Data link layer tunneling technique for high-speed data in a noisy wireless environment

• US 8,407,548 B2
• Filed: 07/11/2012
• Issued: 03/26/2013
• Est. Priority Date: 10/24/2000
• Status: Expired due to Fees

• Current Assignee: AT&T Wireless Services Incorporated (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Chintada, Lakshmana Rao, Hong, Liang A., Moinzadeh, Kamyar
• Primary Examiner(s): CHAUDRY, MUJTABA M
• Application Number:
  US13/546,533
• Publication Number:
  US 20120275308A1
• Time in Patent Office: 258 Days
• Field of Search: 714/749, 714/751, 370/236
• US Class Current: 714/749
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/189 Transmission or retransmission of more than one copy of a message
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365

Abstract

A data link layer tunneling technique improves the throughput of high speed data in noisy wireless environments. Recovering lost frames transmitted between a packet sending unit and a packet receiving unit in a data communications system generally comprises (a) identifying a failure to successfully receive a missed frame at the packet receiving unit; (b) establishing a logical tunnel channel at the packet receiving unit to acknowledge the next successfully received frame; (c) starting a first timer at the packet receiving unit; (c) upon receiving a tunnel establishment request from the packet receiving unit, the packet sending unit resending the missed frame on the logical tunnel channel and starting a second timer; and (d) the packet sending unit resending the missed frame a specified number of times until receiving an acknowledgement from the packet receiving unit.

Claims

1. A method comprising:

at a data receiving unit, receiving a first frame via a first channel;

at the data receiving unit, determining a first sequence number of the first frame;

at the data receiving unit, determining that a second frame associated with a second sequence number has not been received within a sliding window of a sliding window protocol, wherein the second sequence number is less than the first sequence number;

at the data receiving unit, responsive to determining that the second frame has not been received, establishing a logical tunnel channel with a data sending unit;

transmitting, from the data receiving unit to the data sending unit via the logical tunnel channel, a first request for retransmission of the second frame, the first request comprising an indication of a number of consecutively missed frames, wherein use of the logical tunnel channel allows a transmit window to advance without detecting an acknowledgement of receipt of the second frame;

at the data receiving unit, starting a first timer;

at the data receiving unit, detecting an expiration of the first timer before the second frame is received; and

at the data receiving unit, responsive to detecting the expiration of the first timer before the second frame is received, transmitting, to the data sending unit via the logical tunnel channel, a second request for retransmission of the second frame, the second request comprising an indication of a number of consecutively missed frames.

2. The method of claim 1, further comprising receiving the second frame via the logical tunnel channel.

3. The method of claim 2, further comprising transmitting the acknowledgement of receipt of the second frame via the logical tunnel channel.

4. The method of claim 1, further comprising receiving the second frame via the first channel.

5. The method of claim 4, further comprising transmitting the acknowledgement of receipt of the second frame via the logical tunnel channel.

6. The method of claim 1, further comprising transmitting a predetermined number of requests for retransmission of the second frame via the logical tunnel channel.

7. The method of claim 1, further comprising recovering the second frame using an alternative method.

8. A method comprising:

at a data sending unit, transmitting a first frame and subsequently transmitting a second frame to a data receiving unit via a first channel;

at the data sending unit, responsive a request from the data receiving unit to establish a logical tunnel channel, establishing the logical tunnel channel with the data receiving unit;

advancing a transmit window at the data sending unit without receiving an acknowledgement of receipt of the first frame;

receiving, at the data sending unit from the data receiving unit via the logical tunnel channel, a first request for retransmission of the first frame, the first request comprising an indication of a number of consecutively missed frames;

responsive to receiving the first request, transmitting the first frame from the data sending unit to the data receiving unit via the logical tunnel channel;

at the data sending unit, starting a first timer;

at the data sending unit, detecting an expiration of the first timer before an acknowledgement of receipt of the first frame is received; and

at the data sending unit, responsive to detecting the expiration of the first timer before the acknowledgement of receipt of the first frame is received, transmitting, to the data receiving unit via the logical tunnel channel, the first frame.

9. The method of claim 8, further comprising transmitting additional subsequent frames without receiving the acknowledgement of receipt of the first frame.

10. The method of claim 8, further comprising receiving the acknowledgement of receipt of the first frame via the logical tunnel channel.

11. The method of claim 8, further comprising transmitting the first frame via the logical tunnel channel a predetermined number times.

12. The method of claim 8, further comprising assigning a first sequence number to the first frame and a second sequence number to the second frame, wherein the second sequence number is subsequent to the first sequence number.

13. The method of claim 8, wherein the first frame and the second frame comprise user data.

14. The method of claim 8, wherein the first frame and the second frame comprise a request for receipt acknowledgement.

15. A device configured to:

transmit a first frame and subsequently transmit a second frame to a second device via a first channel;

responsive a request from the second device to establish a logical tunnel channel, establish the logical tunnel channel with the second device;

advancing a transmit window without receiving an acknowledgement of receipt of the first frame;

receive, from the second device via the logical tunnel channel, a first request for retransmission of the first frame, the first request comprising an indication of a number of consecutively missed frames;

responsive to receiving the first request, transmit the first frame to the second device via the logical tunnel channel;

start a first timer;

detect an expiration of the first timer before an acknowledgement of receipt of the first frame is received at the device; and

responsive to detecting the expiration of the first timer before the acknowledgement of receipt of the first frame is received, transmit, to the second device via the logical tunnel channel, the first frame.

16. The device of claim 15, wherein the device is further configured to transmit additional subsequent frames without receiving the acknowledgement of receipt of the first frame.

17. The device of claim 15, wherein the device is further configured to receive the acknowledgement of receipt of the first frame via the logical tunnel channel.

18. The device of claim 15, wherein the device is further configured to transmit the first frame via the logical tunnel channel a predetermined number times.

19. The device of claim 15, wherein the device is further configured to assign a first sequence number to the first frame and a second sequence number to the second frame, wherein the second sequence number is subsequent to the first sequence number.

20. The device of claim 15, wherein the first frame and the second frame comprise a request for receipt acknowledgement.