Mohamed Bachir Yagoubi

Adaptation of the MCDS broadcasting protocol to VANET safety applications

Broadcast mechanisms are widely used in self-organizing wireless networks as support for other network layer protocols, in this paper we investigate the broadcast techniques proposed in literature for vehicular ad hoc network (VANET). For the safety applications the broadcast protocol has to guaranty the performance and the reliability. In this paper, we propose an implementation the minimum connected dominating set (MCDS), taking into count the safety applications constraint and the specifics of the VANET context. Simulation results demonstrate the good performances and the robustness of such protocol compared to other ones.

Intelligent UAV-assisted routing protocol for urban VANETs

The process of routing in Vehicular Ad hoc Networks (VANET) is a challenging task in city environments. Finding the shortest end-to-end connected path satisfying delay restriction and minimal overhead is confronted with many constraints and difficulties. Such difficulties are due to the high mobility of vehicles, the frequent path failures, and the various obstructions, which may affect the reliability of the data transmission and routing. Commercial Unmanned Aerial Vehicles (UAVs) or what are commonly referred to as drones can come in handy in dealing with these constraints. In this paper, we study how UAVs operating in ad hoc mode can cooperate with VANET on the ground so as to assist in the routing process and improve the reliability of the data delivery by bridging the communication gap whenever it is possible. In a previous work, we have proposed UVAR a UAV-Assisted VANETs routing protocol, which improves data routing and connectivity of the vehicles on the ground through the use of UAVs. However, UVAR does not fully exploit UAVs in the sky for data forwarding because it uses UAVs only when the network is poorly dense. In this paper, we propose an extension of this protocol by supporting two different ways of routing data: (i) delivering data packets exclusively on the ground using UVAR-G; and (ii) transmitting data packets in the sky using a reactive routing based on UVAR-S. Simulation results demonstrate that the hybrid communication between vehicles and UAVs is ideally suited for VANETs compared to traditional vehicle-to-vehicle (V2V) communications.

High capacity diacritics-based method for information hiding in Arabic text

New promising technique for information hiding in vocalized Arabic text is proposed in this paper. This technique makes use of diacritics (vowel signs), which are optional to put, by showing or omitting them to hide bits. The technique is found to be very useful due to the considerable provided capacity, and because every possible diacritic in the cover text is used to hide bits. In this method, even excluded or omitted diacritics will be hiding bits. Tests and comparisons show that the proposed technique is superior in matter of capacity to any related published work.

UVAR: An intersection UAV-assisted VANET routing protocol

It is a challenging task to develop an efficient routing solution for a reliable data delivery in urban vehicular environments. Indeed, it is difficult to find a shortest end-to-end connected path especially in urban city given the mobility pattern of the vehicles and the various obstructions to a clear transmission such as buildings. To overcome these difficulties, we investigate how unmanned aerial vehicles (UAVs) can assist vehicles on the ground in relaying in urban areas. In this paper, we propose UVAR (UAV-Assisted VANET Routing Protocol), a new routing technique for Vehicular Ad hoc Networks (VANets). This protocol is based on the use of the traffic density and the knowledge of vehicular connectivity in the streets. With this approach UAVs collect information about the traffic density on the ground and the state of vehicles connectivity, and exchange them with vehicles through Hello messages. These information allow UAV to place themselves so as to allow relaying data when connectivity between sole vehicles on the ground is not possible. Through vehicle-to-UAV (V2U) communication, the overall connectivity between vehicles is improved and therefore the routing process is efficiently improved. The performance of the proposed protocol is evaluated and the results to different scenarios are discussed.

An efficient and robust clustered data gathering protocol (CDGP) for vehicular networks

Data collection in Vehicular Ad-hoc Networks (VANets) is considered as an interesting application which aims at delivering road traffic, environmental information and other kinds of data to interested entities. The protocols developed for the wireless mobile networks and particularly for WSN cannot be applied directly to vehicular networks due to the high mobility and the frequent disconnection especially in the highway. Therefore, the design of an efficient protocol is depending firstly on the use of an efficient technique for medium access and secondly on a correct data delivery. In this paper, we propose a data collection protocol based on clustering and on he use of a dynamic medium access technique. This protocol is based on acknowledged delivery and allows retransmission of data in the case of loss or errors. We present simulation results which show the feasibility, the effectiveness and the robustness of our proposed protocol.

A survey on position-based routing protocols for Flying Ad hoc Networks (FANETs)

Abstract The last decade has seen a growing interest in the use of Unmanned Aerial Vehicles (UAVs) for various applications and services. UAVs, or drones as referred to, have shown to be efficient in completing complex tasks when organized as ad hoc connected groups, thus forming a Flying Ad hoc Network (FANET). Although similar to Mobile Ad hoc Network (MANET) and Vehicular Ad hoc Network (VANET), FANETs have their own characteristics. One of the main difference is the fact that UAVs in general, but particularly when organized are FANETs, are mission-based, and their mobility models are often dictated by the purpose of their mission and the nature of the task they plan to accomplish. Therefore, routing protocols for FANETs should take into consideration the nature of the applications and services that the UAVs are deployed for, and factor in the mobility models. However, designing routing protocols for FANETs is not an easy task given the highly dynamic topology of FANETs and the flying constraints they are subjected to. Compared to topology-based routing, position-based routing demonstrated high efficiency and resilience to handle the high mobility of FANET nodes. To this end, in this paper, we propose a comprehensive survey of position-based routing protocols for FANETs with their various categories. We propose a classification and a taxonomy of these protocols, including a detailed description of the routing schemes used in each category. We propose a comparative study based on various criteria, and discuss the advantages and weaknesses of each protocol. Furthermore, new challenges for future research are presented, which introduce a new kind of coordination between UAVs and existing VANETs on the ground. The originality of this survey is that it complements the existing surveys on the same theme by providing more details on some aspects that have been addressed only ostensibly by other surveys in the literature.

IRTIV: Intelligent Routing Protocol Using Real Time Traffic Information in Urban Vehicular Environment

Routing in vehicular Ad hoc networks is a challenging task due to the high mobility of nodes and the network fragmentations. The challenge is most important in urban environment where many constraints are added like multipath and the presence of obstacles. In this way, many protocols are proposed. In this paper, we introduce a new position-based routing scheme called IRTIV, conceived exclusively for inter-vehicle communication in a city environment, the proposed protocol aims to find the shortest connected path to the destination by taking into account the real time traffic variation which is estimated by a completely distributed manner based on the periodic exchange of Hello messages. Simulation results show that the proposed protocol increases the packet delivery ratio and reduces the end to end delay.

ETAR: Efficient Traffic Light Aware Routing Protocol for Vehicular Networks

Routing in Vehicular Ad hoc Networks (VANETs) is an important factor to ensure a reliable and efficient delivery of data packets. In urban environments, routing protocols must efficiently handle the constantly changing network topology and frequent disconnections due to the high mobility and direction changes of vehicles. The challenge is greater when there are traffic lights fixed along intersections which affect directly the mobility and therefore can greatly impact routing in urban areas. In our previous work [1] we have proposed IRTIV (Intelligent Routing protocol using real time Traffic Information in urban Vehicular environment) that takes into account the real time traffic variation without any use of pre-installed infrastructures or additional messages. However, IRTIV does not take into consideration the traffic lights impact. In this paper, we propose ETAR (Efficient Traffic Light Aware Routing Protocol for Vehicular Networks). This protocols objective is to find the most stable path for delivering data packets based on traffic lights and traffic density of vehicles using the periodical exchange of Hello messages. We present simulation-based performance results, which show that the proposed protocol increases the packet delivery ratio and reduces the end-to-end delay.

CRUV: Connectivity-based traffic density aware routing using UAVs for VANets

The advent of commercial drones or unmanned areal vehicles (UAV) is expected to facilitate the deployment of a plethora of UAV-based applications. As a result, we expect UAVs to cooperate in ad hoc fashion and joint existing vehicular ad hoc networks. In this paper, we propose a novel routing scheme for Vehicular Ad hoc Networks (VANets) by using unmanned aerial vehicles (UAVs) through cooperative and collaborative communication. Our approach is based on information exchange between vehicles and UAVs to help vehicles in the ground find the best multi-hop path by selecting the most appropriate next intersection to deliver the data packets successfully to their destinations. We use the real time traffic variation which is estimated with a completely distributed manner based on the periodic exchange of Hello messages between all vehicles and UAVs in the system. In this work, we aim at integrating UAV-to-Vehicle (U2V) and Vehicle-to-UAV (V2U) communications to make routing in the presence of UAVs more efficient and more reliable, and to ensure packet delivery with a minimum of packet losses. This protocol is beneficial to develop more intelligent connected nodes in the future.

Novel geocast routing protocols for Safety and Comfort Applications in VANets

Routing in cooperative vehicular networks is a challenging work due to high mobility of vehicles and difficulty of localization. In this paper, we study the geocast routing problem in Vehicular Ad-Hoc Networks (VANets), which aims at delivering data to a specific group of mobile vehicles identified by their geographical location. Although many geocast routing protocols have been proposed, only partial inherent constraints of VANets (such as mobility, frequent fragmentation and overload) are taken into account. Therefore, we propose two novel robust geocast routing protocols: The first one called Robust Geocast Routing Protocol for Safety Applications (RGRP-SA), while the other one, namely Robust Geocast Routing Protocol for Comfort Applications (RGRP-CA). Simulations conducted in NS-2 demonstrate that our safety-oriented RGRP-SA protocol outperforms the counterpart protocols in terms of number of sent packets and end-to-end delay. Besides, it is also shown that our comfort-oriented RGRP-CA protocol serves well comfort applications by providing reliable data delivery and high throughput.