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In this paper, promising technologies and a network architecture are presented for future optical packet switched networks. The overall network concept is presented and the major choices are highlighted and compared with alternative solutions. Both long and shorter term approaches are considered, as well as both the wide-area network and multiple-area networks parts of the network. The results presented in this paper were developed in the frame of the research project DAVID (Data And Voice Integration over DWDM) project, funded by the European Commission through the IST-framework.

In this paper, promising technologies and a network architecture are presented for future optical packet switched networks. The overall network concept is presented and the major choices are highlighted and compared with alternative solutions. Both long and shorter term approaches are considered, as well as both the wide-area network and multiple-area networks parts of the network. The results presented in this paper were developed in the frame of the research project DAVID (Data And Voice Integration over DWDM) project, funded by the European Commission through the IST-framework.

In this paper, promising technologies and a network architecture are presented for future optical packet switched networks. The overall network concept is presented and the major choices are highlighted and compared with alternative solutions. Both long and shorter term approaches are considered, as well as both the wide-area network and multiple-area networks parts of the network. The results presented in this paper were developed in the frame of the research project DAVID (Data And Voice Integration over DWDM) project, funded by the European Commission through the IST-framework.

In this paper, promising technologies and a network architecture are presented for future optical packet switched networks. The overall network concept is presented and the major choices are highlighted and compared with alternative solutions. Both long and shorter term approaches are considered, as well as both the wide-area network and multiple-area networks parts of the network. The results presented in this paper were developed in the frame of the research project DAVID (Data And Voice Integration over DWDM) project, funded by the European Commission through the IST-framework.

L'influence des anions minéraux sur la décomposition de l'ozone est étudiée. Les expériences mettent en oeuvre les anions SO42-, PO43-, BO33-, SiO22-, NO3-, HCO3-+ CO32- à des concentrations identiques à celles habituellement rencontrées dans le domaine des eaux potables. Un plan d'expérience simple qui permet d'attribuer ou non une influence à chaque espèce minérale et de voir l'interaction éventuelle avec le pH est utilisé. Les manipulations sont réalisées sur un pilote de laboratoire conçu pour éliminer toutes traces de matières organiques.L'étude fait apparaître que seuls les carbonates et les bicarbonates ont une influence notable sur cette décomposition et que le pH interfère en jouant sur l'équilibre carbonates-bicarbonates. Ceci permet de vérifier l'équation théorique établie par YURTERI et GUROL (1988) en l'absence de matières organiques. L'ordre apparent de la réaction varie entre 1 et 2 : ordre 2 pour les teneurs en bicarbonates faibles (30 mg.l-1) et ordre 1 pour une teneur forte (300 mg.l-1) lorsque le pH basique déplace l'équilibre vers les carbonates. Pour 300 mg.l-1 et des pH neutres l'ordre de la réaction oscille entre 1,5 et 2. Pour un ordre 1, on peut calculer la constante d'initiation de la décomposition de l'oxydant par l'ion hydroxyle OH- (k = 80 l.mol-1 s-1)., The influence of anionic mineral species on the decomposition of ozone in water was studied. The experiments involved the anions SO42-, PO43-, BO33-, SiO22-, NO3-, HCO3-+ CO32- at concentrations identical to those usually found in drinking water. The manipulations were carried out with a simple experimental procedure which allowed to determine whether or not the mineral species had an influence on this decomposition and to observe thereof the effect of the pH. A laboratory pilot made of glass and teflon, in order to eliminate any traces of organic compounds, was used.Results of this work prove that only the carbonates and bicarbonates have a notable influence on this decomposition and that the pH interferes by disrupting the bicarbonate-carbonate equilibrium. The theoretical equation established without organic compounds by YURTERI and GUROL (1988) is verified.The order of the reaction varies from 1 to 2. The order is 1 when the amount of bicarbonates is weak (30 mg/l). The order is 2 in the case of a 300 mg.l-1 concentration when the basic pH changes the equilibrium towards the carbonates. For 300 mg.l-1 concentrations and a neutral pH, the order of the reaction reaches values from 1,5 to 2. In the case of an order 1, the constant rate of the oxidant decomposition by hydroxyle ion OH¯ is calculated. Its value is 80 l.mol-1 s-1.