Question:
mobile phone was first used in what country? Which company developed the first production? How is it developed?

Answer:
the concept of mobile phones, as early as 40 years has emerged. At that time, is the largest communications company began trial production of the Bell Labs. In 1946, Bell Labs has created the first so-called mobile phone. At that time, AT & T leased a large volume of mobile phones, customers can put the phone on board an in calories. AT & T’s vision is the future, be able to develop a mobile phone, power is 10 watts, on the use of radio equipment on the truck to communicate with them. Cooper believes that this phone too heavy and can not move people to go. As a result, Motorola, the Federal Communications Commission to the United States made a request to the provisions of mobile communication equipment, power should only be one tile, the largest not more than three watts. In fact, most of today’s mobile phone radio power, the largest is only 500 mW.

phone registered patent from 1973 until 1985, before the birth of a first in the modern sense, the real can move the phone. It is the power supply and antenna placed in a box, weighing about 3 kg, very heavy and inconvenient, the user should be like carrying a backpack as it is to walk, I was called “shoulder phone.”

and the present shape close to the phone, was born in 1987. And the “shoulder phone” in comparison, it seems much more lightweight, and easy to carry. Nevertheless, its weight, about 750 grams, with today’s cell phone weighs just 60 grams compared to, like a big brick.

Since then, mobile phones becoming more and more rapidly. In 1991, the phone weighs 250 grams; the fall of 1996, there has been volume of 100 cubic centimeters, weight of 100 grams mobile phone. Since then further miniaturization and light, to 1999 on the light to 60 grams. In other words, a cell phone is not much more than a weight of the eggs.

In addition to the quality and volume getting smaller and smaller, the modern mobile phones have more and more like a multi-purpose Swiss Army knife of. In addition to basic phone functions, the new phone also can be used to send and receive e-mail and short messages, access the Internet, play games, take pictures, or even a movie! This is the original inventor of mobile phones beyond the expectation.

in communications technology, the modern cell phone also has significant progress. When Cooper playing the world’s first GSM mobile phone, he can use any of the electromagnetic spectrum. In fact, the first-generation analog phones that rely on different frequencies to distinguish different users of different mobile phones. Second-generation mobile phones - GSM system, is relying on an extremely small time difference to distinguish between users. Even today, the frequency resources are obviously insufficient, mobile users exponentially growing rapidly. As a result, the updated and rely on different codes to distinguish the different machines CDMA technology have emerged. Application of this technology, cell phone not only has better call quality and confidentiality, but also reduce the radiation, can be regarded as a “green phone.”

Reference URL:
http://classad.163.com/html/area/58/46/2006-04-13/1144911374.html

Chinese:手机{zx0}是哪个国家使用的？

问题:
手机{zx0}是哪个国家使用的？{zx0}是哪个公司开发生产的？它是怎样发展起来的？

回答:
手机这个概念，早在40年代就出现了。当时，是美国{zd0}的通讯公司贝尔实验室开始试制的。1946年，贝尔实验室造出了{dy}部所谓的移动通讯电话。
一直到了60年代末期，AT&T和摩托罗拉这两个公司才开始对这种技术感兴趣起来。当时，AT&T出租一种体积很大的移动无线电话，客户可以把这种电话安在大卡车上。AT&T的设想是，将来能研制一种移动电话，功率是10瓦，就利用卡车上的无线电设备来加以沟通。库帕认为，这种电话太大太重，根本无法移动让人带着走。于是，摩托罗拉就向美国xx通讯委员会提出申请，要求规定移动通讯设备的功率，只应该是一瓦，{zd0}也不能超过三瓦。事实上，今天大多数手机的无线电功率，{zd0}只有500毫瓦。

从1973年手机注册专利，一直到1985年，才诞生出{dy}台现代意义上的、真正可以移动的电话。它是将电源和天线放置在一个盒子中，重量达3公斤，非常重而且不方便，使用者要像背包那样背着它行走，所以就被叫做“肩背电话”。

与现在形状接近的手机，诞生于1987年。与“肩背电话”相比，它显得轻巧得多，而且容易携带。尽管如此，其重量仍有大约750克，与今天仅重60克的手机相比，像一块大砖头。

从那以后，手机的发展越来越迅速。1991年时，手机的重量为250克左右；1996年秋，出现了体积为100立方厘米、重量100克的手机。此后又进一步小型化、轻型化，到1999年就轻到了60克以下。也就是说，一部手机比一枚鸡蛋重不了多少了。

除了质量和体积越来越小外，现代的手机已经越来越像一把多功能的瑞士军刀了。除了最基本的通话功能，新型的手机还可以用来收发邮件和短消息，可以上网、玩游戏、拍照，甚至可以看电影！这是最初的手机发明者所始料不及的。

在通讯技术方面，现代手机也有着明显的进步。当库帕打世界{dy}通移动电话时，他可以使用任意的电磁频段。事实上，{dy}代模拟手机就是靠频率的不同来区别不同用户的不同手机。第二代手机——GSM系统则是靠极其微小的时差来区分用户。到了今天，频率资源已明显不足，手机用户也呈几何级数迅速增长。于是，更新的、靠编码的不同来区别不同的机的CDMA技术应运而生。应用这种技术的手机不但通话质量和保密性更好，还能减少辐射，可称得上是“绿色手机”。

参考网址：
http://classad.163.com/html/area/58/46/2006-04-13/1144911374.html