Pakistan Zindabad.....

1. AMRA IQBAL NEELAM ASMA & NAZIA AKTHER cellular phones by

3. INTRODUCTION A type of wireless communication that is most familiar to mobile phones users. It's called 'cellular' because the system uses many base stations to divide a service area into multiple 'cells'. Cellular calls are transferred from base station to base station as a user travels from cell to cell. -

4. DEFINITION A mobile phone is a device which behaves as a normal telephone whilst being able to move over a wide area ( cf. cordless phone which acts as a telephone only within a limited range). Mobile phones allow connections to be made to the telephone network , normally by directly dialing the other party's number on an inbuilt keypad. Most current mobile phones use a combination of radio wave transmission and conventional telephone circuit switching , though packet switching is already in use for some parts of the mobile phone network, especially for services such as internet access and WAP .

5. HISTORY The basic concept of cellular phones began in 1947, when researchers looked at crude mobile (car) phones and realized that by using small cells (range of service area) with frequency reuse they could increase the traffic capacity of mobile phones substantially. However at that time, the technology to do so was nonexistent. Anything to do with broadcasting and sending a radio or television message out over the airwaves comes under Federal Communications Commission (FCC) regulation

6. cell phone is a type of two-way radio. In 1947, AT&T proposed that the FCC allocate a large number of radio-spectrum frequencies so that widespread mobile telephone service would become feasible and AT&T would have a incentive to research the new technology. We can partially blame the FCC for the gap between the initial concept of cellular service and its availability to the public. The FCC decided to limit the amount of frequencies available in 1947, the limits made only twenty-three phone conversations possible simultaneously in the same service area - not a market incentive for research. HISTORY

7. HISTORY The FCC reconsidered its position in 1968, stating "if the technology to build a better mobile service works, we will increase the frequencies allocation, freeing the airwaves for more mobile phones." AT&T and Bell Labs proposed a cellular system to the FCC of many small, low-powered, broadcast towers, each covering a 'cell' a few miles in radius and collectively covering a larger area. Each tower would use only a few of the total frequencies allocated to the system. As the phones traveled across the area, calls would be passed from tower to tower.

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