RFID interrogator and data communication method thereof
First Claim
1. An interrogator to transmit and receive a signal to and from a wireless tag, comprising:
- a carrier sense unit to detect an idle channel in a plurality of channels used for communications with the wireless tag;
a transmitting unit to transmit the signal to the wireless tag by use of the detected idle channel;
a detecting unit to detect communication timeout when an abnormality in the communications with the wireless tag continues for a predetermined timeout period; and
a control unit to control the transmitting unit to interrupt the transmission to the wireless tag when the detecting unit detects the communication timeout within a predetermined observation period from a point of time when starting the transmission of the signal to the wireless tag, while continue the transmission to the wireless tag when the detecting unit detects the communication timeout after the predetermined observation period, and to control the carrier sense unit and the transmitting unit to re-detect an idle channel after elapse of a predetermined halt period from the transmission interruption due to the detection of the communication timeout and resume the transmission to the wireless tag by using the re-detected idle channel.
1 Assignment
0 Petitions
Accused Products
Abstract
An interrogator autonomously reduces interference of receiving radio waves in a wireless tag. The interrogator transmitting and receiving a signal to and from a wireless tag, comprises a carrier sense unit detecting an idle channel in a plurality of channels used for communications with the wireless tags, a transmitting unit transmitting the signal to the wireless tag by use of the detected idle channel, an abnormality detecting unit detecting communication abnormality in the communications with the wireless tag, and a control unit controlling so as to interrupt, when detecting the communication abnormality, the transmission to the wireless tag, re-detect an idle channel after an elapse of a predetermined transmission halt period, and resume the signal transmission to the wireless tag by using the re-detected idle channel.
16 Citations
10 Claims
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1. An interrogator to transmit and receive a signal to and from a wireless tag, comprising:
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a carrier sense unit to detect an idle channel in a plurality of channels used for communications with the wireless tag; a transmitting unit to transmit the signal to the wireless tag by use of the detected idle channel; a detecting unit to detect communication timeout when an abnormality in the communications with the wireless tag continues for a predetermined timeout period; and a control unit to control the transmitting unit to interrupt the transmission to the wireless tag when the detecting unit detects the communication timeout within a predetermined observation period from a point of time when starting the transmission of the signal to the wireless tag, while continue the transmission to the wireless tag when the detecting unit detects the communication timeout after the predetermined observation period, and to control the carrier sense unit and the transmitting unit to re-detect an idle channel after elapse of a predetermined halt period from the transmission interruption due to the detection of the communication timeout and resume the transmission to the wireless tag by using the re-detected idle channel. - View Dependent Claims (5)
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2. An interrogator to transmit and receive a signal to and from a wireless tag, comprising:
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a carrier sense unit to detect an idle channel in a plurality of channels used for communications with the wireless tag; a transmitting unit to transmit the signal to the wireless tag by use of the detected idle channel; a detecting unit to detect communication timeout when an abnormality in the communications with the wireless tag continues for a predetermined timeout period; a control unit to control the carrier sense unit and the transmitting unit to interrupt, when detecting the communication timeout, the transmission to the wireless tag, re-detect an idle channel after elapse of a predetermined halt period from the transmission interruption due to the detection of the communication timeout, and resume the transmission to the wireless tag by using the re-detected idle channel; and a changing unit to change the predetermined timeout period depending on a priority level of the transmission to the wireless tag. - View Dependent Claims (3, 4)
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6. A data communication method in an interrogator to transmit and receive a signal to and from a wireless tag, comprising:
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detecting an idle channel in a plurality of channels used for communications with the wireless tag; transmitting the signal to the wireless tag by use of the detected idle channel; detecting communication timeout when an abnormality in the communications with the wireless tag continues for a predetermined timeout period; interrupting the transmission to the wireless tag when detecting the communication timeout within a predetermined observation period from a point of time when starting the transmission of the signal to the wireless tag, while, not-interrupting the transmission to the wireless tag when detecting the communication timeout after the predetermined observation period; re-detecting an idle channel after elapse of a predetermined halt period from the transmission interruption due to the detection of the communication timeout; and resuming the transmission to the wireless tag by using the re-detected idle channel. - View Dependent Claims (10)
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7. A data communication method in an interrogator to transmit and receive a signal to and from a wireless tag, comprising:
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detecting an idle channel in a plurality of channels used for communications with the wireless tag; transmitting the signal to the wireless tag by use of the detected idle channel; detecting communication timeout when an abnormality in the communications with the wireless tag continues for a predetermined timeout period; interrupting the transmission to the wireless tag when detecting the communication timeout; re-detecting an idle channel after elapse of a predetermined halt period from the transmission interruption due to the detection of the communication timeout; resuming the transmission to the wireless tag by using the re-detected idle channel; and changing the predetermined timeout period depending on a priority level of the transmission to the wireless tag. - View Dependent Claims (8, 9)
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Specification