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What is a Mobile Phone?


Everybody knows what a cell phone is so I’ll be short. A mobile phone, as its name suggests, is a portable device with wireless transmission, which anyone can use while on the go. You can use one for making phone calls, receive phone calls, which is its main function, but you can also transfer and receive files with music, videos, images and, of course, text.

Cellular Phone Parts

After making a mobile phone research, I am inviting you inside the cell phone to see its components.

First take a look at your own model. What do you see? It has a Liquid Crystal Display, a keypad like the one on your TV remote, while inside it has an antenna (which can be external and visible at some models), a removable battery, a microphone, a speaker, and another thing that you can’t see if you don’t disassembly the handset is the circuit board, in charge with processing the commands you type.



On the circuit board, a specialist can identify easily the conversion chips that translate the analog audio signal emitted when you are in a phone call, into digital signal, and the digital signal that comes to your handset over the air, back into analog. The smart piece that handles the digital signal is called the Digital Signal Processor, which uses complex algorithms to make calculations in order to transform the analog and digital signals in real time.



Same as personal computers, cell phones have also a microprocessor that handles the commands from the keyboard making them displayable on the LCD.
The operating system and directories are kept in the Random Access Memory and Flash memory chips, while the power issues are controlled by the Radio Frequency and the power area.
Cell phone speakers are incredibly small, as well as microphones, but with the latest technologies they have powerful capabilities.

Cell Phone Manufacturing

The manufacturing process involves 40% metals, 40% plastics and 20% ceramics and trace materials, while the circuit board uses copper, lead, nickel, gold, zinc, beryllium, tantalum, coltan and others. Some of the raw materials are processed before the cell phone manufacturing, like the crude oil used for plastics, which has to be mixed with natural gas and chemicals in a special plant. The copper, for example, has to be mined, ground, heated and treated with chemical substances and electricity, in order to isolate the pure metal used also in batteries.
Cell Phone Screens with LCDs have liquid crystalline substances like mercury, and are sandwiched between glass and plastic layers. The batteries have the two electrodes made of metals.

This is a cell phone diagram for your curiosity:



How Does a Mobile Phone Work?

How does a cell phone work? This is simple. If a standard radio uses a simplex communication system so that you can hear the moderator talking, without having the possibility to reply, a cell phone is a duplex device permitting you to talk to the person who started the call. It sends and receives radio signals using cell sites located on specially built towers, poles or buildings, all being connected to a large cabled network with a switching system. The smart thing is that cell phones send data to the nearest cell sites located at maximum 13 Km away, this after they are turned On, moment when it registers with the switch, using a unique identifier.



When you are on the go, carrying your phone with, it is permanently detecting the strongest signals from the base stations, so if a signal weakens, the handset care is passed to the nearest cell site.
Your cell phone receives the phone call from a friend and this digital signal is transformed into analog signal, processed by the Digital Signal Processor, and finally amplified via the built-in speaker. When you talk, the voice is detected by the small microphone as analog, processed, and in the end transformed into digital signal to be sent over the air.

The SIM card is a microchip called a Subscriber Identity Module, and the phone is dependent on it to work. It is in charge with storing information like the calling plan and other phone’s details, while having a unique numerical identifier used to lock the device permanently after the first activation.

History of the Cell Phone

Who Invented the Cell Phone? If you want to know who was the first who got the idea of creating a cellular phone the answer is the American Telephone & Telegraph which is no other than AT&T from the United States, which was the world's largest telephone company and the world's largest cable television operator, with $300 billion dollars revenue. It was purchased by Baby Bell SBC Communications in 2005.

In April 1973, Dr Martin Cooper, former general manager for the systems division at Motorola, invented the mobile phone prototype and made the first call to Joel Engel, his rival, head of research at Bell Labs.



Copper was a project manager at Motorola and the world’s first mobile phone was Motorola Dyna-Tac, a 2.5 pounds handset measuring 9 x 5 x 1.75 inches, featuring 30 circuit boards, 35 minutes talk time, 10 hours recharge time, and having just three functionalities: dial, talk and listen. He, together with his colleagues, published the patent for the world’s first portable duplex radio telephone system.



AT&T’s concept couldn’t pass by the monopoly on the wired service in the US in 1915, so someone else had to finalize this, and the answer for your next question - When was the first mobile phone invented? - is the year 1978 and the place Japan. There, the Nippon Telegraph and Telephone Corporation, known as the most popular cell phone operator in the country, NTT DoCoMo, created the world’s first commercial cell phone.

There are different types of mobile phones. Nokia Communicator launched in 1996 was the world’s first cell phone with Internet connectivity and email functionality. The same company created the world’s first Smartphone.
NTT DoCoMo launched i-Mode, the first mobile Internet service, in 1999 in Japan.
The first http://en.wikipedia.org/wiki/Short_message_service Short Message Service message was sent in 1992 in the United Kingdom, but from a computer to a cell phone, and the first text message sent from a phone to another phone was in 1993 in Finland.

How many people own cell phones at this moment? We can’t be sure about the number, but at the end of last year there were 3.3 billion subscribers worldwide, meaning half of the population on the globe, and if you take into account the fact that maybe 50% of them own more than one cell phone, you could imagine a higher number, of almost 4.5 billion. The cellular phone technology is the most widely spread and the most popular gadget in the world.