Wireless terminal and wireless communication method

• US 20070230433A1
• Filed: 05/25/2007
• Published: 10/04/2007
• Est. Priority Date: 11/26/2004
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yamada, Kenji, Okamasu, Takayuki
• Granted Patent: US 8,270,379 B2
• Time in Patent Office: Days
• US Class Current: 370/347
• CPC Class Codes: H04L 1/1657 Implicit acknowledgement of correct or incorrect reception, e.g. with a moving window
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A wireless terminal and wireless communication method that can improve data transfer efficiency and reduce traffic. A frame transmitter of a wireless terminal transmits a frame by wireless. A wireless terminal receives the frame transmitted from the frame transmitter and transmits the received frame by wireless to a wireless terminal. A frame receiver receives the frame transmitted from the succeeding wireless terminal to the wireless terminal. When the frame is received by the frame receiver, a frame reception recognizer recognizes that the frame has been received by the succeeding wireless terminal. It is therefore unnecessary for the wireless terminal to receive, from the succeeding wireless terminal, a frame indicative of reception of the frame, so that the data transfer efficiency improves and the traffic reduces.

Claims

1. A wireless terminal constituting an ad-hoc network to perform communication, comprising:

frame transmitter means for transmitting a frame by wireless;

frame receiver means for receiving the frame transmitted by wireless from a succeeding wireless terminal, which has received the frame, to another wireless terminal; and

frame reception recognizer means, responsive to reception of the frame by the frame receiver means, for recognizing that the frame has been received by the succeeding wireless terminal.

2. The wireless terminal according to claim 1, further comprising:

identifier memory means for storing an identifier assigned to the frame transmitted by wireless from the frame transmitter means; and

identifier comparator means for comparing the identifier of the frame received by the frame receiver means with the identifier stored in the identifier memory means,

wherein, if the identifier comparator means provides a comparison result indicating coincidence of the identifiers, the frame reception recognizer means recognizes that the frame has been received by the succeeding wireless terminal.

3. The wireless terminal according to claim 2, wherein, when the wireless terminal is an originating wireless terminal, the wireless terminal further comprises identifier assigning means for assigning the identifier to the frame to be transmitted by wireless from the frame transmitter means.

4. The wireless terminal according to claim 1, wherein, when the wireless terminal is a last wireless terminal, the wireless terminal further comprises response frame transmitter means operative in response to reception of the frame from a preceding wireless terminal to transmit a response frame to the preceding wireless terminal.

5. The wireless terminal according to claim 1, wherein when the succeeding wireless terminal is a last wireless terminal, the wireless terminal further comprises response frame receiver means for receiving, from the succeeding wireless terminal, a response frame indicative of reception of the frame.

6. The wireless terminal according to claim 1, wherein, if the frame receiver means does not receive the frame within a predetermined time, the frame transmitter means retransmits the frame.

7. The wireless terminal according to claim 1, wherein, when the frame retransmitted from a preceding wireless terminal is received and if the frame has already been received and transmitted to the succeeding wireless terminal, the wireless terminal transmits, to the preceding wireless terminal, a completion-of-transmission frame indicative of completion of transmission of the frame.

8. The wireless terminal according to claim 1, wherein the frame receiver means receives, from a last wireless terminal, a response frame indicative of reception of the frame.

9. The wireless terminal according to claim 1, wherein the frame receiver means receives the frame also from a wireless terminal following the succeeding wireless terminal.

10. The wireless terminal according to claim 1, further comprising:

information memory means for storing information which is attached to the frame and which varies each time the frame is relayed; and

frame transmission decision means for looking up the information to determine a wireless terminal which has transmitted the frame.

11. The wireless terminal according to claim 1, wherein the frame transmitter means receives the frame from a preceding wireless terminal and transmits the received frame by wireless to the succeeding wireless terminal.

12. A wireless communication method for a wireless terminal constituting an ad-hoc network to perform communication, comprising the steps of:

transmitting a frame by wireless;

receiving the frame transmitted by wireless from a succeeding wireless terminal, which has received the frame, to another wireless terminal; and

recognizing, in response to reception of the frame, that the frame has been received by the succeeding wireless terminal.