Evangelos Topalis

ZRP versus DSR and TORA: a comprehensive survey on ZRP performance

Ad hoc networks are characterized by dynamic topology caused by node mobility, multihop wireless connectivity and channel non-deterministic behavior (interference, multipath, hidden and exposed node problem make the wireless channel very difficult to predict). The behavior of ad hoc networks must be analyzed in detail as a result of the pairing of the selected MAC and routing protocols. We focus our studies in the routing layer while closely observing the developments in MAC layer. We present and examine analytical simulation results for the routing protocols DSR, TORA and ZRP especially focusing in ZRP and the impact of some of its most important attributes to network performance, using the well known network simulator OPNET 10.0.PL2

A generic network management architecture targeted to support home automation networks and home Internet connectivity

This paper proposes a generic network management architecture targeted to support home automation networks and home Internet connectivity for the purpose of control and monitoring. The core of the architecture is a new management protocol residing at the OSI application layer. The paper is structured as follows: state-of-the-art and main objective are primarily presented, and then the proposed architecture and protocol are detailed. Finally, conclusions and open issues are highlighted.

Implementation of power aware features in AODV for ad hoc sensor networks. A simulation study

Ad hoc wireless networks are power constrained since nodes operate with limited battery energy. Thus, energy consumption is crucial in the design of new ad hoc routing protocols. To design such protocols, we have to look away from the traditional minimum hop routing schemes. This paper presents an energy-aware routing mechanism to balance the energy consumption among the nodes of the network. The mechanism was based on the AODV protocol using a realistic energy consumption model which takes into account the battery of a node and the transmission energy. The results show that the modified AODV protocol reduces the energy consumption of the nodes by routing packets to their destination using energy-optimal routes. The outcome is the improvement of network survivability by maintaining the network connectivity without affecting negatively the others parameters of the protocol.

A novel architecture for remote home automation e-services on an OSGi platform via high-speed Internet connection ensuring QoS support by using RSVP technology

This paper discusses a novel architecture for remote home automation networks e-services on an OSGi platform via high speed Internet connections ensuring QoS support. These connections can be ADSL links, an emerging technology which provides the user of the local loop with broadband speeds. Since ADSL is a technology in the local loop, the presence of a signaling mechanism based on RSVP is necessary to maintain the high speed links through the network. So, a remote enduser who manages a home automation network can use an ADSL connection to assure the home automation e-services. Thus, guaranteed bandwidth as well as limited delay advances services can be achieved.

Evaluation Analysis of the Performance of IEEE 802.11b and IEEE 802.11g Standards

The IEEE 802.11 Wireless LAN standard is one of the most popular wireless standards in the market today. Since 1997 when the first version of the IEEE 802.11 was launched in the market, a lot of different versions has been announced and developed. In this paper, a comprehensive evaluation analysis of the IEEE 802.11b and IEEE 802.11g has been carried out, examining the performance of both standards at the MAC sub-layer, in terms of QoS, using two different simulation tools. Finally, the comparison for both cases is discussed.

802.15.4: The Effect of Different Back-off Schemes on Power and QoS Characteristics

IEEE 802.15.4 LR-WPAN is intended as a specification for low-cost, low-powered networks with no critical concerns about throughput and latency. These features enable applications in the fields of industrial, agricultural, vehicular, residential and medical sensors as well as actuators, such as wireless monitoring and control of lights, security alarms, motion sensors, thermostats and smoke detectors, which cannot make use of current wireless technologies or have to use proprietary solutions. However, when dealing with wireless networks, optimized power management and better QoS characteristics are always a topic of great importance. In this paper, an evaluation of the effect of different back-off schemes of MAC algorithm, on power and QoS characteristics is presented.

Security and DRM in indoor/outdoor heterogeneous networking applications for user - centric frameworks

As networks become more and more complicated and applications more and more demanding, a very common network topology for state-of-the-art multimedia applications supporting emerging user - centric frameworks is a heterogeneous wired/wireless architecture. A network architecture solution for indoor/outdoor heterogeneous networking applications, to support both multimedia and sensor applications suitable for such frameworks is proposed in this paper. Furthermore, an integrated DRM system architecture is proposed for the protection of intellectual property, characterized by its interoperability aspect.

QoS support for real-time home automation networks management via high-speed Internet connection

This paper presents a novel architecture for home automation network management through high speed Internet connections ensuring QoS support. These connections can be ADSL links, an emerging technology which provides the user of the local loop with broadband speeds. So, a remote end-user who manages a home automation network can use an ADSL connection to assure the real-time transmission of images, video, signals, etc. Since ADSL is a technology in the local loop, the presence of a signalling mechanism based on RSVP is necessary to maintain the high speed links through the network.

A framework architecture supporting QoS-power trade-offs for heterogeneous network systems

Power awareness and quality of service (QoS) integration in wireless systems are two of the main research activities in wireless systems today. As frameworks are developed to handle dynamic reconfiguration, the need for a power optimization methodology to investigate alternative cross-layer configurations is imposed as critical. However, as networks become more complex and energy savings become critical, this leads to the consideration of constructs for treating QoS-power trade-offs and adjust to the heterogeneous nature of network systems. In this paper, we propose an interoperable architecture for a hybrid wired-wireless network, where communication is treated transparently and enhancements are proposed to improve QoS by the definition of a framework also supporting dynamic power optimization

Framework Design Supporting QoS-Power Trade-Offs for Heterogeneous Networked Systems

The work reported here was performed as part of the ongoing research Program PYTHAGORAS II and funded by the European Social Fund (ESF), in particular by the Operational Program for Educational and Vocational Training II (EPEAEK II).Two of the main research efforts in wireless systems, nowadays, are the Power awareness and Quality of Service (QoS) integration. As frameworks are developed to handle dynamic reconfiguration, the need for a power optimization methodology to investigate alternative cross-layer configurations is critical. However, as networks become more complex and energy savings become crucial, this leads to the consideration of constructs for treating QoS-power trade-offs and adjust to the heterogeneous nature of network systems. In this paper, we propose an interoperable framework design for heterogeneous network systems, where communication is treated transparently and enhancements are proposed to improve QoS by the definition of a framework also supporting dynamic power optimization.