Path Selection based Routing Protocols for Urban Vehicular Ad Hoc Networks

Abstract

Urban Vehicular Ad Hoc Network (UVANET) is an advanced wireless communication technology to provide safety and comfort services to the passengers and drivers. To provide better services to the users, routing plays an important role to send the valuable information from the source to the destination in a minimum time. However, UVANET suffers from frequent topology change due to high speed of vehicles in the network. This leads to link disruption problem, where a vehicle is out of the communication range, and it is difficult for a vehicle to forward the data to the next vehicle. This motivates us to propose novel routing solutions for UVANET. The performance of the system mainly depends on the QoS parameters such as end-to-end delay and packet delivery ratio. However, these parameters are affected by the link breakage problem. In addition to this, the parameters are also affected by the faulty vehicles and malicious vehicles in the network. Therefore, the routing protocol should have a fault detection technique to detect the faulty vehicles in the network, and it should have a security mechanism to detect the malicious vehicles in the network. In this work, the above routing issues and challenges are addressed, mainly focusing on developing position based routing protocols for UVANET to improve the routing performance. Simulation and experimental works are conducted to evaluate the performance of the proposed routing protocols.
A path selection based routing protocol (PSBRP) is proposed for UVANET to send the messages from the source to the destination in a minimum time. In this protocol, the next path for data forwarding is selected based on a path value calculated by the Road Side Unit (RSU) at the junction. The path value is calculated by approximating the number of communication gaps between the junctions, packet forwarding delay from one junction to other, and closeness of the destination. The path with the minimum path value is selected as the next data forwarding path. Simulation results show that the packet delivery ratio (PDR) for PSBRP is improved by 1.44 %, 6.08 %, 3.68 %, and 3.52 % with respect to GyTAR, A-STAR, P-GEDIR, and GSR routing protocols respectively. When the average density is greater than equal to 30 (vehicles/Km), then the average end-to-end delay for PSBRP routing protocol is less than 0.035 sec. To validate the PSBRP routing protocol, experiments are conducted in an indoor laboratory environment using a prototype.
A cloud based PSBRP (CB-PSBRP) routing protocol is proposed for UVANET to send the data to the destination in a minimum time. This protocol further improves the performance of PSBRP routing protocol by reducing the end-to-end delay. This is performed by minimizing the number of hops between the source to the destination. Instead of depending on inter-vehicular communication, the protocol use Internet facility to send the data to the destination. In this protocol, cloud provides location service by providing destination location and the last RSU information. By using the internet facility, packet forwarding delay and link disruption problem are reduced. This also improves the packet delivery ratio. Simulation results show that the PDR for CB-PSBRP is improved by 16.57 %, 17.11 %, 17.78 %, 21.65 %, 19.65 %, and 19.51 % with respect to PSBRP, VehiCloud, GyTAR, A-STAR, P-GEDIR, and GSR routing protocols respectively. When the average density is greater than equal to 20 (vehicles/Km), then the average end-to-end delay for CB-PSBRP routing protocol is less than 0.009 sec. To validate the CB-PSBRP routing protocol, experiments are conducted in an indoor laboratory environment using a prototype.
A novel soft-fault detection based PSBRP (SFD-PSBRP) routing protocol is proposed for UVANET to send the data to the destination in a minimum time. Routing protocols in UVANET mainly depends on the correct information provided by the neighbor vehicles in the form of beacons. If the On Board Unit (OBU) is soft faulty, it provides incorrect data and this reduces the performance of the system. This fault detection based routing technique enhances the routing performance by sending the data through the fault-free vehicles. The performance of the fault detection technique is evaluated by Fault Detection Rate (FDR) and False Alarm Rate (FAR). From the simulation results, it is observed that the average FDR percentage and average FAR percentage at fault probability of 10 % - 40 % are 92.86 % and 1.99 % respectively. The average PDR and average end-to-end delay for SFD-PSBRP at fault probability of 10 % - 40 % are 93.25 % and 2.25 sec respectively. To validate the SFD-PSBRP routing protocol, experiments are conducted in an indoor laboratory environment using a prototype.
A secure PSBRP (S-PSBRP) routing protocol is proposed to transmit the data to the destination in a minimum time through the genuine vehicles, by avoiding the malicious vehicles. Vehicles in the network transfer valuable information and this communication should be secured. Selecting genuine vehicles in the path protects the system from the malicious attacks, and this enhances the routing performance. For secure communication, the vehicles in the network generates a symmetric session key using modified Diffie-Hellman key agreement protocol. Security analysis is performed to check the robustness of the security mechanism against the malicious attacks. From the simulation results, it is observed that the average PDR and average end-to-end delay for S-PSBRP at attacker probability of 10 % - 40 % are 93.71 % and 2.254 sec respectively. To validate the S-PSBRP routing protocol, experiments are conducted in an indoor laboratory environment using a prototype.