How to change ringtones on Huawei mobile phones

You can change this in the local music settings, or you can change it in our music software. Here are some irrelevant ones, sourced from Baidu Encyclopedia! ! !

In April 1973, the famous American Motorola engineering technician "Martin Cooper" invented the world's first mobile phone for civilian use. When Cooper made the world's first mobile phone call, he could use any electromagnetic spectrum. In fact, the first generation of analog mobile phones relied on different frequencies to distinguish different mobile phones for different users. The second generation of mobile phones, the GSM system, relies on extremely small time differences to distinguish users. Today, frequency resources are obviously insufficient, and mobile phone users are growing exponentially. As a result, newer CDMA technology, which relies on different encodings to distinguish different machines, came into being. Mobile phones using this technology not only have better call quality and confidentiality, but can also reduce radiation and can be called "green mobile phones."

Development History

In 1832, Faraday of England discovered the phenomenon of electromagnetic induction. Maxwell further used mathematical formulas to elaborate on the research results of Faraday and others, and extended the theory of electromagnetic induction to space. . More than 60 years later, Hertz confirmed the existence of electromagnetic waves in experiments. The discovery of electromagnetic waves became the turning point from "wired telecommunications" to "radio communications" and the origin of the entire mobile communications. As one scientist said, "The mobile phone was born on the shoulders of the telegraph and telephone. Without the efforts of predecessors, wireless communication would have been impossible.

May 24, 1844 [4]. Morse's telegraph machine sent the first telegram in human history from Washington to Baltimore, "What a miracle God has created!"

On June 2, 1875, while doing experiments, Bell accidentally dropped sulfuric acid It splashed on his leg. He was so painful that he shouted to his colleague in the other room, "Huote, come and help me!" This sentence was transmitted to Huote who answered the phone in the other room through the phone in the experiment. In 1902, an American named "Nathan Stubblefield" lived in the countryside of Murray, Kentucky. The first wireless phone device was made inside. This phone with wireless mobile communication was the earliest human exploration and research of "mobile phone" technology [6]

In 1940, Bell Labs in the United States manufactured it. Battlefield Cell Phone.

The world's first phone call was made from a moving car in St. Louis in 1946.

1957. In 1958, the outstanding Soviet engineer Leonid Kupriyanovich invented the ЛК-1 mobile phone. In 1958, he had further improved the weight of his mobile phone from 3 kilograms to 500 kilograms. Gram (including battery weight), the shape is reduced to the size of two cigarette boxes, it can make calls to any place in the city, and can connect to any landline. By the early 1960s, Kuprijanovic's mobile phone had already been used. Able to work effectively within a range of 200 kilometers [8]

In 1958, the Soviet Union began to develop the world's first fully automatic mobile phone communication system "Altai" (Алтай) [9]. The outstanding "Altai" system won the gold medal at the Brussels World Expo[8].