an apparatus and a method for performing a protocol that optimizes a transmission power in a network . the apparatus and the method perform a protocol that optimizes the transmission power in the network for point - to - multipoint communication . the apparatus includes a communication unit for sending and receiving a data packet through the air , and a control unit that outputs a control signal for controlling the transmission power according to connection information of the data packet received through the communication unit . the connection information includes a reception signal strength and / or link quality information . since the transmission power is adjustable , communication is carried out among nodes of the network with an adequately minimum power consumption and a proper communication quality .