Communication system, dependent station thereof and dependent-station relay transmission method

• US 8,848,595 B2
• Filed: 07/17/2009
• Issued: 09/30/2014
• Est. Priority Date: 08/28/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kanda, Tetsuo
• Primary Examiner(s): Shah, Chirag
• Assistant Examiner(s): ULYSSE, JAEL M
• Application Number:
  US12/999,720
• Publication Number:
  US 20110096716A1
• Time in Patent Office: 1,901 Days
• Field of Search: 370/204, 370/270, 370/315, 370/346, 370/350, 370/376, 370/400, 370/401, 370/445, 370/458, 370/470, 455/422, 455/452, 455/509
• US Class Current: 370/315
• CPC Class Codes: H04H 20/08 among terminal devices
• CPC Class Codes: H04H 20/42 Arrangements for resource management
• CPC Class Codes: H04L 1/0027 Scheduling of signalling, e.g. occurrence thereof
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 1/0079 Formats for control data H04L1/16 takes precedence; training sequences H04L25/00 and H04L27/00
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1829 Arrangements specially adapted for the receiver end
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding

Abstract

In a communication system that includes a control station and dependent stations, the control station broadcasts data intended for the dependent stations on a per-superframe basis. The dependent stations relay the data received from the control station among themselves. If a dependent station has received the data transmitted from the control station, the dependent station transmits an acknowledgement response. If a dependent station does not receive an acknowledgement response from another dependent station, then the dependent station relays the data intended for the other dependent station.

Claims

1. A communication system in which a control station broadcasts data intended for a plurality of dependent stations, on a per-superframe basis, each of the plurality of dependent stations comprising:

a first receiving unit that receives data broadcast from the control station in an Nth (where N is an integer) superframe;

a second receiving unit that receives a response that indicates a reception condition of the data on another dependent station; and

a relaying unit that relays the data received by the first receiving unit to the other dependent station in a time slot that has been allocated to the dependent station in an (N+1)th superframe when the response received in an Nth superframe by the second receiving unit indicates that the other dependent station did not receive the data, and restricts to relay the data received by the first receiving unit to the other dependent station when the response received by the second receiving unit indicates that the other dependent station received the data.

2. The system according to claim 1, wherein

the data intended for the other dependent station is relayed when the response indicating that the data from the control station was received correctly is not received from the other dependent station.

3. The system according to claim 1, wherein

the data intended for the other dependent station is relayed when the response indicating that the data from the control station was not received correctly was received from the other dependent station.

4. The system according to claim 1, wherein

the dependent station transmits other data in a time period that has been reserved for a relay in a time slot that has been allocated to the dependent station when each of the plurality of dependent stations does not relay data intended for another dependent station.

5. The system according to claim 1,

wherein the control station comprises a detecting unit that detects a time period that is not being used, in order that each dependent station may relay data intended for another dependent station;

wherein other data is transmitted in the detected time period.

6. The system according to claim 1, wherein

each of the plurality of dependent stations transmits the response and relayed data in one frame.

7. The system according to claim 1, wherein data broadcast

from the control station and relayed among the plurality of dependent stations is synchronous data.

8. A dependent station, comprising:

a first receiving unit that receives data broadcast from a control station in an Nth (where N is an integer) superframe;

a second receiving unit that receives a response that indicates a reception condition of the data on another dependent station; and

a relaying unit that relays the data received by the first receiving unit to the other dependent station in a time slot that has been allocated to the dependent station in an (N+1)th superframe when the response received in an Nth superframe by the second receiving unit indicates that the other dependent station did not receive the data, and restricts to relay the data received by the first receiving unit to the other dependent station when the response received by the second receiving unit indicates that the other dependent station received the data.

9. The dependent station according to claim 8, wherein the data intended for the other dependent station is relayed when the response indicating that the data from the control station was received correctly is not received from the other dependent station.

10. The station according to claim 8, wherein the data intended for the other dependent station is relayed when the response indicating that the data from the control station was not received correctly was received from the other dependent station.

11. The dependent station according to claim 8, wherein the dependent station transmits other data in a time period that has been reserved for relaying in a time slot that has been allocated to the dependent station when each of the plurality of dependent stations does not relay data intended for another dependent station.

12. The dependent station according to claim 8,

wherein the control station includes a detecting unit that detects a time period that is not being used, the time period having been reserved, in order that each dependent station may relay data intended for another dependent station, and

wherein other data is transmitted in the detected time period.

13. A method of relay transmission by a dependent station, comprising:

receiving data broadcast from a control station in an Nth (where N is an integer) superfame;

receiving a response that indicates a reception condition of the data on another dependent station; and

relaying the data received from the control station to the other dependent station in a time slot that has been allocated to the dependent station in an (N+1)th superframe when the response in an Nth superframe indicates that the other dependent station did not receive the data; and

restricting to relay the data received from the control station to the other dependent station when the response indicates that the other dependent station received the data.

14. A non-transitory computer-readable recording medium storing a program for causing a computer to perform the method set forth in claim 13.

15. A first communication apparatus comprising:

a reception unit configured to receive data transmitted from a second communication apparatus, the data being transmitted in an Nth superframe which includes at least a transmission period of said first communication apparatus and a transmission period of the second communication apparatus;

a determination unit configured to determine a reception condition of data on a third communication apparatus, which has been transmitted from the second communication apparatus in the Nth superframe; and

a transmission unit configured to transmit at least data addressed to the third communication apparatus in the Nth superframe or later in an (N+1)th superframe when it is determined that the third communication apparatus did not receive the data, and restrict to transmit the data to the third communication apparatus when it is determined that the third communication apparatus received the data.

16. The apparatus according to claim 15, wherein the transmission unit transmits at least the data addressed to the third communication apparatus, which was received by the reception unit,

in of the Nth superframe or later in case that the third communication apparatus cannot receive the data transmitted from the second communication apparatus in the Nth superframe, and the transmission unit transmits other data using the period assigned for transmitting data addressed to the third communication apparatus in case that the third communication apparatus can receive the data transmitted from the second communication apparatus in the Nth superframe.

17. The apparatus according to claim 15, wherein the determination unit determines the reception condition on the third communication apparatus based on a receipt acknowledgement signal.

18. The apparatus according to claim 15, wherein the determination unit determines the reception condition on the third communication apparatus based on a signal indicating that data have not been normally received.

19. The apparatus according to claim 15, wherein when the reception unit receives the data addressed to the third communication apparatus and the third communication apparatus was not able to receive the data, the transmission unit transmits at least the data addressed to the third communication apparatus, which has been received by the reception unit, in of the Nth superframe or later.

20. The apparatus according to claim 15, wherein the determination unit determines a reception condition of data transmitted by the second communication unit, which include data addressed to the first communication apparatus and data addressed to the third communication apparatus.

21. The apparatus according to claim 15, wherein the determination unit determines reception condition of data addressed to the third communication apparatus, which was transmitted by the second communication apparatus.

22. The apparatus according to claim 15, wherein reception of data by the reception unit and transmission of data by the transmission unit are performed by wireless communication.

23. A control method of a first communication apparatus, the method comprising:

receiving data transmitted from a second communication apparatus, the data being transmitted in Nth superframe which includes at least a transmission period of said first communication apparatus and a transmission period of the second communication apparatus;

determining a reception condition of data on a third communication apparatus, which has been transmitted from the second communication apparatus in the Nth superframe; and

transmitting at least data addressed to the third communication apparatus in a cycle of the Nth superframe or later in an (N+1)th superframe when it is determined that the third communication apparatus did not receive the data, and restricting to transmit the data to the third communication apparatus when it is determined that the third communication apparatus received the data.

24. A non-transitory computer-readable recording medium storing a program which, when executed by a computer, causes the computer to perform the method set forth in claim 23.