Mohamed Shawky - Academia.edu (original) (raw)

Papers by Mohamed Shawky

IEEE Transactions on Vehicular Technology, 2007

Abstract—Many solutions have been developed for routing mes-sages in ad hoc networks. However, fe... more Abstract—Many solutions have been developed for routing mes-sages in ad hoc networks. However, few of them are efficient when the network is highly dynamic. Indeed, building a routing table, discovering and maintaining a route, or localizing a node is a great challenge when ...

Eurasip Journal on Wireless Communications and Networking, 2010

The main objective of congestion control is to best exploit the available network resources while... more The main objective of congestion control is to best exploit the available network resources while preventing sustained overloads of network nodes and links. Appropriate congestion control mechanisms are essential to provide effcient operation of a network. Ensuring congestion control within vehicular ad hoc networks faces special challenges, due to the specificities of such environment (High mobility of nodes, high rate of topology changes, high variability in nodes density and neighborhood configuration, broadcast/geocast communication nature, etc.). In this context, we present in this paper a cooperative and fully distributed congestion control approach, based on dynamic scheduling and transmission of priority-based messages, to ensure reliable and safe communication architecture within VANET. Messages priorities are dynamically evaluated according to their types, the network context, and the neighboring nodes configuration. Considering the context of high reliability and real-time response required for intervehicular communications (including emergency breaking notification for example), we propose a complete validation method of our congestion control algorithms, taking into account reliability, temporal, and operational aspects.

Appropriate congestion control mechanisms are essential to maintain the efficient operation of a ... more Appropriate congestion control mechanisms are essential to maintain the efficient operation of a network. Ensuring congestion control within vehicular ad hoc networks address special challenges, due to the characteristic and specificities of such environment (High dynamic and mobility of nodes, high rate of topology changes, high variability in nodes density and neighborhood, broadcast/geocast communication nature ...). In this context, we present in this paper a cooperative and fully distributed congestion control approach, based on the concept of dynamic priorities-based scheduling and transmission, to ensure a reliable and safe communications architecture within VANET. The real applicability of our congestion control approach is validated through its formal verification and performance evaluation.

Abstract—The basic objective of congestion control is to best exploit the available network resou... more Abstract—The basic objective of congestion control is to best exploit the available network resources while preventing sustained overloads of network nodes and links. Appropriate congestion control mechanisms are essential to maintain the efficient operation of a network. Ensuring ...

Abstract—The growth of wireless local area networks based on the IEEE 802.11 standard these last ... more Abstract—The growth of wireless local area networks based on the IEEE 802.11 standard these last years represents a practical network solution offering mobility, flexibility and low cost deployment. This encourages the use of this protocol for new nomadic applications. ...

Abstract Many solutions have been developed for routing messages in ad hoc networks. However, few... more Abstract Many solutions have been developed for routing messages in ad hoc networks. However, few of them are efficient when the network is highly dynamic. Indeed, when the dynamic is high, building a routing table, discovering and maintaining a route or localizing a node ...

Ad hoc networks, particularly around IEEE 802.11 standards, are subject to increasing research in... more Ad hoc networks, particularly around IEEE 802.11 standards, are subject to increasing research interest. For a class of applications, involving terminals with high mobility, the experimentation is sometimes hardly affordable. The simulation is thus essential to explore new communication services. In this paper we explain the modification of ns-2 simulator, fed back with experimentation data, in order to obtain enhanced results more complying to the reality.

... salah dot bouassida at utc.fr Mohamed Shawky Heudiasyc UMR 6599 CNRS Université de Technologi... more ... salah dot bouassida at utc.fr Mohamed Shawky Heudiasyc UMR 6599 CNRS Université de Technologie de Compiègne Centre de Recherche BP 20529, 60205 mohamed dot shawky at utc.fr ABSTRACT The basic objective of ...

International Journal of Network Security, 2009

A Vehicular Ad hoc Network is a collection of mobile hosts forming a temporary network without th... more A Vehicular Ad hoc Network is a collection of mobile hosts forming a temporary network without the aid of any established infrastructure. This flexibility in space and time induces new challenges towards the security needed to support secure communications. Indeed, VANET are subject to attacks due to their vulnerabilities; one of the most compromising attacks is the Sybil nodes attack. We present in this context a Sybil detection approach, based on received signal strength variations, allowing a node to verify the authenticity of other communicating nodes, according to their localizations. In addition, we define an estimated metric of the distinguishability degree between two nodes, allowing to determine Sybil and malicious ones within VANET. The applicability of our contributions is validated through geometrical analysis, simulations and real measurements.

This paper presents a software framework called SCOOT-R that was developed in our laboratory to d... more This paper presents a software framework called SCOOT-R that was developed in our laboratory to design and implement real-time distributed applications. This architecture allows the exchange of objects between processes running on interconnected computers. It is based on client/server model with real-time extensions. The paper describes the possibilities of our approach to allow the integration of independently designed modules in a coherent real-time system. Finally, we present a typical automotive application involving our system: real-time accurate vehicle positioning on a digital map.

In recent years, networking issues have become more and more important in the design of vehicle c... more In recent years, networking issues have become more and more important in the design of vehicle control systems and driver assistance functions. We present a pragmatic approach for validating real-time in-vehicle applications using IEEE-1394 bus. By validation, we mean the verification of real-time constraints that is met by the automotive applications. We describe how the IEEE-1394 standard can respond to hard real-time constraints of critical and non-critical applications. We then present a software architecture based on distributed calculators interconnected by IEEE-1394 bus and well adapted for integrating multi-sensors automotive applications.

AUTOSAR standard provides a common framework for software development in the automotive domain. I... more AUTOSAR standard provides a common framework for software development in the automotive domain. It enables to manage the growing of the automotive architecture complexity by facilitating the integration and reuse of software components. However, additional work is needed to enable scheduling analysis and to handle with more timing properties in the system. In this paper, we propose an approach to enable a model transformation of the AUTOSAR timing model to a classical scheduling one. This allows to apply directly fundamentals scheduling theories for timing analysis. Then, we apply our approach through a steering-by-wire case study. Finally, we analyze the results given by the holistic algorithm and those given by a compositional one.

This paper presents a framework for distributed in-vehicle real-time applications. The framework ... more This paper presents a framework for distributed in-vehicle real-time applications. The framework is based on a client/server and emitter/receiver models with real-time extensions. The system allows the exchange of distributed data objects between calculators interconnected by a network bus. A dynamic reconfiguration and fault detection mechanisms are developed to ensure a reliable system. Interactions between processes are performed using the IEEE-1394 bus and are modeled as invocations to communicating active objects via an object oriented middleware called SCOOT-R that we developed. Finally, we present a typical automotive application involving our system: real-time accurate vehicle positioning on a digital map.

IEEE Transactions on Vehicular Technology, 2007

Abstract—Many solutions have been developed for routing mes-sages in ad hoc networks. However, fe... more Abstract—Many solutions have been developed for routing mes-sages in ad hoc networks. However, few of them are efficient when the network is highly dynamic. Indeed, building a routing table, discovering and maintaining a route, or localizing a node is a great challenge when ...

Eurasip Journal on Wireless Communications and Networking, 2010

The main objective of congestion control is to best exploit the available network resources while... more The main objective of congestion control is to best exploit the available network resources while preventing sustained overloads of network nodes and links. Appropriate congestion control mechanisms are essential to provide effcient operation of a network. Ensuring congestion control within vehicular ad hoc networks faces special challenges, due to the specificities of such environment (High mobility of nodes, high rate of topology changes, high variability in nodes density and neighborhood configuration, broadcast/geocast communication nature, etc.). In this context, we present in this paper a cooperative and fully distributed congestion control approach, based on dynamic scheduling and transmission of priority-based messages, to ensure reliable and safe communication architecture within VANET. Messages priorities are dynamically evaluated according to their types, the network context, and the neighboring nodes configuration. Considering the context of high reliability and real-time response required for intervehicular communications (including emergency breaking notification for example), we propose a complete validation method of our congestion control algorithms, taking into account reliability, temporal, and operational aspects.

Appropriate congestion control mechanisms are essential to maintain the efficient operation of a ... more Appropriate congestion control mechanisms are essential to maintain the efficient operation of a network. Ensuring congestion control within vehicular ad hoc networks address special challenges, due to the characteristic and specificities of such environment (High dynamic and mobility of nodes, high rate of topology changes, high variability in nodes density and neighborhood, broadcast/geocast communication nature ...). In this context, we present in this paper a cooperative and fully distributed congestion control approach, based on the concept of dynamic priorities-based scheduling and transmission, to ensure a reliable and safe communications architecture within VANET. The real applicability of our congestion control approach is validated through its formal verification and performance evaluation.

Abstract—The basic objective of congestion control is to best exploit the available network resou... more Abstract—The basic objective of congestion control is to best exploit the available network resources while preventing sustained overloads of network nodes and links. Appropriate congestion control mechanisms are essential to maintain the efficient operation of a network. Ensuring ...

Abstract—The growth of wireless local area networks based on the IEEE 802.11 standard these last ... more Abstract—The growth of wireless local area networks based on the IEEE 802.11 standard these last years represents a practical network solution offering mobility, flexibility and low cost deployment. This encourages the use of this protocol for new nomadic applications. ...

Abstract Many solutions have been developed for routing messages in ad hoc networks. However, few... more Abstract Many solutions have been developed for routing messages in ad hoc networks. However, few of them are efficient when the network is highly dynamic. Indeed, when the dynamic is high, building a routing table, discovering and maintaining a route or localizing a node ...

Ad hoc networks, particularly around IEEE 802.11 standards, are subject to increasing research in... more Ad hoc networks, particularly around IEEE 802.11 standards, are subject to increasing research interest. For a class of applications, involving terminals with high mobility, the experimentation is sometimes hardly affordable. The simulation is thus essential to explore new communication services. In this paper we explain the modification of ns-2 simulator, fed back with experimentation data, in order to obtain enhanced results more complying to the reality.

... salah dot bouassida at utc.fr Mohamed Shawky Heudiasyc UMR 6599 CNRS Université de Technologi... more ... salah dot bouassida at utc.fr Mohamed Shawky Heudiasyc UMR 6599 CNRS Université de Technologie de Compiègne Centre de Recherche BP 20529, 60205 mohamed dot shawky at utc.fr ABSTRACT The basic objective of ...

International Journal of Network Security, 2009

A Vehicular Ad hoc Network is a collection of mobile hosts forming a temporary network without th... more A Vehicular Ad hoc Network is a collection of mobile hosts forming a temporary network without the aid of any established infrastructure. This flexibility in space and time induces new challenges towards the security needed to support secure communications. Indeed, VANET are subject to attacks due to their vulnerabilities; one of the most compromising attacks is the Sybil nodes attack. We present in this context a Sybil detection approach, based on received signal strength variations, allowing a node to verify the authenticity of other communicating nodes, according to their localizations. In addition, we define an estimated metric of the distinguishability degree between two nodes, allowing to determine Sybil and malicious ones within VANET. The applicability of our contributions is validated through geometrical analysis, simulations and real measurements.

This paper presents a software framework called SCOOT-R that was developed in our laboratory to d... more This paper presents a software framework called SCOOT-R that was developed in our laboratory to design and implement real-time distributed applications. This architecture allows the exchange of objects between processes running on interconnected computers. It is based on client/server model with real-time extensions. The paper describes the possibilities of our approach to allow the integration of independently designed modules in a coherent real-time system. Finally, we present a typical automotive application involving our system: real-time accurate vehicle positioning on a digital map.

In recent years, networking issues have become more and more important in the design of vehicle c... more In recent years, networking issues have become more and more important in the design of vehicle control systems and driver assistance functions. We present a pragmatic approach for validating real-time in-vehicle applications using IEEE-1394 bus. By validation, we mean the verification of real-time constraints that is met by the automotive applications. We describe how the IEEE-1394 standard can respond to hard real-time constraints of critical and non-critical applications. We then present a software architecture based on distributed calculators interconnected by IEEE-1394 bus and well adapted for integrating multi-sensors automotive applications.

AUTOSAR standard provides a common framework for software development in the automotive domain. I... more AUTOSAR standard provides a common framework for software development in the automotive domain. It enables to manage the growing of the automotive architecture complexity by facilitating the integration and reuse of software components. However, additional work is needed to enable scheduling analysis and to handle with more timing properties in the system. In this paper, we propose an approach to enable a model transformation of the AUTOSAR timing model to a classical scheduling one. This allows to apply directly fundamentals scheduling theories for timing analysis. Then, we apply our approach through a steering-by-wire case study. Finally, we analyze the results given by the holistic algorithm and those given by a compositional one.

This paper presents a framework for distributed in-vehicle real-time applications. The framework ... more This paper presents a framework for distributed in-vehicle real-time applications. The framework is based on a client/server and emitter/receiver models with real-time extensions. The system allows the exchange of distributed data objects between calculators interconnected by a network bus. A dynamic reconfiguration and fault detection mechanisms are developed to ensure a reliable system. Interactions between processes are performed using the IEEE-1394 bus and are modeled as invocations to communicating active objects via an object oriented middleware called SCOOT-R that we developed. Finally, we present a typical automotive application involving our system: real-time accurate vehicle positioning on a digital map.