ACTIVE TAG APPARATUS, COMMUNICATION APPARATUS AND SYSTEM

• US 20100176930A1
• Filed: 12/22/2009
• Published: 07/15/2010
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yamada, Isamu, Shiotsu, Shinichi, Yamashita, Daisuke, Tanaka, Hideki, Inano, Satoshi
• Granted Patent: US 8,558,671 B2
• Time in Patent Office: Days
• US Class Current: 340/10.400
• CPC Class Codes: G06K 7/10475 arrangements to facilitate interaction with further interrogation devices, e.g. such that at least two interrogation devices may function and cooperate in a network of such devices
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication apparatus and an active tag apparatus that conduct radio communication with for data transmission and reception by radio with each other are provided. A frequency designation data including local transmission frequency used for data transmission and specifying data on a frequency of a carrier sense to be carried by the active tag apparatus is provided. A controller commands the active tag apparatus to use the frequency designation data for radio communication.

Claims

1. A communication apparatus capable of radio communication with an active tag apparatus capable of data transmission and reception by radio, comprising:

a radio communication unit that conducts radio communication with the active tag apparatus;

a data storage unit that stores a frequency designation data including a local transmission frequency used for data transmission by the radio communication unit and specifying data on a frequency of a carrier sense to be carried out by the active tag apparatus; and

a control unit that causes the radio communication unit to transmit the frequency designation data stored in the data storage unit to the active tag apparatus at the local transmission frequency.

2. The communication apparatus according to claim 1,

wherein the control unit causes the radio communication unit to carry out the carrier sense at a plurality of given frequencies, and stores the detected carrier frequency data in the data storage unit.

3. An active tag apparatus capable of radio communication with a communication apparatus, comprising:

a radio communication unit capable of carrying out carrier sense at a plurality of frequencies and adapted to transmit and receive data at a specified radio frequency to and from the communication apparatus; and

a control unit which, upon detection that the data received from the communication apparatus by the radio communication unit contains a frequency designation data specifying a frequency for the carrier sense to be carried out, designates to the radio communication unit, based on the received frequency designation data, the frequency for the carrier sense to be carried out.

4. A system comprising an active tag apparatus capable of data transmission and reception by radio and a communication apparatus for conducting radio communication with the active tag apparatus;

wherein the communication apparatus includes;

a radio communication unit that conducts the radio communication with the active tag apparatus;

a data storage unit that stores a frequency designation data including a local transmission frequency used by the radio communication unit at a time of data transmission and specifying data on a frequency for carrier sense to be carried out by the active tag apparatus; and

a control unit for causing the radio communication unit to transmit the frequency designation data stored in the data storage unit to the active tag apparatus at the local transmission frequency; and

wherein the active tag apparatus includes;

a radio communication unit capable of carrying out the carrier sense at a plurality of frequencies and conducting data transmission and reception at a specified frequency by radio with the communication apparatus; and

a control unit which, upon detection that the data received from the communication apparatus by the radio communication unit contains a frequency designation data specifying data on a frequency for the carrier sense to be carried out, designates to the radio communication unit the frequency for the carrier sense to be carried out, based on the received frequency designation data.

5. An active tag apparatus capable of radio communication with a communication apparatus, comprising:

a radio communication unit capable of carrying out carrier sense at a plurality of frequencies and measuring a reception strength of a received radio wave to transmit and receive data at a specified radio frequency to and from the communication apparatus;

a data storage unit that stores, in correspondence with each other, a maximum reception strength frequency and a designated frequency specifying a frequency for the carrier sense to be carried out; and

a control unit that

causes the radio communication unit to carry out the carrier sense at the plurality of frequencies,

receives a result of measuring the reception strength for each of the plurality of frequencies,

specifies a particular frequency from among the plurality of frequencies as the maximum reception strength frequency from the measurement result,

reads the designated frequency corresponding to the particular frequency from the data storage unit and

causes the radio communication unit to carry out the carrier sense at the designated frequency.

6. A computer program product stored on a tangible computer-readable medium for a communication apparatus capable of conducting radio communication with an active tag apparatus capable of data transmission and reception by radio, the computer program product comprising computer executable instructions that causes a computer of the communication apparatus to execute:

reading frequency designation data from a data storage unit storing a frequency designation data including a local transmission frequency used for data transmission by radio communication and specifying data on a frequency for carrier sense to be carried out by the active tag apparatus; and

causing transmission by radio communication of the read frequency designation data at the local transmission frequency to the active tag apparatus.

7. A computer program product stored on a tangible computer-readable medium for an active tag apparatus having a radio communication unit adapted to carry out carrier sense at a plurality of frequencies and transmit and receive data to and from a-communication apparatus at a specified radio frequency, the computer program product comprising computer executable instructions that causes a computer functioning as the active tag apparatus to execute:

judging whether the data received by the radio communication unit from the data read-write apparatus contains frequency designation data specifying data on a frequency for the carrier sense to be carried out; and

upon judgment that the frequency designation data is so contained, designating to the radio communication unit a frequency for the carrier sense to be carried out, based on the received frequency designation data.

8. A computer program product stored on a tangible-readable medium for an active tag apparatus including a radio communication unit adapted to carry out carrier sense at a plurality of frequencies while at a same time measuring a reception strength of received radio wave to transmit and receive data to and from a communication apparatus at a specified radio frequency, and a reception strength measurement unit for measuring the reception strength of the received radio wave from output of the radio communication unit, the computer program product comprising computer executable instructions that cause a computer functioning as the active tag apparatus to execute:

causing the radio communication unit to carry out the carrier sense at the plurality of frequencies;

receiving a measurement result of the reception strength for each of the plurality of frequencies;

specifying a particular frequency from among the plurality of frequencies as a maximum reception strength frequency from the measurement result;

reading the designated frequency corresponding to the particular frequency from a data storage unit storing, in correspondence with each other, the maximum reception strength frequency and the designated frequency specifying a frequency for the carrier sense to be carried out; and

causing the radio communication unit to carry out the carrier sense at the designated frequency.

9. A system, comprising:

a plurality of communication apparatuses for conducting radio communication at a plurality of frequencies; and

an active tag apparatus capable of data transmission and reception by radio with the communication apparatus only by executing carrier sense at selected frequencies from among the plurality of frequencies of communication apparatuses within transceiving range of the active tag apparatus.

10. The system according to claim 9, wherein one or more of the communication apparatuses each comprise:

a data storage unit that stores frequency designation data including a local transmission frequency used for data transmission by the radio communication and data on a frequency of a carrier sense to be carried out by the active tag apparatus; and

a controller that transmits the frequency designation data stored in the data storage unit to the active tag apparatus at the local transmission frequency for causing the active tag apparatus to select a frequency for executing a carrier sense according to the frequency designation data when the communication apparatus enters the active tag apparatus transceiving range.

11. The system according to claim 9, wherein the active tag apparatus comprises:

a data storage unit that stores, in correspondence with each other, a maximum reception strength frequency and a selected frequency specifying a frequency for the carrier sense to be executed; and

a controller

executing carrier sense at a plurality of frequencies;

measuring a reception strength of a received radio wave to transmit and receive data at a specified radio frequency to and from the communication apparatuses;

receiving a result of measuring the reception strength for each of the plurality of frequencies,

determining a particular frequency from among the plurality of frequencies as the maximum reception strength frequency according to the measurement result,

selecting a frequency corresponding to the particular frequency as the maximum reception strength frequency from the data storage unit, and

executing the carrier sense at the selected frequency.

12. The system according to claim 10, wherein the controller executes carrier sense at the plurality of frequencies according to frequencies use by other communication apparatuses, and stores the detected carrier frequency data in the data storage unit.