 We very well know the overall engine architecture with its own service stratum on top of the transport stratum the services by mainly managed by the service control function in the service stratum are mainly linked to the Way in which these services can be provisioned But there are some interesting Dimensions to the service delivery and service provisioning which need to be Incorporated in our understanding for engines. So we'll start with the concept of the open service environment We'd look at its requirements in in specific and we'll see some sample Protocols so what is open service environment? Open service environment as the name suggests is is an open interface for creating and registering and invoking and providing and Terminating services and once the service is no more needed Removing a service. So these services are basically going to be provisioned through the Transport and service stratum of course, but each service requires triple a Admission and resource control quality of service provisioning etc. Now, whatever each service requires The functionality it needs comes from the the service stratum Let's look at the overall service architecture in NGN from the Open service environment perspective here. You can see that we have the Transport stratum below. We have the service stratum within the service stratum. We have the open service Environment that contains some functional entities. These functional entities may be used all at once Maybe some of these are used then we have the application support functions and the service support functions which is shown to you as The outside block it means that the open service environment is a sub part of the ASF and SSF within the service stratum So you can see here that we have the application on the top This application is connected to the service stratum Using the application to network interface Then we have the service stratum that is connecting to the functions from other service providers through the service to network interface Other interfaces are not exactly in our scope for now, but we'll talk about them on need to do basis So you can see here. Let's name a few we have the service composition service description service management service discovery service registration Etc. Now the policy enforcement and the joint or interworking with other service creation environments are the additional responsibilities which are scope of the open service environment We can actually go from from the service composition or service creation on one end followed by the service description and then service registration by the service provider then the service Discovery can be actually used by the Service solicitor or someone who wants to use service the service management Along with the policy enforcement and the interworking with other service creation environments We can actually look at the end-to-end execution. However for brevity We are going to just consider some instances. So the overall service provisioning architecture for NGNs Necessitates certain requirements to to be met from the open service environment and all the functional entities We've seen in OSC are all poised to meet these requirements. So there are a total of six requirements Let's start with the first one that is to provide a standard Application programming interface to develop and install applications in a quick and seamless manner So the focus here is on on convenience that is Without much moderation. It should be instantaneously done. So that's the first requirement It means the standard API means whomsoever as a third party wants to provide certain services to To end users through the NGN should be facilitated through some kind of standard in interface Then the next requirement is or whatever Services have to be provided some kind of Interoperability should be supported because the networks which are connecting to the NGN are going to be different in their Intrinsic or internal design different operating systems like Windows Mac Linux etc are going to be used Different hosting platforms for service delivery and the service execution could be used Different programming languages could be used and then different web Based services could be offered each coming on certain Web description Framework, so it means that the interoperability is a very important requirement for the OSC to meet Then the service development service creation should be made independent of the manufacturers of the network and the user equipment Because whatever services are to be created have to run on a variety of Networks which could get Upgrade the technology could all together change the user equipment could be a handheld device It could be a laptop or it could be Fidget for that matter in that case it is important to Look at the service development In the absence of any dependence on the underlying infrastructure Then the service creation process has to be Transparent or aloof to the location, which could be a geographical location, which could be an IP address based location It should be independent and it should stay consistent across different geographies different IP addressing and different other addressing schemes the Networks to which are going to offer these services have to Be transparent the protocol transparency and the technology and the Terminal should be Transparent as well. It means that the service has to be offered in a very seamless and transparent manner and This can only be done when a standard API is provided which hides the Network complexity from the eyes of OSC then Whatever services are to be offered service management capabilities have to be met that is a service has to be made a discoverable service has to be Defined or described through service description then the live monitoring of service Like service tracking has to be ensured some kind of updation version control have to be implemented and authorization to use a certain service or Refusing has to be incorporated as well Then the services which have to be Provided there should be a provision to actually Create services as well as applications service is more Atomic or Singular in nature whereas an application can Bundle multiple services and it can provide a single graphical user interface So it means that the OSC has to now incorporate the Service creation and provisioning not only for services, but also applications Then these services and applications have to be Provided to the user in terms of deploying it on the customer premises equipment or the handheld device then some kind of Trial testing user experience has to be offered then Then once a user has used it then it has to be Removed from the user repository. So it means that this the process has to be carried out end to end Let's look at some protocols. This is just a very brief View on the kind of protocols which can be used in the engine architecture within the scope of the open service environment The there is a protocol known as the UDDI that is universal Description discovery and integration protocol. This is actually used to allow a certain service to be registered with the OSC environment for service provisioning through the service and transport strata Then we have the WSDL WSDL is basically a Description language that describes like XML schema the attributes the features the limitations and other details for the end user to make a choice Then whenever a service is to be offered then the service is to be managed effectively So there is something known as the Web service distribution management Framework and protocols now these wisdom protocols and services allow the end user to subscribe to these web services through the incorporation of Hyperlink or URL or a URI so it means that a UDDI WSDL wisdom are just Some of the protocols which can be used. It's not the end. There are other protocols and suites as well