Evolution of the mobile phoneThe mobile phone, also referred to as a cellular phone is described as gadget that is used to make and receive telephone calls via radio signals over a specific geographical area as specified by the users network provider. The mobile phone is a small handheld gadget that fits perfectly in the palm of the hand. It has gone under so many changes due to changes in technology coupled with the new customer preferences. The mobile phone operates only with the aid of the cellular network that allows the user to be connected from whatever location they please so long as they are within the networks operation range. The mobile enables the user to use other services such as multimedia messaging, short messaging service, emails, internet access, short wireless communication such as Bluetooth and infrared (Agar,2004).Mobile telephones date back to the early 1940s when the Second World War was in progress. Handheld devices were used by the United States military to communicate in the battlefield via radio signals. The mobile phones during that period were very different in almost every aspect except the radio signals as a communication medium. The mobile phone has evolved significantly such that there exists generations of the mobile phone namely the zero, first, second, third generation and the new fourth generations. These levels of generations clearly mark the stages that the mobile phone has undergone to meet the new consumer needs and the new technology that has prompted the new changes. The mobile phone was first put to use by the Mobile Telephone Service in St.Louis in the year 1946.by then there were few radio channels available to broadcast the signals of the mobile phone, which required the presence of a mobile operator to make a call set-up. In the year 1964, Improved Mobile Telephone Service was introduced that enabled the presence of more channels and automatic handling of calls, which facilitated the transition from one telephone technology to another. During that period, due to increase in demand for the technology arising from the increase in the number of users of mobile phones, there were new competitors who wanted a share of the market. A new competitor, Radio Common Carrier, arose and proved to be highly competitive. However, this service operated for the period between 1960 and 1980 when it was rendered obsolete after the entry of new player Advanced Mobile Telephony System (AMTS). This forced the regulators to enhance security by introducing new regulations to control the rapid growth of the cellular market. Mobile phone use was only limited to phones installed in vehicles in the period before 1973 (Agar, 2004).The mobile telephone services were followed by modern telephone technology. These kinds of technologies are regarded as the zero generation of cellular phones. They were characterized by the push to talk similar to a walkie-talkie whereby the user only presses the buttons in order to communicate with a person on the other end. The new technology was very different from the initial radiotelephone systems in that they were available for commercial purposes to the public on the public switched telephone network. The mobile radiotelephones were characterized by the presence of a transmitter and were usually enabled to offer communication in two ways. In the year 1947, Bell labs engineers proposed the use of hexagonal cells for mobile phones. A mobile phone during this period had to be inside the coverage area of the network that was serviced by a single base station during a phone call. This meant that there was no connection if the cell phone moved from one place to another.The first automated mobile phone system was first launched and used in Sweden in the year 1960. They named it Mobile Telephone System A, as it enabled the user to make and receive calls in the car by means of a rotating dial. The system also enabled the car phone to be paged. In addition, the calls made from the car were direct, and only incoming calls required the assistance of a mobile operator to determine which base station the phone was using. Later in 1962, an improved version of the system named, Mobile System B, was developed. It was a push button telephone that had transistors for better signal quality and for enhanced operation quality. It was used until the year 1983 and was regarded as a commercial success. In the year 1973, Martin Cooper a Motorola executive saw the development of the Motorola DynaTAC 8000X, which was a bulky analogue phone that was overpriced due to the high demand. This marked the beginning of intense competition amongst companies seeking to develop the best products. The development in the technology saw a transition from the zero generation of mobile phones to the first generation. Unlike the previous generations, the new generation facilitated the use of several multiple cell sites and enabled the transfer of calls from one site to another as a user moved from one cell to another while still conversing on the mobile phone. The first cellular network in the world was developed in the year 1977, in Chicago, by AT&T after their proposal that they had placed in the year 1971 was accepted by the Federal Communications Commission.In 1979, a first generation network was launched in Japan to become the first generation network to cover a complete geographical area of a nation. After this launch, Nordic Mobile Telephone Company was the first network provider to launch international roaming. Later in 1984, Bell Labs made a modern commercial mobile technology that used several base stations all controlled from a central location with each base station providing access to a small cell area. For minimal interference, the sites were put up in a way that the cells were to some extent overlapped and each base station using similar frequencies. More innovations enhanced the capabilities of these early networks to meet the increased demand by the cellular users. The base stations used different levels of transmission power that allowed varied cell size and a range of transmission. These changes allowed the reduction in the transmission power created room for new cells to be added thus smaller cells with greater capacities. This is still evident in the modern era by the presence of soaring cell site towers that do not have antennae present on top of their towers.Second Generation (2G) mobile systems emerged in the year ranging 1990 that used the GSM standard that enabled international wireless communications network (Meurling&Jeans, 1994). .The second-generation system was different in that they used digital transmission unlike their predecessors. The second generation was an era that was marked by significant usage of mobile telephones, more than any other period in time. The introduction of the second generation also enhanced the introduction of lesser phones that were considerable in size unlike their predecessors that were bulky. This was made possible by the technological advancements that occurred with time and the presence of higher density cells to enable growing usage. It enabled the user to be able to use the cell phone over a wider area of transmission and prolonged battery life. The Second-Generation also facilitated new short messaging service (SMS) (Meurling&Jeans, 1994).It was only available to GSM networks but eventually became available to other digital networks across the world. The first text message is said to have been machine generated and was sent in the United Kingdom on 3 December 1992 and later in the year 1993 the first man to man text message was sent in Finland (Meurling&Jeans,1994). The spread of text messaging was fueled by the presence of prepaid advents, which became the preferred method of communication among the young. This group communicates via text messages, as they consider them cheap yet effective to their needs.Moreover, Second Generation (2G) also enabled the ease to access to media content via the mobile phones. In the year 1998, the ring tone became the first item downloadable via the mobile phone in Finland. This set a precedent such that there were more advertisements via the phone, which meant a new source of revenue to the network providers. The Second-Generation systems also enabled the introduction of mobile payments, which were first made in Finland and Sweden .In addition there were breakthroughs in internet connections via the mobile phone that became fully functional after its introduction in Japan by NTT DoCoMo in 1999 (Agar,2004).The third generation was developed because of the markets hunger for fast mobile phones that would enable the users to access the internet and get information with ease. The mobile phone has evolved to become a personal gadget that people use to manage personal tasks. This prompted mobile phone developers to make phones that had high performance to meet the consumer needs of mobile phones that have very high performance due to the complicated schedules of the users. The difference between the Second generation and the First generation is the use of packet switching. The Third generation uses circuit switching, unlike the second generation. The Third generation networks enabled the mobile phone users to access data at speeds of 2Megabytes maximum data rate for indoors and 384 Kilobytes for outdoor access. The development of the third generation brought about new vendors creating their own technologies in efforts to gain shares of a very lucrative market such as CDMA. The third generation technology brought about new ways of using the mobile phone and the development of new mobile phones that would meet the standards of the third generation technology (Morris, 2007).Media streaming of television and radio content via the internet became possible due to the high data speed associated with the technology. This also enabled the development of new types of products such as the compact wireless router whereby the third generation technology enables the connectivity to several computers concurrently over the Wi-Fi broadband with the use of cables. Such devices are popular with the use of laptops due to their ease of portability. This has led to the development of complex devices that have 3G functions on their own by the use of SIM cards without the aid of the mobile phone. There are also satellite mobiles that were not present in the past. Earth satellites cover remote areas that do not have wired networks. The technology allows the user to make calls from anywhere in the world (Morris, 2007).The changes that have brought about the evolution of the mobile phones have had both positive and negative impacts in the world. The communication in the periods when the telephone was a bulky gadget was only limited to certain areas and to certain people. In the current age people are able to communicate in spite of their locations. This is facilitated by the presence of network systems that enable movement of signals to very far locations outside their jurisdiction. When the mobile phone was developed, it became only a preserve for the affluent in society that meant that very few people were able to own a mobile phone, which is a total contrast to the current times. People are able to purchase mobile phones, which are at very low prices. The presence of numerous mobile phone producers has created more employment for people in a world that has seen several global economic meltdowns. The evolution of the mobile phone has enabled easier communication and cheaper modes of communicating such as text messaging and emails via the mobile phone internet. In addition, the costs of accessing the internet have drastically reduced owing to the easy access posed by mobile phones unlike the access via the computer, which is associated with higher costs. Access to the internet enables the people to communicate and do business across the world. This aspect has played a very huge role in globalization.The use of the mobile phone is countered with many challenges such as; it increases the risk of accidents while used on the road due to reduced concentration on the roads (Heath, 2007). Accidents caused by mobile phones are attributed to the development of complex phones that require adequate attention to operate. The phone is considered an addictive device because it demands the users adequate attention. The new mobile phones are usually equipped with modern applications that are very entertaining to the user. The mobile phone poses health risks due to the exposure to the radiofrequency fields emitted by mobile phones. Research indicates that the use of the mobile phone pose a risk to exposure to diseases such as cancer and electromagnetic interference when they are used close to health devices such as pacemakers and hearing aids (Gezondheidsraad ,2002). Mobile phones also pose health risks such as change in the brain activity, reaction times and sleep patterns. There are however, no conclusive studies to prove these facts but research is still underway (Lin, 2009).Research shows that exposure to dielectric heat as a result of microwave radiation occurs on the head while using the mobile phone, thus distorting the body temperature of the organs around the head such as the eyes and ears and its internal organs. In addition, research also shows that the frequent use of the mobile use can have devastating effects on the ears leading to impairment or reduced activity .The young generations are prone to the new technological advancements posed by the telephone due to their perceived notion of wanting to fit with their peers who dictate what they should use. This has a huge impact in their lives, as they tend to take what is said in the media as the gospel truth, whereas those are just efforts of trying to get these young people to purchase the mobile phones. Blood brain barrier is also an effect that is described to be because of frequent mobile use .the chemicals in the battery f the mobile phone leak to the brain by radiation leading to cancers in the brain (Gezondheidsraad, 2002).Like any other addiction, the mobile phone use to an addictive level can be very devastating to the user and those that he or she has a relationship with due to misunderstandings arising from use of mobile phones. Some studies show that some people have lost jobs or even severed relationships they had considered very close due to the addiction of the cell phone. The studies suggested that 7% of people had stated they lost a job or a relationship due to an addiction with the mobile phone. The mobile phone has facilitated brainwash of young people who view what they see in the media as real life yet it is just entertainment for commercial purposes. Research shows that the mobile phone addicts develop negative psychological response by withdrawal such that they begin to live in solitude and develop this detachment form family and friends. Mobile phones are also claimed to cause sleep interruptions due to their effects on brain function. Studies show that people experience interrupted sleep as a result of frequent mobile use.ReferencesAgar, J. (2004). . Cambridge: Icon PublishersBurgess, A. (2010). . Saarbrucken: VDM Verlag Publishers.Gezondheidsraad. (2002). . 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