Phones - a very useful and versatile item.With the phone, we can solve many problems without leaving your home or office.Today already almost unthinkable any business without a phone.And if suddenly all the phones stopped working, the economy of any country would be shaken.What are the phone today?The answer to this question will be discussed in detail below.
Mobile phones and phone types
Mobile is convenient because it is a portable device and the owner of such a vehicle can use it to communicate (voice mode) to another person, regardless of his place of residence.Now across the globe cellular communication has a leading position.Cellular communication - a type of mobile radio.The first of these devices humanity has learned in the middle of the last century in the United States.Company AT & amp;T Bell Laboratories began testing a new method of communication - car radiotelephone.The distance between the devices was small - twenty kilometers, but we see less than a hundred years, these phones can
- Cell Phones.These devices are designed to work in communication networks such as honeycombs.They use a small radiopriёmoperedatchik and telephone switching.Even the very first cell phones, despite its bulkiness, were complex high-tech devices.The cell phone includes such components: transceiver, a specialized management controller display (monochrome / color), an interface device, battery.It is worth noting that virtually every device has its own unique number, which prevents a phone from "stealing".Almost all countries use the SIM-card - it helps to identify the subscriber.
- Radiotelephones.These phones are phones that can transmit it through the radio.The average citizen of our country used to call a telephone apparatus with handset (wireless), which has a base.Use single sideband modulation, frequency modulation and amplitude modulation.
- satellite phone.Now we consider the kinds of mobile phones (satellite) and how they differ from our usual, cell.It is also a kind of mobile phone.Just such a device can transmit information using satellite immediately (communication).Some operators such communication may include in its broadcasting aura of the whole earth.This may be due to low-flying satellites or satellites that are in geostationary orbit.The dimensions of this device are approximately the same as that of the cell, just be sure to include an external antenna.Satellite phone may be stationary.Here operators providing satellite services: Thuraya, Inmarsat, Iridium, Globalstar.
mobile phone cases
- Bar.This is the usual consumer, the standard form of a mobile phone.It is considered the most reliable version of this technique, such as safe housing for its owner.
- clamshell.Mobile Phone Case - clamshell consists of two parts.These hinge parts are connected.One part includes a keyboard, cell battery, microphone, important elements (e).The second part contains a loudspeaker and a display.Of course, there are models in which one or the other part is located in another part of the apparatus.The first phone with such a body appeared in the late eighties of the last century.
- slider.What are the sliders phones?The body of this cell phone slides, so you can flick of a finger to change its size.This telephone also has two parts.These parts are mounted on the same axis and are connected by a special mechanism.At the top is a display, speaker, camera, flashlight (depending on the manufacturer and model), at the bottom - the keyboard, battery and other major components of the phone.