio tag shown in the following embodiment will be described with reference to FIG.

In Fig. 1, the memory mounted on the radio tag is largely composed of three areas.

The first is the "system area".

In the system area, H / W (Hardware) -specific information such as a maker number, a product type name, and a serial number of a wireless tag are stored. The capacity is tens to hundreds of bits.

The second is a "tag ID area".

In the tag ID area, a unique tag ID for identifying a wireless tag is stored, and its capacity is tens to hundreds of bits.

In the conventional RFID system, the area mainly read by the reader / writer is this tag ID area.

The third is the "user memory area".

The user memory area is an area that can be freely read / written by the user and has a capacity of several tens of kilos to hundreds of kilobits.

The user memory area is a large area compared to other areas, and is an area that increases the amount of communication.

The contents shown in the following examples are mainly assumed to have an effect in large-capacity communication during read / write access for the user memory area.

Next, the command format of the read command and the write command, which is used when performing read / write access from the reader / writer device for the wireless tag, will be described with reference to FIG. 2.

Fig. 2A shows an example of the format of the read command and Fig. 2B shows an example of the format of the write command.

As shown in Fig. 2A, the read command is composed of five parameters.

The first is a "command code", which is a code for identifying a read command.

The second is the "reader memory area", which shows which area of the three areas constituting the memory of the wireless tag is read.

The third is a "reader address", which indicates a head address at which reading starts in the read destination memory area designated by the "reader memory area".

The fourth is "read size", which indicates the data size to be read from the "read address".

Upon reception of the read command, the wireless tag reads data of the size specified by the "read size" from the memory and returns it to the reader / writer as a response to the read command.

Increasing the "reading size" can shorten the overall processing time. However, since the response length of the radio tag, which is a very weak radio wave, becomes long, the communication can be failed if the communication environment is poor.

Therefore, in the embodiment described below, when performing the read processing from the radio tag, the communication in which both high speed and high stability are achieved by optimizing the "read size" parameter according to the communication environment.

The fifth is "Cyclic Redundancy Check" (CRC), which is an error detection code for the entire command.

As shown in Fig. 2B, the write command is composed of six parameters.

The first is a "command code", which is a code for identifying a write command.

The second is a " recording destination memory area " which indicates which area of the three areas constituting the memory of the wireless tag is recorded.

The third is a "write destination address", which indicates a head address at which recording starts in the recording destination memory area designated by the "recording destination memory area".

The fourth is "recording size", which shows the data size to be recorded from the "recording address". When the radio tag receives the recording command, the radio tag receives the recording data of the size designated by the "recording size" from the reader / writer and records it in the memory.

Increasing the "recording size" can shorten the overall processing time. However, in a wireless tag operating at a very low power, the load on the reception process and the memory recording process increases, so if the communication environment is poor, the power shortage may occur. It is more likely that the process will fail.

Therefore, in the embodiment described below, when performing the recording process to the radio tag, the communication that achieves both high speed and high stability is realized by optimizing the "record size" parameter according to the communication environment.

Fifth is "recording data", which indicates recording data corresponding to the data length specified by "recording size".

Sixth is "CRC", which is an error detection code of the entire command.

Next, the relationship between the propagation intensity and the optimum value of the communication parameter will be described with reference to FIGS. 3 to 5.

3 shows instructions for setting the read data length according to the received radio wave strength.

Fig. 4 shows instructions for setting the recording data length according to the received radio wave strength.

5 shows instructions for setting an upper limit of the command retry count according to the received radio wave strength.

By lengthening the read / write data length in the communication parameters, the number of commands issued by the reader / writer can be reduced, and the overall processing time can be shortened.

Therefore, as shown in Figs. 3 and 4, when the radio wave strength is strong and the communication environment is estimated to be stable, that is, the communication success rate is high, the read / write data length is lengthened.

On the contrary, in the case where the radio wave strength is weak and the communication environment is estimated to be unstable, that is, the communication success rate is low, the read / write data length is shortened because the probability of communication failure increases if the read / write data length is long.

Next, the upper limit of the number of command retries among the communication parameters indicates the maximum number of consecutive retry processing for issuing the same command again when the command communication fails.

If it is estimated that the radio wave strength is strong and the communication environment is stable, the success rate of the communication is expected to be high, and the read / write data length is long and the overhead due to retry increases, so that the command retry is shown in FIG. Make the upper limit of number less.

On the contrary, when it is assumed that the radio wave strength is weak and the communication environment is unstable, the failure rate of the communication is expected to be high, and the read / write data length is short and the overhead due to retry is small, thereby increasing the upper limit of the command retry count. .

These can derive the optimum communication parameter according to a communication environment.

The following describes two embodiments in which the reader / writer for issuing a radio tag and a read / write command differs in a method of optimizing communication parameters.

(Example 1)

The reader / writer 1 according to the present embodiment measures the communication quality of the radio communication path with the radio tag 3 and optimizes the communication parameters.

Specifically, as described above, the communication parameters are optimized based on the received radio wave strength of the response wave from the radio tag.

Hereinafter, the system of the reader / writer according to the present embodiment will be described with reference to FIGS. 6, 7, and 8.

Fig. 6 shows the components of the reader / writer 1 and the control PC 4 in the present embodiment.

The reader / writer device 1 is an example of a wireless communication device, and the radio tag 3 is an example of a memory device.

In FIG. 6, the control PC interface unit 1a controls data transmission and reception with the control PC 4.

The transmission / reception control unit 1b controls data transmission and reception with the radio tag 3 in accordance with a request from the control PC 4.

The transmitter 1c modulates and transmits the command to the radio tag 3.

The reception unit 1d receives and demodulates a response from the radio tag 3.

The reception propagation intensity measuring unit 1e measures the reception propagation intensity of the response wave of the radio tag 3 received by the reception unit 1d.

The communication parameter adjusting unit 1g adjusts the communication parameter according to the radio wave strength measured by the reception radio wave intensity measuring unit 1e.

The communication parameter optimum value storage unit 1h stores the optimum value of the communication parameter corresponding to the received radio wave strength of the response wave from the radio tag 3.

As described above, in this embodiment, the received radio wave intensity of radio waves transmitted from the radio tag 3 is measured as the communication quality of the radio communication path with the radio tag 3, and the communication parameters are determined according to the received radio wave intensity. .

The received radio wave intensity measuring unit 1e is an example of the communication quality measuring unit, and the communication parameter adjusting unit 1g is an example of the communication parameter determining unit.

In addition, the antenna 2 is connected to the reader / writer 1 and performs wireless communication with the radio tag 3.

In addition, the radio tag 3 communicates with the reader / writer 1.

In addition, the control PC 4 controls the reader / writer 1 to cause communication with the wireless tag 3.

The reader / writer device control unit 4a controls the reader / writer device 1.

The reader / writer device interface unit 4b controls communication with the reader / writer device 1.

Next, Figs. 7 and 8 show the operation of the reader / writer device 1 which derives and sets the optimum value of the communication parameter from the communication parameter optimum value table based on the received radio wave strength of the response wave from the radio tag 3. Explain using

Fig. 7 is a communication parameter optimum value stored in the communication parameter optimum value storage unit 1h and describing an optimum communication parameter (read data length, record data length, upper limit of retry count) according to the radio wave strength of the radio tag response. Represents a table.

FIG. 8 is a flowchart showing a series of operations for reading / writing a large amount of data from the wireless tag 3 in which the reader / writer device 1 is equipped with a large amount of user memory in this embodiment.

8, a process flow for optimizing communication parameters in accordance with the received radio wave strength of the radio tag response and reading / writing a large amount of data will be described.

(1) Wireless tag read / write request step

First, the step of sending a read / write request to the radio tag 3 from the control PC 4 to the reader / writer device 1 will be described.

In step 101, a reader / writer request is sent to the reader / writer 1 from the reader / writer device control section 4a of the control PC 4 via the reader / writer device interface section 4b.

The reader / writer device 1 receives the radio tag read request via the control PC interface unit 1a and proceeds to step 102.

(2) wireless tag ID reading / propagation strength measurement step

Next, the step of reading the radio tag 3 by the reader / writer device 1 and measuring the radio wave strength of the response (Fig. 8 step 102) (communication quality measurement step) will be described.

In step 102, the reader / writer 1 transmits an ID read command to the radio tag 3 from the transmission / reception control unit 1b via the transmission unit 1c and the antenna 2.

If there is a response from the radio tag 3, the transmission / reception control unit 1b receives the ID via the antenna 2 and the reception unit 1d, and the radio wave tag measuring unit 1e receives the ID. The propagation intensity of the response wave is measured, and the flow proceeds to step 103.

(3) Communication parameter optimization step

Next, the step of optimizing communication parameters (Fig. 8 step 103) (communication parameter determining step) in accordance with the radio wave strength measured in step 102 will be described.

In step 103, the communication parameter adjusting unit 1g stores the optimum communication parameter according to the radio wave strength of the radio tag response measured in step 102 in the communication parameter optimum value storage unit 1h. Derived from the table, the reader / writer 1 is set, and the process proceeds to step 104.

(4) User Memory Read / Write Execution Step

Next, a step (steps 104-107) in which the reader / writer device 1 reads / writes the user memory of the radio tag 3 using the communication parameters optimized in step 103 will be described.

In step 104, the reader / writer apparatus 1 reads and writes the command of FIG. 2 to which the communication parameter (read size / write size) optimized in step 103 is transmitted from the transmission / reception control unit 1b to the transmitter 1c and the antenna 2. Is issued to the wireless tag 3 and proceeds to step 105.

In step 105, the response of the radio tag 3 to the read / write command is received by the transmission / reception control unit 1b via the antenna 2 and the reception unit 1d to determine whether the read / write process is successful, The radio wave strength of the radio tag response is measured by the radio wave strength measurement unit 1e. If the read / write process succeeds, the process proceeds to step 106; if the process fails, the process proceeds to step 107.

In step 106, the transmission / reception control unit 1b determines whether the read / write of the size requested from the control PC 4 is completed in step 101, and if so, determines that the read / write process is successful and proceeds to step 108. In the case of incomplete completion, the process proceeds to step 104.

In step 107, the transmission / reception control section 1b determines whether the number of times of retrying the read / write command when the read / write processing fails exceeds the communication parameter (upper limit of command retries) optimized in step 103. If the number is exceeded, it is determined that the read / write process is an error, and if not, the process proceeds to step 108.

(5) Execution result notification step

Next, the step of notifying the control PC 4 of the execution result of the read / write process for the radio tag 3 (Fig. 8, step 108) will be described.

In step 108, the transmission / reception control unit 1b of the reader / writer device 1 notifies the control PC 4 of the read / write processing result via the control PC interface unit 1a.

As described above, by measuring the radio wave strength each time a response is received from the radio tag and setting the optimum communication parameter according to the strength and weakness, the communication environment is always estimated in real time and is not influenced by the change in the communication environment. It is possible to realize high-speed and stable communication without the need.

As described above, in the present embodiment, an RFID system for performing non-contact communication between the wireless tag and the reader / writer device includes: a wireless tag equipped with a memory that can be accessed in response to a request from the reader / writer device; and a memory of the wireless tag. A possible reader / writer, the reader / writer, a radio wave strength measuring unit for measuring the radio wave strength at the time of receiving the response wave from the radio tag, and a response wave from the radio tag acquired by the radio wave strength measurement unit The RFID system having a communication parameter adjusting unit for deriving an optimal communication parameter based on the radio wave strength of the above has been described.

In addition, in the present embodiment, the reader / writer has described that the reader / writer has a communication parameter optimum value storage unit for holding the optimum value of the communication parameter according to the radio wave strength of the response wave from the radio tag.

In addition, in the present embodiment, the communication parameter optimum value storage section described that the data size of the read data to which the radio tag responds to the read request from the reader / writer is held as the communication parameter.

In addition, in the present embodiment, the communication parameter optimum value storing unit holds the data size of the recording data transmitted to the radio tag at the time of the recording request from the reader / writer as a communication parameter.

In addition, in the present embodiment, the communication parameter optimum value storing unit has described the number of command retries when the command request from the reader / writer device fails as the communication parameter.

(Example 2)

In the present embodiment, a method of optimizing communication parameters based on the received radio wave strength of the response wave from the radio tag and the number of failures of the read / write command will be described with reference to FIGS. 9, 10, and 11.

9 shows components of the reader / writer 1 and the control PC 4 in the present embodiment.

The difference with FIG. 6 of Example 1 is only the addition of the communication result analysis part 1f, and the change of the role of the communication parameter adjustment part 1g accompanying this.

In FIG. 9, the control PC interface unit 1a controls data transmission and reception with the control PC 4.

The transmission / reception control unit 1b controls data transmission and reception with the radio tag 3 in accordance with a request from the control PC 4.

The transmitter 1c modulates and transmits the command to the radio tag 3.

The reception unit 1d receives and demodulates a response from the radio tag 3.

The reception propagation intensity measuring unit 1e measures the reception propagation intensity of the response wave of the radio tag 3 received by the reception unit 1d.

The communication result analysis unit 1f counts the number of failures of the command sent to the radio tag 3.

The communication parameter adjusting unit 1g adjusts the communication parameters and the communication parameter optimum value storage unit according to the radio wave strength measured by the received radio wave intensity measuring unit 1e and the number of command failures counted by the communication result analyzing unit 1f. Correct the optimum value in 1h).

The communication parameter optimum value storage unit 1h stores the optimum value of the communication parameter corresponding to the received radio wave strength of the response wave from the radio tag 3.

In this embodiment, the communication result analyzing unit 1f and the communication parameter adjusting unit 1g are examples of the communication parameter determining unit, and the communication parameter optimum value storage unit 1h is an example of the communication parameter information storage unit.

The antenna 2 is an antenna that is connected to the reader / writer device 1 and performs wireless communication with the radio tag 3.

In addition, the radio tag 3 communicates with the reader / writer 1.

In addition, the control PC 4 controls the reader / writer 1 to cause communication with the wireless tag 3.

The reader / writer device control unit 4a controls the reader / writer device 1.

The reader / writer device interface unit 4b controls communication with the reader / writer device 1.

Next, based on the received radio wave strength of the response wave from the radio tag 3, the optimum value is derived and set from the communication parameter optimum value table, and the command to the radio tag 3 succeeds or fails in succession. The operation of the reader / writer for correcting the optimum value in the communication parameter optimum value table will be described with reference to FIGS. 10 and 11.

Fig. 10 is stored in the communication parameter optimum value storage unit 1h, and corrects the optimum communication parameters (read data length, recorded data length, upper retry count upper limit) according to the radio wave strength of the radio tag response, and corrects these optimum values. The communication parameter optimum value table (communication parameter information) is described in which the change condition (the upper limit of the number of consecutive communication failures, the upper limit of the number of consecutive communication failures) to be satisfied is described.

Fig. 11 is a flowchart showing a series of operations for reading / writing a large amount of data from the wireless tag 3 in which the reader / writer device is equipped with a large amount of user memory for this embodiment.

Hereinafter, a process flow for optimizing communication parameters according to the received radio wave strength of the radio tag response and reading / writing a large amount of data will be described with reference to FIG. 11.

201 to 205 in FIG. 11 and 101 to 105 in FIG. 8 in Example 1 are the same processes.

(1) Wireless tag read / write request step

First, a step (step 201 in FIG. 11) of sending a read / write request to the wireless tag from the control PC 4 to the reader / writer 1 will be described.

In step 201, a read / write request to the wireless tag 3 is sent to the reader / writer device 1 from the reader / writer device control unit 4a of the control PC 4 via the reader / writer device interface unit 4b. .

The reader / writer 1 receives the radio tag read request via the control PC interface unit 1a, and proceeds to step 202.

(2) wireless tag ID reading / propagation strength measurement step

Next, the step of reading the radio tag 3 by the reader / writer device 1 and measuring the radio wave strength of the response (Fig. 11 step 202) (communication quality measurement step) will be described.

In step 202, the reader / writer 1 transmits an ID read command to the radio tag 3 from the transmission / reception control unit 1b via the transmission unit 1c and the antenna 2. If there is a response from the radio tag 3, the transmission / reception control unit 1b receives the ID via the antenna 2 and the reception unit 1d, and the radio wave tag measuring unit 1e receives the ID. The propagation intensity of the response wave is measured, and the flow proceeds to step 203.

(3) Communication parameter optimization step

Next, a step of optimizing communication parameters (Fig. 11 step 203) (communication parameter determining step) according to the radio wave strength measured in step 202 will be described.

In step 203, the communication parameter adjusting unit 1g stores the optimum communication parameter according to the radio wave strength of the radio tag response measured in step 202 in the communication parameter optimum value storage unit 1h in FIG. It derives from a table, it sets to a reader / writer, and it progresses to step 204.

(4) User memory read / write execution step

Next, using the communication parameters optimized in step 203, the step in which the reader / writer 1 performs reading / writing to the user memory of the radio tag 3 (steps 204 to 206 in Fig. 11) will be described. .

In step 204, the reader / writer 1 receives the read / write command of FIG. 2 to which the communication parameters (read size / write size) optimized in step 203 are transmitted from the transmission / reception control unit 1b to the transmitter 1c and the antenna 2. Is issued to the wireless tag 3 and proceeds to step 205.

In step 205, the response of the radio tag 3 to the read / write command is received by the transmission / reception control unit 1b via the antenna 2 and the reception unit 1d to determine whether the read / write process is successful, and The radio wave strength of the radio tag response is measured by the radio wave strength measurement unit 1e. If the read / write process succeeds, the process proceeds to step 207, and if it fails, the process proceeds to step 206.

In step 206, the transmission / reception control unit 1b determines whether the number of times of retrying the read / write command when the read / write processing fails exceeds the communication parameter (upper limit of command retries) optimized in step 203. If the number is exceeded, it is determined that the read / write process is an error, and if not, the process proceeds to step 212.

(5) Communication parameter optimum value change condition check step 1

Next, when command communication with the radio tag 3 succeeds, a step (steps 207 to 208 of Fig. 11) (communication parameter determination step) of checking whether the optimum value of the communication parameter is changed will be described.

In step 207, when it is determined that the read / write process is successful in response to the response from the radio tag 3 in step 205, the communication result analyzing unit 1f determines the number of successive command communication successes in the currently applied communication parameters. It counts up and clears the command communication continuation failure count to zero. Subsequently, in the communication parameter optimum value table of FIG. 10 stored in the command communication continuation success count and the communication parameter optimum value storage unit 1h, an optimum value change condition corresponding to the communication parameter that is currently applied (communication succession success). Upper limit of the number of times) is compared. If the current number of command communication successes exceeds the optimum value change condition (the upper limit of the number of succession of communication successes), the process proceeds to step 208, and if not, the process proceeds to step 211.

In step 208, the communication result analysis unit 1f judges that the communication environment is stable when the number of command communication successive successes exceeds the optimum value change condition (the upper limit of the number of successive communication successes) in step 207, and the entire communication is performed. In order to shorten the time, the communication parameter adjusting unit 1g is used to increase the corresponding communication parameter optimum value (read data length or write data length) and proceed to step 211.

(6) Confirmation of communication parameter optimum value change condition Step 2

Next, when command communication with the radio tag 3 fails, a step (steps 209-210 of Fig. 11) (communication parameter determination step) of checking whether the optimum value of the communication parameter is changed will be described.

In step 209, when it is determined that the read / write process has failed in response to the response from the radio tag 3 in step 205, the communication result analyzing unit 1f determines the number of command communication sequential failures in the currently applied communication parameters. It counts up and clears the command communication consecutive success count to zero.

Subsequently, in the communication parameter optimum value table of FIG. 10 stored in the command communication continuation failure count and the communication parameter optimum value storage unit 1h, an optimum value change condition (communication continuation failure) corresponding to the communication parameter currently applied. Upper limit of the number of times). If the current number of command communication consecutive failures exceeds the optimum value change condition (the upper limit of the number of communication continuous failures), the process proceeds to step 210;

In step 210, the communication result analysis unit 1f determines that the communication environment is unstable when the number of command communication continuation failures exceeds the optimum value change condition (the upper limit of the number of communication continuation failures) in step 209, thereby improving communication stability. For this purpose, the corresponding communication parameter optimum value (read data length or write data length) is reduced via the communication parameter adjusting unit 1g, and the flow proceeds to step 203.

(7) Confirm all data read / write completion

Next, a step (step 211 in FIG. 11) for confirming whether all data reading / writing is completed will be described.

In step 211, it is determined whether the read / write of the size requested from the control PC 4 is completed in step 201, and when it is completed, it is determined that the read / write process is successful, and the procedure proceeds to step 212. Proceed to step 204.

(8) Execution result notification step

Next, the step of notifying the control PC 4 of the execution result of the read / write process for the radio tag 3 (step 1112 in FIG. 11) will be described.

In step 212, the transmission / reception control unit 1b of the reader / writer device 1 notifies the control PC 4 of the read / write processing result via the control PC interface unit 1a.

As described above, by measuring the radio wave strength each time a response is received from the radio tag and setting the optimum communication parameter according to the strength and weakness, the communication environment is always estimated in real time and is not influenced by the change in the communication environment. It is possible to realize high-speed and stable communication without the need.

Further, by considering the number of successes and the number of failures of the command communication, the optimum value of the communication parameter itself can also keep the value appropriate for the change in the communication environment, thereby improving the adaptability to the communication environment.

In the above embodiment, the reader / writer has described that the reader / writer has a communication result analyzing unit which analyzes the number of times the command request from the reader / writer has succeeded and reflects it in the optimum value of the communication parameter.

In addition, in the present embodiment, the reader / writer has explained that the reader / writer has a communication result analyzing unit which analyzes the number of times a command request from the reader / writer has failed and reflects it in the optimum value of the communication parameter.

Finally, a hardware configuration example of the reader / writer 1 shown in the first and second embodiments will be described.

Fig. 12 is a diagram showing an example of hardware resources of the reader / writer 1 shown in the first and second embodiments. In addition, the structure of FIG. 12 shows an example of the hardware structure of the reader / writer device 1 to the last, and the hardware structure of the reader / writer device 1 is not limited to the structure of FIG. 12, and may be another structure. .

In FIG. 12, the reader / writer 1 includes a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, a computing unit, a microprocessor, a microcomputer, and a processor) that executes a program. have. The CPU 911 is connected to, for example, a read only memory (ROM) 913, a random access memory (RAM) 914, a communication board 915, and a magnetic disk device 920 via a bus 912. To control these hardware devices. Instead of the magnetic disk device 920, a storage device such as a flash memory, an optical disk device, a memory card read / write device, or the like may be used.

RAM 914 is an example of volatile memory. Storage media such as the ROM 913 and the magnetic disk device 920 are examples of nonvolatile memories. These are examples of storage devices.

The communication board 915 is an example of an input device or an output device.

As shown in FIG. 6 and FIG. 9, the communication board 915 can perform wireless communication with the radio tag 3 via the antenna 2. It is also connected to the control PC. In addition, the communication board 915 may be connected to a network such as a local area network (LAN), a wide area network (WAN), or the Internet.

In the magnetic disk device 920, an operating system 921 (OS), a window system 922, a program group 923, and a file group 924 are stored. Programs in the program group 923 are executed by the CPU 911, the operating system 921, and the window system 922.

In the program group 923, a program for executing a function described as "~ part" in the description of the first and second embodiments is stored. The program is read and executed by the CPU 911.

The file group 924 is a process described as "determination of", "calculation of", "compare of", "detection of", "control of ...", and the like in the following description. Information, data, signal values, variable values, and parameters indicating the result of the data are stored as respective items of the "file" or the "database." "-File" and "-database" are stored in a recording medium such as a disk or a memory. Information, data, signal values, variable values, and parameters stored in a storage medium such as a disk or a memory are read out to a main memory or a cache memory by the CPU 911 via a read / write circuit, and are extracted, searched, referenced, compared, and calculated. Used for CPU operation such as calculation, processing, editing, output, printing, and display. During CPU operation of extraction, search, reference, comparison, operation, calculation, processing, editing, output, printing, and display, information, data, signal values, variable values, and parameters are temporarily stored in main memory, registers, cache memory, buffer memory, etc. I remember.

In addition, the part of the arrow of the flowchart demonstrated below mainly shows the input / output of data or a signal, and a data or signal value is a memory of RAM 914, the magnetic disk of the magnetic disk apparatus 920, the other flexible disk, the compact disk, It is recorded on recording media such as an optical disc, a mini disc, and a DVD. Data or signals are transmitted online by the bus 912, signal lines, cables or other transmission media.

In addition, in the description of the first and second embodiments, the descriptions of "parts" may be "circuits", "devices", "devices", "means", and "steps". , "Order", "processing" may be sufficient. In other words, what is described as "~ part" may be implemented by the firmware stored in the ROM 913. Alternatively, the software may be implemented only by hardware such as an element, a device, a substrate, and a wiring, or a combination of software and hardware, or a combination of firmware. The firmware and software are stored in recording media such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD as a program. The program is read by the CPU 911 and executed by the CPU 911. That is, the program causes the computer to function as "~ part" of the first and second embodiments. Alternatively, the computer executes the procedures and methods of the "parts" of the first and second embodiments.

As described above, the reader / writer 1 shown in the first and second embodiments is a computer including a communication board such as an input device and an output device, such as a CPU as a processing device, a memory as a storage device, a magnetic disk, and the like. As shown, the functions shown as "parts" are realized using these processing units, storage units, input units, and output units.

1 is a diagram showing an example of a memory configuration of a radio tag according to the first and second embodiments;

2 is a diagram showing examples of a read command format and a write command format according to the first and second embodiments;

3 is a diagram showing an example of setting guidelines of the read data length according to the received radio wave strength according to the first and second embodiments;

4 is a diagram showing an example of setting guidelines for recording data length according to received radio wave strength according to Embodiments 1 and 2;

FIG. 5 is a diagram showing an example of setting guidelines for the upper limit of the number of command retries based on the reception radio wave strength according to the first and second embodiments; FIG.

6 is a view showing a system configuration example including a reader / writer device according to the first embodiment;

7 is a diagram showing an example of a communication parameter optimum value table according to the first embodiment;

8 is a flowchart illustrating an operation example of a reader / writer device according to the first embodiment;

9 is a view showing a system configuration example including a reader / writer device according to the second embodiment;

10 is a diagram showing an example of a communication parameter optimum value table according to the second embodiment;

11 is a flowchart showing an operation example of a reader / writer device according to the second embodiment;

12 is a diagram showing a hardware configuration example of a reader / writer device according to the first and second embodiments.

Explanation of the sign

1: Reader / Writer Device 1a: Control PC Interface

1b: transmission and reception control unit 1c: transmission unit

1d: receiving unit 1e: receiving wave strength measuring unit

1f: communication result analyzing unit 1g: communication parameter adjusting unit

1h: communication parameter optimum value storage unit 2: antenna

3: wireless tag 4: control PC

4a: reader / writer device control unit 4b: reader / writer device interface unit

Claims (13)

A wireless communication device performing wireless communication with a memory device having a wireless communication function, A communication quality measuring unit measuring a communication quality of a wireless communication path with the memory device; A communication parameter determining unit that determines a communication parameter when wirelessly communicating with the memory device according to the communication quality measured by the communication quality measuring unit Wireless communication device having a. The method of claim 1, The communication quality measuring unit measures the received radio wave strength of the radio wave transmitted from the memory device, The communication parameter determining unit determines the communication parameter according to the received radio wave strength measured by the communication quality measuring unit. A wireless communication device, characterized in that. The method according to claim 1 or 2, And the communication parameter determining unit determines a data length of communication data performing wireless communication with the memory device as the communication parameter according to the communication quality measured by the communication quality measuring unit. The method of claim 3, wherein The communication parameter determining unit increases the data length of the communication data as the communication quality measured by the communication quality measuring unit is higher. The method of claim 1, The communication parameter determining unit determines, according to the communication quality measured by the communication quality measuring unit, the upper limit value of the number of communication retries when wireless communication with the memory device fails as the communication parameter. Wireless communication device. The method of claim 5, wherein The communication parameter determining unit reduces the upper limit of the number of communication retry attempts as the communication quality measured by the communication quality measuring unit is higher. The method of claim 1, The wireless communication apparatus further has a communication parameter information storage unit for storing communication parameter information in which the communication quality level is displayed in a plurality of steps and the communication parameter and the condition for changing the communication parameter are displayed for each communication quality level, The communication parameter determining unit extracts, from the communication parameter information, a communication parameter of a communication quality level corresponding to the communication quality measured by the communication quality measuring unit and a condition for changing the communication parameter, and the current state is determined by the extracted condition. Determining whether or not a match is made, and using a communication parameter other than the extracted communication parameter when the current state matches the change condition. A wireless communication device, characterized in that. The method of claim 7, wherein The communication parameter information storage unit stores communication parameter information indicating the number of consecutive successes of wireless communication as a condition for changing the communication parameter, The communication parameter determining unit counts the number of successive successes in wireless communication with the memory device, determines whether the counted count is equal to or greater than the successive success count indicated by the extracted change condition, and the counted count is the successive count. In the above case, using the communication parameter corresponding to the communication quality level higher than the communication quality level corresponding to the extracted communication parameter. A wireless communication device, characterized in that. The method according to claim 7 or 8, The communication parameter information storage unit stores communication parameter information indicating the number of consecutive failures of wireless communication as a condition for changing the communication parameter, The communication parameter determining unit counts the number of consecutive failures in wireless communication with the memory device, determines whether the counted number is equal to or greater than the consecutive failure number indicated in the extracted change condition, and the counted number is equal to or greater than the continuous failure number. In the case of using a communication parameter corresponding to a communication quality level lower than the communication quality level corresponding to the extracted communication parameter. A wireless communication device, characterized in that. The method of claim 1, The wireless communication device receives the read data read from the wireless tag device from the wireless tag device by wireless communication, The communication parameter determining unit determines the data length of the read data as the communication parameter according to the communication quality measured by the communication quality measuring unit. A wireless communication device, characterized in that. The method of claim 1, The wireless communication apparatus transmits recording data recorded in the wireless tag apparatus to the wireless tag apparatus by wireless communication, The communication parameter determining unit determines the data length of the recording data as the communication parameter according to the communication quality measured by the communication quality measuring unit. A wireless communication device, characterized in that. A communication quality measuring step of measuring a communication quality of a wireless communication path with the memory device by a computer performing wireless communication with a memory device having a wireless communication function; A communication parameter determining step of determining, by the computer, a communication parameter when wirelessly communicating with the memory device according to the communication quality measured by the communication quality measuring step Wireless communication method having a. In a computer performing wireless communication with a memory device having a wireless communication function, A communication quality measurement process of measuring a communication quality of a wireless communication path with the memory device; To execute communication parameter determination processing for determining communication parameters when performing wireless communication with the memory device in accordance with the communication quality measured by the communication quality measurement processing. A storage medium for storing a program, characterized in that.

Images