 In continuation with with our understanding of IPTV service provisioning on engine based IMS architecture, let's look at the functions that we are continuing to cover. So we have already seen the end user functions and we've seen the application functions. Now we are interested in looking at the content delivery function and the transport control functions management and content provider functions. So let's look at the service control functions. The service control function, if we go back to the figure again, service control functions actually are related to the IMS functionality. It means it is part of the service stratum and it is actually going to make use of services which are either available in the IMS or available in the control function blocks that we've seen are there in non IMS based IPTV service provisioning architectures. So the service control functions actually are meant to provide the service and manage the service in a way that if the connection has to be initiated, if it has to be modified and if IP service has to be terminated. So the service control functions are going to be utilized at the service stratum part of the IMS architecture and non IMS based service blocks. So it provides the service access control, essentially that is the summary. So it establishes and maintains the network resources, the overall end system resources, the content provider resources for IPTV service provisioning. It actually makes use of the service user profile. So the service user profile functional block, essentially if you look at it here is a database that provides certain user related information for instance to which all IP televisions as a user subscribe the services to. Then what is the ID of the user and what is the location of the user, what is the status of the user, if the user is online, offline, intermittently connecting and then the overall management of the data associated with the user. So this service control function is also responsible to generate responses to the query for user profile. For instance, if someone is interested in authenticating the user that is the triple layer functionality related for the NSCF and the RSCF, the resource and admission control function, including the location which is again needed for the continuity service continuity. So we have the content delivery function after the service control function. The content delivery function actually can be categorized into two functional subgroups. One is the content delivery and the location control function and the second one is content delivery and the storage functions. Each one has its own responsibility. So essentially the it is related to the delivery. Delivery means we need some kind of storage space so caching, storing, etc are the primary concerns here. So it actually deals with and interacts with the service control block or in terms of NGN, IMS, the service control function. So it actually needs to gather some information for content distribution and storage. For instance, certain resources which are going to be utilized and the status of the service, for instance, if the service is needing the resources or the service does not need any resources anymore and the capabilities of the user in terms of the memory that the user has the processing power and the user space which it is which is allowed to run this particular IPTV service. The content delivery and storage function actually is responsible for delivering the content down to the client that is the end user. It uses certain network functionalities which are underlying at the transport stratum. For instance, if it is going to be a unicast service or a multicast service that we've already covered because at the more core and transport level, we've got multicast service and at the access side, we've got unicast service. Now in addition to these primary functions, functional groups, we have certain other functions as well, which is relatively have equal importance, but their scope is rather limited. The network functions, we have the management functions and we have the content creation functions. Let's look at all of these one by one. So we have the network functions. It provides the connectivity related issues and path establishment services right at the core level at the access side and in the transport networks because when certain IPTV service has to be offered, then a lot of network resources shall be utilized. So allocating these resources at the access core and transport networks is a very important concern, though in terms of the complexity, we have seen very complex functions already. Then we have the management functions. That is management is all about monitoring and configuring to get the F caps realization that is fault management, configuration management, accounting management, performance management and security management. So the management of the application, the content delivery mechanism, the service control, the user device, the transport, all these actually are coming under the umbrella of management. So whatever we've studied, whatever functions we know, whatever functional groups we know, management is going to touch upon each one of these. Then we have the content provider functions. Content provider functions are actually related to the preparation of content. Now the content and the associated metadata that is the tags or the keywords which are used to discover a certain audio visual content, all this is actually needed to be made available. So the content provider function actually makes all these available. Now in addition to ensuring that the content is provided, all the copyright issues, the access limitations to the authorized users and the encryption of it is again a concern that comes under the protection rights. Now all these protection mechanisms are a concern for this particular content provider function as well. So finally, we are looking at this figure again. We have summarized the end user functions, the application functions, content delivery functions. We have seen the management related in content provider functions. Now the transport control functions and the transport functions as such are not exactly in the scope of IPTV because whatever the service is going to be, whether it is streaming if it is voice over IP or if it is a best effort. The transport functions and the transport control functions are anyways going to be executed. So we've not covered it but it is implied that engine architecture is heavily dependent upon the transport stratum for its end to end success of course.