Method and apparatus for dynamic media access control in a multiple access system

Abstract

An electronic device may be operable to control access to a physical medium (e.g., airwaves, a copper cable, or an optical fiber) utilizing carrier sense multiple access (CSMA). The amount of time that the electronic device must sense the physical medium as being inactive before it permits transmission of a message onto the physical medium may be determined based on: the size of the message, the type of the message, the symbol rate at which the message is to be transmitted, and/or a channel onto which the message is to be transmitted. Similarly, other aspects of how and when electronic device transmits and/or receives on the physical medium may be controlled via one or more dynamically configurable parameters which may be configured based on characteristics of received and/or to-be-transmitted messages.

What is claimed is: 
     
         1 . A system comprising:
 an electronic device operable to control access to a physical medium utilizing carrier sense multiple access (CSMA), wherein the amount of time that said electronic device must sense said physical medium as being inactive before said electronic device permits transmission of a message onto said physical medium is determined based on the size of said message.   
     
     
         2 . The system of  claim 1 , wherein said amount of time that said electronic device must sense said physical medium as being inactive before said electronic device permits transmission of said message onto said physical medium is determined based on a type of said message. 
     
     
         3 . The system of  claim 1 , wherein said amount of time that said electronic device must sense said physical medium as being inactive before said electronic device permits transmission of said message onto said physical medium is determined based on a symbol rate at which said message is to be transmitted. 
     
     
         4 . The system of  claim 1 , wherein said amount of time that said electronic device must sense said physical medium as being inactive before said electronic device permits transmission of said message onto said physical medium is determined based on a channel onto which said message is to be transmitted. 
     
     
         5 . The system of  claim 1 , wherein:
 said message is in response to a request received by said electronic device via said physical medium; and   said channel onto which said message is to be transmitted is determined based on a field of said received request.   
     
     
         6 . The system of  claim 5 , wherein:
 said field of said received request comprises a list of channels;   said electronic device sequentially listen to channels in said list of channels until a channel meeting certain requirements is found or until a timeout occurs.   
     
     
         7 . The system of  claim 1 , wherein:
 said message is in response to a request received via said physical medium by said electronic device; and   the maximum amount of time that said electronic device attempts to transmit said message onto said physical medium is determined based on a field of said previously-received request message.   
     
     
         8 . The system of  claim 1 , wherein:
 said message is in response to a request received via said physical medium by said electronic device; and   while said message is pending transmission, a portion of said electronic device alternates between a listen state and a wait state, wherein the amount of time that said portion of said electronic device spends in one or both of said listen state and said wait state is determined based on one or more fields of said received request.   
     
     
         9 . The system of  claim 8 , wherein said one or more fields of said received request determine an equation and/or algorithm utilized by said electronic device for said determining said amount of time that said portion of said electronic device spends in one or both of said listen state and said wait state. 
     
     
         10 . The system of  claim 1 , wherein said electronic device comprises memory and a receiver and is operable to:
 read a series of n-tuples from said memory, each of said n-tuple comprising a channel identifier, a scan duration value, and a time-to-next-scan value; and   for each of said read n-tuples:
 configure said receiver to receive on the channel associated with said channel identifier for an amount of time equal to said scan duration value; and 
 power-down said receiver for an amount of time equal to said time-to-next-scan value minus said scan duration value. 
   
     
     
         11 . The system of  claim 1 , wherein said electronic device comprises memory, a transmitter, and a receiver and is operable to:
 read a series of n-tuples from said memory, each of said n-tuple comprising a channel identifier, a contention period value, and a time-to-next-scan value; and   for each of said read n-tuples:
 configure said transmitter to transmit a beacon on the channel associated with said channel identifier; 
 configure said receiver to listen for a response to said beacon for an amount of time equal to said contention period value; and 
 wait a period of time equal to said time-to-next-scan value minus said contention period value before operating based on the next n-tuple in said series of n-tuples. 
   
     
     
         12 . A method comprising:
 in an electronic device which utilizes carrier sense multiple access (CSMA) for communicating over a physical medium:
 determining the amount of time that said electronic device must sense said physical medium as being inactive before permitting transmission of a message onto said physical medium based on the size of said message. 
   
     
     
         13 . The method of  claim 12 , wherein said determining said amount of time that said electronic device must sense said physical medium as being inactive before said electronic device permits transmission of said message onto said physical medium is based on a type of said message. 
     
     
         14 . The method of  claim 12 , wherein said determining said amount of time that said electronic device must sense said physical medium as being inactive before said electronic device permits transmission of said message onto said physical medium is based on a symbol rate at which said message is to be transmitted. 
     
     
         15 . The method of  claim 12 , wherein said determining said amount of time that said electronic device must sense said physical medium as being inactive before said electronic device permits transmission of said message onto said physical medium is based on a channel onto which said message is to be transmitted. 
     
     
         16 . The method of  claim 12 , wherein:
 said message is in response to a request received by said electronic device via said physical medium; and   said channel onto which said message is to be transmitted is determined based on a field of said received request.   
     
     
         17 . The method of  claim 16 , wherein:
 said field of said received request comprises a list of channels;   said electronic device sequentially listen to channels in said list of channels until a channel meeting certain requirements is found or until a timeout occurs.   
     
     
         18 . The method of  claim 12 , wherein:
 said message is in response to a request received via said physical medium by said electronic device; and   the maximum amount of time that said electronic device attempts to transmit said message onto said physical medium is determined based on a field of said previously-received request message.   
     
     
         19 . The method of  claim 12 , wherein:
 said message is in response to a request received via said physical medium by said electronic device; and   while said message is pending transmission, a portion of said electronic device alternates between a listen state and a wait state, wherein the amount of time that said portion of said electronic device spends in one or both of said listen state and said wait state is determined based on one or more fields of said received request.   
     
     
         20 . The method of  claim 19 , wherein said one or more fields of said received request determine an equation and/or algorithm utilized by said electronic device for said determining said amount of time that said portion of said electronic device spends in one or both of said listen state and said wait state.