Francine Krief

Power Control and Clustering in Wireless Sensor Networks

The use of the wireless sensor networks (WSNs) should be increasing in different fields. However, the sensor’s size is an important limitation in term of energetic autonomy, and thus of lifetime because battery must be very small. This is the reason why, today, research mainly carries on the energy management in the WSNs, taking into account communications, essentially. In this context, we compare different clustering methods used in the WSNs, particularly EECS, with an adaptive routing algorithm that we named LEA2C. This algorithm is based on topological self-organizing maps. We obtain important gains in term of energy and thus of network lifetime.

A Survey on Dynamic Spectrum Access Techniques in Cognitive Radio Networks

A Mobile Ad hoc NETwork (MANET) is a wireless communication network with minimum physical infrastructure with diverse communication applications. Mobility and Multihopping are the main characteristics of MANET. Multipath routing protocols establish multiple routes between nodes. The construction of multiple routes should be done with minimum overhead and bandwidth consumption. The purpose of this article is to analyze the characteristics and functionality of various multipath routing protocols and to do the performance comparison between these multipath routing protocols to choose the best among them to use in large networks.

AGEM: Adaptive Greedy-Compass Energy-Aware Multipath Routing Protocol for WMSNs

This paper presents an Adaptive Greedy-compass Energy-aware Multipath protocol (AGEM), a novel routing protocol for wireless multimedia sensors networks (WMSNs). AGEM uses sensors node positions to make packet forwarding decisions. These decisions are made online, at each forwarding node, in such a way that there is no need for global network topology knowledge and maintenance. AGEM routing protocol performs load-balancing to minimize energy consumption among nodes using twofold policy: (1) smart greedy forwarding, based on adaptive compass and (2) walking back forwarding to avoid holes. Performance evaluations of AGEM compared to GPSR (Greedy Perimeter Stateless Routing) show that AGEM can: (a) maximize the network lifetime, (b) guarantee quality of service for video stream transmission, and (c) scale better on densely deployed wireless sensors network.

eHealth: Survey on research projects, comparative study of telemonitoring architectures and main issues

Abstract Today, the number of elderly people and patients with reduced autonomy or with chronic diseases are steadily increasing. In addition, a stay in hospital or nursing home is very expensive. Thus, in recent years we have witnessed the development of projects to keep these people at home while providing them the needed care and assistance. The number of research projects that have emerged around the world during these last years is very important. Thus we are interested in studying a number of these projects. In this study, we focus on European projects because there is a great similarity with other projects (American, Asian and African projects). After a detailed study of various European research projects conducted in the telemonitoring of patients field, we identify the main requirements of a telemonitoring system. Then, we introduce the common components of these systems. After that, we provide a comparative study in terms of offered services, technical issues, supported functionalities and tools involved in the implementation of the proposed systems. Finally, we introduce some interesting perspectives for the patient telemonitoring research field.

A user assistant for QoS negotiation in a dynamic environment using agent technology

This paper presents an assistant to help the user in negotiating the desired quality of service in a dynamic environment using the agent technology. A multi-agent system is proposed in order to solve problems and accomplish tasks in a distributed and autonomous way. This user assistant negotiates dynamically the QoS (quality of service) on the users behalf, follows the users behavior to be able to predict his future location in wireless networks, anticipate the negotiation and manage the re-negotiation. The negotiation can take place in two different manners, using agents that will reach an agreement with the best provider or using a dynamic negotiation protocol called SLN NSLP.

An intelligent user interface for the dynamic negotiation of QoS

IP networks have to provide a service adapted to the needs of applications (particularly real time ones), including a guaranteed quality of service (QoS). The IETF proposed a general framework for the control and management of these networks. Configuration, control and management are governed by policy rules. In providing a service with QoS guarantees, it is interesting to be able to create or modify these policy rules dynamically. We investigate the use of an intelligent user interface in order to make access to the services presented by Internet providers easier. We use agent technology to help the user to choose the best service provider, dynamically negotiate the service level specification on the users behalf, follow the users behavior to be able to anticipate negotiations and manage the re-negotiations.

Resource Management for End-to-End QoS in a Mobile Environment

The major challenge in a mobile environment is the provisioning of quality of service (QoS) guarantees that different applications demand considering the highly dynamic nature of this environment. In this context, providing QoS to mobile terminals is a very important field of research. In the integrated networks services, the majority of research seeks to extend the RSVP protocol to a mobile environment. Another way to obtain a better use of the resources is to determine the future locations of the mobile terminal. This paper describes a resource management approach for end-to-end QoS in the mobile networks; it is based on the QoS NSLP signaling application resulting from NSIS working group. This reservation is based on an object called MSpec (mobility specification) which determines the future location of the mobile terminal. The MSpec object is a part of a users mobility profile

Toward Cognitive Radio Resource Management Based on Multi-Agent Systems for Improvement of Real-Time Application Performance

Cognitive Radio (CR) is a promising technology that can alleviate the spectrum shortage problem by enabling unlicensed users equipped with CRs to coexist with incumbent users in licensed spectrum bands while causing no interference to incumbent communications. In this paper, we propose a new approach which uses CR for improving real-time application performance related to only one cognitive radio mobile terminal (CRMT). We also present a synthesis of research relating to dynamic spectrum allocation and sharing in the context of CR networks using multi-agent systems. In our future work, we will seek to improve real-time application performance related to many CRMT.

GEAMS: A Geographic Energy-Aware Multipath Stream-based routing protocol for WMSNs

Because sensor nodes operate on power limited batteries, sensor functionalities have to be designed carefully. In particular, designing energy-efficient packet forwarding is important to maximize the lifetime of the network and to minimize the power usage at each node. This paper presents a Geographic Energy-Aware Multipath Stream-based (GEAMS) routing protocol for WMSNs. GEAMS routing decisions are made online, at each forwarding node in such a way that there is no need to global topology knowledge and maintenance. GEAMS routing protocol performs load-balancing to minimize energy consumption among nodes using twofold policy: (1) smart greedy forwarding and (2) walking back forwarding. Performances evaluations of GEAMS show that it can maximize the network lifetime and guarantee quality of service for video stream transmission in WMSNs.

Introduction of Security in the Service Level Negotiated with SLNP Protocol

Today, the evolution of IP networks and the diversity of the data flowing through these networks require domain managers to ensure quality of service (QoS), security and mobility for various communications. Security and QoS can be negotiated between domain managers implied in a service offer. The SLNP (Service Level Negotiation Protocol) protocol allows the negotiation of a service level QoS and it functions in the interoperable environment of web services. The objective of this paper is to consider QoS requirements of the communications when security is introduced in the service level negotiated with the SLNP protocol.