iXen - context-driven service oriented architecture for the internet of things in the cloud.

iXen’s ambition is to overcome the limits of existing IoT platforms in the cloud and deal with challenges of security and interoperability. Therefore, iXen is interoperable and expandable (i.e. services can be added or removed) while being secure by design: access to services is granted only to authorized users (or other services) based on user roles and access policies. Leveraging principles of Service Oriented Architectures (SOA) and the most recent EU standards for context information management, iXen is implemented as a composition of RESTful micro-services in the cloud. iXen adopts a 3-tier architecture design model. The first layer supports connectivity of the vast diversity of IoT devices with the cloud. The second (middle) layer implements IoT data functionality including, database, security and context management services allowing devices to publish information and, users (or other services) subscribed to devices to get notified about the availability of this information. Flow-based programming services in the middle layer allow fast development of new applications by wiring together IoT devices and services. The third layer makes IoT applications available to customers based on subscriptions. The experimental analysis shows that iXen is responding in real-time to complex service requests under heavy workloads.