DATA COMMUNICATION APPARATUS, COMMUNICATION METHOD, AND PROGRAM

• US 20100085161A1
• Filed: 12/11/2006
• Published: 04/08/2010
• Est. Priority Date: 12/11/2006
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Nishikawa, Koji
• Granted Patent: US 8,594,580 B2
• Time in Patent Office: Days
• US Class Current: 340/10.300
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

In a data reading apparatus performing contactless data communications with IC tags, a multi channel setting section sets a plurality of frequencies to be used for data communication with an IC tag in advance; a multi channel interference detecting section detects radio interference from other data reader in each of the set plurality of frequencies, prior to occurrence of a data communication request with an IC tag; a carrier sense lapse time holding section holds a period of no interference based on an interference detection result from the multi channel interference detecting section; a time comparing section determines whether the carrier sense lapse time held by the carrier sense lapse time holding section is on or above a predetermined carrier sense time upon occurrence of the data communication request with the IC tag, and permits the data communication with the IC tag when the carrier sense lapse time is on or above the carrier sense time; a transmitting section transmits data to the IC tag; and hence wait time for interference detection may be reduced.

Claims

1. A data communication apparatus performing a wireless data communication with a communication destination device, comprising:

an interference monitoring section that monitors radio interference in a usage scheduled frequency to be used for the wireless data communication with the communication destination device, prior to receipt of a request to start the wireless data communication with the communication destination device;

a time comparing section that compares a duration of no interference, during which the interference monitoring section detects no radio interference in the usage scheduled frequency, with a threshold corresponding to the duration of no interference, upon receipt of the request to start the wireless data communication with the communication destination device, and permits the wireless data communication in the usage scheduled frequency when the duration of no interference exceeds the threshold; and

a communicating section that performs the wireless data communication with the communication destination device in the usage scheduled frequency based on a permission issued by the time comparing section.

2. The data communication apparatus according to claim 1, wherein the time comparing section permits the wireless data communication in the usage scheduled frequency when the duration of no interference is less than the threshold at a time of receipt of the request to start the wireless data communication with the communication destination device, but the duration of no interference exceeds the threshold, as a result of no radio interference detected in the usage scheduled frequency by the interference monitoring section even after receipt of the request to start the wireless data communication with the communication destination device.

3. The data communication apparatus according to claim 1 further comprising:

a usage scheduled frequency setting section that sets a plurality of frequencies as usage scheduled frequencies, and also sets an order of monitoring radio interference by the interference monitoring section in the plurality of usage scheduled frequencies;

wherein the interference monitoring section monitors radio interference in one of the plurality of usage scheduled frequencies according to the order of monitoring set by the usage scheduled frequency setting section, and monitors radio interference in a next usage scheduled frequency in the order of monitoring when radio interference is detected in the one of the plurality of usage scheduled frequencies being monitored.

8. The data communication apparatus according to claim 1, wherein the data communication apparatus is a data reading apparatus that is configured to communicate with a contactless IC tag as the communication destination device.

4. A data communication apparatus performing a wireless data communication with a communication destination device, comprising:

a usage scheduled frequency setting section that sets a plurality of frequencies as usage scheduled frequencies to be used for the wireless data communication with the communication destination device;

an interference monitoring section that monitors radio interference in the plurality of usage scheduled frequencies set by the usage scheduled frequency setting section in parallel;

a time comparing section that compares a duration of no interference, during which the interference monitoring section detects no radio interference, with a threshold corresponding to the duration of no interference in the plurality of usage scheduled frequencies, and permits the wireless data communication in one of the plurality of usage scheduled frequencies in which the duration of no interference exceeds the threshold; and

a communicating section that performs the wireless data communication with the communication destination device in the one of the plurality of usage scheduled frequencies permitted for the wireless data communication by the time comparing section.

5. The data communication apparatus according to claim 4, wherein the time comparing section permits the wireless data communication in a usage scheduled frequency in which the duration of no interference exceeds the threshold the fastest among the plurality of usage scheduled frequencies.

6. The data communication apparatus according to claim 4 further comprising:

an interference level holding section that holds a radio interference level of each usage scheduled frequency detected by the interference monitoring section when monitoring a radio interference situation in the plurality of usage scheduled frequencies,

wherein the time comparing section permits the wireless data communication in a usage scheduled frequency in which the duration of no interference exceeds the threshold, and the radio interference level held by the interference level holding section is the lowest among the plurality of usage scheduled frequencies.

7. The data communication apparatus according to claim 4, wherein the interference monitoring section monitors a radio interference situation in the plurality of usage scheduled frequencies in parallel on a time sharing basis.

13. The data communication apparatus according to claim 4, wherein the data communication apparatus is a data reading apparatus that is configured to communicate with a contactless IC tag as the communication destination device.

9. A communication method, where a data communication apparatus performs a wireless data communication with a communication destination device, comprising:

monitoring, by the data communication apparatus, radio interference in a usage scheduled frequency to be used for the wireless data communication with the communication destination device, prior to receipt of a request to start the wireless data communication with the communication destination device;

comparing, by the data communication apparatus, a duration of no interference, during which no radio interference is detected in the usage scheduled frequency, with a threshold corresponding to the duration of no interference, upon receipt of the request to start the wireless data communication with the communication destination device; and

performing, by the data communication apparatus, the wireless data communication with the communication destination device in the usage scheduled frequency, when the duration of no interference exceeds the threshold.

10. A communication method, where a data communication apparatus performs a wireless data communication with a communication destination device, comprising:

setting, by the data communication apparatus, a plurality of frequencies as usage scheduled frequencies to be used for the wireless data communication with the communication destination device;

monitoring, by the data communication apparatus, radio interference in the set plurality of usage scheduled frequencies in parallel;

comparing, by the data communication apparatus, a duration of no interference, during which no radio interference is detected, with a threshold corresponding to the duration of no interference in the plurality of usage scheduled frequencies; and

performing, by the data communication apparatus, the wireless data communication with the communication destination device in one of the plurality of usage scheduled frequencies in which the duration of no interference exceeds the threshold.

11. A computer readable storage medium including computer executable instructions stored therein, the computer executable instructions causing a computer performing a wireless data communication with a communication destination device to execute:

an interference monitoring process, for monitoring radio interference in a usage scheduled frequency to be used for the wireless data communication with the communication destination device, prior to receipt of a request to start the wireless data communication with the communication destination device;

a time comparing process, for comparing a duration of no interference, during which no radio interference is detected in the usage scheduled frequency in the interference monitoring process, with a threshold corresponding to the duration of no interference, upon receipt of the request to start the wireless data communication with the communication destination device, and for permitting the wireless data communication in the usage scheduled frequency, when the duration of no interference exceeds the threshold; and

a communicating process, for performing the wireless data communication with the communication destination device in the usage scheduled frequency based on a permission issued in the time comparing process.

12. A computer readable storage medium including computer executable instructions stored therein, the computer executable instructions causing a computer performing a wireless data communication with a communication destination device to execute:

a usage scheduled frequency setting process, for setting a plurality of frequencies as usage scheduled frequencies to be used for the wireless data communication with the communication destination device;

an interference monitoring process, for monitoring radio interference in the plurality of usage scheduled frequencies set in the usage scheduled frequency setting process in parallel;

a time comparing process, for comparing a duration of no interference, during which no radio interference is detected in the interference monitoring process, with a threshold corresponding to the duration of no interference in the plurality of usage scheduled frequencies, and for permitting the wireless data communication in one of the plurality of usage scheduled frequencies in which the duration of no interference exceeds the threshold; and

a communicating process, for performing the wireless data communication with the communication destination device in one of the plurality of usage scheduled frequencies permitted for the wireless data communication in the time comparing process.