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Introduction:
3G services were introduced into the market with the intention that people would get exciting new features such as video conferencing, internet access, paging facilities and interactive multimedia. However, 3G services offered maximum coverage for a peak rate of 384 kbps and a limited coverage to 2mbps. Therefore, it can be concluded that providing exciting and fast internet broadband options would be the primary motive of 4G wireless systems.
Comparison with 3G:
Let us visualize the ways in which 4G betters 3G. 4G
services have a frequency band of 2 to 8 GHz as compared to only 1.8 to 2.5 GHz in 3G. It has the same bandwidth as 3G i.e. 5 to 20 MHz. 3G has a data rate of 2 mbps. 4G betters it substantially by offering a data rate of 20 mbps or more. Both have the same mobile top speed i.e. 200 kmph.
Upper layer issues with 4G:
4G will be a pocket based network. As it will carry internet traffic along with voice, it should be able to provide an altogether different level of quality of service. There are other issues as well. Some of them are discussed below.
Management of mobility:
Management of mobility comprises of paging, local registration and handover. The MT should work in such a way that it should access all kinds of services at any given place. A flawless service is also essential. The techniques for handover should be made in such a manner that they can make optimum use of the network available.
Control of Congestion:
Control of congestion is going to be one more of the serious subjects in the optimum performance of 4G services. The 2 essential steps that could be taken to prevent congestion are avoiding congestion and detection of congestion if it happens.
Quality of service:
4G services are supposed to provide real time and internet similar services. These services could be categorized into 2 distinct parts. Guaranteed services and better than best services. Because of the provision of these services, 4G can be classified into the high quality of services category.
Conclusions:
4G is still in the experimenting stage. It will be available in the market in the latter half of 2010. Voice traffic will go down to about 20-30%. The remaining 70-80 % traffic will be multimedia traffic. The complete network would become packet switched and there will be a large array of apps like tele-medicine and navigation.
