850-894MHz CDMA Mobilephone Signal
CDMA is a common 3G signal frequency, which is mainly used to block SMS signals and can effectively solve students' text messages in class. Despite the fact that 4G signals are now available, the simple 4G jammer does not prevent students from sending text messages because of the frequency range. If you need a cell phone jammer that prevents students from cheating on exams, it is best to choose interference devices that can block both CDMA and 4G signals at the same time.
Currently, in China, Japan and other countries have started to use such jamming devices to prevent students cheating in exam and distracting themselves in class.