**2. Related Work**

## *2.1. Video Streaming in Vehicular Ad-Hoc Networks*

Real-time Video transmission over VANETs can improve emergency responses' effectiveness for road safety applications. The high rates and low delay are the most challenging aspects of video transmission over VANETs [15]. Recently, some works have been proposed to solve this problem. Different video applications over VANETs need different resources. The collaborative vehicle to vehicle communication approach is presented to enhance the scalable video quality in intelligent transportation systems (ITS), and different methods are developed to enhance the quality of experience and quality of service during scalable video transmission over VANETs [16]. Meanwhile, the use of redundancy for video streaming over VANETs has been analyzed, and a selective additional redundancy approach is proposed to improve the video quality [17]. Moreover, in Ref. [18], a vehicle rewarding method for video transmission over VANETs using real neighborhood and relative velocity is presented to optimize video transmission. Although previous works have studied the issues of video streaming over VANETs, the performance of video codec to support real-time video transmission is missing.
