History of development of mobile phone technology humans have a very long history of mobile phones. For thousands of years, people have been using the language, icons, bells and drums, fireworks, bamboo, paper books, murals and other transmission of information, the ancient people of the flames smoke signals, IP Messenger letter, postal stagecoach is an example in this regard. Now there are individual tribes mobile phone accessories recycling centers in some countries, such as drumming Ming Hao still retains the old phones such way. In modern society, the police command of sign language, sailing the semaphore, etc. but is the result of an ancient way of further development of the mobile phone. The basic method of information transfer are relying on human visual and auditory. ^ Capacity: Since each transmission channel bandwidth increases the channel bandwidth of 200 dagger 92, analog constraints 25 ^ only 2), so that the same frequency multiplexing carrier to interference ratio is reduced to 938, so that 05 ^ a system with frequency reuse can be schema reduced to 4/12 or 3/9, or even smaller [modeled as 7/21>. Coupled with the introduction of the half-rate speech coding technology and traffic distribution of professional mobile phone accessories recycling, so 05 ^ 1 capacity efficiency of the system (number of channels per MHz per cell> than an 'eight 03 3? 5 times higher. ^ Voice quality High system just above the threshold, the voice quality will always reach the same level regardless of the transmission quality ^ Security: Through authentication, encryption and D ^ 131 number to reach safety, and to 130 \ ,?. 3 D \ etc interconnection roaming in 31 Yi card basis. 15-9500 ^ an eight North American digital cellular standard another mobile phone accessories recycling business, Jian 2 ^ 1 800 and 1900 bands, which uses narrowband code division multiple access technology, mainly in North America and Korea use. Because of the narrow-band technology than eight 00 ^ 1 ^ 1 051 reasons such as mature late, making its application in the world is less than 051 ^ 1, but with a? 01 \ 4 eight and Ding eight compared to 01 ^ 1, 001 ^ 1 August has many unique advantages, so 1: 01 ^ six third-generation mobile phone technology as the core technology to sum up, the advantages of 00 eight-Yi used in digital mobile phones are: system six large capacity digital mobile phone network system capacity is theoretically 20 times bigger than the analog network, in fact, 10 times larger than the analog network, five times larger than the 03 recycling centers mobile phone accessories, electronic Obo (certified), Quam phone accessories recycling Obo provided by Shenzhen Electronic Technology Co., Ltd. Shenzhen Electronic Technology Obo (www.aobodz.com) is Shenzhen, the other leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum limits to meet customer needs in Obo electronic leadership with the staff warmly welcome all inquiries negotiations to create a better future for electronic Obo.