# Stochastic Modeling for Intelligent Software-Defined Vehicular Networks: A Survey
## 4 Integrating into VANET System Model for iSDVN
### Intelligent Digital Twin with SDVN
By performing the local processing and filtering of data, edge devices can send only the most important information to higher-level systems for further analysis and decision making [132]. Overall, the edge layer is important in enabling the efficient and effective operation of intelligent digital twin networks, particularly in applications where real-time decision making is critical, as shown in Figure 8.
2. _Communications_: Reliability refers to the ability of the network to deliver data without loss or errors. High reliability is critical for applications that require constant and accurate data delivery, such as real-time control systems or medical applications [133]. Latency is the time delay between the transmission of data and their arrival at the destination. Video conferencing or online gaming, which require real-time responses, depend on low latency. During a given period, a network's capacity is how much data it can transmit. High capacity is critical for applications that require large data transfers, such as video streaming or file sharing. Connectivity refers to the ability of a network to connect devices and enable communication between them. Good connectivity enables communication between devices and provides a seamless user experience. These metrics are often considered to estimate communication networks' QoS and design new networks that meet the requirements of specific applications. 3. _Internet of Things_: A network can be segmented into multiple virtual networks by using network slicing, each with its own characteristics and set of resources [134]. This allows for the creation of customized network environments to meet specific application requirements, such as low latency or high bandwidth. Network optimization is the process of improving the performance of a network by maximizing its efficiency and minimizing its latency, congestion, and packet loss. This can be accomplished through various techniques, including traffic engineering, load balancing, and resource allocation. Routing is the process of selecting the best path for data to travel across a network from a source to a destination. This involves determining the most efficient route based on factors such as distance, traffic congestion, and network topology [135]. Various routing protocols, such as OSPF (Open Shortest Path First) and BGP (Border Gateway Protocol), are used to accomplish this. Digital twin SDVN is an emerging concept that combines digital twin and SDN technologies to extend the performance of the vehicular network [136]. In this way, network management can be more efficient. Digital twin SDVN refers to the creation of a virtual representation of a vehicular network, known as a digital twin, and its integration with the physical network. Digital twins provide a real-time view of the physical network, collecting and analyzing data to provide insights into traffic patterns, network performance, and other metrics [137]. This information is then used to optimize network operations and improve the overall user experience. SDN technology manages the digital twin and the underlying physical network, providing centralized control and programmability. This enables the network operator to allocate resources dynamically, reroute traffic, and adjust network configurations as needed to optimize network performance and meet changing user demands. Digital twin SDVN can be used to support a wide range of vehicular applications, including connected vehicles, ITS, and autonomous driving. By providing real-time insight into network performance and enabling dynamic network management, it can help to improve safety, reduce congestion, and enhance the overall efficiency of vehicular networks.