The initial application of wireless networks can be traced back decades ago during World War II, when the U.S. Army used radio signals to transmit data. They developed a radio transmission technology and used very strong encryption technology. At the beginning, both the US military and the Allied forces used this technology extensively. This technology has inspired many scholars. In 1971, researchers at the University of Hawaii created the first radio communication network based on packet technology. This network, called ALOHNET, can be regarded as quite early. wireless local area network (WLAN). This earliest WLAN included seven computers using a bi-directional star topology across four Hawaiian islands, with the central computer placed on Oahu Island. From this point on, wireless networks can be said to have been officially born.