COMMUNICATION APPARATUS, COMMUNICATION METHOD, COMPUTER PROGRAM, AND COMMUNICATION SYSTEM

摘要

A communication apparatus which appropriately controls beam patterns while performing access control based on physical carrier sensing. The communication apparatus, in conditions when signals cannot reach the other party without beam pattern forming, transmits a frame having a long preamble and enables access control based on physical carrier sensing. In conditions when signals can sufficiently reach the other party even without beam pattern forming, the communication apparatus transmits a frame having a shorter preamble and keeps the transmission overhead low. Further, the communication apparatus determines the beam pattern and the preamble type based on the transmission-reception history of access control following the CSMA/CA method.