# Supporting Immersive Video Streaming via V2X Communication
## 2 Bandwidth Allocation for Diverse Streaming Services in V2X Communication  
In this study, each RSU on the road segment coordinates the allocation of bandwidth. We utilize mmWave and THz bands to provide bandwidth for vehicular multimedia applications. Furthermore, our architecture incorporates a CF XL-MIMO system to improve communication reliability and transmission rates, as depicted in Figure 1.  
We consider various types of videos, including traditional 2D video, 360-degree video, and 6 DoF video. Both real-time and non-real-time application scenarios are addressed, such as live video and video on demand (VoD). To cater to diverse user needs, we classify users into premium and regular categories. Premium users, through a fee-based model, receive enhanced video quality, featuring higher resolution, lower latency, and a more immersive viewing experience. Regular users have access to standard quality basic services. Advanced encoding technologies are employed to optimize video quality and transmission efficiency across different types of video content and application scenarios. For 2D and 360-degree videos, VVC encoding technology is used for non-real-time applications, while AVC encoding technology is utilized for real-time applications, ensuring improved transmission efficiency while maintaining high video quality. Emerging 6 DoF video content is supported in two formats: PtCl and MVD. PtCl VoD utilizes the V-PCC encoding standard with higher compression rates to reduce bandwidth requirements. Premium users benefit from the superior quality All-Intra (AI) encoding mode, while regular users utilize the default Random Access (RA) mode. For PtCl live video, the faster G-PCC encoding standard is employed. For MVD video format, we employ the MIV encoding standard to effectively manage multi-view and depth information. Premium users benefit from the higher-quality MIV View mode, which includes a 120-degree Field of View (FoV) to prevent quality fluctuations or stuttering in the FoV area caused by sudden head movements. Additionally, LCEVC is implemented to reduce video complexity and required bandwidth. This technology separates the basic layer and enhancement layer, allowing RSUs to allocate bandwidth resources more flexibly. This ensures that vehicle passengers can access at least the basic layer during network congestion, thereby maintaining a satisfactory viewing experience. Figure 2 illustrates the architecture of the bandwidth allocation algorithm. The ellipsis on the right side of the image indicates that all RSUs and vehicles contain the same corresponding modules as depicted in the diagram. Before departure, the app installed in the vehicle activates the \"Route Planning and Adjustment Module for Vehicles\". This module plans the route based on the passenger's destination and real-time traffic conditions, estimating time periods for each road segment and communicating this information to the RSUs located along the route. Figure 1: Illustration of Video Applications Supported in V2X Communication. When a passenger in a vehicle activates a multimedia application while on the road, the \"Bandwidth Calculation Module for Vehicle Video Applications\" is initiated by the app on the passenger's vehicle. This module retrieves application requirements and specifications from the application provider's server and sends the bandwidth demand to the RSUs along the vehicle's route. Upon receiving a bandwidth demand request, the corresponding RSUs process it using the \"Bandwidth Assignment Coordination\" module. For real-time video applications, this module strives to meet the immediate bandwidth requirements. For non-real-time applications, the \"Bandwidth Allocation for Non-Real-Time Applications\" module is activated. RSUs coordinate with CF XL-MIMO base stations covering the road segment to collectively provide services to vehicle passengers. During periods of network congestion, RSUs dynamically adjust bandwidth allocation based on the characteristics of each application.