Department of Electronics Engineering
M Tech. ECE (Regular)
Abstract---Due to the increase in demand for speed, multimedia support and other resources, the wireless world is looking forward for a new generation technology to replace the third generation. This is where the fourth generation wireless communication comes into play. 4G wireless communication is expected to provide better speed, high capacity, lower cost and IP based services. The main aim of 4G wireless is to replace the current core technology with a single universal technology based on IP. Yet there are several challenges that inhibit the progress of 4G and researchers throughout the world are contributing their ideas to solve these challenges. This project deals with understanding the features and challenges, the proposed architectural frameworks, multimedia support and multiple access schemes for 4G. I. INTRODUCTION.
his wireless communication filed is a very fast growing area with the number of users and their demand for better resources increasing day by day. The R&D departments of many companies are working on a future technology that can meet these demands at a lower cost. 3G is necessary but not sufficient for the demands today. So the world is taking its leap towards the fourth generation wireless communication that promises to bring an end to most of the problems faced. 4G wireless is expected to be launched by 2011, but there are numerous challenges faced by researchers in achieving the desired features. Most of the ongoing researches are in the area of distributed computing, mobile agents, multimedia support etc. Some other research area is to improve the Quality of Service from the viewpoint of both the user and service providers. 4G wireless infrastructures are expected to be deployed in an environment where many other types of wireless and wired communication systems already exist. This paper is organized as follows. Section II provides a brief review of the previous generations, desired features and research challenges faced by 4G. Section III describes the core architectural framework and some architectural models proposed for 4G. Section IV provides some proposed solution for hand off mechanism for 4G. In Section V, the multiple access schemes for 4G are discussed. Section VI deal with multimedia support for 4G. Section VII gives some applications of 4G and finally section VIII gives the conclusion. II. 4G VISION
A. Brief History of Generations
1. First Generation: 1G was based on analog technology and basically intended for analog phones. It was launched in the early 1980s. It introduced the first basic framework for mobile communications like the basic architecture, frequency multiplexing, roaming concept etc. Access technology used was AMPS (Advances Mobile Phone Service) 2. Second Generation: 2G was a revolution that marked the switching of mobile communication technology from analog to digital. It was introduced in the late 1980s and it adopted digital signal processing techniques. GSM was one of the main attractive sides of 2G and it introduced the concept of SIM (Subscriber Identity Module) cards. Main access technologies were CDMA (Code Division Multiple Access) and GSM (Global System for Mobile Communication). 3. 2.5 Generation: 2.5 G was basically an extension of 2G with packet switching incorporated to 2G. It implemented hybrid communication which connected the internet to mobile communications. 4. Third Generation: The basic idea of 3G is to deploy new systems with new services instead of just provide higher bandwidth and data rate. Support for multimedia transmission is another striking feature of 3G. It employs both circuit switching and packet switching strategies. The main access technologies are CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), and TSSDMA (Time division Synchronous CDMA).
B. Limitations of 3G
Why do we need 4G? To answer this...