24-12-2010, 01:41 PM
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Submitted by:KAPIL JOSHI
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.
Introduction:-
Consumers demand more from their technology. Whether it be a television, cellular phone, or refrigerator, the latest technology purchase must have new features. With the advent of the Internet, the most-wanted feature is better, faster access to information. Cellular subscribers pay extra on top of their basic bills for such features as instant messaging, stock quotes, and even Internet access right on their phones. But that is far from the limit of features; manufacturers entice customers to buy new phones with photo and even video capability. It is no longer a quantum leap to envision a time when access to all necessary information the power of a personal computer, sits in the palm of one’s hand. To support such a powerful system, we need pervasive, high-speed wireless connectivity.
A number of technologies currently exist to provide users with high-speed digital wireless connectivity; Bluetooth and 802.11 are examples. These two standards provide very high speed network connections over short distances, typically in the tens of meters. Meanwhile, cellular
providers seek to increase speed on their long-range wireless networks. The goal is the same: long-range, high-speed wireless, which for the purposes of this report will be called 4G, for fourth-generation wireless system. Such a system does not yet exist, nor will it exist in today’s market without standardization. Fourth-generation wireless needs to be standardized throughout the world due to its enticing advantages to both users and providers.
Economic Impact:-
Advantages of 4G:-
In a fourth-generation wireless system, cellular providers have the opportunity to offer data access to a wide variety of devices. The cellular network would become a data network on which cellular phones could operate-as well as any other data device. Sending data over the cell phone network is a lucrative business. In the information age, access to data is the “killer app” that drives the market. The most telling example is growth of the Internet over the last 10 years. Wireless networks provide a unique twist to this product: mobility. This concept is already beginning a revolution in wireless networking, with instant access to the Internet from anywhere.
Problems with the Current System
One may then wonder why ubiquitous, high-speed wireless is not already available. After all, wireless providers are already moving in the direction of expanding the bandwidth of their cellular networks. Almost all of the major cell phone networks already provide
data services beyond that offered in standard cell phones, as illustrated in Table 1.
Unfortunately, the current cellular network does not have the available bandwidth necessary to handle data services well. Not only is data transfer slowly - at the speed of analog modems - but the bandwidth that is available is not allocated efficiently for data. Data transfer tends to come in bursts rather than in the constant stream of voice data. Cellular providers are continuing to upgrade their networks in order to meet this higher demand by switching to different protocols that allow for faster access speeds and more efficient transfers. These are collectively referred to as third generation, or 3G, services. However, the way in which the companies are developing their networks is problematic — all are currently preceding in different directions with their technology improvements. Figure 1 illustrates the different technologies that are currently in use, and which technologies the providers plan to use.
Although most technologies are similar, they are not all using the same
protocol. In addition, 3G systems still have inherent flaws. They are not well-designed for data; they are improvements on a protocol that was originally designed for voice. Thus, they are inefficient with their use of the available spectrum bandwidth. A data-centered protocol is needed. If one were to create two identical marketplaces in which cellular providers used 3G and 4G respectively, the improvements in 4G would be easy to see. Speaking on the topic of 3G, one of the worlds leading authorities on mobile communications, William C.Y. Lee, states that 3G would be “a patched up system that could be inefficient”, and it would be best if the industry would leapfrog over 3G wireless technologies, and prepare for 4G (Christian). 4G protocols use spectrum up to 3 times as efficiently as 3G systems, have better ways of handling dynamic load changes (such as additional cellular users entering a particular cell), and create more bandwidth than 3G systems. Most importantly, fourth-generation systems will draw more users by using standard network protocols, which will be discussed later, to connect to the Internet. This will allow simple and transparent connectivity.
