Packet transmission scheduling technique

• US 20030101274A1
• Filed: 11/22/2002
• Published: 05/29/2003
• Est. Priority Date: 11/24/2001
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, So Young, Yi, Seung June, Yeo, Woon Young
• Granted Patent: US 7,515,616 B2
• Time in Patent Office: Days
• US Class Current: 709/232
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/2458 Modification of priorities while in transit
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/286 Time to live
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04L 47/36 by determining packet size, e.g. maximum transfer unit [MTU]
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 92/12 between access points and access point controllers

Abstract

A packet data transmission method of the HSDPA system includes collecting information on the quality of physical channels, a status of the MAC buffer, the priority level of data, the delay of data, and the like, determining the transmission order of data and the size of a data block to be transmitted based on the collected information, and transmitting the data block through the physical according to the order of transmissions. Since the HSDPA scheduler takes into account the delay of data, the quality of real-time services can be improved.

Claims

1. A packet data transmission method of a High Speed Downline Packet Access (HSDPA) system, comprising:

collecting information on at least one of a quality of physical channels, a status of a MAC buffer, a priority level of data, and a delay of data;

determining a transmission order of data and a size of a data block to be transmitted based on the collected information; and

transmitting the data block through a physical layer according to the determined transmission order.

2. The method of claim 1, wherein the delay of data information comprises a delay of data in an upper layer.

3. The method of claim 2, wherein the delay of data in the upper layer is converted to a value in a unit of Transmission Time Interval (TTI).

4. The method of claim 2, wherein the delay of data in the upper layer comprises a value of a discard timer operated at a radio access control (RLC) layer.

5. The method of claim 2, wherein the delay of data information is transferred together with corresponding data by a transport protocol on one of a lub interface and a lur interface.

6. The method of claim 5, wherein the transport protocol uses at least one of two frame formats.

7. The method of claim 6, wherein the transport protocol selects one of two frame formats depending on a type of data to be transmitted.

8. The method of claim 7, wherein a header in each frame format of the transport protocol includes a data type field to identify the type of data being transmitted.

9. The method of claim 8, wherein the type of data is one of real-time data and non-real-time data.

10. The method of claim 7, wherein a first frame format of the transport protocol comprises a data priority field.

11. The method of claim 10, wherein the first frame format is used if the data type is non-real-time data.

12. The method of claim 10, wherein if the data type is the non-real-time service data, the data is transmitted together with data priority information using the first frame format.

13. The method of claim 7, wherein a second frame format of the transport protocol comprises a delay field.

14. The method of claim 13, wherein the second frame format is used if the data type is real-time data.

15. The method of claim 13, wherein if the data type is the real-time data, the data is transmitted together with delay information in the upper layer using the second frame format.

16. The method of claim 6, wherein a single frame format of the transport protocol comprises both a priority field and a delay field.

17. The method of claim 16, wherein a header in the frame format of the transport protocol comprises a data type field to identify the type of data.

18. The method of claim 16, wherein the transport protocol sets the priority field when the data is non-real-time service data and sets the delay field when the data is real-time service data.

19. The method of claim 1, wherein a priority level of data is set based on the delay of data if the data is real-time service data.

20. The method of claim 19, wherein the priority level of the data becomes larger as the delay of data in the upper layer increases to reach the maximum delay limit or the delay of data increases.

21. The method of claim 1, wherein the delay information comprises a delay of data in a MAC layer.

22. The method of claim 21, wherein the delay of data in the MAC layer delay is measured by a timer separately provided at the MAC layer.

23. The method of claim 22, wherein the timer is initialized when it is acknowledged that the data is successfully transmitted or discarded.

24. The method of claim 22, wherein an initial value of the timer is set to a value that is delivered from the upper layer.

25. The method of claim 1, wherein a scheduler that is responsible for transmission of data blocks uses the delay of data information as a scheduling factor for transmissions.

26. The method of claim 25, wherein a delay of data is the delay of data in a MAC layer.

27. The method of claim 25, wherein the delay of data is a sum of a delay in a MAC layer and a delay in an upper layer.

28. The method of claim 25, wherein the scheduler compares the delay of data with a prescribed delay limit.

29. The method of claim 28, wherein the closer the delay of data comes to the prescribed maximum delay limit or the longer the delay of data is, the faster the data is transmitted.

30. The method of claim 28, wherein if the delay of data exceeds the prescribed maximum delay limit, the data is discarded and the discarded data is reported to an upper layer.

31. The method of claim 28, wherein the maximum delay limit is determined by a control plane protocol when service is being established.

32. The method of claim 31, wherein the control plane protocol uses ae Radio Network Subsystem Application Part (RNSAP) protocol on a lur interface.

33. The method of claim 31, wherein the control plane protocol uses a Node B Application Part (NBAP) protocol on a lub interface.

34. A method of packet data transmission for a High Speed Downline Packet Access (HSDPA) system, comprising:

collecting information on at least one of a quality of physical channels, a status of a MAC buffer, a priority level of data, and a delay of data;

determining a type of data to be transmitted from among non-real-time data and real-time data;

determining a transmission order of data and a size of a data block to be transmitted based on the collected information and the type of data; and

transmitting the data block through a physical layer according to the determined transmission order using a prescribed frame format, wherein the prescribed frame format indicates at least one of a delay value and a priority value and further indicates the type of data to be transmitted.

35. The method of claim 34, wherein the prescribed frame format comprises a single frame format configured to provide delay information for real-time data formats and further configured to provide priority information for non-real-time data formats, and wherein a header of the frame comprises a field to indicate the data type.

36. The method of claim 34, wherein the frame format is selected from a non-real-time data frame format and a real-time data frame format.

37. The method of claim 34, wherein the delay time is converted to priority information calculated in accordance with an amount of the delay, and wherein the frame format indicates the converted delay time as priority information.