How do mobile phones work?| Explore | joejonaschile.tk

 

mobile telephone waves

A mobile phone (also known as a hand phone, cell phone, or cellular telephone) is a small portable radio telephone.. The mobile phone can be used to communicate over long distances without wires. It works by communicating with a nearby base station (also called a "cell site") which connects it to the main phone network. Mobile phones communicate with base stations using radiofrequency (RF) radiation. If RF radiation is high enough, it has a ‘thermal’ effect, which means it raises body temperature. There are concerns that the low levels of RF radiation emitted by mobile phones could cause health problems such as headaches or brain joejonaschile.tk last reviewed: 29 Jun May 05,  · The International EMF Project: The World Health Organization project dedicated to studying the health and environmental effects of electromagnetic radiation. News reports. Mobile phone child health risk investigation by Nick Triggle, BBC News, 20 May A major new study into health risks is announced by researchers at Imperial College, London.


What Is the Difference Between Radio Waves & Cell Phone Waves? | Sciencing


Last updated: May 5, W alking and talking, working on the train, always in contact, never out of touch—cellphones have dramatically changed the way we live and work. No one knows exactly how many little plastic handsets there are in the world, but the best guess is that there over 7. That's more than the planet's population!

In developing countries, where large-scale land line networks ordinary telephones wired to the wall are few and far between, over 90 percent of the phones in use are cellphones. Cellphones also known as cellular phones and, chiefly in Europe, as mobile phones or mobiles are radio telephones that route their calls through a network of masts linked to the main public telephone network. Here's how they work, mobile telephone waves.

Photo: Most people now use smartphones as their cellphones, which are actually small computers with cellphone circuitry built in. Mobile telephone waves in the s, cellphones were simpler and could only be used for making voice calls.

Now networks are faster and capable of handling greater volumes of traffic, smartphones are used as portable communication centers, mobile telephone waves, capable of doing all the things you can do with a telephone, digital camera, MP3 player, GPS "sat nav," and laptop computer. Photo: Cellphones as they used to be. This Nokia dates from the early s and has a mobile telephone waves keypad. Although it has a camera and a few other basic functions, mobile telephone waves, it doesn't have anything like the computing power of a modern smartphone.

Phones like this are sometimes called "handhelds" or "feature phones" to distinguish them from mobile telephone waves and other smartphones. Although they do the same job, land lines and cellphones work in a completely different way. Land lines carry calls along electrical cables. Cut out all the satellitesmobile telephone waves, fiber-optic cables, switching offices, and other razzmatazz, and land lines are not that much different to the toy phones you might have made out of a piece of string and a couple of mobile telephone waves bean cans, mobile telephone waves.

The words you speak ultimately travel down a direct, wired connection between two handsets, mobile telephone waves. What's different about a cellphone is that it can send and receive calls without wire connections of any kind. How does it do this? By using electromagnetic radio waves to send and receive the sounds that would normally travel down wires.

Whether you're sitting at home, walking down the street, driving a caror riding in a train, you're bathing in a sea of electromagnetic waves. TV and radio programs, signals from radio-controlled cars, cordless phone calls, and even wireless doorbells—all these things work using electromagnetic energy : undulating patterns of electricity and magnetism that zip and zap invisibly through space at the speed of lightkm ormiles per second.

Cellphone networks are by far the fastest growing source of electromagnetic energy in the world around us. When you speak into a cellphone, a tiny microphone in the handset converts the up-and-down sounds of your voice into a corresponding up-and-down pattern of electrical signals.

A microchip inside the phone turns these signals into strings of numbers, mobile telephone waves. The numbers are packed up into a radio wave and beamed out from the phone's antenna in some countries, the antenna is called an aerial. The radio wave races through the air at the speed of light until it reaches the nearest cellphone mast.

Photo: Engineers repair a cellphone mast. The mast receives the signals and passes them on to its base stationwhich effectively coordinates what happens inside each local part of the cellphone network, which is called a cell.

From the base station, the calls are routed onward to their destination. Calls made from a cellphone to another cellphone on the same network travel to their destination by being routed to the base station nearest to the destination phone, and finally to that phone itself.

Calls made to a cellphone on a different network or a land line follow a more lengthy path. They may have to be routed into the main telephone network before they can reach their ultimate destination. At first glance, cellphones seem a lot like two-way radios and walkie talkiesmobile telephone waves, where each person has a radio containing both a sender and a receiver that bounces messages back and forth directly, like tennis players returning a ball.

The problem with radios like this is that you can only use so many of them in a certain area before the signals from one pair of callers start interfering with those from other pairs of callers, mobile telephone waves.

That's why cellphones are much more sophisticated—and work in a completely different way. A cellphone handset contains a radio transmitter, for sending radio signals onward from the phone, and a radio receiver, for receiving incoming signals from other mobile telephone waves. The radio transmitter and receiver are not very high-powered, which means cellphones cannot send signals very far, mobile telephone waves.

That's not a flaw— it's a deliberate feature of their design! All a cellphone has to do is communicate with its local mast and base station; what the base station has to do is pick up faint signals from many cellphones and route them onward to their destination, mobile telephone waves, which is why the masts are huge, high-powered antennas often mounted on a hill or tall building.

If we didn't have masts, we'd need cellphones with enormous antennas and giant power supplies—and they'd be too cumbersome to be mobile, mobile telephone waves.

A cellphone automatically communicates with the nearest cell the one with the strongest signal and uses as little power to do so as it possibly can which makes its battery last as long mobile telephone waves possible and reduces the likelihood of it interfering with other phones nearby. So why bother with cells?

Why don't mobile telephone waves simply talk to one another directly? Suppose several people in your area all want to use their cellphones at the same time. If their phones all send and receive calls in the same way, using the same kind of radio waves, the signals would interfere and scramble together and it would be impossible to tell one call from another.

One way to get around this is to use different radio waves for different calls. If each phone call uses a slightly different frequency the number of up-and-down undulations in a radio wave in one secondthe calls are easy to keep separate.

They can travel through the air like different radio stations that use different wavebands. That's fine if there are only a few people calling at once. But suppose you're in the middle of a big city and millions of people are all calling at once. Then you'd need just as many millions of separate frequencies—more than are usually available.

The solution is to divide the city up into smaller areas, mobile telephone waves, with each one served by its own masts and base station. These areas mobile telephone waves what we call cells and they look like a patchwork of invisible hexagons. Each cell has its base station and masts and all the calls made or received inside that cell are routed through them. Cells enable the system to handle many more calls at once, because each cell uses the same set of frequencies as its neighboring cells.

The more cells, the greater the number of calls that can be made at once. This is why urban areas have many more cells than rural areas and why the cells in urban areas are much smaller. If a phone in cell A calls a phone in cell B, the call doesn't pass directly between the phones, but from the first phone to mast A and its base station, then to mast B and its base station, and then to the second phone.

Cellphones that are moving between cells when people are walking along or driving are regularly sending signals to and from nearby masts so that, at any given time, the cellphone network always knows which mast is closest to which phone. If a car passenger is making a call and the car drives between cells C, mobile telephone waves, D, and E, the phone call is automatically "handed off" passed from cell to cell so the call is not interrupted.

The key to understanding cells is to realize that cellphones and the masts they communicate with are designed to send radio waves only over a limited range; that effectively defines the size of the cells, mobile telephone waves. It's also worth pointing out that this picture is a simplification; it's more accurate to say that the masts sit at the intersections of the cells, but it's a little easier to understand things as I've shown them.

The first mobile phones used analog technology. This is pretty much how baked-bean can telephones work too. When you talk on a baked-bean can phone, your voice makes the string vibrate up mobile telephone waves down so fast that you can't see it. The vibrations go up and down like your voice. In other words, they are an analogy of your voice—and that's why we call this analog technology, mobile telephone waves.

Some land lines still work in this way today. Most cellphones work using digital technology : they turn the sounds of your voice into a pattern of numbers digits and then beam them through the air. Using digital technology has many advantages. It means cellphones can be used to send and receive computerized data. That's why most cellphones can now send and receive text SMS messages, Web pages, MP3 music filesand digital photos. Digital technology means cellphone calls can be encrypted scrambled using a mathematical code before they leave the sender's phone, so eavesdroppers cannot intercept them.

This was mobile telephone waves big problem with earlier analog phones, which anyone could intercept with a miniature radio receiver called a scanner. That makes digital cellphones much more secure. Cellphones have dramatically changed the way the world connects. In the mobile telephone waves s, only one per cent of the world's population owned a cellphone; today, in a growing number of countries people spend more time on their mobiles than on their landlines.

According to the ITU-Tmobile telephone waves, inonly 58 percent of the world's population had access to a 2G cellphone network; bythat had risen to 98 percent. By the end ofmobile telephone waves, there were over 7. Cellphones have also powered a big leap in Internet access.

At the end ofmobile smartphone and tablet Internet traffic passed desktop traffic for the first time ever. Mobile telephone waves the end of56 percent of the world's people had cellphone-based, broadband Internet access, which is over four times as many as have traditional wired broadband just 13 percent.

Chart: Cellphone mobile telephone waves The most dramatic cellphone growth has happened in developing countries, which now represent almost 80 percent of subscriptions. Cellphones are also used in different ways by different people.

Back in the early s, cellphones were used entirely for voice conversations and sending short "texts" text messages, also known as SMS messages. A lot of people owned a mobile phone purely for occasional emergency use; and that still remains a popular reason for owning a phone according to the FCCabout 70 percent of all emergency calls in the United States are made from cellphones.

Today, smartphones are everywhere and people use them for emailing, browsing the web, downloading music, social media, and running all kinds of apps. Where old-fashioned cellphones relied entirely on a decent signal from a cellphone network, smartphones hop back and forth, as necessary, between ordinary networks and Wi-Fi. Where old cellphones were literally "mobile phones" wireless landlinesmodern smartphones are essentially pocket computers that just happen to make phone calls.

If you want to find out how cellphone networks have evolved from purely voice networks to form an important part of the Internet, please see our separate article on broadband and mobile broadband. Photo: A simple, modern Nokia cellphone. New phones like this generally operate at lower power than older ones, producing less electromagnetic radiation and theoretically less risk to health. People have been asking that question pretty much since cellphones first appeared—and the debate has intensified over the last decade or so.

Why is it even an issue? As we discovered up above, cellphones communicate using radio waves, and we've all been bathing in massive doses of those things since radio and TV became popular in the early part of the 20th century. But the long-wave radio waves used in broadcasting are very different from the short-wavelength, high-frequency, high-energy radio waves at the opposite end of the electromagnetic spectrum. Generally speaking, the shorter the wavelength of radio waves the more dangerous they are to our health.

 

Cell Phones and Cancer Risk Fact Sheet - National Cancer Institute

 

mobile telephone waves

 

New data from German authorities provide us with a smartphone radiation ranking list detailing the mobile phones with the highest and the lowest radiation emissions. In addition, the Chicago tribune conducted independent smartphone radiation tests and found some popular smartphones have . Mobile phones communicate with base stations using radiofrequency (RF) radiation. If RF radiation is high enough, it has a ‘thermal’ effect, which means it raises body temperature. There are concerns that the low levels of RF radiation emitted by mobile phones could cause health problems such as headaches or brain joejonaschile.tk last reviewed: 29 Jun As you chat away, your phone converts your voice into an electrical signal, which is then transmitted as radio waves and converted back into sound by your friend’s phone. A basic mobile phone is therefore little more than a combined radio transmitter and a radio receiver, quite .