[Patent application number] 20090234932 [Published] 09-17-2009 [Description] 
COMMUNICATION APPARATUS, METHOD OF CONTROLLING SAME, AND COMMUNICATION SYSTEM - A communication apparatus operating by selectively switching between a master mode and a slave mode includes: a determination unit configured to determine whether an apparatus that operates in the master mode exists; a control unit configured to exercise control in such a manner that the communication apparatus operates in the master mode if it is determined that such an apparatus does not exist, and to exercise control in such a manner that the communication apparatus operates in the slave mode if it is determined that such an apparatus does exist; and a transceiver unit configured to transmit a message for updating the management table to the apparatus in the network in case of operation in the master mode, and to receive a message transmitted from another apparatus that operates in the master mode in case of operation in the slave mode.