The cell phone

Materie:	Appunti
Categoria:	Lingue
Download:	17
Data:	13.09.2001
Numero di pagine:	3
Formato di file:	.doc (Microsoft Word)

The Cellphone

The cell phone is a mobile telephone that communicates through base station situated in areas called ‘Cells’.

A ‘cell’ is an area of ground that has the shape of a bee cell in a hive, its size can vary between 1 to 30 kilometres depending principally on the output power of transmitters, on the conformation of the environment, on the electromagnetic traffic etc. e.g. in Italy the power of transmitters allows themselves to send a signal for about 5 kilometres with lower damages for the surrounding.

A base station is an electronic controller situated in the centre of every cell and linked to the transmitter. The base station has the task of receiving messages from any cellphone that is physically inside the cell and relaying these messages to a Main Switching Centre (MSC). A MSC is a mainframe, a very powerful computer that is connected to any other MSC and with public exchange.

Cellphones were invented during the Second World War to communicate with ships and aeroplanes but they were only a prototype and they were called Radiophones.
According to an Article of the San Francisco Chronicle, the Cell Phone that we know was invented by Martin Cooper in 1983 who at that time was a vice-president at Motorola.
The article states that he made the first cell-phone call on a street corner in New York using a base station at the top of a tall building in that city. He called an acquaintance at AT&T who at that time was a rival and perhaps said something like "we've done it"

The cellphone is a very powerful machine. With a cellphone the consumer can send or receive telephone calls such as a normal telephone but this is not what really sets the mobile phone apart. It is the incredible empowerment and flexibility it offers in a single package. Using the cellular phone you are able to send or receive Short Message of text called SMS, you can plan your work with the integrated diary, you can enjoy yourself playing games or listening to music. That’s not all, there are more. When the new generation phone will came, there will be a revolution on the concept of mobile communication. With these new telephones, the UMTSs (Universal Mobile Telecommunication System), the user will be able to have videoconferences, he might watch television, browse the internet, send/receive e-mail, have the exact position on the Earth by Global Positioning System, know the best way to arrive in a city etc. They will become such as a pocket Personal Computers.

Parts of Cell Phone:

- Data display: it visualizes the contents of telephone book, the text of the SMSs, the numbers used in the moment, the reception of the signal, the charge of battery, the time and many others. LCD.
- Microphone.
- Speaker.
- Aerial: it is used to communicate with base stations through electromagnetic signal.
- Alphanumeric Keyboard: used to write the telephone numbers, the text of SMSs etc.
- Battery: it supplies the power to the telephone.

Inside:

- Vibracall: if available it allows feeling an incoming telephone call without bother people near you.
- SIM CARD: Subscriber identity module, it contains the data of the user that allows it to be recognized from the Telephone Company.
- Work memory and flash memory.
- Chips: that contains every information and command about the telephone and his working.
- Microprocessor: this is the brain of the cellphone; it manages the work of every part of the telephone.
- IC with resistors, capacitors, LEDs, potentiometers etc.

In Italy the diffusion of mobile telephones has been having three phases principally:

- At the beginning people bought cellphones for their job and the cell phone and its rates were very expensive. They were often used by emergency services and other services such as taxis.
- After about five years, in the first half of the 90’s, the cellphone became a Status Symbol. In those years having a cell phone meant belonging to the upper-middle classes.
- Since the second half of the 90’s till nowadays, the cell phone has taken the role of a powerful instrument that permits to be reached wherever you are and whatever you want, practically a global tool for a global communication. The positive features that have made mobile phones so popular are: the low cost of it, the low cost of calls and other services, its compactness, Telephone Companies that cover every part of the state with their cells and many others.

Since its inventions to today cellphones had, in this way, improved the quality of life of a large number of people and companies; but there are also negative aspect of this large diffusion. Recent studies says that the electromagnetic waves emitted from the telephones and the base stations can damage the human body permanently , particularly the brain; but at present it’s only advised to have a moderate use of these devices because, like in all good things in life, too much breaks the bag.