Amilcare Francesco Santamaria

Routing Optimization in Vehicular Networks: A New Approach Based on Multiobjective Metrics and Minimum Spanning Tree

Recently, distributed mobile wireless computing is becoming a very important communications paradigm, due to its flexibility to adapt to different mobile applications. As many other distributed networks, routing operations assume a crucial importance in system optimization, especially when considering dense urban areas, where interference effects cannot be neglected. In this paper a new routing protocol for VANETs and a new scheme of multichannel management are proposed. In particular, an interference-aware routing scheme, for multiradio vehicular networks, wherein each node is equipped with a multichannel radio interface is investigated. NS-2 has been used to validate the proposed Multiobjective routing protocol (MO-RP) protocol in terms of packet delivery ratio, throughput, end-to-end delay, and overhead.

An enhanced QoS CBT multicast routing protocol based on Genetic Algorithm in a hybrid HAP-Satellite system

A QoS multicast routing scheme based on Genetic Algorithms (GA) heuristic is presented in this paper. Our proposal, called Constrained Cost-Bandwidth-Delay Genetic Algorithm (CCBD-GA), is applied to a multilayer hybrid platform that includes High Altitude Platforms (HAPs) and a Satellite platform. This GA scheme has been compared with another GA well-known in the literature called Multi-Objective Genetic Algorithm (MOGA) in order to show the proposed algorithm goodness. In order to test the efficiency of GA schemes on a multicast routing protocol, these GA schemes are inserted into an enhanced version of the Core-Based Tree (CBT) protocol with QoS support. CBT and GA schemes are tested in a multilayer hybrid HAP and Satellite architecture and interesting results have been discovered. The joint bandwidth-delay metrics can be very useful in hybrid platforms such as that considered, because it is possible to take advantage of the single characteristics of the Satellite and HAP segments. The HAP segment offers low propagation delay permitting QoS constraints based on maximum end-to-end delay to be met. The Satellite segment, instead, offers high bandwidth capacity with higher propagation delay. The joint bandwidth-delay metric permits the balancing of the traffic load respecting both QoS constraints. Simulation results have been evaluated in terms of HAP and Satellite utilization, bandwidth, end-to-end delay, fitness function and cost of the GA schemes.

PAMTree: partitioned multicast tree protocol for efficient data dissemination in a VANET environment

The way to distribute a wide range of services on Vehicular Ad Hoc Networks is going to be a very interesting research topic, due to the willingness of the investors and the standardization institutions. In fact, the higher the number of available services is, the higher the impact and the market penetration of the considered technology will be. Also governance institutions appreciate the benefits of VANETs, having the possibility to increase safety level along the roads, saving lots of human lives, and reducing the severity of the collisions among vehicles. In this work we propose a multicast protocol, called partitioned multicast tree (PAMTree), which is suitable for spreading several kinds of services, increasing the reliability of the network, and giving the possibility to a higher number of users of having access to those services. The proposed protocol aims to exploit the characteristics of the VANET architecture in order to distribute services along the nodes of the network; owing to the high nodes mobility, several issues have to be faced to supply an optimal distribution, having a look at the quality of service (QoS) satisfaction.

A reactive routing protocol for VANETs based on composite metric concept

In the last years, the interest on vehicular networking has incredibly increased in the scientific and industrial community, due to the enormous potentialities that this emerging technology offers. In this context, routing protocols become fundamental for enhancing QoS, related to the different services offered to final users. The implementation of new routing protocols becomes challenging in VANETs so, at this aim, we propose a new reactive routing scheme in which the available channels are exploited for the optimization of a new metric, which takes into account different characteristics. Network Simulator 2 (NS2) has been employed to validate the Reactive Routing Protocol for VANETs (RRPV), showing how it performs better than other protocols in terms of different performance variables.

Safety Enhancement and Carbon Dioxide (CO2) reduction in VANETs

Nowadays one of the hottest theme is the application of the newest technologies in road safety. Several proposals have been made and both US and European standardization institutes are working on them. In this work we present a novel cooperative architecture that allows vehicles to communicate between them exploiting Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) connections. In order to spread information we propose a network protocol called Safety Enhancement for WAVE based protocol (SeAWave) that takes advantages of IEEE802.11p standard and tries to enhance it adding useful messages increasing vehicles’ passive and active safety systems. In this work we propose a novel protocol in order to gather important data about environment such as collisions, block, emission levels and so on. These data are collected by the City Traffic Manager (CTM) exploiting dedicated messages sent by the vehicle and infrastructure devices. They are used by the system to activate alerting mechanism using protocol messages in a controlled broadcasting. In addiction, CTM knowing the whole status of the road network can avoid traffic blocks making some high level decisions. Also a smart traffic management system is addressed in the proposed framework in order to reduce vehicles’ CO2 emissions in the urban area increasing, where possible, air quality. In order to validate proposed framework and protocol we use a well know Discrete-Event Simulator (DES) simulator with a dynamic mobility generator that allow us to change and control reference areas, area size, and loads rate.

Interdisciplinary issues for the management of next generation autonomic wireless systems: nature-inspired techniques and organic computing

Next generation communication systems have become a hot research issue in these last few years. For an efficient management of these networks, multidisciplinary knowledge and cooperation between different research fields is important. In particular, the next generation of wireless systems needs to satisfy some self-properties such as self-describing, self-organising, self-managing, self-configuring, self-optimising, self-monitoring, self-adapting and self-healing. In order to provide these features traditional approaches cannot be employed, owing to the computing complexity involved, so new solutions must be considered. The most suitable techniques to solve the above-mentioned issues is certainly organic computing and nature inspired techniques. Therefore, the main goal of our work is to provide a description of the principal characteristics of these new kinds of network and an overview in the various nature-inspired and organic computing techniques such as the neural network, molecular computing, Cellular Automata (CA), Genetic Algorithms (GAs), epidemic propagation strategies and finally, Swarm Intelligence (SI).

A two stages fuzzy logic approach for Internet of Things (IoT) wearable devices

In the last few years the process of monitoring people health status has grown in interest in the researcher community and led to the develop of new devices able to detect and analyse information gathered from many kind of sensors. These devices are commonly designed to monitor or diagnose disease in the medical field. Moreover, a remarkable interest is growing in the field of sports. In amateur activities such as jogging, running, climbing a set of smart devices are used to improve and monitor performances. Another field of interest is represented by those people that wants to monitor their health status by using low cost devices. In this work we propose a two stage fuzzy logic approach in which the device tries to learn and fit customer habits in order to discover outlier warning signals. The two stages approach proposed consists of monitoring the normal activities of the user in order to build a reference of its condition; Then a real-time monitoring and analysis of gathered data from body sensors is accomplished. User status is carried out using a Fuzzy Logic based network. First stage will give us the current activity of the user while second stage will provide information about health status in terms of heart rate.

Novel MF-TDMA/SCPC switching algorithm for DVB-RCS/RCS2 return link in railway scenario

This work focuses on the return channel resource allocation in the DVB-RCS/RCS2 system for mobile terminals. A continuous carrier (CC) operation mode based on DVB-S2/S2X is considered and investigated. The paper focuses on the possibility of transmitting simultaneously in multifrequency-time division multiple access (MF-TDMA) or single channel per carrier (SCPC) medium access techniques, as suggested by a previous DVB-RCS+M standard. The introduction of this capability has also been analyzed for a new DVB-RCS2 standard that gives the possibility of using both return link (RL) modalities. Moreover, we propose a detailed study of the RL channel in a satellite platform in order to understand the operative range of SCPC and MF-TDMA techniques. The contribution seeks to provide some threshold indications to network operators for dynamically managing satellite resources.We considered the railway market, which is characterized by an N-LOS condition due to blockage caused by tunnels, vegetation, and buildings, as the reference scenario. Furthermore, we introduced a transparent gap filler (GF) solution to overcome this issue. Simulation campaigns are shown, in order to give satellite operators some guidelines, when they want to make use of this hybrid channel modality.

A new call admission control scheme based on pattern prediction for mobile wireless cellular networks

Recently, cellular networking has become really popular, because of its different and growing fields of interest. It is able to satisfy user requirements in terms of Quality of Service, especially when mobility is present, managing hand-over issues in an adequate manner. So, it is very important to decide whether a new connection can be accepted into the system, in order to maximize bandwidth utilization while avoiding quality degradations, with more emphasis for non-tolerant applications. In this paper, the attention is not focused on a particular prediction scheme, but it is shown how a statistical approach can enhance system performance. We employ a general predictor (that can be based on Markov theory, neural networks, data mining approach or similars) and then we integrate it with a threshold-based statistical bandwidth multiplexing scheme in order to propose the Prediction-Based MUltipleXing Call Admission Control (PB-MUX CAC) scheme for cellular networks with mobile hosts. It is able to manage users mobility and to mitigate it, minimizing the amount of wasted bandwidth. Many simulation campaigns have been carried-out, giving us the possibility of evaluating the performance of the proposed idea in terms of number of admitted flows, bandwidth utilization and call blocking/dropping probability.

Managing Emergency Situations in VANET Through Heterogeneous Technologies Cooperation

Nowadays, the research on vehicular computing enhanced a very huge amount of services and protocols, aimed to vehicles security and comfort. The investigation of the IEEE802.11p, Wireless Access in Vehicular Environments (WAVE) and Dedicated Short Range Communication (DSRC) standards gave to the scientific world the chance to integrate new services, protocols, algorithms and devices inside vehicles. This opportunity attracted the attention of private/public organizations, which spent lot of resources and money to promote vehicular technologies. In this paper, the attention is focused on the design of a new approach for vehicular environments able to gather information during mobile node trips, for advising dangerous or emergency situations by exploiting on-board sensors. It is assumed that each vehicle has an integrated on-board unit composed of several sensors and Global Position System (GPS) device, able to spread alerting messages around the network, regarding warning and dangerous situations/conditions. On-board units, based on the standard communication protocols, share the collected information with the surrounding road-side units, while the sensing platform is able to recognize the environment that vehicles are passing through (obstacles, accidents, emergencies, dangerous situations, etc.). Finally, through the use of the GPS receiver, the exact location of the caught event is determined and spread along the network. In this way, if an accident occurs, the arriving cars will, probably, avoid delay and danger situations.