Method for unacknowledged data frame delivery in a noisy wireless environment

• US 5,970,063 A
• Filed: 07/31/1997
• Issued: 10/19/1999
• Est. Priority Date: 07/31/1997
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Chapman, Randy G., Wright, Andrew S.
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Tran, Maikhanh
• Application Number:
  US08/903,821
• Time in Patent Office: 810 Days
• Field of Search: 370/346, 370/465, 370/449, 340/825.07, 340/825.08, 340/825.49, 395/200.54
• US Class Current: 370/346
• 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 1/1803 Stop-and-wait protocols
• CPC Class Codes: H04L 1/1806 Go-back-N protocols
• CPC Class Codes: H04L 1/1874 Buffer management

Abstract

Fading on a data link prevents a mobile station from acknowledging a received base station poll message. Responsive thereto, the data link is transitioned to an unacknowledged mode of operation. A group of frames of a data communication are then transmitted to the mobile station with no base station expectation of receiving a mobile station acknowledgment. Following group frame transmission, the data link is transitioned back to acknowledged mode of operation. To insure delivery of the data communication, the sent frames a queued (stored) by the base station until such time as a delivery confirmation with respect to the group of frames can be obtained.

Claims

1. A method for delivering frames of a data communication from a transmit entity to a receive entity, comprising the steps of:

polling by the transmit entity for the receive entity over a data link operating in an acknowledged mode;

waiting for receipt of a polling acknowledgment from the receive entity; and

responsive to a failure to receive the polling acknowledgment;

transitioning operation of the data link to an unacknowledged mode; and

sending a group of frames of the data communication from the transmit entity to the receive entity without requiring receive entity acknowledgment.

2. The method as in claim 1 further responsive to a failure to receive the polling acknowledgment further including the step of transitioning operation of the data link back to the acknowledged mode after sending the group of frames.

3. The method as in claim 1 further responsive to a failure to receive the polling acknowledgment further including the steps of:

saving by the transmit entity of the sent group of frames;

confirming successful delivery of the sent group of frames; and

dropping the saved group of frames following confirmed delivery.

4. The method of claim 3 wherein the step of confirming comprises the steps of:

requesting by the transmit entity of a receive entity confirmation of receipt; and

receiving a confirmation acknowledgment from the receive entity.

5. The method of claim 1 further including the step of repeating the steps of polling and waiting a predetermined number of times before executing the steps of transitioning and sending.

6. The method as in claim 1 wherein the step of transitioning comprises the step of sending with each frame in the group of frames an indication that receive entity acknowledgment of the frame is not required.

7. The method as in claim 1 wherein the step of sending includes the step of sending with a last one of the frames in the group of frames an indication that the frame is the last frame in the group.

8. The method as in claim 7 further including the step of transitioning operation of the data link back to the acknowledged mode following the sending of the last frame in the group.

9. A communications system, comprising:

a transmit entity;

a receive entity; and

a data link between the transmit entity and the receive entity, the data link operating in an acknowledged mode and in an unacknowledged mode, wherein;

the transmit entity polls for the receive entity in acknowledged mode, and sends a group of frames of a data communication to the receive entity over the data link in unacknowledged mode following a receive entity failure to acknowledge the poll.

10. The system as in claim 9 wherein each frame in the sent group of frames includes an indication that receive entity acknowledgment of the frame is not required.

11. The system as in claim 9 wherein a last one of the frames in the group of frames includes an indication that the frame is the last frame in the group.

12. The system as in claim 9 wherein the transmit entity operates to store the sent group of frames of the data communication until such time as successful delivery of the group of frames to the receive entity can be confirmed.

13. A method for processing a received frame of a data communication, comprising the steps of:

determining from an indication included with the frame whether receipt of the frame should be acknowledged;

acknowledging the frame if indicated; and

otherwise;

comparing a sequence number for the frame with an expected sequence number;

discarding the frame if the sequence numbers do not match; and

passing on the frame for further handling if the sequence numbers do match.

14. The method as in claim 13 further including the steps of:

determining from an indication included with the frame whether the frame is a last frame in a group of transmitted frames; and

waiting for a next frame if the frame is not the last frame.

15. The method as in claim 14 wherein the method is executed by a mobile station operating in a wireless communications system, and further includes the steps of:

determining whether to implement power conservation measures after either discarding the frame or identifying the frame as the last frame in the group; and

taking power conservation measures if the determination is affirmative.