## 3 Multimedia
### Challenges and Metrics of Study in Multimedia
To enhance the Quality of Experience within a network by improving the peak signal-to-noise ratio while transmitting video, Ref. [35] proposes an adaptive video streaming scheme for highway VANETs that utilizes inter-vehicle relays to boost video streaming performance. The primary objective of this scheme is to provide an optimal streaming experience by dynamically adjusting the video quality in real time to align with the available network bandwidth. This is accomplished through dynamic adaptation of the video quality and the utilization of relay vehicles to mitigate channel impairments and enhance the reliability of video delivery. By adapting to changing network conditions, it efficiently utilizes network resources, enabling the vehicle to stream video. Simulated results illustrate the effectiveness of the adaptive video streaming scheme in achieving improved video quality and reduced packet loss in highway VANETs. However, a drawback of this study is that it only tested the scheme with three vehicles. Similarly, [PERSON]. [35; 36] explore the challenges of video streaming in VANETs and propose a multilayer video encoding approach to manage Quality of Service (QoS) in this environment. The authors also pointed out the dynamic nature of VANETs, which can result in varying network conditions and limited resources. The multilayer video-encoding scheme aims to adaptively adjust video quality based on network conditions and available bandwidth. The results demonstrate the effectiveness of this approach in achieving improved video quality and enhanced Quality of Service (QoS) in VANETs. Particle swarm optimization (PSO) has recently been used to optimize video transmission in VANETs. This algorithm is a population-based optimization algorithm inspired by the social behavior of bird flocking and fish schooling [37]. In PSO, a group of particles represents potential solutions to an optimization problem, and these particles explore the search space by adjusting their positions and velocities based on their own experiences and information from other particles [37]. Also, the investigation of Particle Swarm Optimization (PSO) utilization for video streaming services over vehicular ad hoc networks (VANETs) is presented in [38]. Work performed by [38] focuses on improving video transmission efficiency and quality in dynamic vehicular environments. The authors introduce a PSO-based algorithm, which effectively optimizes the selection of relay vehicles for video data transmission in VANETs. The PSO algorithm as presented by [38] operates through an iterative process that involves updating particle positions and velocities, following specific rules aimed at converging toward the optimal solution [39; 40]. Despite the importance of multimedia transmission in VANETs, there are practical considerations and implementation challenges to address [41]. There is a need for VANET system design and architecture to accommodate the requirements of multimedia transmission [42], ensuring efficient data exchange, synchronization, and integration with existing communication technologies. Among the challenges faced in DSRC networks is the limited bandwidth, which directly impacts packet loss and the need for error resilience [43]. DSRC networks are prone to packet loss and errors caused by channel conditions and interference. It is imperative to develop robust error-resilience techniques and packet-loss-recovery mechanisms specifically tailored for multimedia data to ensure the integrity of the transmitted content [43]. As ascertained by [43], multimedia applications, such as video streaming and live navigation, require a lot of bandwidth, which can constrain the amount of multimedia data that can be transmitted. Another challenge is the stringent Quality of Service (QoS) requirements of DSRC applications [44]. In support of addressing Quality of Service (QoS) issues in VANETs, it has been underscored that more concentrated research is warranted [45].