Control device, terminal device, and communication system and communication method, using the same

• US 8,335,179 B2
• Filed: 07/06/2009
• Issued: 12/18/2012
• Est. Priority Date: 07/15/2008
• Status: Expired due to Fees

• Current Assignee: Sovereign Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Hayashino, Hiroshi, Ohta, Yoshitaka, Nakae, Hironori
• Primary Examiner(s): CHRISS, ANDREW W
• Application Number:
  US12/677,916
• Publication Number:
  US 20100232415A1
• Time in Patent Office: 1,261 Days
• Field of Search: None
• US Class Current: 370/321
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

A terminal device, used in communication system conducting communication by periodically switching frequency channels in a predefined sequence, communicates with a control device using a predefined channel. The terminal device includes: an antenna; a reception section receiving, from the control device, via the antenna, data and a beacon containing control information indicating the sequence and its timing; a transmission section transmitting data to the control device via the antenna; a data volume determining section determining whether a transmission can be completed within a predefined period; and a control section controlling, within the period, the reception section to receive the data and the beacon, and the transmission section to transmit the data, and when the data volume determining section determines that the transmission cannot be completed, further controlling the transmission section to, determine a next-to-be-used channel based on the control information, switch to the channel after the period, and continue the transmission.

Claims

1. A terminal device, which is used in a communication system that conducts a communication by periodically switching a plurality of frequency channels in a predefined sequence, and which communicates with a control device that uses a predefined frequency channel of the plurality of frequency channels, the terminal device comprising:

an antenna that conducts transmission and reception of a wireless signal;

a reception section that receives, from the control device, via the antenna, a beacon that contains control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a transmission section that transmits transmission data to the control device via the antenna;

a data volume determining section that determines whether or not it is possible to complete a transmission of the transmission data within an assigned period assigned to the terminal device to use the predefined frequency channel to conduct a communication with the control device; and

a control section that controls, during the assigned period, a reception of the beacon by the reception section and a transmission of the transmission data by the transmission section,

wherein, when the data volume determining section determines that it is not possible to complete the transmission of the transmission data within the assigned period, the control section (i) ascertains a frequency channel, of the plurality of frequency channels, that is to be used by another terminal device for a communication with the control device after the assigned period, based on the control information, (ii) switches to the ascertained frequency channel after the assigned period has elapsed, and (iii) controls the transmission section to continue the transmission of the transmission data using the ascertained frequency channel.

2. The terminal device according to claim 1,

wherein the reception section further receives reception data from the control device, and

wherein, when the control information included in the beacon further includes an identifier of the terminal device for indicating that the transmission of the reception data from the control device to the terminal device will not be completed within the assigned period, the control section (i) ascertains the frequency channel that is to be used during the period while the other terminal device conducts the communication with the control device after the assigned period, based on the control information, (ii) switches to the ascertained frequency channel after the assigned period has elapsed, and (iii) controls the reception section to continue the reception of the reception data using the ascertained frequency channel.

3. The terminal device according to claim 2, wherein the control section determines, when the switching to the ascertained frequency channel that is to be used during the period while the other terminal device conducts the communication with the control device after the assigned period is not conducted, based on the control information, the switching timing in which the predefined frequency channel assigned to the terminal device is used again, and causes the terminal device to wait in a power-saving mode until the determined switching timing.

4. The terminal device according to claim 1, wherein the control section determines, when the switching to the ascertained frequency channel that is to be used during the period while the other terminal device conducts the communication with the control device after the assigned period is not conducted, based on the control information, the switching timing in which the predefined frequency channel assigned to the terminal device is used again, and causes the terminal device to wait in a power-saving mode until the determined switching timing.

5. The terminal device according to claim 1, wherein the data volume determining section determines that it is not possible to complete the transmission of the transmission data within the assigned period, when a data volume of the transmission data to be transmitted to the control device exceeds a data volume that allows for the transmission within the assigned period.

6. A control device, which is used in a communication system that conducts a communication using a plurality of frequency channels and periodically switches the plurality of frequency channels in a predefined sequence, and which conducts a communication with one or more terminal devices respectively assigned with a predefined frequency channel of the plurality of frequency channels, the control device comprising:

an antenna that conducts transmission and reception of a wireless signal;

a beacon generating section that generates a beacon containing control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a transmission section that transmits the beacon and transmission data to the one or more terminal devices via the antenna;

a data volume determining section that determines whether or not it is possible to complete a transmission of the transmission data to a destination terminal device, of the one or more terminal devices, that is a transmission destination of the transmission data within a period while a frequency channel, of the plurality of frequency channels, assigned to the destination terminal device is in use; and

a control section which (i) periodically switches to a frequency channel, of the plurality of frequency channels, in the predefined sequence, (ii) controls the beacon generating section to generate the beacon, and (iii) controls the transmission section to perform, during a period while the frequency channel obtained as a result of the switching is in use, the transmission of the beacon and the transmission of the transmission data to a terminal device, of the one or more terminal devices, assigned with the frequency channel obtained as the result of the switching,

wherein, when the data volume determining section determines that it is not possible to complete the transmission of the transmission data to the destination terminal device, the control section (i) controls the transmission section to transmit the beacon or a data frame containing an identifier of the destination terminal device to the destination terminal device, and continue the transmission of the transmission data to the destination terminal device that recognizes the identifier and (ii) switches to a switched to frequency channel, of the plurality of frequency channels, used for a communication with a terminal device other than the destination terminal device, by using the switched to frequency channel after the period while the frequency channel obtained as the result of the switching is in use.

7. The control device according to claim 6, wherein the data volume determining section determines that it is not possible to complete the transmission of the transmission data within the assigned period, when a data volume of the transmission data to be transmitted to the destination terminal device exceeds a data volume that allows for the transmission within the period while the frequency channel assigned to the destination terminal device is in use.

8. A communication system that conducts a communication between a control device and one or more terminal devices by periodically switching a plurality of frequency channels in a predefined sequence,

wherein each respective terminal of the one or more terminal devices includes:

a first antenna that conducts transmission and reception of a wireless signal;

a first reception section that receives, from the control device, via the first antenna, reception data and a beacon that contains control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a first transmission section that transmits transmission data to the control device via the first antenna;

a first data volume determining section that determines whether or not it is possible to complete a transmission of the transmission data within an assigned period assigned to the respective terminal device to use the predefined frequency channel to conduct a communication with the control device; and

a first control section that controls, during the assigned period, a reception of the beacon and the reception data by the first reception section and a transmission of the transmission data by the first transmission section,

wherein, when the first data volume determining section determines that it is not possible to complete the transmission of the transmission data within the assigned period, the first control section (i) ascertains a frequency channel, of the plurality of frequency channels, that is to be used by another terminal device, of the one or more terminal devices, for a communication with the control device after the assigned period, based on the control information, (ii) switches to the ascertained frequency channel after the assigned period has elapsed, and (iii) controls the first transmission section to continue the transmission of the transmission data using the ascertained frequency channel, and

wherein, when the control information included in the beacon further includes an identifier of the respective terminal device for indicating that the transmission of the reception data from the control device to the respective terminal device will not be completed within the assigned period, the first control section (i) ascertains the frequency channel that is to be used during the period while the other terminal device conducts the communication with the control device after the assigned period, based on the control information, (ii) switches to the ascertained frequency channel after the assigned period has elapsed, and (iii) controls the first reception section to continue the reception of the reception data using the ascertained frequency channel, and

wherein the control device includes;

a second antenna that conducts transmission and reception of a wireless signal;

a second reception section that receives reception data from the one or more terminal devices via the second antenna;

a beacon generating section that generates a beacon containing control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a second transmission section that transmits the beacon and the transmission data to the one or more terminal devices via the second antenna;

a second data volume determining section that determines whether or not it is possible to complete a transmission of the transmission data to a destination terminal device, of the one or more terminal devices, that is a transmission destination of the transmission data within a period while a frequency channel, of the plurality of frequency channels, assigned to the destination terminal device is in use; and

a second control section which (i) periodically switches to a frequency channel, of the plurality of frequency channels, in the predefined sequence, (ii) controls the beacon generating section to generate the beacon, and (iii) controls the second transmission section to perform, during a period while the frequency channel obtained as a result of the switching is in use, the transmission of the beacon and the transmission of the transmission data to a terminal device, of the one or more terminal devices, assigned with the frequency channel obtained as the result of the switching,

wherein, when the second data volume determining section determines that it is not possible to complete the transmission of the transmission data to the destination terminal device, the second control section, (i) controls the second transmission section to transmit the beacon or a data frame containing an identifier of the destination terminal device to the destination terminal device, and continue the transmission of the transmission data to the destination terminal device that recognizes the identifier and (ii) switches to a switched to frequency channel, of the plurality of frequency channels, used for a communication with a terminal device other than the destination terminal device, by using the switched to frequency channel after the period while the frequency channel obtained as the result of the switching is in use.

9. An integrated circuit, which is used in a communication system that conducts a communication by periodically switching a plurality of frequency channels in a predefined sequence, and which includes a communication function that conducts a communication with a control device that uses a predefined frequency channel of the plurality of frequency channels, the integrated circuit comprising circuits which act as:

a reception section that receives, from the control device, via an antenna, a beacon that contains control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a transmission section that transmits transmission data to the control device via the antenna;

a data volume determining section that determines whether or not it is possible to complete a transmission of the transmission data within an assigned period assigned to use the predefined frequency channel to conduct a communication with the control device; and

a control section that controls, during the assigned period, a reception of the beacon by the reception section and a transmission of the transmission data by the transmission section,

wherein, when the data volume determining section determines that it is not possible to complete the transmission of the transmission data within the assigned period, the control section (i) ascertains a frequency channel, of the plurality of frequency channels, that is to be used by an element other than the integrated circuit for a communication with the control device after the assigned period, based on the control information, (ii) switches to the ascertained frequency channel after the assigned period has elapsed, and (iii) controls the transmission section to continue the transmission of the transmission data using the ascertained frequency channel.

10. An integrated circuit, which is used in a communication system that conducts a communication using a plurality of frequency channels and periodically switches the plurality of frequency channels in a predefined sequence, and which includes a communication function that conducts a communication with one or more terminal devices respectively assigned with a predefined frequency channel of the plurality of frequency channels, the integrated circuit comprising circuits which act as:

a reception section that receives reception data from the one or more terminal devices via an antenna;

a beacon generating section that generates a beacon containing control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a transmission section that transmits the beacon and transmission data to the one or more terminal devices via the antenna;

a data volume determining section that determines whether or not it is possible to complete a transmission of the transmission data to a destination terminal device, of the one or more terminal devices, that is a transmission destination of the transmission data within a period while a frequency channel, of the plurality of frequency channels, assigned to the destination terminal device is in use; and

a control section which (i) periodically switches to a frequency channel, of the plurality of frequency channels, in the predefined sequence, (ii) controls the beacon generating section to generate the beacon, and (iii) controls the transmission section to perform, during a period while the frequency channel obtained as a result of the switching is in use, the transmission of the beacon and the transmission of the transmission data to a terminal device, of the one or more terminal devices, assigned with the frequency channel obtained as the result of the switching,

wherein, when the data volume determining section determines that it is not possible to complete the transmission of the transmission data to the destination terminal device, the control section, (i) controls the transmission section to transmit the beacon or a data frame containing an identifier of the destination terminal device to the destination terminal device, and continue the transmission of the transmission data to the destination terminal device that recognizes the identifier and (ii) switches to a switched to frequency channel, of the plurality of frequency channels, used for a communication with a terminal device other than the destination terminal device, by using the switched to frequency channel after the period while the frequency channel obtained as the result of the switching is in use.

11. A communication method, which is used in a communication system that conducts a communication by periodically switching a plurality of frequency channels in a predefined sequence, and which conducts a communication with a control device that uses a predefined frequency channel of the plurality of frequency channels, the communication method comprising:

a step of receiving, from the control device, via an antenna, a beacon that contains control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a step of transmitting transmission data to the control device via the antenna;

a step of determining whether or not it is possible to complete a transmission of the transmission data within an assigned period assigned to a destination terminal device to use the predefined frequency channel to conduct a communication with the control device, the destination terminal device being a transmission destination of the transmission data; and

a step of controlling, during the assigned period, an execution of the step of receiving to receive the beacon, and an execution of the step of transmitting to transmit the transmission data,

wherein, when the step of determining determines that it is not possible to complete the transmission of the transmission data within the assigned period, the step of controlling (i) ascertains a frequency channel, of the plurality of frequency channels, that is to be used by a terminal device other than the destination terminal device for a communication with the control device after the assigned period, based on the control information, (ii) switches to the ascertained frequency channel after the assigned period has elapsed, and (iii) executes the step of transmitting to continue the transmission of the transmission data using the ascertained frequency channel.

12. A communication method, which is used in a communication system that conducts a communication using a plurality of frequency channels and periodically switches the plurality of frequency channels in a predefined sequence, and which conducts a communication with one or more terminal devices respectively assigned with a predefined frequency channel of the plurality of frequency channels, the communication method comprising:

a step of receiving reception data from the terminal devices via an antenna;

a step of generating a beacon containing control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a step of transmitting the beacon and transmission data to the one or more terminal devices via the antenna;

a step of determining whether or not it is possible to complete a transmission of the transmission data to a destination terminal device, of the one or more terminal devices, that is a transmission destination of the transmission data within a period while a frequency channel, of the plurality of frequency channels, assigned to the destination terminal device is in use; and

a step of performing a control to (i) periodically switch to a frequency channel, of the plurality of frequency channels, in the predefined sequence, (ii) execute the step of generating to generate the beacon, and (iii) execute the step of transmitting to perform, during a period while the frequency channel obtained as a result of the switching is in use, the transmission of the beacon and the transmission of the transmission data to a terminal device, of the one or more terminal devices, assigned with the frequency channel obtained as the result of the switching, wherein

the step of performing the control further includes, when the step of determining determines that it is not possible to complete the transmission of the transmission data to the destination terminal device (i) executing the step of transmitting to transmit the beacon or a data frame containing an identifier of the destination terminal device to the destination terminal device, and continue the transmission of the transmission data to the destination terminal device that recognizes the identifier and (ii) switching to a switched to frequency channel, of the plurality of frequency channels, used for a communication with a terminal device other than the destination terminal device, by using the switched to frequency channel after the period while the frequency channel obtained as the result of the switching is in use.

13. A non-transitory computer-readable recording medium having a computer program recorded thereon, the computer program being used by a terminal device which is used in a communication system that conducts a communication by periodically switching a plurality of frequency channels in a predefined sequence and which communicates with a control device that uses a predefined frequency channel of the plurality of frequency channels, the communication program causing a computer to execute a method comprising:

a step of receiving, from the control device, via an antenna, a beacon that contains control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a step of transmitting transmission data to the control device via the antenna;

a step of determining whether or not it is possible to complete a transmission of the transmission data within an assigned period assigned to the terminal device to use the predefined frequency channel to conduct a communication with the control device; and

a step of controlling, during the assigned period, an execution of the step of receiving to receive the beacon, and an execution of the step of transmitting to transmit the transmission data,

wherein, when the step of determining determines that it is not possible to complete the transmission of the transmission data within the assigned period, the step of controlling (i) ascertains a frequency channel, of the plurality of frequency channels, that is to be used by another terminal device for a communication with the control device after the assigned period, based on the control information, (ii) switches to the ascertained frequency channel after the assigned period has elapsed, and (iii) executes the step of transmitting to continue the transmission of the transmission data using the ascertained frequency channel.

14. A non-transitory computer-readable recording medium having a computer program recorded thereon, the computer program being used by a control device which is used in a communication system that conducts a communication using a plurality of frequency channels and periodically switches the plurality of frequency channels in a predefined sequence, and which conducts a communication with one or more terminal devices respectively assigned with a predefined frequency channel, of the plurality of frequency channels, the computer program causing a computer to execute a method comprising:

a step of receiving reception data from the terminal devices via an antenna;

a step of generating a beacon containing control information indicating at least a switching sequence and a switching timing of a frequency channel of the plurality of frequency channels;

a step of transmitting the beacon and transmission data to the one or more terminal devices via the antenna;

a step of determining whether or not it is possible to complete a transmission of the transmission data to a destination terminal device, of the one or more terminal devices, that is a transmission destination of the transmission data within a period while a frequency channel, of the plurality of frequency channels, assigned to the destination terminal device is in use; and

a step of performing a control to (i) periodically switch to a frequency channel, of the plurality of frequency channels, in the predefined sequence, (ii) execute the step of generating to generate the beacon, and (iii) execute the step of transmitting to perform, during a period while the frequency channel obtained as a result of the switching is in use, the transmission of the beacon and the transmission of the transmission data to a terminal device, of the one or more terminal devices, assigned with the frequency channel obtained as the result of the switching, wherein

the step of performing the control further includes, when the step of determining determines that it is not possible to complete the transmission of the transmission data to the destination terminal device (i) executing the step of transmitting to transmit the beacon or a data frame containing an identifier of the destination terminal device to the destination terminal device, and continue the transmission of the transmission data to the destination terminal device that recognizes the identifier and (ii) switching to a switched to frequency channel, of the plurality of frequency channels, used for a communication with a terminal device other than the destination terminal device, by using the switched to frequency channel after the period while the frequency channel obtained as the result of the switching is in use.