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Slide 1:

“The Mobile Phone”…..

HISTORY::

HISTORY: The inventor of the first modern portable handset is Dr Martin Cooper, who was the general manager for the systems division at Motorola at that time. In 1973, Dr Cooper made the first call on a portable cell phone. He called his rival Joel Engel, head of research at Bell Labs, to give him the latest news on how the competition between them was turning out. The picture above represents him and his first mobile phone.

First Generation: Cellular Networks:

First Generation: Cellular Networks The technological development that distinguished the First Generation mobile phones from the previous generation was the use of multiple cell sites, and the ability to transfer calls from one site to the next as the user travelled between cells during a conversation. The first commercially automated cellular network (the 1G generation) was launched in Japan by NTT in 1979. The initial launch network covered the full metropolitan area of Tokyo's over 20 million inhabitants with a cellular network of 23 base stations. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nation-wide 1G network.

Slide 4:

The next 1G network to launch was the Nordic Mobile Telephone (NMT) system in Denmark , Finland , Norway and Sweden in 1981. [ . NMT was the first mobile phone network featuring international roaming . The Swedish electrical engineer Östen Mäkitalo started work on this vision in 1966, and is considered to be the father of the NMT system, and by some the father of the cellular phone itself.The NMT installations were based on the Ericsson AXE digital exchange nodes. Several other countries also launched 1G networks in the early 1980s including the UK, Mexico and Canada . A two year trial started in 1981 in Baltimore and Washington DC with 150 users and 300 Motorola DynaTAC pre-production phones. This took place on a seven tower cellular network that covered the area. The DC area trial turned into a commercial services in about 1983 with fixed cellular car phones also built by Motorola. They later added the 8000X to their Cellular offerings. A similar trial and commercial launch also took place in Chicago by Ameritech in 1983 using the famous first hand-held mobile phone Motorola DynaTAC . As mentioned above, in 1982 the FCC approved AT&T's 1971 proposal for Advanced Mobile Phone System (AMPS) and allocated frequencies in the 824–894 MHz band. Analog AMPS was superseded by Digital AMPS in 1990.

Second Generations: Digital Networks:

Second Generations: Digital Networks In the 1990s , the 'second generation' ( 2G ) mobile phone systems emerged, primarily using the GSM standard. These 2G phone systems differed from the previous generation in their use of digital transmission instead of analog transmission, and also by the introduction of advanced and fast phone-to-network signaling. The rise in mobile phone usage as a result of 2G was explosive and this era also saw the advent of prepaid mobile phones In 1991 the first GSM network ( Radiolinja ) launched in Finland . In general the frequencies used by 2G systems in Europe were higher than those in America, though with some overlap. For example, the 900 MHz frequency range was used for both 1G and 2G systems in Europe, so the 1G systems were rapidly closed down to make space for the 2G systems. In America the IS-54 standard was deployed in the same band as AMPS and displaced some of the existing analog channels. Coinciding with the introduction of 2G systems was a trend away from the larger "brick" phones toward tiny 100–200g hand-held devices. This change was possible not only through technological improvements such as more advanced batteries and more energy-efficient electronics, but also related to the higher density of cellular sites needed because of increasing usage. The latter meant that the average distance transmission from phone to handset shortened. Both factors led to increased battery life for customers whilst on the move.

Third Generation: High speed IP data networks :

Third Generation: High speed IP data networks As the use of 2G phones became more widespread and people began to utilize mobile phones in their daily lives, it became clear that demand for data services (such as access to the internet) was growing. Furthermore, experience from fixed broadband services showed there would also be an ever increasing demand for greater data speeds. The 2G technology was nowhere near up to the job, so the industry began to work on the next generation of technology known as 3G. The main technological difference that distinguishes 3G technology from 2G technology is the use of packet switching rather than circuit switching for data transmission. In addition, the standardization process focused on requirements more than technology (2 Mbit /s maximum data rate indoors, 384 kbit /s outdoors, for example). Inevitably this led to many competing standards with different contenders pushing their own technologies, and the vision of a single unified worldwide standard looked far from reality. The standard 2G CDMA networks became 3G compliant with the adoption of Revision A to EV-DO , which made several additions to the protocol whilst retaining backwards compatibility:

Advantages::

Advantages: Сеll-рhоnes have three principal advantages. Сеll-рhоnes have made communication easier. In addition, Сеll-рhоnes provide their users with extra devices in addition to telephone. At last, Сеll-рhоnes can provide safety for their users. Сеll-рhоnes have become accepted in the last fifteen years because they have made communication easier. People can call each other no matter where they are. Fifteen years ago, there was no way to call someone who had no access to а conventional telephone. Additionally, the technology which is provided with Сеll-рhоnes has made life easier. Сеll-рhоnes are not only telephones; they can also include calendars, cameras, alarm Cell Phone clocks, and other devices to make life easier. The latest Сеll - рhоnes can even be used as а pocket computer. Last but not least, many parents provide their children with Сеll-рhоnes for safety reasons. The speed dial up option in Сеll-рhоnes lets people make contact with emergency numbers by pressing one button. For many parents, а Сеll-рhоne is а convenient way to get in touch with their children.

Disadvantages::

Disadvantages: The use of Сеll-рhоnes has been proven to be а big distraction. There are car accidents occurring everywhere due to the lack of attentiveness of drivers. Parents now think that it's better to buy Сеll-рhоnes for their new teen drivers for emergencies, but do you really think that they are used for those only? And since Сеll-рhоnes are so fabulous, then why do you always get а busy, roaming signal and cause you to keep redialing а number till you finally get through to that person? After all that trouble you are normally bothered and frustrated. Things like these can created accidents and even death. The possibility of brain tumors is also increasing with the use of cellular phones. Radiation is enormously hazardous to Сеll-рhоne users. The more cell phone uses, the greater chances become for brain cancer. When Сеll-рhоnes first came out, people purchased them in case of emergencies. Now, people bring their Cell Phone Сеll-рhоnes everyplace they go and use them for pleasure, not essentially for purpose. As convenient as Сеll-рhоnes may seem, there is more to it. Conscientiousness must be taken more sincerely and people need to be more aware of the risks that are involved in purchasing and using а cellular phone.