QoSHVCP: hybrid vehicular communications protocol with QoS prioritization for safety applications

This paper introduces a hybrid communication paradigm for achieving seamless connectivity in Vehicular Ad hoc Networks (VANETs), wherein the connectivity is often affected by changes in the dynamic topology, vehicles' speed, as well as the traffic density. Our proposed technique named QoS-oriented Hybrid Vehicular Communications Protocol (QoSHVCP) exploits both existing network infrastructure through a Vehicle-to-Infrastructure (V2I), as well as a traditional Vehicle-to-Vehicle (V2V) connection that could satisfy Quality-of-Service requirements. QoSHVCP is based on a V2V-V2I protocol switching algorithm, executed in a distributed fashion by each vehicle and is based on the cost function for alternative paths each time it needs to transmit a message. We utilize time delay as a performance metric and present the delay propagation rates when vehicles are transmitting high priority messages via QoSHVCP. Simulation results indicate that simultaneous usage of preexisting network infrastructure along with intervehicular communication provide lower delays, while maintaining the level of user's performance. Our results show a great promise for their future use in VANETs

Universidade Federal da Bahia

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On the Behavior of Broadcasting Protocols for MANETs Under Omission Faults Scenarios

Abstract. Ensuring reliable communication between nodes is a major challenge in mobile ad-hoc networks due to wireless signal propagation that can be significantly affected by terrain, obstacles, battery exhaustion and node mobility. Existing broadcasting protocols for MANETs are able to deal with mobility, as well as congestion and collision, but only when under a fail-stop failure model. However, this model is not a good representative of the real scenarios of faults frequent in MANETs such as link failures, temporary network partitions, topology changes and momentary node failures. In this work we evaluate – through the aid of simulation experiments – how well MANET broadcasting protocols behave when under a more realistic failure model, which are characterized by omission faults. We also discuss their properties and behaviors when taking reliability into consideration. The study conducted here show that most protocols are highly impacted by node failures and are not capable of maintaining high delivery rate. Some even exhibit coverage levels that are unreasonable to expect from broadcasting protocols when placed in a real world scenario

¡ Pós-Graduação em Mecatrônica

Abstract. Broadcasting in MANETs is a fundamental building block for dealing with routing and reaching consensus. In this kind of network, faults are commonplace. In spite of this, existing broadcast protocols are not adequate to deal with failures present in a real world scenario, such as link failures, network partitions, topology change during broadcasts and momentary node failures. Moreover, the ones that are capable of dealing with faults, are not suitable for MANETs. In this paper, we conduct simulations in order to evaluate the impact of faults on MANET broadcasting protocols under various network scenarios and situations. Although previous studies show that these protocols are very mobile resilient and support well congestion and collisions, the study conducted here show that they are not capable of supporting omission faults. In presence of this type of faults, they are unable to provide a high delivery rate of messages. 1

A V2X-based approach for reduction of delay propagation in Vehicular Ad-Hoc Networks ∗

Abstract–In this paper we investigate the time delay propagation rates in a Vehicular Ad-Hoc Network, where vehicular connectivity is supported by both Vehicle-to-Vehicle (V2V) and Vehicleto-Infrastructure (V2I) protocols. In our vision, seamless connectivity issues in a VANET with nearby network infrastructure, can be fixed by an opportunistic choice of a vehicular protocol between V2V and V2I. Such a decision is taken by each vehicle whenever it needs to transmit messages. Our technique —called as Vehicle-to-X — represents a handoff procedure between V2V and V2I, and vice versa, in order to keep vehicles connected independent of mobility issues and traffic scenarios. We investigate the time delay as a performance metric for protocol switching, and present the time propagation rates which occur when vehicles are transmitting warning messages, via V2V or V2I. Simulation results show how the simultaneous usage of pre-existing network infrastructure, together with inter-vehicular communications, provides low delays; while traditional opportunistic vehicular communications increases the transmission time delays and does not guarantee seamless connectivity to vehicles

Water Birds: Compositional collaboration with clarinets, wireless sensors, and RTcmix

"Water Birds" is an interactive composition for Bb and bass clarinet, computer music and wireless sensor system by Mara Helmuth and Rebecca Danard. A wireless sensor network with infra-red sensors responds to the clarinetist’s movements, and sends data into MaxMSP for signal processing control. The wireless sensor configuration was developed by Jung Hyun Jun, Talmai Oliveira, Amitabh Mishra, Ahmad Mostafa and Dharma Agrawal, and extended for this project in collaboration with Helmuth. MaxMSP Mxj Java objects were created to receive data from the programmed tmote sensors. Helmuth’s score consists of four sound-generating ideas. Her Max patch and RTcmix scripts process the clarinet sound with spectral delays through the rtcmix~ plugin for Max5. Danard created a working score solidifying her decisions about materials played and order of events. Helmuth and Danard’s interactive compositional process allowed to piece to evolve organically into a work commenting on the interaction of people, nature and technology.Conference PaperPre-prin

Wireless sensor networks and computer music, dance, and installation implementation

Collaboration between the University of Cincinnati College-Conservatory of Music Center for Computer Music and the School of Engineering’s Computer Science has resulted in the development of interactive performance systems for computer music. Several of the systems involved music generated by the movements of dance, culminating in a series of well-produced performances with 20 dancers and the music of two composers. Another system contributed interactive aspects to an installation environment based on a Tibetan monastery. Tmote sensors with light and received signal strength indication, and attached acceleration sensors provided data to the computer music system. Java instrument and client objects were created to bring this data into MaxMSP and Jitter to control selection of audio and visual material and digital signal processing. This paper is an overview of recent projects.Conference PaperPre-prin