HISTORY OF MOBILE PHONES FROM 1G TO 4G

           HISTORY OF MOBILE PHONES FROM 1G TO 4G

                                                           

         The history of mobile phones charts the development of devices that connect wirelessly to the public switched telephone network. The transmission of speech by radio has a long and varied history going back to Reginald Fessenden's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links. Handheld radio transceivers have been available since 1940. Mobile phones to automobiles became available from some telephone companies in the 1940s. The first devices are bulky, high power consumption and network support only a few simultaneous conversations. Modern cellular networks allow automatic and pervasive use of mobile phones for voice and data communications.


 1 G NETWORK
                         

The first analog cellular system published widely in North America advanced mobile phone system (AMPS)and introduced commercially in the Americas in 1978, and Israel in 1986, and Australia in 1987.
AMPS was leading technology that helped drive mass market use of cellular technology, but many of the serious issues in accordance with modern standards. Was unencrypted it easily and vulnerable to eavesdropping through a scanner, but was vulnerable to cell phone "cloning"; frequency used for a multi-class (FDMA) scheme and large amounts of wireless spectrum needed to support. Was in the end a lot of the iconic early commercial mobile phones such as AMPS Analog Motorola DynaTAC replaced Digital AMPS (D-AMPS) in 1990, and closed down by AMPS service most airlines in North America by the year 2008.


2G NETWORK
                   

     In the 1990s, there was mobile phone "second generation" of systems. Systems competition for supremacy in the world market: the European standard and the U.S. developed GSM CDMA standard developed. It differs from the previous generation using digital instead of analog, and also to quickly scale phone signals to the network. The increase in mobile phone use as a result of the explosive for 2G and this era also saw the rise of prepaid mobile phones.
In 1991 launched the first GSM network (Radiolinja) in Finland. Overall, the frequencies used by 2G systems in Europe are higher than those in America, but with some overlap. For example, the use of the frequency band of 900 MHz for both systems in Europe 2G 1G, 1G closed systems as quickly down to make way 2G systems. United States has been the standard implementation is -54 in the same band AMPS and displaced some current analog channels.
In 1993, IBM introduced Simon. Perhaps this was the first smartphone in the world. A mobile phone, pager, fax and PDA all in one. Includes a calendar, address book, clock, calculator, notepad, e-mail, and a touch screen with a QWERTY keyboard. [20] Simon was IBM pen used to take advantage of the touch screen. Included in word completion could guess the characters that come as you tap. Applications, or at least a way to provide more functions by connecting the PCMCIA 1.8 MB of memory on the phone.
In conjunction with the introduction of 2G systems trend away from the largest mobile "brick" to a small handheld 100-200g. This change was made possible not only through technological improvements, such as more advanced batteries and energy-efficient electronics, but also due to the high density of cell sites to accommodate increased use. The latter means that the average distance of transmission from the phone to the base station fails, leading to the life of the battery increases during this step.

3G NETWORK
                                             

As the use of 2G phones are becoming more frequent and people began using mobile phones in their daily lives, it became clear that the demand for data services (eg Internet access) was growing. Furthermore, experience has shown fixed broadband services will also increasing demand for faster data. 2G technology was nowhere near up to the job, how the industry began working on the next generation of technology known as third generation 3G. The main difference that distinguishes technological technology 2G 3G technology is the use of packet switching instead of circuit for converting the data transfer.  In addition, the standardization process that focuses on the requirements of more than technology that you can download the data in no time more.Enable connection speeds high 3G technology shift in the industry: for the first time, streaming media of radio (and TV so) content to the devices of 3G became possible, with companies such as Real Networks and Disney among the early pioneers in this type of offering.
In the mid-2000s (the contract), began the development of 3G technology, which will be carried out, a high-speed access to download the data packets (HSDPA). It a 3G Optimizer (third generation) protocol mobile telephony in the arrival of packages high-speed (HSPA) family, also coined 3.5G, 3G + 3G or Turbo, which allows networks based on the global system for mobile communications (UMTS) to be higher data transfer speed and capacity. HSDPA deployments support current down-link speeds of 1.8, 7.2, 3.6 and 14.0 Mbit / s. Increases the speed of other available with HSPA +, which provides speeds of up to downlink Mbit / S 42 and 84 Mbit / s with version 9 of the 3GPP standards.
By the end of 2007, there were 295,000,000 subscribers on 3G networks worldwide, which reflected 9% of the total subscriber base worldwide. About two-thirds of the WCDMA level and third-level EV-DO. Communications 3G services generated more than $ 120 billion of revenue in 2007, and many of the markets in most new phones activate third-generation phones 3G. In Japan and South Korea in the market no longer supplies of second-generation phones.

4 G NETWORK

                                                 After 3g In March 2008, the International Telecommunication Union telecommunications Radiocommunication (ITU-R) to identify a set of requirements for 4G standards, and named the Advanced International Mobile Telecommunications (IMT-Advanced) specification, and development needs tip speed of 4G service at 100 megabits per second (Mbit / s) to connect to the high mobility (eg, trains and cars) and 1 Gigabit per second (Gb / s) to connect to a low mobility (as pedestrians and stationary users).

Since the first version of the release of Mobile WiMAX and LTE support much less than the speed of 1 Gbit / s peak bit, do not fully support IMT-Advanced, but often described by the 4G service providers. On December 6, 2010, ITU-R recognized that, however, could these two technologies and other techniques beyond-3G that do not meet the requirements of IMT-Advanced, is considered "4G", provided that represent applicants for compatible IMT Advanced and "a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed.

Mobile WiMAX Release 2 (also known as WirelessMAN IEEE 802.16m advanced or ') and LTE Advanced (LTE-A) is compatible with versions of IMT-Advanced compatible between the two systems, linked through the spring of 2011, [citation needed] and promising speeds in the order of 1 Gbit / s. The service is expected in 2013.

Unlike previous generations, a 4G phone service does not support traditional circuit switched, but all Internet Protocol (IP)-based IP telephony as. As discussed below, was abandoned spectrum technology used in broadcast systems, 3G, 4G systems in all candidate and replaced by OFDMA multi carrier transmission schemes and other frequency-domain equalization (FDE), which makes possible transfer bit rates very high in spite of the huge radio-track (echoes). It has been enhanced to increase the maximum bit rate of smart antenna arrays for multiple entries and communications (MIMO) and multiple outputs.