Galvanic coupling intra-body communication is a low power consumption method, which is especially suitable for the Body Area Network (BAN) in medical or healthcare domain. Based on the physical layer modeling to get an insight in the propagation mechanism in the human body, it is necessary to analyze the MAC layer performance for the galvanic coupling IBC. A multi-node physiological signal monitoring and transmission system was assumed as the application scenario in this paper. Two common protocols, namely TDMA and CSMA/CA were selected to calculate and compare the energy consumption per bit in wireless networks consisting of intra-body communication and ZigBee nodes. The results showed that, due to the low power consumption during the transmitting and receiving period, the TDMA protocol in an IBC network had the lowest energy consumption of around 1.3
J/bit, which was also nearly constant with the number of nodes. The energy consumption of CSMA/CA protocol in an IBC network increased slowly along with the number of nodes, and was a little lower than the consumption of a TDMA protocol in a ZigBee network, because of the higher data rate of ZigBee. A large amount of energy was consumed in channel listening to avoid data packet collision. So the CSMA/CA protocol in a ZigBee network used the highest amount of energy per bit.