Method and apparatus for power line communication

Abstract

The variation cycle L of the characteristics of a transmission line is divided into a plurality of sections (n sections), a procedure is repeated in which transmission line estimation is performed for only one section among n sections in one beacon period, and thus transmission line estimation is performed for all of the n sections. The beacon period T is set based on (T=L×m/n), where n is an integer that is 2 or larger, and m is an integer that is n or larger and whose greatest common measure with n is 1.

1 . A communication apparatus performing periodical communications with another communication apparatus via a transmission line, the communication apparatus comprising: 
 a communication control portion operable to set a communication period to a plurality of sections to perform communications,    a transmission line estimation portion operable to estimate the characteristics of the transmission line in a predetermined section after an offset time has passed since the communication period started, and    a communication parameter determination portion operable to determine a communication parameter to be used by the communication control portion, based on a result of estimation by the transmission line estimation portion.    
   
   
       2 . The communication apparatus according to  claim 1 , 
 wherein when receiving a beacon, to which information on time allocation for estimating the transmission line is added, the transmission line estimation portion estimates the characteristics of the transmission line based on the information.    
   
   
       3 . The communication apparatus according to  claim 2 , 
 wherein the information also includes to prohibiting other apparatuses from transferring data.    
   
   
       4 . The communication apparatus according to  claim 1 , 
 wherein the transmission line estimation portion estimates the characteristics of the transmission line based on a PHY rate of a tonemap in the predetermined section.    
   
   
       5 . A computer-readable recording medium having a program recorded thereon, the program for being executed by a communication apparatus which performs periodical communications with another communication apparatus via a transmission line, the program comprising the steps of: 
 setting a communication period to (L×m/n) (L is a variation cycle of characteristics of a transmission line, n is an integer that is 2 or larger, and m is an integer that is n or larger and whose greatest common measure with n is 1) to perform communications,    estimating the characteristics of the transmission line within a time (L/n) after a certain offset time has passed since the communication period started, and    determining a communication parameter to be used in the communicating step, based on a result of estimation in the estimating step.