# [22/03/2021] xApps in Near-RT RIC ### Notes by Salman :memo: ### Sooo what are xApps? :question: Apart from sounding cool, xApps play a major role in the functionality of the Near-RT RIC. From my understanding the Near-RT RIC is not made up of one big block of hardware that is made to perform one specific task in the O-RAN Arcitecture. Instead, ==it is made up of different Microservices that can be hosted in the Near-RT RIC.== These Microservices are made to be interchangable and developed separately , thus making the Near-RT RIC not dependent in a software or platform. These Microservices, as the title of this section suggests, are called **xApps**. ### The relationship between xApps and the Near-RT RIC :face_with_raised_eyebrow: While one may say that the Near-RT is powered by the xApps, there are other components the Near-RT RIC that manage these xApps, such as the xApps Subscription Mgmt. in the Near-RT RIC. This component will group subscriptions of different xApps into one. For example, xApps that are subscribed to an interface such as the E2 Node can be grouped with the xApps Subscription Mgmt so that they act as one subscription through this interface. ![](https://i.imgur.com/exvtxdc.png) The Near-RT RIC will also do other things such as manage their Lifecycle, and hold a database called the Shared Data Layer that can be used for these xApps. --- ### References: - O-RAN Software Community - [Their Presentation at the Open Networking Summit](https://wiki.o-ran-sc.org/download/attachments/10715420/Near_RT_RIC_for_ONS.pdf?version=1&modificationDate=1569917902737&api=v2) - [The Scope of Near-RT RIC](https://wiki.o-ran-sc.org/pages/viewpage.action?pageId=10715416) - [Nick's Near-RT RIC Training Course](https://hackmd.io/@Nick-Bowei/H1wx1kMld)