Radio link protocols for a wireless communication system

• US 7,839,834 B2
• Filed: 12/22/2004
• Issued: 11/23/2010
• Est. Priority Date: 06/18/2004
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chakravarty, Sumantra, Horn, Gavin Bernard, Agrawal, Avneesh, Jain, Nikhil, Gillies, Donald William
• Primary Examiner(s): Bost; Dwayne D
• Assistant Examiner(s): Gonzalez; Amancio
• Application Number:
  US11/020,410
• Publication Number:
  US 20050281243A1
• Time in Patent Office: 2,162 Days
• Field of Search: 370/94.1, 370310-345, 709/227, 455/515, 455/517
• US Class Current: 370/343
• CPC Class Codes: H04L 1/1803 Stop-and-wait protocols
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint

Abstract

A forward link (FL) RLP and a reverse link (RL) RLP that are different in design are used for data transmission on the forward and reverse links, respectively. The asymmetric RLP designs may be quantified by, e.g., different feedback mechanisms and/or different data transmission mechanisms used for these RLPs. The FL RLP may utilize a negative acknowledgment (NAK)-based feedback mechanism whereas the RL RLP may utilize an acknowledgment (ACK)-based feedback mechanism. The NAK-based FL RLP may transmit each RLP frame once in sequential order and retransmit RLP frames out of sequence when not received correctly. The ACK-based RL RLP may transmit RLP frames in sequential order, one frame at a time until the frame is received correctly or the maximum number of transmissions have been attempted. Timers with adaptive values computed based on actual traffic conditions may be used to facilitate data transmission by the NAK-based FL RLP.

Claims

1. A method of exchanging data in a communication system, comprising:

transmitting data in accordance with a first radio link protocol (RLP) via a forward link; and

receiving data in accordance with a second RLP via a reverse link, wherein the first and second RLPs are asymmetric and have different feedback mechanisms for the first RLP via the forward link and for the second RLP via the reverse link, the forward link employing a negative acknowledge (NAK)-based feedback and the reverse link employing an acknowledgement (ACK)-based feedback;

retransmitting the transmitted data in response to receiving a NAK;

setting a NAK timer to an adaptive value when there is no more data to transmit, wherein the adaptive value of the NAK timer is a function of frame inter-arrival times at a forward link receiving entity; and

retransmitting a portion of last transmitted data upon expiration of the timer.

2. The method of claim 1, further comprising:

sending acknowledgments (ACKs) for the received data.

3. The method of claim 1, wherein the transmitting data comprises transmitting each of a plurality of data frames once and in a sequential order to a receiving entity, and

retransmitting out of sequence data frames decoded in error by the receiving entity.

4. The method of claim 1, wherein the transmitting data comprises transmitting a plurality of data frames in a sequential order, one data frame at a time until the data frame is decoded correctly by a receiving entity or a maximum number of transmissions has been reached for the data frame.

5. An apparatus in a communication system, comprising:

a first entity operative to transmit data in accordance with a first radio link protocol (RLP) via a first link, the first RLP is negative acknowledgement (NAK)-based such that negative acknowledgments (NAKs) are received for missing transmitted data; and

a second entity operative to receive data in accordance with a second RLP via a second link, the second RLP is acknowledgement (ACK)-based,

wherein the first and second RLPs are asymmetric and have different feedback mechanisms for the first RLP via the first link and for the second RLP via the second link such that the second entity receives a NAK requesting retransmission of missing transmitted data; and

a NAK timer with an adaptive value, wherein the adaptive value is determined as a function of inter-arrival times of RLP frames at a receiving entity.

6. The apparatus of claim 5, wherein the second entity is operative to send acknowledgments (ACKs) for the received data.

7. The apparatus of claim 5, wherein the first entity is operative to transmit each of a plurality of data frames once and in a sequential order to a receiving entity and to retransmit out of sequence data frames decoded in error by the receiving entity.

8. The apparatus of claim 5, wherein the first entity is operative to transmits a plurality of data frames in a sequential order, one data frame at a time until the data frame is decoded correctly by a receiving entity or a maximum number of transmissions have been reached for the data frame.

9. The apparatus of claim 5, wherein the first entity is operative to transmit data via a forward link, and wherein the second entity is operative to receive data via a reverse link.

10. The apparatus of claim 5, wherein the first entity is operative to transmit data via a reverse link, and wherein the second entity is operative to receive data via a forward link.

11. An apparatus in a communication system, comprising:

means for transmitting data in accordance with a first radio link protocol (RLP) via a first link based in part on a negative acknowledgement (NAK) scheme;

means for receiving data in accordance with a second RLP via a second link based in part on an acknowledgement (ACK) scheme, wherein the first and second RLPs are asymmetric and have different feedback mechanisms for the first RLP via the first link and for the second RLP via the second link; and

means for timing data retransmissions that can be set to an adaptive value based at least on one or more functions of inter-arrival times of RLP frames at a receiving entity.

12. The apparatus of claim 11, wherein the means for transmitting data comprises means for transmitting each of a plurality of data frames once and in sequential order by a receiving entity, and

means for retransmitting out of sequence data frames decoded in error by the receiving entity.

13. The apparatus of claim 12, wherein the means for transmitting data comprises

means for transmitting a plurality of data frames in sequential order, one data frame at a time until the data frame is decoded correctly or a maximum number of transmissions has been reached for the data frame.

14. A method of exchanging data in a communication system, comprising:

transmitting data in accordance with a first radio link protocol (RLP) via a forward link based in part on a negative acknowledgement (NAK) scheme; and

receiving data in accordance with a second RLP via a reverse link based in part on an acknowledgement (ACK) scheme, wherein the first and second RLPs are asymmetric and have different feedback mechanisms for the first RLP via the forward link and for the second RLP via the reverse link;

retransmitting missing data in response to receiving a NAK;

computing a value based on statistics of inter-arrival times for RLP frames received by the first RLP from higher layers;

setting a timer to the computed value when there is no more data to transmit; and

retransmitting a portion of last transmitted data upon expiration of the timer.

15. The method of claim 14, wherein the transmitting data in accordance with the first RLP comprises transmitting sequential order to a receiving entity, and each of a plurality of data frames once and in a retransmitting out of sequence data frames decoded in error by the receiving entity.

16. The method of claim 14, wherein the receiving data in accordance with the second RLP comprises receiving a plurality of data frames on the reverse link in a sequential order, one data frame at a time unless a maximum number of transmissions has been reached for the data frame.

17. The method of claim 14, further comprising:

sending an acknowledgment (ACK) for each data frame decoded correctly by the second RLP via the reverse link.

18. The method of claim 17, wherein the sending the ACK comprises sending the ACK on a signaling channel having a low probability of erroneous detection of an ACK if none was sent.

19. The method of claim 14, further comprising:

scheduling transmission of data on the reverse link; and

scheduling retransmission of the data if not received within a predetermined amount of time after scheduling the transmission of the data.

20. A method of exchanging data in a communication system, comprising:

receiving data in accordance with a first radio link protocol (RLP) via a forward link based in part on a negative acknowledgement (NAK) scheme; and

transmitting data in accordance with a second RLP via a reverse link based in part on an acknowledgement (ACK) scheme, wherein the first and second RLPs are asymmetric and have different feedback mechanisms for the first RLP via the forward link and for the second RLP via the reverse link;

detecting missing data in a data stream received by the first RLP;

sending a negative acknowledgment (NAK) to request retransmission of the missing data;

setting a timer by the first RLP, upon sending the NAK to an adaptive value computed in accordance with statistics of inter-arrival times for RLP frames received; and

sending another NAK upon expiration of the timer.

21. The method of claim 20, wherein the receiving data in accordance with the first RLP comprises for each of a plurality of data frames, receiving the data frame in a sequential order if transmitted once, and receiving the data frame out of sequence if retransmitted at least one due to decoding error.

22. The method of claim 20, wherein the transmitting data in accordance with the second RLP comprises transmitting a plurality of data frames in a sequential order, one data frame at a time until the data frame is decoded correctly by a receiving entity or a maximum number of transmissions has been reached for the data frame.

23. The method of claim 20, further comprising:

sending another NAK if a predetermined number of data frames are received without receiving a retransmission of the missing data requested for retransmission.

24. The method of claim 20, further comprising:

sending another NAK if data with lower priority is received prior to the missing data requested for retransmission.

25. The method of claim 20, further comprising:

receiving an acknowledgment (ACK) for each data frame transmitted by the second RLP and decoded correctly by a receiving entity; and

retransmitting each data frame for which an ACK was not received.

26. The method of claim 25, wherein the receiving the ACK for each correctly decoded data frame comprises receiving the ACK via a signaling channel having a low probability of erroneous detection of an ACK if none was sent.

27. A method of transmitting data in a communication system, comprising:

transmitting data in accordance with a first radio link protocol (RLP) via a communication link based in part on a negative acknowledgement (NAK) RLP scheme;

detecting no more data to transmit;

computing a value based an average and a mean deviation of inter-arrival times for data packets received by the RLP from higher layers;

setting a timer to the computed value;

retransmitting a portion of previously transmitted data upon expiration of the timer; and

receiving data in accordance with a second RLP via a disparate communication link based in part on an acknowledgement (ACK) RLP scheme, wherein the first RLP via the communication link and the second RLP via the disparate communication link each use a different feedback mechanism.

28. The method of claim 27, wherein computing the value comprises limiting the value to be smaller than a timeout value for a higher layer protocol transmitting the data.

29. A method of receiving data in a communication system, comprising:

receiving data frames in accordance with a first radio link protocol (RLP) via a communication link based in part on a negative acknowledgement (NAK) RLP scheme;

detecting missing data in a data stream received by the RLP via the communication link;

sending a NAK to request retransmission of the missing data;

computing a value based on statistics of inter-arrival the data frames received by the RLP;

setting a NAK timer to the computed value;

sending another NAK upon expiration of the NAK timer; and

transmitting data in accordance with a second RLP via a disparate communication link based in part on an acknowledgement (ACK) RLP scheme, wherein the first RLP via the communication link and the second RLP via the disparate communication link each use a different feedback mechanism.

30. The method of claim 29, wherein the computing the value comprises

determining an average and a mean deviation of inter-arrival times for the data frames received by the RLP, and

computing the value based on the average and the mean deviation of the inter-arrival times.

31. The method of claim 29, wherein the sending the NAK comprises sending the NAK if less than a maximum number of retransmission requests has been sent for the missing data.