4G NETWORK
ABSTRACT
1G and 2G networks supported low-bit-rate and were primarily designed for voice communication. Third-generation networks offer multimedia transmission, global roaming across a cellular or other single type of wireless network, and bit rates ranging from 384 Kbps to several Mbps. Analysts expect worldwide migration to 3G to continue through 2005, depending on market needs, carrier and operator incentives, recovery on investments in existing 1G and 2G wireless systems, and perceived threats to monopolistic wireless carriers in many countries.
Meanwhile, researchers and vendors are expressing a growing interest in 4G wireless networks that support global roaming across multiple wireless and mobile networks—for example, from a cellular network to a satellite-based network to a high-bandwidth wireless LAN. With this feature, users will have access to different services, increased coverage, the convenience of a single device, one bill with reduced total access cost, and more reliable wireless access even with the failure or loss of one or more networks. 4G networks will also feature IP interoperability for seamless mobile Internet access and bit rates of 50 Mbps or more.
ACKNOWLEDGEMENT
It is my proud privilege to epitomize my deepest sense of gratitude and indebtedness to my guide, Mr. Rakesh Roshan for his valuable guidance, keen and sustained interest, intuitive ideas and persistent endeavor. His inspiring assistance, laconic reciprocation and affectionate care enabled me to complete my work smoothly and successfully.
I am also thankful to Mr. G.V. Kiran Kumar, Technical Seminar Coordinator for giving his valuable time and support during the preparation of this report.
I acknowledge with immense pleasure the sustained interest, encouraging attitude and constant inspiration rendered by Mr. Sangram Mudali, Director, NIST. His continued drive for better quality in everything that happens at NIST and selfless inspiration has always helped us to move ahead.
1. INTRODUCTION
Cellular service providers are slowly beginning to deploy third-generation (3G) cellular services. As access technology increases, voice, video, multimedia, and broadband data services are becoming integrated into the same network. The hope once envisioned for 3G as a true broadband service has all but dwindled away.
While 3G hasn't quite arrived, designers are already thinking about 4G technology. To achieve the goals of true broadband cellular service, the systems have to make the leap to a fourth-generation (4G) network. 4G is intended to provide high speed, high capacity, low cost per bit, IP based services. The goal is to have data rates up to 20 Mbps. Most probable the 4G network would be a network, which is a combination of different technologies (current cellular networks, 3G cellular network, wireless LAN, etc.) working together using suitable interoperability protocols (for example Mobile IP). There is standardization work on 4G already on the way. For example IEEE is standardizing 4G cellular networks. The aim is to support up to 4 Mbit/s speeds. The network is expected to support communications to moving vehicle up to speeds of 250 km/h. This 4G system is going to be based on OFDM modulation, CDMA and multiple antenna technology. The aim is to bring together 4G mobile technology, WLAN and satellite communications so that they can all work seamlessly together.
The move to 4G is complicated by attempts to standardize on a single 3G protocol. Without a single standard on which to build, designers face significant additional challenges. Table 1 compares some of the key parameters of 3G and 4G (4G does not have any solid specification as of yet, so the parameters rely on general proposals). It is clear that some standardization is in order.