Although vehicular ad hoc networks are emerging as a novel paradigm for safety services, supporting real-time applications (e.g., video-streaming, Internet browsing, online gaming, etc.) while maintaining ubiquitous connectivity remains a challenge due to both high vehicle speed, and non-homogeneous nature of the network access infrastructure. To guarantee acceptable Quality-of-Service levels and to support seamless connectivity, vertical handovers across different access networks are performed. In this work we prove the counterintuitive result that in vehicular environments, even if a candidate network has significantly higher bandwidth, it is not always beneficial to abandon the serving network. To this end, we introduce an analytical model for a vertical handover algorithm based on vehicle speed. We argue that the proposed approach may help providers incentivize safety by forcing vehicular speed reduction to guarantee acceptable Quality-of-Service for real-time applications.

On modeling speed-based vertical handovers in vehicular networks: “Dad, slow down, I am watching the movie”

Vehicular ad hoc networks represent one of the most important applications of wireless ad hoc networks. In highways, where different networks exist, frequent and sometimes unnecessary switches from one network to another may occur, which degrade network performance and affect applications, especially those that require high quality networks such as multimedia applications (Video conferencing, Video On-Demand, etc.). This work presents an analytical model and a Vertical Handover decision method for Highways called VHH. It is based on position, velocity, jitter, and density as mandatory inputs which aim to both minimize Vertical handover frequency and avoid unnecessary handoffs and ping pong effect between different networks, in the goal of enhancing multimedia streaming services in highways. A simulation is provided to prove the performance of the algorithm.

Vertical Handover Decision Algorithm for Multimedia Streaming in VANET

Reliability and timely information delivery are highly concerned factors in Vehicular ad-hoc network. A better handover mechanism plays an important role in the handover process between the vehicle nodes during the vehicles on the road. Vertical handover is very much essential to ensure service continuity in Vehicular Ad-hoc network. When we compared with conventional handover decision taken by single criteria, multi criteria decision methods reduce handover rate and effectively utilizing the usage of network resources. In Vehicular Ad-hoc Network continuous connectivity is a great challenge, because of vehicles speed and ever changing topology of the network. In VANET vehicles can communicate through Vehicle-to-Vehicle communication mode and Vehicle-to-Infrastructure communication mode. Users in the vehicular network can access internet while on the move from one place to another with V2I. Due to heterogeneous wireless access, vertical handover is needed to maintain continuous connectivity between the vehicles and infrastructures. In this paper advanced methods of vertical handover decision algorithm is used to select best available network by comparing multiple parameter values (such as network traffic and vehicle speed). The algorithm is evaluated by assessing the performance through the number of handoff occurs, throughput gained and level of latency attained. The performance of the simulation shows that the number of handover and latency can be minimized where as throughput can be maximized, if we consider vehicle speed and network traffic parameters for taking handover decision process.

Vertical handover in Vehicular ad-hoc network using multiple parameters

We investigate into the potentiality of an enhanced Power and Location-based Vertical Handover (PLB-VHO) approach, based on a combination of physical parameters (i.e., location and power attenuation information), for mobile-controlled connectivity across UMTS and WLAN networks. We show that the location information in a multiparameter vertical handover can significantly enhance communication performance. In the presented approach a power attenuation map for the visited area is built and kept updated by exploiting the information sharing of power measurements with other cooperating mobile devices inside the visited networks. Such information is then used for connectivity switching in handover decisions. The analytical model for the proposed technique is first presented and then compared with a traditional Power-Based approach and a simplified Location-Based technique. Simulation results show the effectiveness of PLB-VHO approach, in terms of (i) network performance optimization and (ii) limitation of unnecessary handovers (i.e., mitigation of ping-pong effect).

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A Cross-Layer Location-Based Approach for Mobile-Controlled Connectivity

Vehicular communication is a part of intelligent transport system (ITS) which provides an intelligent way of transport to avoid accidents. Vehicle-to-Vehicle communication (V2V) is carried out through Vehicular Ad hoc Networks (VANET). This paper discusses about the MAC (Media Access Control) layer protocol, features of IEEE802.11p standard, and the handover protocol problems it is facing. Due to vehicle high speed and the non-homogeneous structure of the network infrastructure, support of connectivity by VANET is still a challenging task. In this paper, a vertical handover algorithm has been analyzed using vehicle speed, and the results have been supported by simulation.

Vehicle-to-Vehicle Communication—A Vertical Handover Algorithm Based on Vehicle Speed

Although Vehicular Ad hoc Networks are emerging as a novel paradigm for new classes of secure and safety services, supporting seamless connectivity remains a challenge, due to the high vehicle speed, and the nonhomogeneous nature of the network infrastructure. In this work we shall present an analytical model in support of a novel vertical handover algorithm that uses the vehicle’s speed as crucial input and overcomes, under our assumptions, network performance of recent related works. We support our initial results with a simulation study.

Esposito

Papers

A Speed-based Vertical Handover Algorithm for VANET