Abstract: The present invention discloses a system and method for implementing prepaid data services in a mobile communication network. In this system, a Data service Access Control Point (DACP), which is used for fulfilling price confirmation function and fee application function for data services, is added between a Service Control Point (SCP) storing prepaid account information of subscribers and a Prepaid Server/Content of Process Gateway (PPS/CP GW) used for data service charging. In the method of the present invention, by means of the interaction among a Packet Data Service Note (PDSN), a Home Authentication Authorization and Accounting (HAAA) server, the PPS/CP GW, the DACP and the SCP, the SCP deducts the fees from the prepaid account, and the PDSN controls the subscriber to utilize data service according to the fees deducted by the SCP.

Abstract: A method of producing a preform for a holey optical fiber having at least one hole longitudinally extending therethrough. A porous preform, such as a glass soot preform, is formed by means of flame hydrolysis, or a gel preform; at least one hole is then formed by drilling the porous preform, the hole extending through the porous preform along the longitudinal direction thereof. A holey fiber can be produced by drawing the holey porous preform, after having submitted it to a consolidation process.

Abstract: Raman amplifier having an optical fiber made of a tellurite glass is disclosed. The tellurite glass has at least two further metal oxides, the metals of said respective two oxides being selected from a first group of Nb, W, Ti, Tl, Ta, and Mo and from a second group of Nb, W, Ti, Pb, Sb, In, Bi, Tl, Ta, Mo, Zr, Hf, Cd, Gd, La, and Ba. The so obtained fiber has improved optical (Raman gain) and/or thermal (thermal stability index) properties. Alternatively, the tellurite based glass compositions of the fiber have at least one additional metal oxide, where the metal is selected among Nb, Ti, Tl, Ta, and Mo, the glass showing a particularly high Raman gain. The maximum Raman gain of these glasses is typically higher than 100 times of the maximum Raman gain of pure silica and the respective total cross-section of the Raman spectrum is typically greater than 100 times the total cross-section of pure silica, in the frequency measurement range of 200 cm?1 to 1080 cm?1.

Abstract: In an induction furnace for the synthesis of glasses, in particular fluorozirconate glasses for optical fibres for telecommunications, the support device (6') for the crucible (3) is associated with a pair of sleeves (7, 9) between which an annular element (8) which constitutes the actual support element is inserted. The first sleeve (7) has such longitudinal dimensions that the crucible (3) is supported in the annular element (8) in such a way as to be spaced from the planar element (5'), and the second sleeve has such longitudinal dimensions that its top edge is at a level higher than that of the top edge of the crucible (3), to obtain a homogeneous temperature region extending at least along the entire height of the crucible (3).