  The Internet of Things has affected all aspects of daily life, and the number
of IoT devices is increasing day by day. According to forecasts, the number of
Internet of Things devices will reach one trillion devices by 2035. The
increase in the number of devices connected to the Internet will cause various
concerns. One of the most important concerns is the energy and power
consumption of these devices. Although Internet of Things modules are low in
energy consumption, their widespread and large-scale use has made the issue of
power consumption become the most important challenge in this field. For this
reason, it is necessary to use communication protocols that, in addition to
establishing efficient communication, impose minimal power consumption on the
network. In this paper, application layer protocols such as MQTT, MQTT-SN,
CoAP, and HTTP are simulated using the tools available in the Contiki operating
system, including COOJA and Powertrace, and they { are evaluated} and compared
with each other in terms of power consumption. According to the simulations
performed by the mentioned tools, the MQTT-SN protocol was the least consuming
protocol in terms of power consumption. After that, the CoAP protocol is
placed, and with a slight difference, the MQTT protocol, which consumes more
than MQTT-SN. Finally, the HTTP protocol consumes the most power, which makes
it unsuitable for communication in the Internet of Things
