 Another important factor or the driving force behind the realization of NGN as we see them today is the convergence of everything onto IP. So we need to first understand formally what does convergence mean. That is the key idea that we shall try to comprehend. Then we'd look at various dimensions of convergence and we'd finally conclude or extract out of those the drivers which led to the importance of the IP into the next generation networks. Convergence as an important word means the confluence or the similarity of interest between different entities. Here more formally in terms of telecommunications and internet, it means to use the same network for a greater range of applications. These applications could be inherently belonging to different physical networks. An important goal here is to reduce the required number of separate networks which were otherwise required for service providing once NGNs were not there. And then since we are going to make one network for all and we are going to provide services on the same network, an important issue that is going to arise is the format, the conflict of the natural behavior of all these. So these issues need to be resolved. We are going to look at these issues as dimensions. So we are going to look at the dimensions of convergence one by one. First of all, let's look at it from the service side. If we are interested in providing same content on different platforms, we have to make sure that different platforms are able to sustain, support, transmit and manage the content which is so very, which is the same, but the underlying infrastructure is so very different. Then in network convergence, we are interested in thinking about a single platform, a unified platform which somehow allows dovetailing to these different access networks to provide multiple services. Then from the terminal convergence point of view, we are interested in identifying is there a super device or a gadget that is multifunction which caters for all or at least some or most of the services which are provided inherently from different networks. Let's look at the service convergence from the technology point of view. Here you can see for fixed network, we have the IPTV which is provided via DSL. And then we have the mobile network which is offering mobile TV via wide band core division multiple access. Then we have the cable TV which is offering its services via co-action. Here you see that all these are TV services. Since these are based on IP, they can easily be translated from one network to the other. So service conversion means providing the same service across different platforms. Let's continue with the dimensions. Now we have the market as a dimension. As we had discussed earlier, different operators which were known for offering a certain kind of service are now investing in multiple sectors. It means initially if some operator was investing and offering services in television broadcasting is now also focusing on providing internet access and providing IP telephony. Likewise the telecommunication operators which were initially meant to provide voice are now also providing the IP television. Cable networks which were there to provide the digital television are providing voice over IP, the internet and the telephone. Then the last but one of the most important factors or the dimension that we must understand is the regulation aspect of it. After all the governance is a very important factor. Regulatory aspects mean that the policies which govern a certain sector usually these are quite different from one sector to the other. But with unified regulation there is going to be a single policy or a consistent or same set of rules which would be applicable to all. It means now the regulatory aspects are also going to determine how the engine are shaped. So the drivers that we eventually take home are number one, we are interested in looking at the convergence from the best viewpoint. That is we are looking at the combination of the technologies, the services, the platforms which result into the best solution. As compared to and we are going to compare it to the traditional telecommunication network and the way traditionally ISPs were providing services. Now the goal of the NGN is to handle this convergence that fits the existing infrastructure and the infrastructure is least affected in terms of physical replacement. Some kind of interoperability and backward compatibility is going to be a very important design consideration or a driver for converging everything to IP.