Patent ID: 8004388
Filing Date: 2011-08-23
Classification: H04B

Abstract:
1. A power line communication apparatus which is assigned a band window and a communication band in alternate and cyclical fashion, said band window being one to which a coexistence signal for band reservation is assignable, said communication band being one to which desired information is assignable, said power line communication apparatus comprising: a reception processor configured to receive and process a signal from a power line communication network; a coexistence signal detector configured to detect, from the signal received by said reception processor, the presence and signal strength of said coexistence signal, and the timing of said band window which is assigned said coexistence signal; a coexistence signal generator configured to generate a coexistence signal; a transmission processor configured to process a signal and transmit the processed signal onto said power line communication network; and a controller configured to effect control to establish either coexistence mode or standalone mode at power-on, said coexistence mode being one in which said band reservation is made by causing said coexistence signal generator to generate said coexistence signal and by having said transmission processor transmitting the generated coexistence signal, said standalone mode being one in which said band reservation utilizing said coexistence signal is not carried out; said controller being further configured to effect control to make transition from one of the two modes to the other; said establishment of one of said two modes and said transition therebetween being controlled on the basis of said coexistence signal being detected by said coexistence signal detector, on the basis of the signal strength of said coexistence signal if the presence of the signal is detected, or on the basis of both the signal strength of said coexistence signal and the timing of said band window which is assigned said coexistence signal, wherein, with said standalone mode in effect, said controller effects transition to the coexistence mode when at least one band window which is assigned a coexistence signal having a signal strength of at least a predetermined level P wherein, with said coexistence mode in effect, said controller effects transition to the standalone mode when every detected coexistence signal has a signal strength of less than a predetermined level P