Patent Application
20120112889
The present invention relates to a data transmission method capable of sensing and correcting an error for high-speed download of large RFID tag memory data.
Since most RFID tags are fabricated to create a low-price tag, the capacity of a memory in the RFID tag is very small or there was no memory. However, while a memory semiconductor technology has been rapidly developed, the price of the memory has been reduced, and a demand for the RFID tag having the mass memory has been generated in an industry in recent years, an RFID tag has been being released, which is capable of accommodating the memory capacity equal to approximately 500 times larger than the existing RFID tag.
However, since most of RFID wireless communication protocols were designed based on the existing memory lease tag or a low-capacity memory, an RFID reader should access the memory of the RFID tag at the minimum 65 times or the maximum 16384 times in order for an RFID reader to receive tag data of approximately 32 Kbyte from the RFID tag by using the existing communication protocol (alternately, transmit the tag data to the RFID tag). At this time, the maximum number of bits of the tag data of which the RFID reader can access the memory of the RFID tag once is limited according to a BER.
Further, when an error occurs while the RFID reader receives the tag data from the RFID tag (alternately, transmits the tag data to the RFID tag), mass data should be all retransmitted. Therefore, a time delay is generated and data transmission efficiency is deteriorated.
In addition, when competition with another RFID reader is generated, a large amount of time may be required for each of the RFID readers to access all stored data.
Next, the structure for a Read/Write Mandatory command and a BlockWrite Optional command for accessing the tag memory in a passive RFID technology of the international standard UHF band is shown.
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The known RFID reader can read only data of the maximum 255 words (1 word equal to 2 bytes (16 bits), that is, 4080 bits (510 bytes) at one-time access and when the amount of data is 4080 bits or more, a read command should be continuously transmitted in order to continuously access the data. Even in the case of the ‘Write’ command, the RFID tag may be stored in the tag memory per unit of 16 bits, that is, 2 bytes at one time. Data with the minimum of 72 bits to the maximum of 4138 bits (510 bytes) may be recorded in the tag memory at one time by the BlockWrite command.
Meanwhile, according to a general UHF-band RFID wireless transmission/reception method, the RFID tag passively transmits a Response to a Request, a command of the RFID reader and senses generation of an error of a command message generated during transmission and reception by a CRC code added in the last part of all command frames. If the error is sensed in the command of the RFID reader, the RFID tag discards the received command.
Further, in order for the RFID reader to read the data of the tag memory, the tag should maintain an “Open” or “Secure” state. The RFID reader continuously transmits the Read command in order to read a large amount of data and the tag transmits the Response message to the Read command. In the case in which the RFID reader is in plural, when a Query is received from another RFID reader between successive Read commands received from any one RFID reader, the state of the tag is again changed to a “Ready” state from the “Open” or “Secure” state. Therefore, the RFID reader suffers from difficulties in requiring enormous tag memory accesses and time in order to read massive tag memory data.
In order to solve the above-problems, an object of the present invention is to provide an RFID reader, an RFID tag, an operation method of the RFID reader, and an operation method of the RFID tag capable of downloading massive tag data at high speed.
The object of the present invention is not limited to the above-mentioned object and other undescribed objects will be apparently appreciated by those skilled in the art from the following descriptions.
In order to achieve the above object, an operation method of an RFID tag according to an aspect of the present invention includes: storing tag data in a user memory bank per unit of a plurality of record blocks having sizes smaller than the memory bank; receiving a download command including an index indicating any one of the plurality of record blocks from an RFID reader; and transmitting the tag data stored in up to all record blocks in the memory bank from the record block having the index.
In order to achieve the above object, an operation method of an RFID reader according to another aspect of the present invention includes: transmitting a download command including an index indicating any one of a plurality of record blocks having sizes smaller than a user memory, which are included in the user memory bank of an RFID tag; and receiving tag data stored in all record blocks having indexes in the user memory bank from a record block having the indicated index from the RFID tag per unit of the record block.
In order to achieve the above object, an RFID tag according to yet another aspect of the present invention includes: a memory unit including a memory bank, which is divided into a plurality of record blocks having sizes smaller than the memory bank and storing tag data; and a transmitting unit transmitting the tag data per unit of the record block in response to a download command of an RFID reader.
In order to achieve the above object, an RFID reader according to still another aspect of the present invention includes: a transmitting unit transmitting a download command for directing downloading tag data stored in a user memory bank of an RFID tag; and a receiving unit receiving the tag data from the RFID tag per unit of a plurality of record blocks having sizes smaller than the memory bank.
Details of other embodiments are disclosed in detail in the detailed description and the accompanying drawings.
Tag data can be successively read with continuous reading of the tag data by intervening of an adjacent RFID reader even under an environment where a plurality of RFID readers are present and as a result, massive tag data can be effectively downloaded.
Advantages and characteristics of the present invention, and methods for achieving them will be apparent with reference to embodiments described below in detail in addition to the accompanying drawings. However, the present invention is not limited to the exemplary embodiments to be described below but may be implemented in various forms. Therefore, the exemplary embodiments are provided to enable those skilled in the art to thoroughly understand the teaching of the present invention and to completely inform the scope of the present invention and the exemplary embodiment is just defined by the scope of the appended claims. Meanwhile, terms used in the specification are used to explain the embodiments and not to limit the present invention. In the specification, a singular type may also be used as a plural type unless stated specifically. “comprises” and/or “comprising” used the specification mentioned constituent members, steps, operations and/or elements do not exclude the existence or addition of one or more other components, steps, operations and/or elements.
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings and components having the same configuration and function refer to the same reference numeral.
Referring to
Referring to
Specifically, when the RFID reader 200_1 transmits the download command to the RFID tag 100, the RFID tag 100 transmits the tag data stored in the memory bank 122 per unit of the record blocks RB1 to RBn having the size smaller than the memory bank 122. That is, after the RFID tag 100 stores the tag data in the memory bank 122 per unit of the record blocks RB1 to RBn, the RFID tag 100 transmits the tag data per unit of the record blocks RB1 to RBn in response to the download command of the first RFID reader 200_1.
For example, the plurality of record blocks RB1 to RBn may be sequentially indexed in the memory bank 122 and the download command transmitted by the RFID reader 200_1 may include an index indicating any one of the plurality of record blocks RB1 to RBn in the memory bank 122. In this case, the RFID tag 100 may transmit the tag data store in all record blocks in the memory bank 122, which have the indexes from a record block having the index included in the transmitted download command, in response to the download command. Herein, the indexes may be memory addresses of the record blocks RB1 to RBn or newly attached identifiers other than the memory addresses.
The operation methods will be described by giving a more detailed example. The tag data in the memory bank 122 are separately stored in the first record block RB1 to the n-th record block RBn and the record blocks RB1 to RBn may be indexed by 1 to n. In addition, when the first RFID reader 200_1 transmits the download command including index 2, the RFID tag 100 may transmit the tag data stored in up to the n-th record block RBn having the subsequent index from the second record block RB2 having the index 2. That is, the RFID tag 100 transmits the tag data stored in n−1 record blocks RB2 to RBn from the index 2 included in the download command among n record blocks RB1 to RBn.
As such, through one-time download command of the first RFID reader 200_1, the RFID tag 100 may transmit the massive tag data. Since the first RFID reader 200_1 may receive the massive tag data through one-time download command, the first RFID reader 200_1 needs not to transmit a plurality of successive Read commands in order to receive the massive tag data.
Further, the first RFID reader 200_1 may not react to a Query of the second RFID reader 200_2 before the RFID tag completes the transmission in response to the download command of the first RFID reader 200_1. That is, by receiving the Query of the second RFID reader 200_2 between the successive Read commands of the first RFID reader 200_1, the state of the RFID tag 100 may not be changed from an “Open” state or “Secure” state to a “Ready” state again. Therefore, it is possible to solve the known problem in that the first RFID reader 200_1 requires numerous tag memory accesses and a large amount of time in order to read the massive tag data.
Unlike the above-mentioned example, the download command may include several indexes and in this case, the RFID tag 100 may transmit the record blocks RB1 to RBn having several indexes in the download command. For example, the indexes of several record blocks which the first RFID reader 200_1 desires to receive may be included in the download command. Alternately, the index of the first record block and the index of the last record block among the record blocks which the first RFID reader 200_1 desires to receive may be included in the download command.
Meanwhile, the first RFID reader 200_1 may perform error detection for each of the plurality of record blocks RB1 to RBn transmitted from the RFID tag 100. In this case, the first RFID reader 200_1 may request retransmission for a record block determined as a transmission error. The RFID tag 100 may retransmit only the record block requested to be retransmitted. When the first RFID reader 200_1 requests retransmission for several record blocks and the RFID tag 100 retransmits several record blocks requested to be retransmitted, the first RFID reader 200_1 and the RFID tag 100 may use the indexes assigned to the record blocks RB1 to RBn.
Further, the first RFID reader 200_1 may format and initialize the memory bank 122 by transmitting a clear command.
Hereinafter, detailed embodiments of the present invention will be described with reference to
First, referring to
For example, the memory unit 120 includes the user memory bank 122 storing the tag data which is the data on the object attached with the tag 101 and/or in the vicinity of the object, an EPC memory bank 124 identifying the object attached with the RFID tag 101, a TID memory bank 126 storing an ID for identifying the RFID tag 101, and a reserved memory bank 128. Herein, the user memory bank 122 may be configured, for example, as shown in
When the structure of the user memory bank 122 will be described in detail with reference to
Meanwhile, the plurality of record blocks RB1 to RBn may be indexed in sequence. Alternately, an identifier or an index may be granted so as to identify each of the record blocks RB1 to RBn. Each of the record blocks RB1 to RBn may include an index area storing the indexes and a record area storing the tag data. Further, each of the record blocks RB1 to RBn may further include an error code area storing an error detection code for checking the transmission error in order for the RFID reader 201 to perform the error detection for each of the received record blocks RB1 to RBn.
Hereinafter, further referring to
First, the RFID tag 101 stores the tag data in the user memory bank 122 per unit of the plurality of record blocks (S610). For example, the RFID tag 101 may dividedly store the tag data in four record blocks RB1 to RB4 of the user memory bank 122 (n=4 in
The first transmitting unit 210 of the RFID reader 201 transmits the download command (S710). Herein, the download command may include an index indicating any one of the plurality of record blocks RB1 to RBn. For example, the download command may have a structure shown in Table 1.
Herein, “Command” of 8 bits defines a command type and for example, the download command may be 11001001. “MemBank” of 2 bits indicates any one of four memory banks 122, 124, 126, and 128 in the memory unit 120 of
The RFID tag 101 receives a download command including, for example, index 1 (S620) and the second transmitting unit 110 may transmit up to all record blocks RB2 to RB4 from the first record block RB1 having index 1, that is, the first to fourth record blocks RB1 to RB4 per unit of the record block (S630). Specifically, the second transmitting unit 110 configures and transmits a response message to the RFID reader 201 so as to transmit the tag data stored in all the record blocks RB2 to RB4 in the memory bank from the record block RB1 having index 1 to the RFID reader 201. For example, as shown in
Meanwhile, the receiving unit 220 receives the tag data per unit of the record block (S720).
In addition, the checking unit 230 may check the transmission error for each of the received record blocks RB1 to RB4 (S730). That is, the checking unit 230 may judge whether or not an error is present using the error code area included in each of the record blocks RB1 to RB4 (S740). In addition, the checking unit 230 may request retransmission for record blocks determined as the transmission error (S750).
In requesting the retransmission, the second transmitting unit 110 may retransmit the record blocks requested to be retransmitted (S640).
A detailed example will be described with reference to
In addition, the receiving unit 220 judges whether or not to receive the error detection blocks for all the record blocks RB1 to RB4 (S760) and if the receiving unit 220 receives the error detection blocks, the receiving unit 220 checks an error for all the received first to fourth blocks RB1 to RB4 by using the received error detection blocks (S770). Meanwhile, if the receiving unit 220 does not receive the error detection blocks for all the record blocks RB1 to RB4, the record blocks RB1 to RB4 are continuously transmitted. Therefore, the receiving unit 220 receives the tag data per unit of the record block (S720).
Next, the RFID reader 201 downloads all tag data and thereafter, transmits the clear command so as to format and initialize the user memory bank 122. Herein, the structure of the clear command may be shown in Table 3 below.
In addition, the RFID tag 101 transmits a Response message shown in Table 4 below in response to the clear command, and may format and initialize the user memory bank 122.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2009-0067866 | Jul 2009 | KR | national |
| 10-2010-0034842 | Apr 2010 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR2010/004853 | 7/23/2010 | WO | 00 | 1/11/2012 |
