Frame aggregation format

• US 20050152359A1
• Filed: 09/30/2004
• Published: 07/14/2005
• Est. Priority Date: 12/23/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.)
• Inventors: Giesberts, Pieter-Paul S., van Leeuwen, Richard M.
• Granted Patent: US 7,590,118 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/26 Special purpose or proprietary protocols or architectures network applications for proprietary or special purpose networking environments H04L67/12
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• 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
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A frame format for frame aggregation into a physical-layer packet employs an aggregated frame descriptor appended to one or more sub-frames. Each sub-frame comprises a header comprising logical-layer and sub-frame protocol information, optional verification information to verify the sub-frame data, and aggregated user data. The aggregated frame descriptor includes information identifying the packet as conforming to an aggregated frame format, and sub-frame descriptors identifying at least one of a position, a length, and a data rate of a corresponding sub-frame. The aggregated frame is then formed into a physical layer packet for transmission through a medium.

Claims

1. A method of generating an aggregate frame for a plurality of sub-frames, each sub-frame containing user data, the method comprising the steps of:

(a) forming an aggregate data unit (ADU) from two or more sub-frames; and

(b) adding an aggregated frame descriptor to the ADU to generate the aggregated frame, wherein the aggregate frame descriptor includes an aggregate frame header indicating a type of frame, a number of sub-frames of the ADU, and a sub-frame descriptor for each of the two or more sub-frames, each sub-frame descriptor including an address of a receiving device for the corresponding sub-frame.

2. The invention as recited in claim 1, further comprising the step of adding an aggregate error control field to the ADU, the aggregate error control field having error detection/correction information for the aggregate frame.

3. The invention as recited in claim 2, wherein the added aggregate error control field is a frame checksum.

4. The invention as recited in claim 1, further comprising the step of generating a physical layer packet from the aggregate frame.

5. The invention as recited in claim 4, further comprising the step of transmitting the physical layer packet through a medium.

6. The invention as recited in claim 4, wherein the step of generating the physical layer packet comprises the step of adding a preamble and a physical layer header.

7. The invention as recited in claim 1, wherein step (a) further comprises the step of ordering the position of each of the sub-frames in the ADU based on a data rate of the sub-frame.

8. The invention as recited in claim 1, wherein, for step (a), the position of each of the sub-frames in the ADU is ordered based on differing data rates of the sub-frames.

9. The invention as recited in claim 1, wherein, for step (a), the position of each of the sub-frames in the ADU is ordered based on increasing data rate.

10. The invention as recited in claim 1, wherein, for step (a), each sub-frame comprises a sub-frame header and sub-frame data.

11. The invention as recited in claim 10, wherein, for step (a), each sub-frame further comprises a sub-frame error control field having error detection/correction information for the sub-frame.

12. The invention as recited in claim 1, wherein, for step (b), the aggregate frame header comprises a frame control field indicating the type of frame is an aggregate frame.

13. The invention as recited in claim 12, wherein, for step (b), the aggregate frame descriptor further comprises an error control field having error detection/correction information for the aggregate frame descriptor.

14. The invention as recited in claim 1, wherein, for step (b), each sub-frame descriptor comprises an address corresponding to a receiving device for the associated sub-frame, and position information identifying a position of the associated sub-frame within the aggregate frame.

15. The invention as recited in claim 14, wherein, for step (b), each sub-frame descriptor comprises an error control field having error detection/correction information for the corresponding sub-frame.

16. The invention as recited in claim 1, wherein the method is implemented as steps in a processor of an integrated circuit (IC).

17. The invention as recited in claim 16, wherein the IC is embodied in a device operating in accordance with an IEEE 802.11 standard for wireless local area networks.

18. Apparatus for generating an aggregated frame for a plurality of sub-frames, the apparatus comprising:

a first circuit adapted to form an aggregate data unit (ADU) from two or more sub-frames; and

a second circuit adapted to add an aggregated frame descriptor to the ADU to generate the aggregated frame, wherein the aggregate frame descriptor includes an aggregate frame header indicating a type of frame, a number of sub-frames of the ADU, and a sub-frame descriptor for each of the two or more sub-frames, each sub-frame descriptor including an address of a receiving device for the corresponding sub-frame.

19. A method of processing a packet by a receiving device, the method comprising the steps of:

(a) receiving a frame type of the packet;

(b) receiving, if the frame type is an aggregate frame, one or more descriptors corresponding to one or more sub-frames of the packet;

(c) determining, for each descriptor, whether the corresponding sub-frame is for the receiving device

(d) extracting, for each sub-frame determined to be for the receiving device, a corresponding data frame.

20. The invention as recited in claim 19, further comprising the step of verifying, for each sub-frame determined to be for the receiving device, error detection/correction information corresponding to the sub-frame.

21. The invention as recited in claim 20, further comprising the step of correcting one or more errors based on the error detection/correction information.

22. The invention as recited in claim 19, wherein step (d) comprises the step of detecting the position and length of the sub-frame in the packet.

23. The invention as recited in claim 19, wherein the method is implemented as steps in a processor of an integrated circuit (IC).

24. The invention as recited in claim 23, wherein the IC is embodied in a device operating in accordance with an IEEE 802.11 standard for wireless local area networks.

25. A receiving device for processing a packet comprising:

a first circuit adapted to receive, if a frame type of the packet is an aggregate frame, one or more descriptors corresponding to one or more sub-frames of the packet;

a second circuit adapted to i) determine, for each descriptor, whether the corresponding sub-frame is for the receiving device and ii) extract, for each sub-frame determined to be for the receiving device, a corresponding data frame.

26. A computer-readable medium having stored thereon a plurality of instructions, the plurality of instructions including instructions which, when executed by a processor, cause the processor to implement a method for generating an aggregate frame for a plurality of sub-frames, each sub-frame containing user data, the method comprising the steps of:

(a) forming an aggregate data unit (ADU) from two or more sub-frames; and

(b) adding an aggregated frame descriptor to the ADU to generate the aggregated frame, wherein the aggregate frame descriptor includes an aggregate frame header indicating a type of frame, a number of sub-frames of the ADU, and a sub-frame descriptor for each of the two or more sub-frames, each sub-frame descriptor including an address of a receiving device for the corresponding sub-frame.

27. A computer-readable medium having stored thereon a plurality of instructions, the plurality of instructions including instructions which, when executed by a processor, cause the processor to implement a method for generating an aggregated frame for a plurality of sub-frames, the method comprising the steps of:

(a) receiving a frame type of the packet;

(b) receiving, if the frame type is an aggregate frame, one or more descriptors corresponding to one or more sub-frames of the packet;

(c) determining, for each descriptor, whether the corresponding sub-frame is for the receiving device

(d) extracting, for each sub-frame determined to be for the receiving device, a corresponding data frame.