Encrypted Wireless Communication System on UHF Frequency Based on Text Messages

Abstract

Communication is a habitual thing for every human, whetherit's communicating directly orindirectly. When a natural

disaster happens, problems can occur on communication systems. These problems can lead to information being not

received properly, so the two parties communicating didn’t know the content of the message. In this situation,

a two-way radio device is the best solution that can be used to communicate. A two-way radio device enables the user

to communicate without any cellular network or internet, because the radio can be both a transceiver or a receiver

in its own frequency. A common two-way radio device uses UHF frequency range (400 MHz - 520 MHz) because

of the characteristics of this frequency range that can penetrate buildings or vegetation that usually interfere with the

radio signal. However, a two-way radio device has a broadcast and unencrypted characteristic, so that every

conversation that is happening between the radio users can be heard by other users. In an emergency situation such

as a natural disaster, important and confidential information shouldn’t be heard by an unauthorized person. So in

this project, the writers have a goal to design an encrypted text based communication system that works on the UHF

frequency band.