Data communication system

• US 20080031138A1
• Filed: 08/01/2007
• Published: 02/07/2008
• Est. Priority Date: 08/02/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Okamasu, Takayuki, Yamada, Kenji
• Granted Patent: US 8,638,677 B2
• Time in Patent Office: Days
• US Class Current: 370/236
• CPC Class Codes: H04L 1/1685 the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 1/1825 Adaptation of specific ARQ protocol parameters according to transmission conditions
• CPC Class Codes: H04L 1/1858 Transmission or retransmission of more than one copy of acknowledgement message
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements

Abstract

In a data communication system which reduces traffic on a wireless network by reducing Ack responses, on a transmitting side, an Ack request provided within a wireless data frame is validated (turned “ON”) to be transmitted; and an Ack request cycle is extended when an Ack in response to the Ack request has been received within a fixed time (timeout period “To”) during a cycle for transmitting the Ack request while if otherwise, the cycle is shortened. On a receiving side, only in case that a frame identifier indicating a sequence of an Ack request is found to be an expected one and the present Ack request receiving interval is found to be longer than the last Ack request receiving interval, a redundant transmission frequency of the Ack in response to the Ack request is decreased while the Ack request receiving interval is updated to the present interval in either case.

Claims

1. A data transmitting method comprising:

a first step of validating an Ack request provided within a wireless data frame to be transmitted; and

a second step of extending or shortening a cycle for transmitting the Ack request depending on whether or not an Ack in response to the Ack request has been received within a fixed time during the cycle.

4. The data transmitting method as claimed in claim 1, further comprising a third step of invalidating the Ack request when the wireless data frame is received.

2. A data receiving method comprising:

a first step of determining whether or not a frame identifier indicating a sequence of an Ack request provided in a received wireless data frame is an expected one, and whether or not a present Ack request receiving interval is longer than a last Ack request receiving interval; and

a second step of decreasing a redundant transmission frequency of an Ack in response to the Ack request only in case that the frame identifier is found to be an expected one and the present Ack request receiving interval is found to be longer than the last Ack request receiving interval at the first step and otherwise increasing the redundant transmission frequency while updating the Ack request receiving interval to the present interval in either case.

3. The data receiving method as claimed in claim 2, wherein only when the Ack request is valid the frame identifier is set in the wireless data frame.

5. A data transmitting apparatus comprising:

a first means validating an Ack request provided within a wireless data frame to be transmitted; and

a second means extending or shortening a cycle for transmitting the Ack request depending on whether or not an Ack in response to the Ack request has been received within a fixed time during the cycle.

8. The data transmitting apparatus as claimed in claim 5, further comprising a third means invalidating the Ack request when the wireless data frame is received.

6. A data receiving apparatus comprising:

a first means determining whether or not a frame identifier indicating a sequence of an Ack request provided in a received wireless data frame is an expected one, and whether or not a present Ack request receiving interval is longer than a last Ack request receiving interval; and

a second means decreasing a redundant transmission frequency of an Ack in response to the Ack request only in case that the frame identifier is found to be an expected one and the present Ack request receiving interval is found to be longer than the last Ack request receiving interval by the first means and otherwise increasing the redundant transmission frequency while updating the Ack request receiving interval to the present interval in either case.

7. The data receiving apparatus as claimed in claim 6, wherein only when the Ack request is valid the frame identifier is set in the wireless data frame.