A Concurrent Transmission Based Broadcast Scheme for Urban VANETs

Abstract

Many Broadcast schemes have been proposed for VANETs, and most of them focused on reducing the broadcast delay increasing the broadcast reliability. The vehicles are scheduled continuously to transmit the message to other vehicles. In the proposed system, the multiple adjacent vehicles can broadcast same packet at same time. The maximum temporal displacement was derived to reduce the excess delay and Concurrent Transmission based Broadcast (CTB) protocol was proposed. The CTB includes two parts, broadcast in a street and broadcast at intersections. When a forwarder is in the street, it only needs to forward the packet to the vehicles in front of the forwarder in the broadcast direction along the street. When the forwarder is near to an intersection, it should be able to forward the packet to not only the vehicles which are in front of it in the broadcast direction, but also the vehicles in the streets above and below. The transmission range in the broadcast direction was divided into segments and schedule the concurrent transmissions of the forwarders in the same segment. Even if some selected forwarders fail to receive the message, other forwarders who received the message will continuously broadcast the message, which reduces the broadcast delay. Compared to conventional broadcast protocols, the proposed method is faster and more reliable.

Existing System

In the existing system, an urban multi-hop broadcast protocol (UMBP) to disseminate emergency messages. To lower emergency message transmission delay and reduce message redundancy. Then, bidirectional broadcast, multi-directional broadcast, and directional broadcast are designed according to the positions of the emergency message senders. Single forwarding was performed. Directional broadcast is adopted at each hop in the message propagation direction until the emergency message reaches an intersection area where multi-directional broadcast is performed again, which finally enables the emergency message to cover the target area seamlessly.

Proposed System

In the proposed system, VANETs provide a new access for drivers to avoid potential traffic accidents and acquire many different kinds of non-safety information. A concurrent based transmission is used for VANET. A Concurrent Transmission based Broadcast (CTB) protocol was proposed. The broadcast protocol includes two parts, broadcast in a street and broadcast at intersections. The transmission range in the broadcast direction is divided into many segments and forwarder candidates in the same segment broadcast concurrently.

Architecture

ARCHITECTURE DIAGRAM