Challenges in VANET


Due to high speed of vehicles, VANET (vehicular ad hoc network) is a highly volatile network. Connection between vehicles remains for a very short time period. Connection and disconnection between nodes is a continuous activity [6]. Also, nodes are moving in opposite directions, which makes the network more volatile. Due to volatility, VANET faces the following challenges.

Maintain Communication on Move

Due to volatility of a network, nodes in the network move randomly and loose connections that are established for communication. Disconnections of nodes cause an interruptions in the previous data packet transmission. It is important to establish a new path between the source and the destination if nodes loss their connection. It adds extra overhead in dynamic networks like VANET. So, it is a challenging task to maintain the communication between the nodes on move.

Delivery of Message Should Be in Short Time

VANET nodes remain in the vicinity of each other for a short time period. Therefore, the time interval between sending message from the source and receiving it by the receiver should be short. It is always a challenging job to achieve low latency in vehicular communication.

High-Speed Routing

Routing is the process of finding path between the source and the destination for communication. As nodes are moving, it is a challenging task to adapt the existing wireless routing protocols as per VANET environment. Connection and disconnection between nodes initiate rerouting frequently. Fast routing plays a crucial role to achieve successful communication and to avoid wastage of the effort already taken for communication.

Real-Time Selection of Alternative Communication Path

Rerouting process is initiated frequently in VANET due to volatility. Finding alternative communication path among the available path is challenging as it not only depends on the distance between nodes but also needs to consider the velocity, direction, and density of nodes. So a real-time selection of path in VANET is a topic of research.

Critical Time Latency of Messages Delivery

Latency is nothing but the time interval between sending message by the source node and receiving messages by the receiver node. In VANET, highly mobile nodes, i.e., vehicles, may be running in opposite directions. The nodes remain in the vicinity of each other for very short time periods. It is important to receive the message by the destination vehicle in a given time period. To achieve this communication, the network should satisfy the critical latency requirement. Communication in VANET network should be with low latency. It is a challenging task to achieve low latency while communication in VANET.

Safety message transmission is the main goal of the vehicular network. Safety messages should be always at higher priority, and it should be reached at destination on time. To achieve this feature needs to overcome a delay in network. The main challenges to overcome a delay in vehicular networks are as follows [1]:

  • • Frequency of changing neighborhood due to high mobility
  • • Drastically increasing load on network due to high-density environment
  • • Connectivity issue due to the variation in the received signal power
  • • Packet dropping due to exposed and hidden terminal problems.

Drastic Increment in Vehicles and Roads

Road network in any country plays an important role in the development of country. Road networks in developing countries are drastically increasing every year. Every year millions of new vehicles are added to the network. The increasing number of vehicles and roads raises the following challenges in the VANET.

To Establish Required Infrastructure for New Roads

To provide VANET services on newly established roads, all essential devices like road side units (RSUs) and servers are needed to deploy. It is challenging to do for drastically increasing infrastructure. It needs both resources and cost of deployment.

Registration and Generation of Credentials for New Vehicles

Every new vehicle is registered with a trusted authority (ТА). The ТА provides certificates or necessary credentials to vehicles for using the network. Every vehicle has a unique identity, which is assigned by the ТА. It is a challenging task to register and assign credential to the increasing number of vehicles. These credentials are also maintained by the ТА throughout the lifespan of vehicles. Monitoring vehicles and providing some common services through the network are becoming tedious tasks if vehicles are increasing in million.

Slow Down the Performance of Network Due to the Increasing Number of Vehicles

The increasing number of vehicles puts extra overhead on the existing network. If an infrastructure is overloaded due to high density of vehicles, the performance of the network will decrease. The network may slow down. There is a need to update network resource capacity to achieve the required performance.

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