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.
['Igor Bisio', 'Mario Marchese']
Efficient Satellite-Based Sensor Networks for Information Retrieval