A theoretical research and numerical simulation of the noise influence caused by spontaneous Raman scattering, four-wave mixing, linear channel crosstalk on performance QKD systems was conducted. Three types were considered: coherent one-way (COW) protocol, subcarrier-wave (SCW) system, continuous-variable (CV) integrated with classical DWDM channels. We calculate secure key generation rate for...

In this work, diffusion processes in thermally connected cylindrical fibers with weakly guiding and circular cross-section, that is, telecommunication fibers, have been presented. There have been discussed diffusion distributions of the core dopant of fibers spliced at T ≈ 2000 °C. Gaussian approximations of the core dopant concentration distribution and refractive index in the connecting area ...

Every nation wants to achieve Universal Access of telecommunication services due to its importance to the economy and national life. Unfortunately in sub-Saharan Africa, telecommunication services are either scarce or non-existent in rural areas. However, previous telecommunication policies have enabled the provision of various network technologies in Africa. What type of policy is needed to pu...

In the past, telecommunication technologies did not present any particular problem for persons with visual disabilities. The telephones themselves were auditory in nature and could be operated by touch. As telecommunication begins to incorporate video and as telecommunication devices become more complex (including the incorporation of visual displays), new barriers are appearing. Fortunately, a...

Due to rapidly changing environment based on triple play, the conovation of competitiveness in telecommunication industry has also changed. The operators should adjust their strategic direction timely according to changes in competitive environment. So how to promote the competitiveness under triple play has become a hot issue in telecommunication industry. Based on ISM (Interpretative Structur...

The technology revolution lead by Internet and ever improving computing power has played pivotal role in justifying the sense of a global village perception. Managing and enabling technological growth is among the top priorities of the organizations today. To meet this priority, organizations must create reliable, secure and cost-effective infrastructures that enable business innovation. Techno...

Direct modeling plays a very important role in many engineering applications including telecommunication, power system, image processing, VLSI design, biological processes, control engineering and geophysics applications. In case of control and telecommunication applications, direct modeling is used for channel estimation, parameter estimation and forecasting. There are standard algorithms and ...

To reproduce a highly realistic sound field reproduction, we have developed a three dimensional sound reproduction system based on the boundary surface control principle. We set up an Internet connection among multiple systems, which enables distant speakers to carry out voice telecommunication by simultaneously hearing the same sound field and perceiving the other speakers' simulated positions...