Monday, July 25, 2011

History of Cell Phones

The history of cell phones embarks on from the early days of 1920s – a period during which radios were emerging as effective communication devices. The very first usage of radio phones were in taxi/cars using two-way radio communication. Like any other electronic equipment, cell phones evolved over time, and each stage or era was most certainly interesting.
The first official cell phone was used by the Swedish police in 1946. They made it functional by connecting a hand-held phone to the central telephone network. It was very similar to the two-way radio phone that was used in cars/taxis for portable communication.
Rising from this type of communication technology, the evolution of modern cellular phones began. A communication architecture of Hexagonal Cells was created for cell phones by D. H. Ring, of Bell Labs, in 1947. An engineer from Bell Labs discovered cell towers which had the capability to not only transmit but to also receive the signals in three different directions. Before this discovery, the cell phones only worked in two directions and through an antenna.
Pre-Mobile Phones
The electronic components used in cell phones of today’s generation were first developed in the 1960s. During this time, the technology of cell phone was already available. The problem that persisted during that time was the user was restricted to a certain block of areas, which were called cell areas. Cell areas were base stations covering a small land area. If the cell phone user traveled beyond the boundaries of the cell area, the user wouldn’t get signal or receive transmitted messages. There were instances when a call could still be made but the call would be cut once a set range has been reached.
The above limitation of distance was resolved by an engineer at Bell Labs. Amos Edward Joel discovered and developed what he termed as the handoff system. This kind of technology enabled to continue the call from one area to the next and the call would not get dropped. The cell areas for the cell phone users weren’t restricted anymore; the user could freely roam across cell areas without disruption in their calls.
During this time, the technology for cell phones had been developed but it was only in 1971 when there was a request for cellular service. AT&T submitted a request public cellular service to the FCC in 1982. The request was processed almost after a decade. Frequencies of 824 to 894 MHz Band to the AMPS (Advanced Mobile Phone Services) were made possible. Cell phones had analog service since 1982 to 1990. In 1990, AMPS turned digital and went online.
First Generation Cell phones
Motorola was the first company to introduce the first portable cell phone called Motorola DynaTAC 8000X. The FCC approved it for public use after much deliberation and testing of the device. Since then, Motorola has been developing the communication technology of cellular phones. The Motorola DynaTAC took 15 years of development before it was made available to the public market. It was considered to be a lightweight cell phone of about 28 ounces. Its dimensions were 13 x 1.75 x 3.5 inches. It was developed by Dr. Martin Cooper. During those times, Motorola DynaTAC assumed to be high-tech and advance cell phone unit.
Cell phones became popular and received demand from the public during the 1983 to 1989 period. The innovations in communication technology and other networks include the ability of cell phones to handle calls from one area to another area way beyond the venue of the call. In the 1980s, a lot of cell phones were not designed to be hand-held. Formally, “car phone” were installed in cars and this had high demand in the market. Aside from car phones, the earliest models of the first generation cell phones were shaped like tote bags. These were hooked up to the battery of the car through the DC outlet. Other models came in the form of briefcases. This was for large batteries that were needed just in case the user had to make emergency calls.
Second Generation Cell phones
During the 1990s, the technology on which the cell phones worked was called 2G or second generation. This worked on systems like IS-95 or the CDMA, IS-136, TDMA and GSM. The United States and Europe used digital cell phone providers and networks at that time. 2G cell phones were also used to switch the transmissions in the digital circuit which made it easier to make calls. 2G cell phones had a faster network which functions on radio signals. This decreased the chances of calls being dropped thus improvising on call quality. These replaced the analog network frequencies. Eventually, the adaption of modern networks made the analog frequencies obsolete.
The 2G cell phones were smaller, around 100 to 200 grams. These were hand-held and were portable. The advancements happened in cell phones, their batteries, computer chips, etc. Due all these improvements, the cell phone customer base expanded rapidly.
Third Generation Cell phones
The cell phones used nowadays are the third generation phones. 3G was soon launched after 2G. However, the standards that are used in 3G cell phones are different from one model of the cell phone to the next. This essentially depends on the network providers.
3G cell phones have set standards which the network providers need to follow. These cell phones could also message other users via SMS (Short Messaging Service), send emails and access the Internet, stream live videos, stream radio, and use the Wi-Fi.

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