Power consumption of Transceiver in WiFi shield


I am trying to separate the transmission consist of “authentication association beacon transmitting a file” when the shield tries to connect to an access point but the problem comes when the power consumption of SPI (Serial ports) mixes in the final phase and recognizing the transmission and SPI power is hard,
Is there any way to measure the power consumption of TRANCEIVER component of WiFi shield just to monitoring transmission and recieving part?

this figure shows the voltage usage when connects to an access point