CSMA with dynamic persistence
AssigneeTetherless Access Ltd. (TAL)
InventorsDean A. Angelico, James A. Hayes
Life of this patent
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Abstract
A method and apparatus for dynamically determining the persistence value P at a node in a P-persistent CSMA wireless network by determining the number of nodes to which the given node has an established link and which have transmitted within a preceding period of time is provided. The preceding period of time is between 5-60 seconds, preferably approximately 10 seconds. The value of P is set to a value between 1/(0.5N+1) and 1/(2N+1), preferably approximately 1/(N+1).
Claims18
A method for dynamically determining the persistence value P at a given node in a P-persistent CSMA wireless network, comprising the steps of:
- monitoring communications over said wireless network;
- determining a number N of nodes having transmitted within a preceding period of time prior to a request to transmit a given message at said given node;
- setting P to a value between 1/(0.5N+1) and 1/(2N+1);
- generating a random number at said given node;
- comparing said random number to P;
- and
- transmitting said given message from said given node if said random number is less than P, otherwise delaying at least a delay period of time before transmitting.
A method for dynamically determining the persistence value P at a given node in a P-persistent CSMA wireless network, comprising the steps of:
- monitoring communications over said wireless network;
- transmitting to nodes on said wireless network to determine the existence of a two-way communication link;
- determining a number X of said nodes in said wireless network having a two-way communication link with said given node;
- determining a number of N of said X nodes having transmitted within a preceding period of time between 5 and 60 seconds prior to a request to transmit a given message at said given node;
- setting P to a value between 1/(0.5N+1) and 1/(2N+1);
- generating a random number at said given node;
- comparing said random number to P;
- and
- transmitting said given message from said given node if said random number is less than P, otherwise delaying at least a delay period of time before transmitting.
An apparatus for dynamically determining the persistence value P at a given node in a P-persistent CSMA wireless network, comprising:
- means for monitoring communications over said wireless network;
- means for determining a number of N of nodes having transmitted within a preceding period of time prior to a request to transmit a given message at said given node;
- means for setting P to a value between 1/(0.5N+1 and 1/(2N+1);
- means for generating a random number at said given node;
- means for comparing said random number to P;
- and
- means for transmitting said given message from said given node if said random number is less than P, otherwise delaying at least a delay period of time before transmitting.
An apparatus for dynamically determining the persistence value P at a given node in a P-persistent CSMA wireless network, comprising:
- means for monitoring communications over said wireless network;
- means for transmitting to nodes on said wireless network to determine the existence of a two-way communication link;
- means for determining a number X of said nodes in said wireless network having a two-way communication link with said given node;
- means for determining a number of N of said X nodes having transmitted within a preceding period of time between 5 and 60 seconds prior to a request to transmit a given message at said given node;
- means for setting P to a value between 1/(0.5N+1) and 1/(2N+1);
- means for generating a random number at said given node;
- means for comparing said random number to P;
- and
- means for transmitting said given message from said given node if said random number is less than P, otherwise delaying at least a delay period of time before transmitting.
Dependencies are inferred from the claim text.