Vehicle density based forwarding protocol for safety message broadcast in VANET.

Area of Science:

• Vehicular networking
• Wireless communication protocols
• Network performance analysis

Background:

• Medium Access Control (MAC) protocols are crucial for time-critical safety applications in Vehicular Ad Hoc Networks (VANETs).
• Current multihop broadcast protocols often select the farthest node as the forwarder to minimize hops, but this can cause significant delays in dense traffic.

Purpose of the Study:

• To propose a novel IEEE 802.11-based multihop broadcast protocol, VDF (Vehicular Density-aware Forwarder selection), for efficient emergency message dissemination in VANETs.
• To address the issue of contention delay in high vehicle density scenarios by adaptively choosing forwarders.

Main Methods:

• Development of the VDF protocol, which dynamically selects forwarders based on real-time vehicle density.
• Simulation-based evaluation of VDF's performance compared to traditional farthest-forwarder approaches.
• Analysis of trade-offs between contention delay and the number of forwarding hops.

Main Results:

• The farthest forwarder strategy can lead to substantial contention delay in high-density VANETs.
• VDF adaptively selects forwarders to balance contention delay and hop count.
• Simulations demonstrate that VDF significantly reduces broadcast delay by mitigating transmission collisions.

Conclusions:

• The proposed VDF protocol offers a more effective solution for emergency message dissemination in VANETs compared to existing methods.
• Adaptive forwarder selection based on vehicle density is key to improving broadcast performance and reducing delay in VANETs.
• VDF enhances network reliability for safety-critical applications in dense traffic conditions.