## 4 Opportunities and Open Research Areas in VANET Multimedia
### Multimedia Transmission in TIMs  
TIMs play a crucial role in improving transportation safety and facilitating efficient communication between vehicles in a VANET. The SAE J2735 DSRC message set specifies the types of messages that can be transmitted over the DSRC network, including TIMs. TIMs are designed to provide drivers with real-time information about traffic conditions, road hazards, and other important events on the road in a textual format. They are generated by government agencies such as the Traffic Management Center (TMC). This information is then forwarded to the vehicle through the roadside unit, helping drivers make informed decisions about their route and driving behavior, leading to improved traffic flow and reduced congestion. TIMs are an essential component of the DSRC message list, providing drivers with important information to improve transportation safety.  
TIMs are broadcast in DSRC using a specific type of message called the Service Advertisement Message (SAM). The SAM is a periodic broadcast message that is transmitted by the roadside unit (RSU) to all nearby vehicles within its transmission range. The SAM message contains information about the available services and data that can be accessed by the vehicles, including TIMs. The SAM message also provides information about the RSU's location and other relevant details. Once the SAM message is received by a vehicle's On-Board Unit (OBU), the vehicle can then request the desired services, such as TIMs,by sending a request message to the RSU (roadside unit). The RSU then responds by transmitting the requested data to the OBU. The format used for TIMs depends on the type of information being transmitted and the specific requirements of the application.  
Overall, DSRC provides an efficient and reliable way to broadcast TIMs to vehicles in a vehicular ad hoc network, allowing for real-time communication between vehicles and infrastructure to enhance transportation safety and efficiency. The frequency of SAMs within a VANET can vary depending on the specific implementation and settings of the system. Typically, SAM messages are broadcast periodically at a fixed time interval, such as every 100 milliseconds or 1 second. The exact frequency of SAM messages within a VANET can be adjusted based on factors such as the expected traffic density and the required response time for services and messages. The goal is to ensure that SAM messages are transmitted frequently enough to provide timely and reliable service to the vehicles while avoiding unnecessary network congestion.  
In the United States, the Federal Communications Commission (FCC) has designated a 5.9 GHz frequency band for the use of Dedicated Short-Range Communications (DSRCs) in vehicular ad hoc networks (VANETs). The DSRC standard SAE J2735 prescribes a default interval of 100 milliseconds for the periodic broadcast of Service Advertisement Messages (SAMs). However, an emerging trend promises to augment these networks' capabilities even further. This trend involves the integration of Artificial Intelligence (AI) into the framework of Traveler Information Messages (TIMs) in VANETs. This integration represents a significant opportunity for progress, with the potential to transform incident detection and notification processes. By leveraging AI algorithms for image recognition and data analysis, the system can autonomously identify and categorize incidents based on visual data from cameras. This not only expedites TIM generation and improves its accuracy but also enables dynamic adjustment of TIM content and urgency in response to real-time traffic conditions and incident severity. This enhancement not only amplifies the efficiency of TIM dissemination but also situates VANETs at the cutting edge of transportation technology innovation, thereby attracting AI experts to contribute their expertise to this field.