2002 - cesnet

Fibre Fibre Pair of Lease Return onlength lease converters of pair Investment[km] [EUR/month] [EUR] [EUR/month] [months]10 267 5,552 417 37.020 467 5,552 833 15.130 700 5,552 1,250 10.140 933 7,773 1,667 10.650 1,167 7,773 2,083 8.560 1,400 14,133 2,500 12.870 1,633 14,133 2,917 11.080 1,867 14,133 3,333 9.69 2,100 14,133 3,750 8.6100 2,333 14,133 4,167 7.7110 2,310 15,301 4,583 6.7125 2,625 15,301 5,208 5.9Example of an implemented circuit:4.4 880 5,257 1,467 9.0Table 4.5: Return on investments concerning single-fibre convertersEM 316WFC/S2 & EM 316WFT/S2 100 Mbps, SM, 1,520&1,560 nm, 1–30 kmEM 316WFC/S3 & EM 316WFT/S3 100 Mbps, SM, 1,520&1,560 nm, 20–50 kmEM 316WFC/S4 & EM 316WFT/S4 100 Mbps, SM, 1,520&1,560 nm, 40–100 kmEM 316WFC/S5 & EM 316WFT/S5 100 Mbps, SM, 1,520&1,560 nm, up to 125 kmTable 4.6: Types of single-fibre converters (NBase-Xyplex)The first experience with the design and operation of single-fibre optical linesreveals that it is possible to make use of this method in order to connect pointswhich could not be otherwise connected with a pair of fibres due to a lack ofavailable fibres or for financial reasons.The price for fibre lease in the Czech Republic reaches from 51 to 70 % of thelease for a pair. With the use of NBase-Xyplex converters for 100 Mbps, thereturn on investment is usually from 4 to 10 months and the reach withoutregeneration is 125 km. Using converters for 1 Gbps, the return of investmentis approximately 6 to 15 months. Single-fibre circuits are available for priceslower than the purchase of SDH services 2–622 Mbps or FE and GE services.In addition, their parameters may be better, as well as the expenses of futurebandwidth increase. The converters mentioned above do not allow for in-lineamplification.Single-fibre circuits are suitable for shorter intercity lines and for the connectionof customers or members’ branches. So far, the following single-fibrecircuits have been contracted: Ostrava–Opava (46.7 km, January 2003) andOstrava–Karviná (54.4 km, May 2003). In collaboration with the Institute of52 High-speed National Research Network and its New Applications 2002