Selective retransmission of data

• US 20030091068A1
• Filed: 11/15/2001
• Published: 05/15/2003
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Pazhyannur, Rajesh S., Ali, Irfan, Rananand, Nol
• Granted Patent: US 7,142,542 B2
• Time in Patent Office: Days
• US Class Current: 370/474
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1838 for semi-reliable protocols, e.g. for less sensitive applications such as streaming video buffer level management for video bitstream receiver H04N21/44004
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements

Abstract

During reception of a higher-layer packet (301), segmented into lower-layer frames (302), a receiver (400) will appropriately determine if a lower-layer frame was correctly received (503). If a lower-layer frame is not correctly received, and the maximum number of NAKs have been sent, the lower-layer frame is categorized as aborted. Once a frame has been categorized as aborted, the receiver will send no more NAKs for a predetermined number of lower-layer frames (302). In particular, those lower-layer frames (302) associated with the higher-layer packet will fail to have NAKs sent even if they are improperly received.

Claims

1. A method for selective retransmission within a communication system wherein higher-layer packets are segmented and transmitted via a link-layer protocol, the method comprising the steps of:

determining that a link-layer frame needs to be aborted;

determining a set of link-layer frames (V(B)) having higher-layer packet boundaries; and

selectively retransmitting link-layer frames by setting V(N) to a next missing link-layer frame after a higher-layer packet boundary if V(B) is not an empty set, otherwise setting V(N) to V(R), wherein V(N) is a next link-layer frame needed for sequential delivery of frames and V(R) is a next new link-layer frame expected.

2. The method of claim 1 wherein the step of determining that the link-layer frame needs to be aborted comprises the step of determining that an Radio Link Protocol (RLP) frame needs to be aborted, wherein the RLP frame comprises a segment from a higher-layer Point-to-Point Protocol (PPP) packet.

3. The method of claim 1 wherein the step of determining that the link-layer frame needs to be aborted comprises the step of determining that a Radio-Link Protocol (RLP) frame needs to be aborted.

4. The method of claim 1 wherein the step of determining a set of link-layer frames having higher-layer packet boundaries comprises the step of determining a set of link-layer frames having Point-to-Point Protocol (PPP) packet boundaries.

5. In a communication system where a higher-layer packet is segmented and transmitted over a link layer utilizing a link-layer protocol, a method for selective retransmission of data, the method comprising the steps of:

receiving a link-layer frame, wherein the link-layer frame comprises data from a first higher-layer packet; and

failing to send a Negative acknowledgment (NAK) for the link-layer frame if a prior-received link-layer frame was aborted, otherwise sending the NAK.

6. The method of claim 5 wherein the step of receiving the link-layer frame comprises the step of receiving a Radio-Link Protocol (RLP) frame comprising data from a first Point-to-Point Protocol (PPP) packet.

7. The method of claim 5 wherein the step of failing to send the NAK for the link-layer frame if a prior-received link-layer frame was aborted, otherwise sending the NAK comprises the step of failing to send the NAK for the link-layer frame if a prior-received link-layer frame was aborted and the aborted frame comprises data from the first higher-layer packet, otherwise sending the NAK.

8. An apparatus comprising:

receiving circuitry having a link-layer frame as an input, the link-layer frame comprising data from a first higher-layer packet; and

transmitting circuitry failing to output a Negative Acknowledgment (NAK) for the link-layer frame if a prior-received link-layer frame was aborted, otherwise sending the NAK.

9. The apparatus of claim 8 wherein the link-layer frame is a Radio-Link Protocol (RLP) frame.

10. The apparatus of claim 8 wherein the first higher-layer packet is a first Point-to-Point Protocol (PPP) packet.

11. The apparatus of claim 10 wherein the first PPP packet is fragmented into multiple RLP frames.

12. The apparatus of claim 8 wherein the transmitting circuitry fails to output the NAK for the link-layer frame if a prior-received link-layer frame was aborted and the prior-received link-layer frame comprises data from the first higher-layer packet, otherwise the transmitting circuitry outputs the NAK.

13. An apparatus comprising:

a receiver having a poorly received link-layer frame as an input, wherein the link-layer frame comprises a segment of a higher-layer data packet; and

logic circuitry determining that the poorly received link-layer frame should be aborted, and setting V(N) to a next missing link-layer frame after a next higher-layer packet boundary if V(B) is not an empty set, otherwise setting V(N) to V(R), wherein V(N) is a next link-layer frame needed for sequential delivery of frames and V(R) is a next new link-layer frame expected.

14. The apparatus of claim 13 wherein the higher-layer data packet comprises a PPP packet.

15. The apparatus of claim 13 wherein the poorly received link-layer packet comprises a poorly-received RLP packet.