JP2008104000A - Active radio tag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that communication can not be performed because active radio tags are in close contact with each other to mutually cause radio interference. <P>SOLUTION: A WPAN (wireless personal area network) module 1 can transmit and receive a radio wave of a different frequency to/from another active radio tag and a base station. An RFID module 3 exchanges memory data with a RFID handy terminal or the like. A memory module 2 stores ID information of an object with this active radio tag attached and exchanges data with the WPAN module and the RFID module. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an active wireless tag attached to an object in logistics, warehouse, incoming inspection, or the like.

  Conventionally, in order to detect the presence position of an object, a recognition number is input to a communication tag attached to the object in advance, and a searcher holds a portable wireless device that transmits a signal radio wave corresponding to the recognition number, and places the object. When a round of the area is completed, a communication tag within the reach of the radio wave is detected, and only the communication tag that matches the identification number emits sound and light so that the target object can be found. A technique is known (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2003-023385 (page 3, FIG. 1)

  However, in the above-described conventional technology, when a plurality of communication tags are concentrated and gathered at a specific location, the radio frequencies used are the same, so when each attempts to communicate with the base station, There is a problem in that interference occurs and communication cannot be performed efficiently.

  Accordingly, an object of the present invention is to provide an active wireless tag that can reliably transmit and receive individual communication tag information without causing radio wave interference even when a plurality of communication tags are concentrated in a specific place.

  The active wireless tag of the present invention includes a WPAN module that can transmit and receive radio waves of different frequencies with other active wireless tags and base stations, and an RFID module that exchanges memory data with an RFID handy terminal, etc. The present invention is characterized by comprising a memory module that stores ID information of an object to which the active wireless tag is attached, and exchanges data between the WPAN module and the RFID module.

  According to the present invention, ID information or user information for identifying an object is transmitted from an active wireless tag using WPAN (IEEE-802.15.4 compliant), using radio waves of different frequencies. It eliminates radio wave interference between active wireless tags, and even if a plurality of objects are concentrated at a specific location, the object can be reliably recognized and searched.

  Next, embodiments of the present invention will be described with reference to the drawings. Referring to FIG. 1, a basic configuration of an active wireless tag as an embodiment of the present invention is shown. This active wireless tag includes a WPAN (Wireless Personal Area Network) module 1, a memory module 2, and an RFID (Radio Frequency Identification) module 3.

  The WPAN module 1 includes an antenna 11, a WPAN chip 12, and an oscillator 13. The WPAN module 1 is a wireless module that is supplied with power from the memory module 2 and can transmit and receive radio waves with other active wireless tags and base stations. This radio wave is generated based on a signal generated by the oscillator 13, and the frequency can be different for each WPAN module 1. As a result, even when a plurality of active wireless tags are concentrated and gathered in a specific place, an object with the active wireless tag can be easily identified.

  The WPAN chip 12 modulates data from the memory module 2 with radio waves and transmits it from the antenna 11, and demodulates data from the radio waves received from the antenna 11 and sends it to the memory module 2. As the WPAN communication method, it is desirable to adopt a tree type or a mesh type among wireless communication technologies compliant with the specification (ZigBee) established in IEEE-802.15.4.

  The memory module 2 includes a memory 21, a control CPU 22, and a battery 23. The memory module 2 exchanges data with the WPAN module 1 and the RFID module 3, and supplies power to the WPAN module 1 and the RFID module 3. The memory 21 stores user information arbitrarily set by the user in addition to the ID information of the object to which the active wireless tag is attached.

  The memory 21 is divided into a system area and a user area, and ID information unique to an object is generally written in the system area at the time of factory shipment, but can be changed by a system administrator as necessary. The user area can be rewritten to arbitrary data (user information) by a general user. The control CPU 22 performs control for exchanging data stored in the memory 21 with the WPAN module 1 or the RFID module 3. The battery 23 is a power source for supplying power to the WPAN module 1 and the RFID module 3.

  The RFID module 3 includes an antenna 31 and an RF circuit 32, and exchanges memory data between the memory module 2 and an RFID handy terminal (not shown). The antenna 31 transmits and receives radio waves to and from an RFID handy terminal and the like, and the RF circuit 32 modulates and demodulates memory data. The frequency of this radio wave is different from the frequency of the radio wave in the WPAN module 1, thereby avoiding interference.

  When attempting to search for an object using this active wireless tag, ID information or user information unique to the object is written in the object to be searched. Normally, ID information is transmitted from an active wireless tag, and user information can be oscillated by radio waves as necessary. A searcher carries a base station antenna and goes around the object. The base station antenna receives the radio wave and decodes the ID information or the user information, thereby finding an object to be searched.

  FIG. 2 is a diagram illustrating a communication state by the active wireless tag. Here, a state where the active wireless tags A, B, C, D, and E transmit data from the terminal active wireless tag A to the base station F while relaying adjacent neighbors is shown. The WPAN modules 1 of the active wireless tags B, C, D, and E on the way function as repeaters. The active wireless tag B indicates that two adjacent active wireless tags B and C can be used as communication routes.

  The radio wave intensity of the active radio tag is determined to be below a certain level by the Radio Law, and the active radio tag may exist at a distance away from the base station. However, even in such a case, wireless communication can be performed by the adjacent wireless tags complementing each other even in a situation where direct wireless communication is not possible due to the cooperative technology of the WPAN module described above. . As a result, the number of base stations can be minimized, and the system scale and cost can be reduced. Further, even if the communication between the active wireless tags B and D is interrupted, the communication can be continued by the presence of the active wireless tag C.

  If it is not necessary to read and write individual tag data by the handy terminal, all of these functions can be included in the protocol for WPAN communication. In that case, the RFID module 3 is not required, the cost of the tag is reduced, and it is possible to construct the system at a lower cost. However, we believe that it will be necessary to install security functions so that tags cannot be freely tampered with remotely.

  As an example of use of the present invention, in logistics, warehouse, receipt / shipment inspection, if it is desired to manage the position, movement, and history management of the product in real time, and the inventory work of these products can be made efficient, the inventory quantity Reduction, production and distribution costs.

The figure which shows the basic composition of the active wireless tag of this invention The figure which illustrates the communication state by an active wireless tag

Explanation of symbols

1 WPAN module 2 Memory module 3 RFID module
11, 31 antenna
12 WPAN chip
13 Oscillator
21 memory
22 Control CPU
23 batteries
32 RF circuit

Claims (3)

WPAN module that can send and receive radio waves of different frequencies with other active wireless tags and base stations,
An RFID module for transferring memory data to and from an RFID handy terminal,
An active wireless tag, comprising: a memory module that stores ID information of an object to which the active wireless tag is attached, and exchanges data between the WPAN module and the RFID module.   2. The active wireless tag according to claim 1, wherein the WPAN module and the RFID module have different frequencies of transmitted radio waves. The active wireless tag according to claim 1 or 2, wherein the memory module stores user information arbitrarily set by a user in addition to the ID information.

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