Early History of Mobile Technology
In 1857, Clark Maxwell derived a theory of electromagnetic radiation, which Guglielmo Marconi used as a basis for the invention of radio transmission in 1901. This was a great achievement, however, it was unable to achieve reasonable data transmission rates for over a half-century.
The first precursors to modern mobile telephony were introduced in the late 1940s in the United States and in the 1950s in Europe. These early "mobile" phones were heavily constrained by limited mobility and poor service. The devices were heavy and also extremely expensive.
1G: First Generation Cellular Phones
In the 1970s, the First Generation, or 1G, mobile networks were introduced. These systems were referred to as cellular, which was later shortened to "cell", due to the method by which the signals were handed off between towers. Cell phone signals were based on analog system transmissions, and 1G devices were comparatively less heavy and expensive than prior devices. Some of the most popular standards deployed for 1G systems were Advanced Mobile Phone System (AMPS), Total Access Communication Systems (TACS) and Nordic Mobile Telephone (NMT). The global mobile phone market grew from 30 to 50 percent annually with the appearance of the 1G network, and the number of subscribers worldwide reached approximately 20 million by 1990.
2G: GSM and GPRS Networks
In the early 1990s, 2G phones deploying GSM technology were introduced. Global System for Mobile communications, or GSM uses digital modulation to improve voice quality but the network offers limited data service.
As demand drove uptake of cell phones, 2G carriers continued to improve transmission quality and coverage. The 2G carriers also began to offer additional services, such as paging, faxes, text messages and voicemail. The limited data services under 2G included WAP, HSCSD and MLS.
An intermediary phase, 2.5G was introduced in the late 1990s. It uses the GPRS standard, which delivers packet-switched data capabilities to existing GSM networks. It allows users to send graphics-rich data as packets. The importance for packet-switching increased with the rise of the Internet and the Internet Protocol, or IP. The EDGE network is an example of 2.5G mobile technology.
Recent 3G Networks
The 3G revolution allowed mobile telephone customers to use audio, graphics and video applications. Over 3G it is possible to watch streaming video and engage in video telephony, although such activities are severely constrained by network bottlenecks and over-usage.
One of the main objectives behind 3G was to standardize on a single global network protocol instead of the different standards adopted previously in Europe, the U.S. and other regions. 3G phone speeds deliver up to 2 Mpbs, but only under the best conditions and in stationary mode. Moving at a high speed can drop 3G bandwidth to a mere 145 Kbps.
3G cellular services, also known as UMTS, sustain higher data rates and open the way to Internet style applications. 3G technology supports both packet and circuit switched data transmission, and a single set of standards can be used worldwide with compatibility over a variety of mobile devices. UMTS delivers the first possibility of global roaming, with potential access to the Internet from any location.
High-Speed 4G Mobile Networks
The current generation of mobile telephony, 4G has been developed with the aim of providing transmission rates up to 20 Mbps while simultaneously accommodating Quality of Service (QoS) features. QoS will allow you and your telephone carrier to prioritize traffic according to the type of application using your bandwidth and adjust between your different telephone needs at a moment's notice.
Only now are we beginning to see the potential of 4G applications. They are expected to include high-performance streaming of multimedia content. The deployment of 4G networks will also improve video conferencing functionality. It is also anticipated that 4G networks will deliver wider bandwidth to vehicles and devices moving at high speeds within the network area.