SYSTEM AND METHOD FOR RETRANSMITTING PACKETS OVER A NETWORK OF COMMUNICATION CHANNELS

• US 20080117929A1
• Filed: 11/19/2007
• Published: 05/22/2008
• 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
• Granted Patent: US 7,742,495 B2
• Time in Patent Office: Days
• US Class Current: 370/442
• CPC Class Codes: H04B 7/212 Time-division multiple access [TDMA]
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1838 for semi-reliable protocols, e.g. for less sensitive applications such as streaming video buffer level management for video bitstream receiver H04N21/44004
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/2861 Point-to-multipoint connection from the data network to the subscribers
• 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 network of communication channels, the system comprising a set of nodes comprising at least first and second nodes and a network access coordinator operative to coordinate the access of the set of nodes to a synchronous network of channels, wherein, if at least one individual packet has been transmitted from the first node to the second node which did not receive at least one packet, the second node is operative to send a retransmission request to the network access coordinator requesting retransmission of at least one individual packet.

Claims

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

first and second nodes in communication with a coax backbone; and

a network access coordinator operative to coordinate access of the nodes to coax backbone;

wherein, if in a time period at least one first packet is transmitted by the first node to the second node, but is not received by the second node, the second node is operative to send a retransmission request to the network access coordinator, the request requesting packet retransmission.

2. The system of claim 1 wherein, when the time period is Media Access Plan (MAP) cycle n, the request occurs in MAP cycle n+1.

3. The system of claim 1 wherein the network access coordinator is operative to:

receive the request; and

accede to the request.

4. The system of claim 3 wherein the first node is operative to retransmit the packet in MAP cycle n+2.

5. The system of claim 1 wherein:

the time period is a Media Access Plan (MAP) cycle;

the network access coordinator is operative to provide in the cycle a slot for packet transmission requests; and

the first node is operative to utilize the slot to transmit to the coordinator;

a first request to transmit a packet to the second node; and

a second request that a third node retransmit a packet.

6. The system of claim 1 wherein, when the at least one packet is a plurality of packets, the second node is operative to send a single burst to the network access coordinator, the burst including retransmission requests corresponding to each of the packets in the plurality.

7. The system of claim 1 wherein:

if the time period is Media Access Plan (MAP) cycle n−

1; and

in the cycle at least one second packet is transmitted by the first node to the second node, and is received by the second node, the retransmission request;

is sent in MAP cycle n; and

requests retransmission of only the first packet.

8. The system of claim 1 wherein:

the time period is Media Access Plan (MAP) cycle n−

1;

in the cycle at least one second packet is transmitted by the first node to the second node, and is received by the second node;

the first and second packets are included in an aggregation frame;

the second packet is successfully deaggregated; and

the retransmission request is;

sent in MAP cycle n+1; and

does not request retransmission of the second packet.

9. The system of claim 1 wherein the retransmission request comprises a slot duration to be used to retransmit a first packet.

10. The system of claim 9 wherein the slot duration is computed by the first node.

11. The system of claim 1 wherein the retransmission request comprises a slot duration to be used to retransmit more than one first packet.

12. The system of claim 1 wherein the retransmission request comprises a slot duration to be used to retransmit all first packets.

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

first, second and third nodes in communication with a coax backbone;

a network access coordinator in communication with the coax backbone, the coordinator operative to;

coordinate access of the nodes to the coax backbone; and

provide a request slot in a Media Access Plan (MAP) cycle;

wherein the first node is operative to utilize the slot to transmit to the coordinator;

a first request to transmit a packet to the second node; and

a second request that the third node retransmit a packet.

14. The system of claim 13 wherein, when there is information that is common to said first and second requests, the first node is operative to transmit the information only once.

15. The system of claim 13 wherein, when in MAP cycle n−

1;

(a) at least one first packet is transmitted by the third node to the first node, but is not received by the second node; and

(b) at least one second packet is transmitted by the first node to the second node, and is received by the second node; and

the second request;

is sent in MAP cycle q and

requests retransmission of only the first packet.

16. The system of claim 13 wherein:

the first and second packets are included in an aggregation frame;

the second packet is successfully deaggregated; and

the second request not request retransmission of the second packet.

17. The system of claim 13 wherein:

the second request comprises a slot duration to be used to retransmit a first packet.

18. The system of claim 17 wherein the slot duration is computed by the first node.

19. The system of claim 13 wherein the second request comprises a slot duration to be used to retransmit more than one first packet.

20. The system of claim 13 wherein the second request comprises a slot duration to be used to retransmit all first packets.

21. A method for transmitting packets over a coax backbone, the method comprising providing a plurality of slots in a Media Access Plan (MAP) cycle for packet transmission requests sent to a coordinator by a first node in communication with the coax backbone, the node being operative to utilize at least one of the slots to transmit to the coordinator both a reservation request and a retransmission request, the reservation request including a request to transmit a first packet to a second node and the retransmission request including a request that a third node retransmit a second packet previously unsuccessfully transmitted from said third node to said first node.

22. A method for transmitting packets over a coax backbone of communication channels, the method comprising coordinating access of first and second nodes to a synchronous backbone of channels interconnecting the nodes, and receiving from the second node a retransmission request requesting retransmission of at least one individual packet if the packet was transmitted from the first node to the second node but not received by the second node.