# Enhancing Heterogeneous Communication for Foggy Highways Using Vehicular Platoons and SDN
## 2 Related Work  
The literature [4] provides very few solutions to overcome the issue of driving in foggy weather by providing safe and stable schemes using various methods, ensuring that drivers reach their destinations safely during foggy weather. Vehicular networks benefit from the use of visual sensors to enhance incidental awareness, ensure safe handling of messages, and enable intelligent vehicle navigation. Providing optimal routing paths in adverse weather conditions with high image quality becomes more challenging due to light absorption and scattering. A three-stage deep network enabled dehazing network (TSDNet) [5] was proposed to improve image quality in foggy environments. Similarly, the efficiency of light-emitting diodes in V2V communication during foggy weather was tested [6; 7] using visible light communication. The test was applied up to a visibility distance of 120 m. The results showed that the signal efficiency was high for 20 m. The performance was affected by the decrease in efficiency of these sensors caused by high fog with visibility less than 20 m.  
The DSRC standard for both V2V and V2I communications has no loss during foggy weather [8]. The network efficiency of this 75 MHz dedicated band is cheaper compared to the visual sensor solutions in the literature because of a low loss of signal strength. Very little research has been conducted in the literature specifically focused on foggy weather using DSRC, incorporating an examination of all the issues discussed above. In [9], a traffic warning message dissemination system (TWMDS) framework along with a protocol called the reverse routing protocol (RRP) was proposed for disseminating traffic warning messages (TWMs) in VANETs. Colored Petri net models were used to formally model and analyze the interaction behavior of TWMDS, providing a feasibility measure for its development and implementation. This method demonstrated that drivers have the ability to reroute their paths to avoid traffic congestion. Considering all the discussion above, no one has focused on implementing SDN to solve this adverse weather issue using the DSRC band. SDVN [2; 3], provides flexibility and reliability in such a highly dynamic environment by reducing delay and overhead, thus ensuring a high delivery ratio. Ref. [10] proposed a truck platooning system using SDN technology. The framework aimed to provide a practical solution for SDVN that can be leveraged for a wide range of applications, including truck platooning. The efficiency of the SDN-based approach compared to traditional routing approaches was demonstrated through the truck platooning use case, highlighting the advantages of dynamic interface management and the use of SDN controllers for improved connectivity. The authors also mentioned the use of micro-commands for coordinating intra-platoon or inter-platoon maneuvers, such as merge, split, and lane change, which rely on the exchange of beacon safety messages. The study considered only homogeneous networks of vehicles, like truck platooning. Similarly, another scheme [11] that considers the impact of fog on visibility was evaluated using an intelligent driver model to address this problem. A platoon of 51 vehicles was used to evaluate the model on a 2.2 km ring road for 250 s. According to the results, the model accurately described the traffic with reduced acceleration and deceleration. Moreover, ref. [12] considers that DSRC technology was proposed as a non-SDN approach for foggy weather. The scheme considered the wireless fog warning system (WFWS) for dissemination of warning messages to control sudden braking on foggy roads. This was a non-SDN approach that took a minimum visibility of 50 m. To manage traffic on foggy roads, the authors used broadcasting of warning messages, which resulted in high overhead. To ensure coverage area, a minimum controller selection mechanism was proposed in [13] to reduce the number of controllers. The scheme considered real-time traffic to determine which controller should be switched on for data transmission.