# Digital Twin-Driven Virtual Network Architecture for Enhanced Extended Reality Capabilities
## 1 Introduction  
In this research, a novel intelligent network empowered with extended Reality Functions (XRFs) is introduced. The novel network exploits the Digital Twin (DT) technology to deploy a Digital Twin Network (DTN). Consequently, the novel network is referred to in this paper as Digital Twin Network plus extended Reality Functions (DTN + XRFs). The DTN can be deployed with different approaches such as network virtualization (NV), while advanced virtualization technologies can be leveraged including OpenStack and open vSwitch, among others. The DTN is realized as a replication of an original network (ON), which can either be a virtual or a physical network. The manager responsible for the ON replication and the deployment and management of the Digital Twin Network is referred to as the Digital Twin Manager (DTM). Furthermore, the DTM is in charge of the synchronization process between the ON and the DTN, which is an asymmetric process that will be explained in Section 3.1, while the XRF module is designed with the objective of enhancing the network experience by means of novel immersive network functionalities including: optimal routing, interactive network status visualizations, critical nodes identification, resource locator and smart monitoring, among others.  
To assist with the DTN + XRF deployment, a supporting architectural framework is required. The supporting architecture must be robust and reliable in order to guarantee appropriate twinning, synchronization and self-management processes with the aim of deploying both the DTN and the XRF empowerment module. The DTN + XRF is conceived as an enhanced and portable Digital Twin replica of the original network; consequently, mobile devices including smartphones, tablets and laptops, are identified as Digital TwinClient Devices (DTCDs). Since the DTCDs commonly lack sophisticated computational processors, it is proposed that the supporting architectural framework offloads expensive computations from DTCDs by leveraging a local data center equipped with two main modules: the Digital Twin Manager (DTM) and the extended Reality Manager (XRM). DTCDs can access data center services via application programming interfaces (APIs), thus ensuring standardization. Moreover, the DTN + XRF is envisioned as an any-location deploying network including extra-terrestrial (space) stations. This paper considers the DTN + XRF deployment in a space station. However, the disadvantageous channel conditions present in space communications can severely compromise the ON-DTN communication and synchronization, thereby raising the necessity to identify mechanisms and tolerant communication protocols to alleviate the aforementioned communication issues.  
It is crucial to emphasize that the proposed intelligent network offers the possibility to access to the replica of any ON including its services and resources. However, this proposal is not aligned with the Network as a Service (NaaS) concept. Rather, this present proposal is a replication from an original network where the XR services are deployed, and is not owned by a third party.  
The rest of this document is organized as follows: In Section 2, a literature analysis is presented; in Section 3, the supporting framework is introduced; in Section 4, the architectural framework is validate; and Section 5 states the paper's conclusions.