07-04-2009, 08:51 PM
Recently the introduction of the third generation mobile networks has just been taking place which holds out the possibilities what have never been seen before. Every mobile generation created something new and more valuable for the users in comparison with previous networks and this will be the case also with the appearance of the fourth generation.
As time and the technology progresses, people get used to having access to information at any time, independently of the presence of any cables. Moreover, people want to have continuous high quality services and, at the same time, are unaware of how they will get it and where they are going next. Hence, they need a functioning mobile infrastructure capable of handling high amounts of data. Current mobile standards (the so called "2G", second generation, networks) can be used to transfer data at very limited speed. The recently implementing generation, 3G, will offer better data transfer capabilities, but its speed is still insufficient for many desired applications like video conferencing. Only the next generation, "4G", the fourth generation, will offer data transfer at fully acceptable rate.
However, since the 4G will need to use higher frequencies, it also provides much smaller coverage area per base station. This means, in particular, that while users could enjoy continuous video conferencing, a more complicated infrastructure of service providers has to be set up. Some effort has been done to elaborate on the 4G technical solutions but less on the economical side of this problem.
4G will provide different features like fully packet switching networks, higher bandwidths for providing multimedia services at cheaper rates, higher bit rates approx 100 mega bits per second, very high network security etc. It will have interactive multimedia services such as wireless internet and teleconferencing.
The 4G technology was predicted to become applicable around 2010 but due to so many features and facilities the researchers had put their efforts and by investing $30 billion the technology will be available by 2006, something which has never happened before.
WHAT IS 4G?
Depending on the level of the reader 4G can be defined in different ways. In simplest terms, 4G is the next generation of wireless networks that will replace 3G networks sometimes in future. In another context, 4G is simply an initiative by academic R&D labs to move beyond the limitations and problems of 3G which is having trouble getting deployed and meeting its promised performance and throughput. In reality, as of first half of 2002, 4G is a conceptual framework for or a discussion point to address future needs of a universal high speed wireless network that will interface with wire line backbone network seamlessly.
Here's something we don't see often: a wireless technology that could actually arrive earlier than predicted. Fourth-generation (4G) cellular services, intended to provide mobile data at rates of 100Mbits/sec or more, were originally scheduled for 2010. Some cell phone companies have moved the target up to 2006, while rival wireless systems could bring similar bandwidth to a few fortunate networkers a lot sooner.
Two aspects characterize the resulting fourth generation wireless network scenario (4G). First, the network consists of a collection of heterogeneous networks that provide end-to-end IP connectivity over wireless. In addition, it is a "stupid network" scenario, where the network only provides packet transport, and therefore it is an "operator-less" network with respect to services. This scenario also implies that the mobile users and devices that participate in communication over 4G must become smarter, i.e., they must be able to respond to a wide range of events.
Whatâ„¢s new in 4G?
¢ Entirely packet-switched networks
¢ All network elements are digital
¢ Higher bandwidths to provide multimedia services at lower cost (up to 100Mbps, higher bit rates)
¢ Tight network security.
¢ Support interactive multimedia services such as teleconferencing, wireless Internet, etc.
¢ Global mobility and service portability, Scalability of mobile networks
¢ Seamless switching
¢ Scheduling and call admission control techniques
¢ Ad hoc networks and multi-hop networks
Challenges in 4G
¢ Multi-access interface, timing and recovery
¢ Higher frequency reuse
¢ Issues in the interface with the ad hoc networks
¢ Voice over multi-hop networks
¢ Variable QoS (Quality of Service) services and tight security
¢ Changing channel conditions
¢ Seamless roaming and transfer of services
