REVIEW OF RELATED LITERATURE
This chapter presents the related literature-local and foreign which helped the researcher conceptualize the effects of cell phone use of students during classes. In addition to the related literature are local and foreign studies that helped the researcher in the analysis of the problems under study. It has provided an insight to enrich this investigation and understanding of the study’s problem.
In today's world, most people communicate through the use cellular phones. It's hard to believe that fifteen years ago cell phones were a rarity. People may not be aware of what is the history chronicling the dawn of the cell phone to its current state.
According to www.symatech.net, the history of cell phone truly began with the creation of radio technology. Two-way radios were, after all, the ancestors of the cell phone. It wasn’t until the 1950s that what people would recognize as a cell phone was created. These were the cell phones that allowed direct dialing. These phones, called the MTA for Mobile Telephone System A, were created by Erickson and were released in 1956 in Sweden. They were very heavy and bulky, and the phones were usually stalled in cars. Only about 150 people used the MTA system. In 1957, Leonid Kupriyanovich created the radiophone, or a wearable mobile phone, in the USSR. These phones required a base station to operate, but each base station could be used by several customers. His phone weighed only 0.5 kg, making it much more portable than the MTA.
The First Generation, or 1G, or the first truly portable cellular phone began in 1983. It was called the Motorola DynaTAC 8000X. The FCC approved it for use in the United States. Motorola developed the technology for cellular phones for decades and this particular phone took 15 years to come to market at an expense of over 100 million dollars in research costs. The DynaTAC800X was extremely lightweight for its time and only weighed about 28 ounces. It was 13 inches x 1.75 inches x 3.5 inches and was known as the Brick for its shape. It was largely developed with the help of Dr. Martin Cooper of Motorola. From 1983 to the end of the 1980's cell phones grew in popularity due to the innovations in cellular networks that were able to handle phone calls in either one area or hand them off to other areas. While most cell phones weren't made to be handy, all phones were made for permanent installation in the car. For a while the term "car phone" was extremely popular. Besides car phones, there were a few models that came in tote bag type configurations that can easily hook up to a car's battery, via the DC outlet to make calls. There were also a few models that came as briefcases, to hold large batteries necssary to make phone calls. Second Generation (2G) or the cellular phones from the early 1990's were able to work on mobile phone systems such as GSM, IS-136 (TDMA) and IS-95 (CDMA). Digital mobile phone networks were in use in the United States in 1990 and in Europe by 1991. 2G mobile phones use digital circuit switched transmissions. This ultimately enabled quicker network signaling, lowering the amount of dropped calls and increasing call quality. As 2G digital networks were online, most of the time, they replaced analog network frequencies, effectively making them obsolete. Phones based on 2G technology were much smaller than the brick telephones of the mid to late 80's. Most 2G cellular phones were usually in the range of 100 to 200 grams, plus they were hand held devices that were truly portable without the need for a large battery. Advances in battery technology, as well as computer chip technology also helped to make 2G cell phones much smaller than their predecessors. With these innovations, cell phone usage soared. The Third Generation cellular phone is the technology that is currently available today and it is commonly referred to as 3G. While...