To ensure that end-users and consumers have access to comprehensive, comparable and user-friendly information regarding the Internet access service quality, it is necessary to implement and regularly ...renew a set of legislative regulatory acts and to provide monitoring of the quality of Internet access services regarding the current European Regulatory Framework. The actual situation regarding the quality of service monitoring solutions in different European countries depends on national regulatory initiatives and public awareness. The service monitoring solutions are implemented using different measurement methodologies and tools. The paper investigates the practical implementations for developing a harmonising approach to quality monitoring in order to obtain objective information on the quality of Internet access services on mobile networks.
In the paper, the authors compare efficiency of two physical dispersion compensation methods for single channel and 8-channel WDM fibre-optical transmission systems using return-to-zero (RZ) and ...non-return-to-zero (NRZ) line codes for operation within optical C-band frequencies by means of computer simulations. As one of the most important destructive effects in fibre optical transmission systems (FOTS) is chromatic dispersion (CD), it is very important to reduce its negative effect on a transmitted signal. Dispersion compensation methods that were implemented in the research were dispersion compensating fibre (DCF) and fibre Bragg grating (FBG). The main goal of the paper was to find out which dispersion compensation method (DCF or FBG) provided the highest performance increase for fibre-optical transmission system and provided the longest transmission distance after dispersion compensation was implemented at different locations in the fibre-optical line while RZ or NRZ line codes were used. In the paper the reference point of signal quality for all measurements, which were obtained at the receiver, was BER<10
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