describes when is the service valid A ServiceContext contains one or more ServiceContextElement It shows the dynamic QoS information the Service is having right at the moment. Each ServiceContext is connected to a Service (the concept Service should be defined somewhere else. Here it is only a reference). A ServiceContext contains one or more ServiceContextElement which describes what kind of Devices are needed. Example are: Printer, Scanner, Display, Sensor. Recources that are needed to run the service, including dependency on other enabler service as well as dependency on devices. When and where is the service valid? For example, a movie search service might only be valid when the user is accessing it inside the cinema. Likewise, a service might only be valid for a given period of time. . It is used to explain the knowledge source of the decision. A PopularitySource can be for example, user feedback, usage frequency, or connectivity by other services It shows the state of the service. E.g, whether it is available/active or not. Ideally, it should refer to the states defined in the life cycle management of services. Example states are: available, active, not available, not active. which describes where is the service valid It shows how popular the service is in the platform. It could take the value of High, Low or Medium. To explain where is the value taken from, we introduce another concept which describes what kind of Enablers are needed. Examples are SMS, MMS, DiscoveryManager, IdentifyManager, Recommender. It tells the service can be accessed via what kind of network. Example are: WLAN, GSM, UMTS, Bluetooth