Method for distributing sets of collision resolution parameters in a frame-based communications network

• US 6,877,043 B2
• Filed: 04/04/2001
• Issued: 04/05/2005
• Est. Priority Date: 04/07/2000
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Fischer, Matthew James, Mallory, Tracy D.
• Primary Examiner(s): Najjar, Saleh
• Assistant Examiner(s): EL CHANTI, HUSSEIN A
• Application Number:
  US09/825,689
• Publication Number:
  US 20020026523A1
• Time in Patent Office: 1,462 Days
• Field of Search: 709206-207, 709216-219, 709225-226, 709251-253, 709/245, 709/238, 709/240, 709/241
• US Class Current: 709/251
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0005 applied to payload information
• CPC Class Codes: H04L 1/0006 by adapting the transmission format
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/1877 for semi-reliable protocols, e.g. for less sensitive applications like streaming video buffer level management for video bitstream control arrangements H04N21/44004
• CPC Class Codes: H04L 1/1883 using multiple timers
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 12/40032 Details regarding a bus interface enhancer
• CPC Class Codes: H04L 12/4013 Management of data rate on the bus systems modifying transmission characteristics according to link quality H04L1/0001
• CPC Class Codes: H04L 12/40136 Nodes adapting their rate to the physical link properties LAN switches H04L49/351
• CPC Class Codes: H04L 12/40156 by using dedicated slots associated with a priority level
• CPC Class Codes: H04L 12/40163 by assigning priority to messages according to a message field
• CPC Class Codes: H04L 12/403 : with centralised control, e.g. polling
• CPC Class Codes: H04L 12/4035 : in which slots of a TDMA packet structure are assigned based on a contention resolution carried out at a master unit TDM/TDMA multiplex systems per se H04J3/1694; hybrid switching systems H04L12/64
• CPC Class Codes: H04L 12/407 : with decentralised control
• CPC Class Codes: H04L 12/413 : with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 12/417 : with deterministic access, e.g. token passing
• CPC Class Codes: H04L 2001/0093 : Point-to-multipoint
• CPC Class Codes: H04L 2001/125 : Arrangements for preventing errors in the return channel
• CPC Class Codes: H04M 11/00 : Telephonic communication systems specially adapted for combination with other electrical systems
• CPC Class Codes: H04M 11/06 : Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A method for distributing sets of collision resolution parameters to be used for resolution of network access contention events among nodes of a non-centralized media access control shared medium network. A set of collision resolution parameters is provided which includes a sequence of fixed numbers for resolving a single network access contention event. A single collision signal slot master node is identified when one or more candidate collision signal slot master nodes exist. Collision signal slot request messages are sent from client nodes addressed to all network nodes. Collision signal slot assignment messages are sent from the master node to the client nodes. A collision resolution parameter set to be employed by that given client node is obtained at a given client node from within a received collision signal slot assignment message. Collision signal slot acknowledgment messages are sent from client nodes addressed to all network nodes. Collision signal slot drop messages are sent from client nodes addressed to all network nodes.

Claims

1. A method for distributing sets of collision resolution parameters to be used for resolution of network access contention events among nodes of a non-centralized media access control shared medium network, comprising:

providing a set of collision resolution parameters which includes a sequence of fixed numbers for resolving a single network access contention event;

identifying a single collision signal slot master node when one or more candidate collision signal slot master nodes exist;

sending collision signal slot request messages from client nodes addressed to all network nodes, wherein a collision signal slot request message includes;

a unique client identifier to indicate source of request;

an indication that a collision resolution parameter set is required by a uniquely identified requesting client node; and

an indication of number of active packet-generating channels at the uniquely identified requesting client node;

sending collision signal slot assignment messages from the master node to the client nodes, wherein a collision signal slot assignment message includes;

a list of unique client identifiers to indicate those client nodes which can find collision resolution parameter set information within the collision signal slot assignment message;

a list of collision resolution parameter set information unambiguously associated on a one-for-one matching basis with the list of unique client identifiers;

obtaining at a given client node from within a received collision signal slot assignment message a collision resolution parameter set to be employed by that given client node;

sending collision signal slot acknowledgment messages from client nodes addressed to all network nodes, wherein a collision signal slot acknowledgment message includes;

a unique client identifier to indicate source of the collision signal slot acknowledgment message; and

collision resolution parameter set information currently assigned to the uniquely identified client node; and

sending collision signal slot drop messages from client nodes addressed to all network nodes, wherein a collision signal slot drop message includes;

a unique client identifier to indicate source of the collision signal slot drop message; and

an indication that a collision resolution parameter set is no longer required by the uniquely identified client node.

2. The method of claim 1, wherein identifying a single collision signal slot master node further includes:

advertising in a collision signal slot mastership capability message sent by a candidate for collision signal slot master node an ability to become a collision signal slot master, a collision signal slot mastership capability message being a message sent at a periodic interval indicating an ability of a sending node to become a collision signal slot master, a candidate for collision signal slot master node being a node that has capability to become, or is, a collision signal slot master node; and

resolving a field of multiple collision signal slot mastership candidates to a single collision signal slot master node.

3. The method of claim 2, wherein resolving a field of multiple collision signal slot mastership candidates to a single collision signal slot master node includes selecting a candidate collision signal slot master node with a lowest valued medium access control address.

4. The method of claim 1, wherein sending collision signal slot request messages from client nodes addressed to all network nodes further includes:

determining based on a change in number of active packet-generating channels whether a collision resolution parameter set is required by the client node; and

sending a collision signal slot request message containing a new number of active packet-generating channels.

5. The method of claim 1, wherein sending collision signal slot assignment messages from the master node to the client nodes further includes:

determining to send a collision signal slot assignment message if any of the following events occur;

reception of a collision signal slot request message from a uniquely identified client node;

reception of a collision signal slot drop message from a uniquely identified client node;

or

aging of acknowledgment of any client node assignment;

having decided to send a collision signal slot assignment message, choosing a collision resolution parameter set from among the set of collision resolution parameter sets; and

sending a collision signal slot assignment message containing the selected collision resolution parameter set to the uniquely identified client node.

6. The method of claim 5, wherein choosing a collision resolution parameter set from among the set of collision resolution parameter sets further includes making a prioritized selection based on number of active packet-generating channels at the uniquely identified client node as compared to number of active packet-generating channels at other uniquely identified client nodes.

7. The method of claim 1, wherein sending collision signal slot acknowledgment messages from client nodes addressed to all network nodes further includes:

determining to send a collision signal slot acknowledgment message if any of the following events occur;

reception of a collision signal slot assignment message which contains a client node unique identifier;

expiration of a periodic timer;

client node recognizes an absence of a collision signal slot master, and has self-selected a set of collision resolution parameters;

or

client node recognizes in the absence of a collision signal slot master a currently-selected set of collision resolution parameters within a collision signal slot acknowledgment message sent by a different client;

selecting a set of-collision resolution parameters to send in the collision signal slot acknowledgment message; and

sending a collision signal slot acknowledgment message containing the selected collision resolution parameter set addressed to all network nodes.

8. The method of claim 7, wherein selecting a set of collision resolution parameters to send in the collision signal slot acknowledgment message further includes:

recognizing absence or presence of a collision signal slot master on the shared medium network;

choosing in a presence of a collision signal slot master on the network the set of collision resolution parameters from the received collision signal slot assignment message which contains the client node unique identifier;

choosing in the absence of a collision signal slot master on the network a set of collision resolution parameters such that the maximum time required for resolution of a single network access contention event among all client nodes is minimized and making a prioritized selection based on number of active packet-generating channels at the client node as compared to the number of active packet-generating channels at all of other known client nodes.

9. The method of claim 1, wherein sending collision signal slot drop messages from client nodes addressed to all network nodes further includes:

determining to send a collision signal slot drop message if any of the following events occur;

reception of a collision signal slot assignment message from a separate uniquely identified client node and containing the identical collision resolution parameter set as is currently assigned to the client node;

or

number of active packet-generating channels at a given client node becomes zero; and

sending a collision signal slot drop message containing a selected collision resolution parameter set, addressed to all network nodes.

10. The method of claim 1, wherein a set of collision resolution parameters includes an ability to specify a random number to be used for any given position within the sequence.

11. The method of claim 1, wherein a set of collision resolution parameters has a common network-wide maximum length such that a maximum length having been reached during resolution of a single network access contention event client nodes revert to the random selection for subsequent steps of the resolution of that single network access contention event.