Wireless Sensor Networks (WSNs) have to be autonomous and less dependent to human's intervening. Most of the scenarios need WSNs for continuous monitoring and it has to be for months or years. However, achieving so, has not been trivial since power consumption affects directly WSNs' lifetime. A sensor node's power supply is the most precious part. Therefore, the idea is to reduce the wasted energy by sensor node as much as possible without raising a trade-off between WSN's performance and energy consumption. Due to the unpredictability of incoming messages from other nodes, asynchronous triggering is a reliable solution to get over the idle listening of radio transceiver. In particular, Wake-Up receivers (WRx) are represented as a solution to take the lead for receiving the wake-up signal. They consume few µW while the whole node remains in sleep mode. On the other hand, MAC protocols can lead to similar results and they are easier to implement, but they suffer from longer communication latency. We have chosen to use B-MAC protocol since its flexibility results in better packet delivery rates, throughput, latency and energy consumption. Moreover, Energy Harvesting solutions can be additional power supplies side-by-side to batteries. In this paper, we demonstrate the efficiency of Medium Access Control protocol implemented in wireless nodes. Therefore, this creates the possibility to power them using Energy Harvesting Modules.