Systems and methods for aggregation of packets for transmission through a communications network

• US 7,697,522 B2
• Filed: 10/25/2007
• Issued: 04/13/2010
• Est. Priority Date: 11/20/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Ohana, Yitshak, Kliger, Avi
• Primary Examiner(s): Shah; Chirag G
• Assistant Examiner(s): Van; Jenkey
• Application Number:
  US11/924,214
• Publication Number:
  US 20080117919A1
• Time in Patent Office: 901 Days
• Field of Search: 370/346, 370/449
• US Class Current: 370/389
• CPC Class Codes: H04L 12/2838 Distribution of signals within a home automation network, e.g. involving splitting/multiplexing signals to/from different paths adaptations of television systems for transmission by electric cable for domestic distribution H04N7/106; hybrid transport H04L12/6418; home network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04L 69/03 Protocol definition or specification protocol conformance testing H04L1/244
• CPC Class Codes: H04L 69/10 Streamlined, light-weight or high-speed protocols, e.g. express transfer protocol [XTP] or byte stream
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC

Abstract

A system for transmitting packets over a home network of communication channels, typically coax cable, including a set of nodes, at least one having a packet aggregation functionality in which the node forms an aggregation frame by aggregating one or more packets which have accumulated at the node and transmits the frame. A network coordinator coordinates access of the nodes to the channels. At least one node is operative to inform the coordinator when it has formed an aggregation frame comprising a plurality of packets and to provide the coordinator with comparison information comparing different transmission possibilities for the frame. The coordinator, preferably responsively, determines whether, when, and which of, the aggregated packets can be transmitted.

Claims

1. A system for transmitting packets over a network of communication channels, the system comprising:

a set of nodes comprising at least one node having a packet aggregation functionality in which the node forms an aggregation frame by aggregating a plurality of packets which have accumulated at the node, wherein, if at least one packet has accumulated at the node, each node is additionally operative to transmit at least one frame, each frame comprising at least one packet;

a network access coordinator, comprising at least partially a hardware component, said coordinator operative to coordinate the access of the plurality of nodes to the network of channels,

wherein at least one node is operative to inform the network access coordinator when it has formed an aggregation frame comprising a plurality of aggregated packets and to provide the network access coordinator with comparison information comparing different transmission possibilities for said aggregation frame,

wherein said comparison information comprises a comparison of the per-packet times required to transmit at least one of the aggregated packets in said aggregation frame using said different transmission possibilities;

and wherein said network access coordinator is operative responsively to determine which portion, if any, of said aggregated packets can be transmitted including determining an integral number of aggregated packets to be transmitted from among said plurality of aggregated packets.

2. A system according to claim 1 wherein said at least one node is operative to send a transmission request and wherein said network access coordinator, responsively, selectively grants or refrains from granting permission to transmit.

3. A system according to claim 2 wherein said at least one node is operative to aggregate packets which have accumulated at the node during each of a set of time intervals extending from each of the node'"'"'s transmission requests vis a vis said packets, to the next of the node'"'"'s transmission polling requests vis a vis said packets.

4. A system according to claim 2 wherein said at least one node is operative to send a transmission request periodically.

5. A system according to claim 4 wherein said at least one node is operative, in addition to sending a transmission request periodically, to send a transmission request each time a set of packets having predetermined characteristics has accumulated thereat.

6. A system according to claim 1 wherein said network access coordinator is operative to repeatedly poll the set of nodes for transmission requests, by sending polling requests to said set of nodes, and to grant at least some of said transmission requests.

7. A system according to claim 6 wherein said at least one node, having accumulated at least one packet in at least one individual class of packets, is operative to respond positively to the next polling request vis a vis said at least one class of packets.

8. A system according to claim 1 wherein said network access coordinator is operative to grant at least one transmission request to transmit an aggregation of a first plurality of packets by allocating a second plurality of slots whose combined length suffices to transmit said first plurality of packets.

9. A system according to claim 8 wherein said network access coordinator is operative to poll once per MAP (Media Access Plan) cycle.

10. A system according to claim 8 wherein said at least one node, having accumulated at least one packet in at least one individual class of packets, is operative to respond positively to a first polling request with respect to said at least one class of packets which follows a predetermined time interval after receipt of said at least one packet.

11. A system according to claim 1 wherein said aggregation frame comprises at least some of the following information:

an indication that the frame is an aggregation frame; and

an indication of the size of at least some of said packets.

12. A system according to claim 1 wherein information characterizing the aggregation frame is stored in the header of said aggregation frame.

13. A system according to claim 1 wherein said at least one node transmits each packet with:

an accompanying header having CRC (Cyclic Redundancy Check) code for the header; and

CRC code for the packet.

14. A system according to claim 1 wherein said at least one node is operative, upon receiving an aggregation frame comprising a plurality of aggregated packets, to de-aggregate said aggregated packets.

15. A system according to claim 1 wherein said network access coordinator comprises a node.

16. A system according to claim 1 wherein at least one of said channels comprises a wired channel.

17. A system according to claim 16 wherein said wired channel comprises a cable.

18. A system according to claim 1 wherein said at least one node comprises a modem having a CL (Convergence) layer, a MAC (Media Access Control) layer and a PHY (Physical) layer and wherein the packet aggregation functionality is performed at the CL layer.

19. A system according to claim 1 wherein said plurality of packets comprises packets of different classes and said at least one node is operative to aggregate packets accumulating at the node as a function of the class to which the packets belong.

20. A system according to claim 19 wherein said classes differ in at least one of the following attributes:

priority level;

membership of the packet in different flows; and

quality of service.

21. A system according to claim 20 wherein node aggregates only packets belonging to classes included in predefined classes and refrains from aggregating packets belonging to classes other than said predefined classes.

22. A system according to claim 1 wherein said at least one node is operative to aggregate no more than a predetermined maximum number of packets into each frame.

23. A method for transmitting packets over a network of communication channels interconnecting a set of nodes, the method comprising:

using a network access coordinator, comprising at least partially a hardware component, said coordinator to coordinate access of the set of nodes to the network of communication channels by granting permission to transmit to individual nodes from among the set of nodes;

forming an aggregation frame by aggregating a plurality of packets which have accumulate at a single node, informing the network access coordinator accordingly, and providing the network access coordinator with comparison information comparing different transmission possibilities for said aggregation frame;

wherein said comparison information comprises a comparison of the per-packet times required to transmit at least one of the aggregated packets in said aggregation frame using said different transmission possibilities; and

if at least one packet has accumulated at a node, transmitting at least one frame, each frame comprising at least one packet;

wherein said using step comprises determining which portion, if any, of said aggregated packets can be transmitted including determining an integral number of aggregated packets to be transmitted from among said plurality of aggregated packets.

24. A method according to claim 23 wherein said packets comprise Ethernet packets and said CL (Convergence) layer comprises an ECL (Ethernet Convergence) layer.