Access systems and methods for a shared communication medium
AssigneeAlcatel Lucent
InventorsSudhakar Ganti, Bijan Raahemi
Life of this patent
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Abstract
Priority-based access systems and methods for shared communication media are provided. The priority and a corresponding weight of traffic to be transmitted on a shared communication medium are determined. This determination may be made, for example, before a first attempt to transmit the traffic, or before a subsequent traffic transmission attempt following an unsuccessful transmission attempt. The weight controls a rate of change of an exponential delay range limit factor in proportion to a number of attempts to transmit the traffic. The resultant weighted delay range limit factor is used to determine a range of delays from which a delay is selected. A transmission back-off time is then determined based on the selected delay.
Claims37
A method of accessing a shared communication medium, comprising:
- determining a priority of traffic to be transmitted on the shared communication medium;
- obtaining a weighted delay range limit factor by applying a weight, in an exponent of an exponential factor for limiting a range of delays, to a number of attempts to transmit the traffic, the weight being based on the priority and controlling a rate of change of the exponent with a change in the number of attempts to transmit the traffic;
- determining a range of delays based on the weighted delay range limit factor;
- calculating a back-off time based on a delay within the range of delays;
- and
- transmitting the traffic on the shared communication medium after the back-off time has elapsed.
A system for providing access to a shared communication medium, comprising:
- a transmitter configured to transmit traffic on the shared communication medium;
- and
- a flow controller configured to determine a priority of the traffic, to obtain a weighted delay range limit factor by applying a weight, in an exponent of an exponential factor for limiting a range of delays, to a number of attempts to transmit the traffic, the weight being based on the priority and controlling a rate of change of the exponent with a change in the number of attempts to transmit the traffic, to calculate a back-off time based on a delay within a range of delays determined using the weighted delay range limit factor, and to control the transmitter to transmit the traffic after the back-off time has elapsed.
An interface card for an access device having a plurality of interfaces configured to receive traffic from a plurality of traffic sources, the interface card for providing access to a shared communication medium and comprising:
- a plurality of transmitters configured to transmit on the shared communication medium traffic received from respective ones of the plurality of interfaces;
- and
- a plurality of flow controllers respectively associated with the plurality of interfaces and the plurality of transmitters, each flow controller being configured to determine a priority of traffic received from its associated interface, to obtain a weighted delay range limit factor by applying a weight, in an exponent of an exponential factor for limiting a range of delays, to a number of attempts to transmit the traffic, the weight being based on the priority and controlling a rate of change of the exponent with a change in the number of traffic transmission attempts, to calculate a back-off time based on a delay within a range of delays determined using the weighted delay range limit factor, and to control its associated transmitter to transmit the traffic based on the calculated back-off time.
An Ethernet communication network access method comprising:
- detecting a collision for traffic transmitted in the Ethernet communication network;
- determining a priority and corresponding weight for the transmitted traffic;
- calculating a back-off time based on a randomly selected delay;
- and
- re-transmitting the transmitted traffic after the back-off time has elapsed,
- wherein the delay is selected from a delay range defined by a weighted delay range limit factor obtained by applying the weight, in an exponent of an exponential limit factor for limiting the delay range, to a number of attempts to transmit the traffic, the weight controlling a rate of change of the exponent with a change in the number of traffic transmission attempts.
An access device for an Ethernet communication network, comprising:
- a transceiver configured to transmit and receive traffic on a shared Ethernet communication medium;
- and
- a flow controller configured to detect a collision of transmitted traffic on the shared Ethernet communication medium, to determine a priority of the transmitted traffic and a corresponding weight, and to re-transmit the transmitted traffic after a delay has elapsed,
- wherein the delay is randomly selected from a delay range defined by a weighted delay range limit factor obtained by applying the weight, in an exponent of an exponential limit factor for limiting the delay range, to a number of attempts to transmit the traffic, the weight controlling a rate of change of the exponent with a change in the number of traffic transmission attempts.
Dependencies are inferred from the claim text.