  Wireless systems using low-power wireless communication protocol are rapidly
gain popularity in the license-free industrial scientific, and medical (ISM)
frequency bands. One such emerging trend in ISM frequency bands is home
automation. Historically, all the home devices were once unconnected, today are
now being connected either by a wired or wireless connection. The low-power
wireless communication protocols enable integration of all the digital home
devices into a single system and enhance end user product experience. The rapid
prototyping of these end user product using programmable radio system such as
software-defined radio (SDR) has been the game-changer in the field of home
automation. In this article, we present an overview of popular ISM bands in
different regions of the world. Furthermore, we analyze the signals from the
wireless electric switch using a software-defined radio in 433 MHz ISM band.
