Showing papers by "Igor Bisio published in 2008"

Efficient Satellite-Based Sensor Networks for Information Retrieval

Abstract: This paper considers a packet-based telecommunication network architecture suited to be used as an Environmental Monitoring System (EMS) over wide areas. It can be employed to retrieve the measures of physical quantities, such as temperature, humidity, and vibrations intensity (physical information) together with the geographical position where the measures are taken (position information). The telecommunication network supporting the EMS is composed of: a network of sensors, a group of earth stations called Sinks, a satellite backbone, and a destination. Each sensor collects physical and position information, encapsulates it into packets and conveys it towards the sinks which give access to the satellite backbone that connects the sinks to the destination. A single sensor transmits the information to all sinks but only one sink transmits it over the satellite channel. Even if the redundant transmission of the same data from more than one sink would increase the safety of the system, it would increase also the costs of it. The selection of the sink which forwards the information of a sensor to the destination is important to increase the performance of the EMS. This paper introduces specific performance metrics to evaluate the functionality of the whole EMS in terms of reliability, reactivity, and spent energy. The reference metrics are packet loss rate, average packet delay, and energy consumption. Then the paper presents an algorithm to select the transmitting sink for each sensor, which is aimed at maximizing the performance in terms of the mentioned metrics. The algorithm is tested through simulation.

Congestion Aware Routing Strategies for DTN-Based Interplanetary Networks

Abstract: The networking and communication challenges posed by interplanetary environments make the design and the deployment of complex telecommunication infrastructures particularly difficult, especially with regard to routing and congestion control issues. To this end, the paper proposes a congestion-aware routing paradigm that applies multi attribute decision making (MADM) concepts for next-hop selection, by formulating an optimisation problem and proposing some possible resolution criteria. Effectiveness of the proposed solutions is assessed through a preliminary performance analysis that shows promising results.

Multi-Attribute Decision Making Routing Strategy for Interplanetary Communications

Abstract: As current Internet frontiers are rapidly extending towards space, the scientific community's interest is increasingly addressed to next-generation network architectures suited to enable data communications over interplanetary networks. In this light, given the networking and communication challenges posed by such environments, the design of complex telecommunication infrastructures deserves particular attention, especially with regard to routing and congestion control strategies. To this end, this paper proposes a congestion-aware routing paradigm that applies multi attribute decision making (MADM) concepts for next-hop selection, by formulating an optimisation problem and proposing some possible resolution criteria. Effectiveness of the proposed solutions is assessed through a preliminary performance analysis that shows promising results.

Attributes Definitions and Measurement Methods for MADM Based Sink Selection Controls in Satellite Sensor Networks

Abstract: The framework of the work is an environmental monitoring system (EMS) realized by a satellite based sensor network (SSN). The paper introduces and formalizes specific performance metrics needed to implement an efficient Sink selection process (where Sink represents a satellite channel access node) based on a multi-attribute decision making algorithm. It is aimed at enhancing the functionality of the whole EMS in terms of reliability, reactivity and spent energy. The reference metrics are packet loss rate, average packet delay, and energy consumption. The algorithm is tested through simulation.

Packet Loss and Delay Combined Optimization for Satellite Channel Bandwidth Allocation Controls

Abstract: The paper studies the bandwidth allocation process over satellite communication systems as a multi-objective programming (MOP) problem and evaluates an allocation method called "combined Utopia minimum distance" (combined UMD). The entities of the system are earth stations and, for each of them, a set of performance metrics (represented by specific analytical functions), which compete to access the satellite channel. Combined UMD is aimed at approaching the performance obtained for each performance metric when there is no conflict among them to access the channel. In short, it assigns the bandwidth so to approach a non-competitive situation where each metric "sees" the overall channel bandwidth availability as close as possible. In more detail, in this work two kinds of performance metric have been considered: the packet loss probability, which is a typical QoS metric for the TCP based traffic and the average delay, which is typical for UDP based traffic. The allocation method is tested through the ns2 simulator by using TCP and UDP traffic generators and by varying the fading level of the satellite channel over time. Combined UMD has been compared with other approaches taken from the literature in the field.

QOS-Constrained MOP-Based Bandwidth Allocation Over Space Networks

Abstract: The paper formalizes and analyzes the bandwidth allocation process over space communication systems modelled as a Multi – Objective Programming (MOP) in presence of Quality of Service (QoS) constraints The reference allocation scheme considered is based on GOAL programming and is called “Minimum Distance” algorithm The work proposes two different versions of the Minimum Distance scheme both aimed at assigning the bandwidth so to approach a non-competitive situation as close as possible and at guaranteeing a fixed performance for each traffic flow traversing the space network The proposals have been tested over a faded channel by using TCP/IP traffic The performance evaluation is carried out analytically by varying the degradation level of the channel