Communication apparatus and method thereof

• US 8,171,365 B2
• Filed: 05/27/2009
• Issued: 05/01/2012
• Est. Priority Date: 06/19/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nabetani, Toshihisa
• Primary Examiner(s): Baker, Stephen
• Application Number:
  US12/472,482
• Publication Number:
  US 20090319852A1
• Time in Patent Office: 1,070 Days
• Field of Search: 714/748
• US Class Current: 714/748
• CPC Class Codes: H04L 1/1614 using bitmaps
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/188 Time-out mechanisms

Abstract

This is disclosed a communication apparatus. A receiving unit receives plural data frames which are transmitted from other communication apparatus. An error detection unit checks whether each data frame is received correctly or incorrectly. A determination unit estimates a first overhead and a second overhead and determines whether or not to send a block acknowledgement frame by comparing the first and the second overheads. The determination unit estimates the first overhead being caused by sending the block acknowledgement frame and the second overhead being caused by not sending the block acknowledgement frame. The receiving unit receives the data frames which are retransmitted from the other communication apparatus after a certain period of time has passed without sending the block acknowledgement frame, the data frames retransmitted from the other communication apparatus including both data frames which are correctly received and incorrectly received.

Claims

1. A communication apparatus for receiving a plurality of data frames from an other communication apparatus and for sending back a block acknowledgement frame including a plurality of information, each indicating whether the corresponding data frame is correctly received or incorrectly received, comprising:

a receiving unit which receives the data frames which are transmitted from the other communication apparatus;

an error detection unit which checks whether each data frame is received correctly or incorrectly; and

a determination unit which estimates a first overhead and a second overhead and which determines whether or not to send the block acknowledgement frame by comparing the first and the second overheads;

wherein

the determination unit estimates the first overhead being caused by sending the block acknowledgement frame and the second overhead being caused by not sending the block acknowledgement frame; and

the receiving unit receives the data frames which are retransmitted from the other communication apparatus after a certain period of time has passed without sending the block acknowledgement frame, the data frames retransmitted from the other communication apparatus including both data frames which are correctly received and incorrectly received.

2. The communication apparatus of claim 1, wherein

the determination unit determines to send the block acknowledgement frame if the first overhead is smaller than the second overhead.

3. The communication apparatus of claim 1, wherein

the determination unit determines not to send the block acknowledgement frame if the first overhead is larger than or equal to the second overhead.

4. The communication apparatus of claim 1, wherein

the first overhead includes a time to transmit the block acknowledgement frame in the case of sending the block acknowledgement frame, and

the second overhead includes a time to retransmit a data frame which has already received correctly in the case of sending no block acknowledgement frame.

5. The communication apparatus of claim 1, wherein

the determination unit determines to send the block acknowledgement frame

after sending no block acknowledgement frame to a same communication apparatus among the other communication apparatus are continued several times.

6. A communication apparatus for receiving a plurality of data frames from an other communication apparatus and for sending back a block acknowledgement frame including a plurality of information, each indicating whether the corresponding data frame is correctly received or incorrectly received, comprising:

a receiving unit which receives the data frames which are transmitted from the other communication apparatus;

an error detection unit which checks whether each data frame is received correctly or incorrectly and detects a number of incorrect data frames or a PER (Packet Error Rate) from the data frames received;

a determination unit which determines whether or not to send the block acknowledgement frame by comparing a threshold and either number of the incorrect data frames or the PER; and

a battery meter which measures remaining battery power;

wherein

the determination unit determines the threshold based on the remaining battery power; and

the receiving unit receives the data frames which are retransmitted from the other communication apparatus after a certain period of time has passed without sending the block acknowledgement frame, the data frames retransmitted from the other communication apparatus including both data frames which are correctly received and incorrectly received.

7. The communication apparatus of claim 6, wherein

the determination unit determines not to send the block acknowledgement frame if either the number of the incorrect data frames or the PER is larger than the threshold which gets smaller with decreasing the remaining battery power.

8. The communication apparatus of claim 6, wherein

the determination unit determines to send the block acknowledgement frame if either the number of the incorrect data frames or the PER is smaller than the threshold which gets smaller with decreasing the remaining battery power.

9. The communication apparatus of claim 6, wherein

the determination unit determines to send the block acknowledgement frame if either the number of the incorrect data frames or the PER is smaller than the threshold which gets smaller with decreasing the remaining battery power and the first overhead is smaller than the second overhead.

10. The communication apparatus of claim 6, wherein

the determination unit determines not to send the block acknowledgement frame if either the number of the incorrect data frames or the PER is smaller than the threshold which gets smaller with decreasing the remaining battery power and the first overhead is larger than or equal to the second overhead.

11. The communication apparatus of claim 6, wherein

the determination unit determines not to send the block acknowledgement frame if the first overhead is smaller than the second overhead and the difference between the first overhead and the second overhead is smaller than the threshold which gets larger with decreasing the remaining battery power.

12. The communication apparatus of claim 6, wherein

the determination unit determines to send the block acknowledgement frame if the first overhead is smaller than the second overhead and the difference between the first overhead and the second overhead is larger than the threshold which gets larger with decreasing the remaining battery power.

13. The communication apparatus of claim 6, wherein

the determination unit determines not to send the block acknowledgement frame if the second overhead is smaller than the threshold which gets smaller with decreasing the remaining battery power.

14. The communication apparatus of claim 6, wherein

the determination unit determines to send the block acknowledgement frame if the second overhead is larger than the threshold which gets smaller with decreasing the remaining battery power.

15. The communication apparatus of claim 6, wherein

the determination unit determines to send the block acknowledgement frame

after sending no block acknowledgement frame to a same communication apparatus among the other communication apparatus are continued several times.

16. A communication method for receiving a plurality of data frames from an other communication apparatus and for sending back a block acknowledgement frame including a plurality of information, each indicating whether the corresponding data frame is correctly received or incorrectly received, comprising:

receiving the data frames which are transmitted from the other communication apparatus;

checking whether each data frame is received correctly or incorrectly;

estimating a first overhead being caused by sending the block acknowledgement frame and a second overhead being caused by not sending the block acknowledgement frame;

determining whether or not to send the block acknowledgement frame by comparing the first and the second overheads; and

receiving the data frames which are retransmitted from the other communication apparatus after a certain period of time has passed without sending the block acknowledgement frame, the data frames retransmitted from the other communication apparatus including both data frames which are correctly received and incorrectly received.

17. A communication method for receiving a plurality of data frames from an other communication apparatus and for sending back a block acknowledgement frame including a plurality of information, each indicating whether the corresponding data frame is correctly received or incorrectly received, comprising:

receiving the data frames which are transmitted from the other communication apparatus;

checking whether each data frame is received correctly or incorrectly;

detecting a number of incorrect data frames or PER from the data frames received;

measuring remaining battery power;

determining whether or not to send the block acknowledgement frame by comparing a threshold and either the number of incorrect data frames or the PER, the threshold being based on the remaining battery power; and

receiving the data frames which are retransmitted from the other communication apparatus after a certain period of time has passed without sending the block acknowledgement frame, the data frames retransmitted from the other communication apparatus including both data frames which are correctly received and incorrectly received.

18. A computer readable storage medium storing instructions of a computer program for receiving a plurality of data frames from an other communication apparatus and for sending back a block acknowledgement frame including a plurality of information, each indicating whether the corresponding data frame is correctly received or incorrectly received, the computer program which when executed by a computer results in performance of steps comprising:

a program module for instructing a computer to receive the data frames which are transmitted from the other communication apparatus;

a program module for instructing the computer to check whether each data frame is received correctly or incorrectly;

a program module for instructing the computer to estimate a first overhead being caused by sending the block acknowledgement frame and a second overhead being caused by not sending the block acknowledgement frame;

a program module for instructing the computer to determine whether or not to send the block acknowledgement frame by comparing the first and the second overheads; and

a program module for instructing the computer to receive the data frames which are retransmitted from the other communication apparatus after a certain period of time has passed without sending the block acknowledgement frame, the data frames retransmitted from the other communication apparatus including both data frames which are correctly received and incorrectly received.

19. A computer readable storage medium storing instructions of a computer program for receiving a plurality of data frames from an other communication apparatus and for sending back a block acknowledgement frame including a plurality of information, each indicating whether the corresponding data frame is correctly received or incorrectly received, the computer program which when executed by a computer results in performance of steps comprising:

a program module for instructing a computer to receive the data frames which are transmitted from the other communication apparatus;

a program module for instructing the computer to check whether each data frame is received correctly or incorrectly;

a program module for instructing the computer to detect a number of incorrect data frames or PER from the data frames received;

a program module for instructing the computer to measure remaining battery power;

a program module for instructing the computer to determine whether or not to send the block acknowledgement frame by comparing a threshold and either the number of incorrect data frames or the PER, the threshold being based on the remaining battery power; and

a program module for instructing the computer to receive the data frames which are retransmitted from the other communication apparatus after a certain period of time has passed without sending the block acknowledgement frame, the data frames retransmitted from the other communication apparatus including both data frames which are correctly received and incorrectly received.