What Is a Smartphone? The Computer That Fits in Your Pocket
A smartphone is a full computer with a radio inside. Making calls is now one of the smallest jobs it does.
The whole idea, in one diagram
It has everything a computer has: a processor, memory, storage and a battery.
It also has radios, so it can talk to a mast, to Wi-Fi and to your headphones without wires.
The country is divided into small areas called cells, each with its own mast. That is why it is called a cellular phone.
What problem did it solve?
A telephone was screwed to a wall or sat on a table. You could not phone a person, only a place, and you had to guess whether they would be standing next to it. If your car broke down on a road at night, you walked until you found a phone box.
Engineers divided the map into small cells, each with its own mast, so that the same handful of radio frequencies could be reused again and again. Then they made a handset small enough to carry.
You now call a person rather than a place. More than that: for most people in the world, this pocket machine is their only computer, their camera, their map, their bank and their classroom.
How it started
- 1947
The cell idea is written down
π€ Douglas Ring and Rae Young at Bell Labs, USA
They suggested splitting an area into small hexagonal cells, each with a low-power mast, so the same radio frequencies could be used again in a cell further away.
Why it mattered: Radio frequencies are limited. Without reuse, a city could only ever support a few dozen calls at once. This idea is why millions of people can talk at the same time.
- 1973
The first handheld mobile call
π€ Martin Cooper, Motorola, New York
On 3 April 1973 Cooper stood on a street in Manhattan and phoned Joel Engel, his rival at Bell Labs, to tell him he was calling from a handheld phone. The handset weighed over a kilogram.
Why it mattered: It proved a phone did not need a car or a building. It took another ten years before anyone could buy one.
- 1983
The first mobile phone goes on sale
π€ Motorola, USA
The DynaTAC 8000X cost about 3,995 US dollars, took around ten hours to charge and gave you about thirty minutes of talking. People nicknamed it the brick.
Why it mattered: Wildly expensive and barely practical, and it still sold. That told everyone the demand was real.
- 1992
The first text message
π€ Neil Papworth, England
In December 1992 he sent the words Merry Christmas from a computer to a phone. There was no way to reply, because phones had no keyboards yet.
Why it mattered: Texting was almost an afterthought in the design, and it became the most used feature on Earth for years.
- 1994
The first smartphone
π€ IBM, USA
The IBM Simon had a touchscreen and a stylus, and it could send email, keep a calendar and take notes as well as make calls. It sold poorly and was withdrawn after about six months.
Why it mattered: Every idea in a modern smartphone was already there in 1994. The parts to make it small, cheap and long lasting simply did not exist yet.
- 2000
Phones grow eyes
π€ Makers in Japan, then everywhere
Cameras were added to handsets. The pictures were poor, and people took them anyway, constantly.
Why it mattered: The best camera is the one you have with you. Putting one in every pocket changed news, families and memory itself.
- 2007
The touchscreen phone arrives
π€ Apple, then Android makers from 2008
A phone that was mostly screen, with a proper web browser and, from 2008, a shop where anyone could sell you software for it.
Why it mattered: The buttons disappeared, so the phone could change shape for every task. This is the moment the phone stopped being a phone and became a pocket computer.
- 2010s onwards
The phone becomes most people's only computer
π€ Billions of people, mostly outside Europe and America
Cheap Android handsets and mobile data reached places that never had landlines or desktop computers.
Why it mattered: Whole countries skipped the desktop era entirely. Banking, learning and business arrived on a phone screen first, and often only.
Who made it happen
Martin Cooper
born 1928 Β· USA
Made the first handheld mobile phone call in 1973, standing on a New York street, to his main rival.
Neil Papworth
born 1969 Β· England
Sent the first text message in December 1992. It said Merry Christmas, and nobody could reply to it.
Douglas Ring and Rae Young
1947 Β· USA
Came up with dividing the map into cells so the same frequencies could be reused. Every mobile network still works this way.
Amos Joel
1918 to 2008 Β· USA
Invented the handover, which passes your call from one mast to the next so it does not drop when you move.
Hedy Lamarr
1914 to 2000 Β· Austria and USA
A film actor and inventor who co-designed a way of hopping between radio frequencies. Related ideas are used in modern wireless.
Frank Canova
1994 Β· USA
Led the team at IBM that built Simon, the first smartphone, thirteen years before the idea caught on.
How your voice reaches someone on the other side of the world
- 1
Your voice becomes numbers
A microphone turns the movement of air into a wobbling electrical signal, and a chip measures that signal thousands of times a second, turning it into a stream of numbers.
- 2
A radio sends it to the nearest mast
The phone broadcasts those numbers as radio waves to the closest mast, usually a few hundred metres to a few kilometres away. It uses only as much power as it needs, to save your battery.
- 3
The mast hands you over as you move
Walk or drive far enough and you leave one cell and enter the next. The network passes your call to the new mast mid-sentence. That is called a handover, and when it fails your call drops.
- 4
It travels the ordinary way
From the mast your call joins the same cables and networks as everything else, often running under the sea, until it reaches the network of the person you are calling.
- 5
It becomes sound again
Their phone receives the numbers and pushes a tiny speaker in and out to recreate the air movement. What they hear is a rebuilt copy of your voice, not the original.
Each invention solved the last one's problem
The home telephone
- Problem before
- You could only reach a place, never a person, and only if somebody happened to be beside it.
- What it solved
- A live voice could travel between two buildings instantly.
- Impact
- Families and businesses could talk across distance, as long as everyone stayed near a wall.
The mobile phone
- Problem before
- The wire held you to one spot, and there were never enough radio frequencies for a whole city.
- What it solved
- Cells and masts let frequencies be reused, so a handset could work anywhere in a network.
- Impact
- You called a person, not a place. At first only the rich could afford it, and it did nothing but calls.
The texting phone
- Problem before
- A call needs both people free at the same moment, and it is expensive.
- What it solved
- Short written messages that wait until the other person is ready, for a fraction of the cost.
- Impact
- A whole generation learned to write in tiny bursts. Texting became the most used feature on the planet.
The smartphone
- Problem before
- A phone was still just a phone, and computers were still stuck on desks.
- What it solved
- A touchscreen, a real browser and an app store turned the handset into a general purpose computer.
- Impact
- Camera, map, bank, classroom, shop and library, in one pocket. For most of the world it is the only computer they own.
It is called a cellular phone because the country is chopped into small cells, each with its own mast. Reusing the same frequencies in far apart cells is the trick that lets millions of people talk at once.
Next time you are in a car, watch the signal bars on a phone as you travel. When they drop and then jump back up, you have just been handed from one mast to the next. See if you can spot the masts themselves: they are often disguised on rooftops or dressed up as trees.
Quiz: how much did you remember?
Quiz time!
10 questions, picked at random from 30. No sign-in and no score is kept. Play as many times as you like, the questions change every time.
Questions about smartphones
What is a smartphone in simple words?
A smartphone is a small computer with radios built in. It has a processor, memory, storage and a battery just like a laptop, plus the ability to talk to a phone mast, to Wi-Fi and to nearby devices.
Why is it called a cellular phone?
Because the map is divided into small areas called cells, each with its own mast. Cells that are far apart can use the same radio frequencies without clashing, which is the only reason millions of people can be on the phone at once.
Who made the first mobile phone call?
Martin Cooper of Motorola, on 3 April 1973, standing on a street in New York. He phoned Joel Engel, his competitor at Bell Labs, to tell him he had got there first.
What was the first smartphone?
The IBM Simon in 1994. It had a touchscreen and a stylus and could handle email, a calendar and notes. It sold badly and was pulled after about six months, thirteen years before the idea took off.
What was the first text message?
Merry Christmas, sent in December 1992 by Neil Papworth from a computer to a phone. Phones had no keyboards then, so there was no way to reply.
How does a phone know which mast to use?
It is constantly listening to nearby masts and measuring which one it hears most clearly. As you move, the network hands your call to the next mast. That handover is why a call usually survives a car journey.
Why does my phone battery drain faster when the signal is weak?
When the mast is far away or blocked, your phone shouts louder, meaning it transmits with more power. Weak signal is one of the fastest ways to flatten a battery.
Is a phone more powerful than the computers used for the Moon landings?
Yes, by an enormous margin. The Apollo guidance computer had a tiny fraction of the memory and speed of any modern phone. That comparison is real, and it is still hard to believe.
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