 Cloud computing a very hot topic indeed. We are going to dedicate a couple of lectures on cloud computing because certain aspects of cloud computing have to be understood if you want to come to terms with it. It's a very essential component of the NGN architecture and services. So let's look at the definition the need for cloud computing and an example of media cloud. So cloud computing is basically it's a framework or a model which enables access to resources which are shareable which are lying as a pool. So these computing resources could be at the application layer applications and the services and virtual hardware components like storage, the network access and the servers. Now this framework of cloud computing allows very conveniently to access these on demand and the request is entertained in almost no time that is real time. The service provider is invisible to the user. So it means the user is just talking to the cloud or the resource provider. This makes the overall relationship between cloud service user and cloud service provider more direct and transparent. The need for cloud computing is simple reducing the costs. Now this cost reduction is the aim for any enterprise because once the costs are low the profits could be maintained and the service could be provisioned to the client without burdening it, burdening the client more often and this would also involve a certain reduction in terms of the storage requirements. So there's going to be less in indigenous or local storage capacity needed. This is going to help the organization to have plans to not worry about the future storage requirements. The dependence on O&M is going to be obviated and since it's less dependent on human intervention so it's more automated. It's very flexible so one could move from one platform like from one OS to another and the user could be mobile. It means that the same services could now be used instead of being localized only globally anywhere. Let's take the example of media clouds. We could also think about other clouds like context aware clouds and certain other context specific application specific clouds but let's take the example of media cloud where the multimedia processing is performed within the cloud. The multimedia could involve audio, video and images and the content is now stored into the cloud. It means that earlier if you look at the figure the video images and audio are coming from the end hosts or the web servers into the cloud. So we have a storage cloud, we have a GPU cloud and CPU cloud. Storage is where the content is archived or stored then it is retrieved for CPU and then the CPU could direct multimedia heavy content to the graphics processing unit cloud. So we have dedicated services which are now provided in the media cloud as specific sub clouds. Here's something interesting is happening that is the content is being created at end it is being pushed into the network away from the edges and the intelligence to provide this content to somewhere is moving away from the network to the edges. It means now the edges are determining where the content has to be placed. This is a big move from the classical router based architecture where it was the router which would determine where to forward the data. So this media cloud is an excellent example in which the heterogeneous user devices like smart phones, tablets, desktops could access the content multimedia content and process it somewhere else get the result. We are going to look at some interesting examples in due course of time as well.