How Cell Phones and a Telecom Tower Work
My nephew just got a cell phone for his birthday. My nephew is also eight years old. Now, I hate to age myself by talking about technology—I age myself enough with my fashion sense. But when I was eight years old, my idea of high tech communications was a couple of old tin cans connected by a string. Now this little moppet is swiping away at "Angry Birds" and texting his friends about their next play date—unbelievable!
I wanted him to understand the little gizmo in his hands a bit better, so I sat him down to explain how cell phones work, and why he should consider himself lucky that he can download his comic books instantly instead of walking 15 miles in the snow to buy them like I used to (OK, maybe a slight exaggeration). I don't think that little Leo paid as much attention to me as he did to his "Fruit Ninja" game, but I figured that you guys might appreciate a little tech know-how more than he did!
Tower of Power
Your cell phone itself is pretty complex, but the way that it communicates with other phones is actually not that complicated. The first thing you have to understand, though, is how a telecom tower works. Telecom towers (short for "telecommunication towers") that power cell phones are all over the world—in fact, there's a lot of them. Basically, each tower stands tall in the ground, and has receivers at the top that pick up cell signals (more on that later). These towers are connected to each other using hardwired connections underground, which run for miles and miles, forming a huge, complex grid that covers—well, basically, the whole country.
These telecom towers are also called cell sites, and the service area is frequently called a cell—hence the name "cell phone." Without them, your phone wouldn't have anywhere to send its signal too. Think of it like a middleman for the message your phone sends out, which I'll explain further.
How Your Cell Phone Responds to a Cell Site
When you (or little Leo) make a call on your cell phone, the phone sends a signal to the nearest telecom tower cell site. Phones and cell sites only have a certain range, and it's affected by factors like tower placement, geography, tall buildings and other things. That's why you can lose service even in the middle of a city—urban and heavily populated areas usually have more towers, but they can be easily obscured by skyscrapers and other big buildings. To combat that problem, the people that erect telecom towers for cell phones often place them high up, where more phones can reach them.
Anyway, your phone sends a signal to the top of the cell tower, which then gets piped down into the service provider's underground cables. The signal shoots through the cables, eventually reaching the cell tower nearest the person on the other end. It travels up from the ground to the top of the telecom tower, and it's broadcasted to the phone being held by the person you're talking to. And of course, it's happening in the other direction, too, so your phones are constantly sending and receiving information from the cell towers nearest their respective locations—and it all happens in only an instant.
Towers, Carriers and Reception
Not every cell phone responds to every telecom tower—your wireless provider has to use the tower for it to work. That's why the big carriers like Verizon, AT&T and T-Mobile are always competing in their ads over who has more towers, because the more towers you have, the better your coverage is.
Think of it this way: When you're talking on your cell phone while driving (using a responsible hands-free system, of course), you move in and out of range of various cell phone towers. As you leave the range of one, your phone switches over to send and receive signals with a different one. If you leave a tower's range and there isn't another one close enough, you're liable to drop the call. That's why cell phone service isn't always as reliable in rural areas as it is in urban areas—the service providers don't necessarily invest as heavily in telecom towers in less-populated areas, so they're farther and farther apart from each other.
The Future of Cell Phones
Obviously, cell phones and cell service have vastly improved since they first hit the scene (it's even more obvious for old fogeys like me). The types of coverage that providers offer, like 3G and 4G, are always changing as well. That means that carriers have to keep adjusting the way they send and receive signals from their telecom towers, and phone manufacturers have to keep changing the phones themselves, too. So while my nephew's fancy, wildly age-inappropriate birthday gift is the hottest piece of tech on the market right now, it's almost guaranteed to be outdated before the little guy hits puberty—who knows what phones will look like then!
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