Low-latency packet forwarding

• US 10,148,580 B2
• Filed: 12/31/2015
• Issued: 12/04/2018
• Est. Priority Date: 04/24/2015
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Torab Jahromi, Payam, Tarighat Mehrabani, Alireza, Ibrahim, Brima Babatunde
• Primary Examiner(s): Adhami, Mohammad S
• Application Number:
  US14/986,378
• Publication Number:
  US 20160316418A1
• Time in Patent Office: 1,069 Days
• Field of Search: None
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 45/245 Link aggregation, e.g. trunking
• CPC Class Codes: H04L 45/566 Routing instructions carried by the data packet, e.g. active networks
• CPC Class Codes: H04L 47/17 Interaction among intermediate nodes, e.g. hop by hop
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 40/06 based on characteristics of available antennas

Abstract

A device implementing low latency packet forwarding may include at least one processor circuit. The at least one processor circuit may be configured to receive a packet, retrieve routing information from the packet prior to performing an integrity check on the packet, and prepare to transmit the packet based at least in part on the routing information. The routing information may be in the form of, for example, a tag, a label, or a segment, and the routing information may be retrieved from at least one of a preamble, a PHY header, or a MAC header. In the case of the preamble, the information retrieved may be used to both perform channel estimation and route the packet. In multiple-input and multiple-output (MIMO) and/or channel aggregation implementations, at least a portion of the preamble of each stream (or channel) can be combined to form the routing information.

Claims

1. A device comprising:

a memory; and

at least one processor circuit configured to;

receive a packet;

retrieve routing information from at least one of a channel estimation field or a short training field of the packet prior to performing an integrity check on the packet, the routing information being excluded from an integrity check value used for the integrity check, wherein the routing information comprises at least one of a label, a tag, or a segment; and

prepare to transmit the packet based at least in part on the routing information.

2. The device of claim 1, wherein the routing information is retrieved from the short training field.

3. The device of claim 1, wherein the routing information is retrieved from the channel estimation field.

4. The device of claim 3, wherein the routing information comprises a Golay sequence of the channel estimation field.

5. The device of claim 3, wherein the at least one processor circuit is further configured to:

perform channel estimation based at least in part on the routing information retrieved from the channel estimation field.

6. The device of claim 1, wherein the routing information comprises the label.

7. The device of claim 1, wherein preparing to transmit the packet comprises preparing a transmit path for transmitting the packet.

8. The device of claim 1, wherein the at least one processor circuit is further configured to:

transmit the packet without performing the integrity check on the packet.

9. The device of claim 1, wherein a copy of the routing information may be included in a portion of the packet that is subject to the integrity check.

10. The device of claim 9, wherein the at least one processor circuit is further configured to:

perform the integrity check on the portion of the packet that is subject to the integrity check.

11. The device of claim 1, wherein the at least one processor circuit is further configured to:

replace the routing information in a first portion of the packet with next hop routing information retrieved from a second portion of the packet.

12. A method comprising:

receiving a packet for transmission;

determining routing information corresponding to a path for the packet to reach an endpoint device, wherein the routing information comprises at least one of a label, a tag, or a segment;

inserting the routing information into a first portion of the packet, the first portion of the packet comprising at least one of a channel estimation field or a short training field;

generating an integrity check value for a second portion of the packet that is distinct from the first portion of the packet;

inserting the integrity check value into the packet; and

transmitting the packet.

13. The method of claim 12, wherein the routing information is inserted into the channel estimation field.

14. The method of claim 12, wherein the routing information comprises the tag.

15. The method of claim 12, further comprising:

inserting a copy of the routing information into the second portion of the packet prior to generating the integrity check value.

16. The method of claim 12, wherein the transmission comprises at least one of a multiple input multiple output (MIMO) transmission comprising at least a first stream and a second stream, or a channel aggregation transmission comprising at least the first stream and the second stream.

17. The method of claim 16, wherein the routing information is split between the first stream and the second stream.

18. A computer program product comprising a non-transitory computer-readable storage medium having instructions stored therein, the instructions comprising:

instructions to receive a packet;

instructions to retrieve routing information from a field of the packet used to perform channel estimation, wherein the field comprises at least one of a channel estimation field or a short training field; and

instructions to route the packet based at least in part on the routing information, wherein the routing information comprises at least one of a label, a tag, or a segment.

19. The computer program product of claim 18, wherein the field comprises the channel estimation field and the routing information comprises the segment.

20. The computer program product of claim 19, wherein the instructions to route the packet based at least in part on the routing information further comprise instructions to route the packet based at least in part on the routing information without performing an integrity check on the packet.