ABSTRACT:- The approaching 4G (fourth generation) mobile communication systems are projected to solve still-remaining problems of 3G (third generation) systems and to provide a wide variety of new services, from high-quality voice to high-definition video to high-data-rate wireless channels. The term 4G is used broadly to include several types of broadband wireless access communication systems, not only cellular telephone systems. One of the terms used to describe 4G is MAGIC—Mobile multimedia, anytime anywhere, Global mobility support, integrated wireless solution, and customized personal service. As a promise for the future, 4G systems, that is, cellular broadband wireless access systems have been attracting much interest in the mobile communication arena. The 4G systems not only will support the next generation of mobile service, but also will support the fixed wireless networks. This paper presents an overall vision of the 4G features, framework, and integration of mobile communication. The features of 4G systems might be summarized with one word—integration. The 4G systems are about seamlessly integrating terminals, networks, and applications to satisfy increasing user demands. The continuous expansion of mobile communication and wireless networks shows evidence of exceptional growth in the areas of mobile subscriber, wireless network access, mobile services, and applications.
DEFINITION:-4G is the short term for fourth-generation wireless, the stage of broadband mobile communications that will supercede the third generation (3G). it is expected that end-to-end IP and high-quality streaming video will be among 4G's distinguishing features. Fourth generation networks are likely to use a combination of WiMAX and WiFi. 4G technologies are sometimes referred to by the acronym "MAGIC," which stands for Mobile multimedia, Anytime/any-where, Global mobility support, Integrated wireless and Customized personal service.
Although 3G networks were really about the technology, 4G networks are both a technology and a business transformation.
4G will potentially reshape not just the wireless industry, but also cable, wireline and handset companies. It will also simultaneously provide the media and entertainment industries another avenue for content delivery.
At the end of the 1940’s, the first radio telephone service was introduced, and was designed to users in cars to the public land-line based telephone network. Then, in the 60s, a system launched by Bell Systems, called IMTS, or, “Improved Mobile Telephone Service", brought quite a few improvements such as direct dialling and more bandwidth. The very first analog systems were based upon IMTS and were created in the late 60s and early 70s. The systems were called "cellular" because large coverage areas were split into smaller areas or "cells", each cell is served by a low power transmitter and receiver.
The 1G, or First Generation. 1G was an analog system, and was developed in the 70s, 1G had two major improvements, this was the invention of the microprocessor, and the digital transform of the control link between the phone and the cell site.
1G analog system for mobile communications saw two key improvements during the 1970s: the invention of the microprocessor and the digitization of the control link between the mobilephone and the cell site.
Advance mobile phone system (AMPS) was first launched by the US and is a 1G mobile system. Based on FDMA, it allows users to make voice calls in 1 country
2G, OR SECOND GENERATION:
2G first appeared around the end of the 1980’s, the 2G system digitized the voice signal, as well as the control link. This new digital system gave a lot better quality and much more capacity (i.e. more people could use there phones at the same time), all at a lower cost to the end consumer. Based on TDMA, the first commercial network for use by the public was the Global system for mobile communication (GSM).
3G, or THIRD GENERATION:-
3G systems promise faster communications services, entailing voice, fax and Internet data transfer capabilities, the aim of 3G is to provide these services any time, anywhere throughout the globe, with seamless roaming between standards. ITU’s IMT-2000 is a global standard for 3G and has opened new doors to enabling innovative services and application for instance, multimedia entertainment, and location-based services, as well as a whole lot more. In 2001, Japan saw the first 3G network launched.
3G technology supports around 144 Kbps, with high speed movement, i.e. in a vehicle. 384 Kbps locally, and up to 2Mbps for fixed stations, i.e. in a building.
4G, or FOURTH GENERATION:-
For 1 and 2G standards, bandwidth maximum is 9.6 kbit/sec, This is approximately 6 times slower than an ISDN (Integrated services digital network). Rates did increase by a factor of 3 with newer handsets to 28.8kbps. This is rarely the speed though, as in crowded areas, when the network is busy, rates do drop dramatically.
Third generation mobile, data rates are 384 kbps (download) maximum, typically around 200kbps, and 64kbps upload. These are comparable to home broadband connections.
Fourth generation mobile communications will have higher data transmission rates than 3G. 4G mobile data transmission rates are planned to be up to 100 megabits per second on the move and 1000gigbits per second stationary, this is a phenomenal amount of bandwidth, only comparable to the bandwidth workstations get connected directly to a LAN.
Motivation for 4G Research Before 3G Has Not Been Deployed?
• 3G performance may not be sufficient to meet needs of future high-performance applications like multi-media, full-motion video, wireless teleconferencing. We need a network technology that extends 3G capacity by an order of magnitude.
• There are multiple standards for 3G making it difficult to roam and interoperate across networks. we need global mobility and service portability
• 3G is based on primarily a wide-area concept. We need hybrid networks that utilize both wireless LAN (hot spot) concept and cell or base-station wide area network design.
• We need wider bandwidth
• Researchers have come up with spectrally more efficient modulation schemes that can not be retrofitted into 3G infrastructure
• We need all digital packet network that utilizes IP in its fullest form with converged voice and data capability.