الفهرس 
The Main Challenges and Solutions of Today’s Telecommunication NetworksOnly 14 pages are availabe for public view
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Abstract
The main challenges of today’s telecommunication networks are to provide more and cheaper bandwidth.
Optical arrayed waveguide grating (AWG) devices, optical add DROP multiplexers (OADMs) and optical amplifiers play an increasing role in the development of optical fiber communication (OFC) systems. Recent progress in the development of these devices has been described in the last decade. They particularly focus on increasing the number of optical transmitted channels and then increase the number of subscriber. So in the present thesis, new materials based AWG optical devices for multi-band multiplexing/demultiplexing applications in ultra-wide wavelength division multiplexing (UW-WDM) have been modeled and parametrically investigated over wide range of the affecting parameters, based on the set of the series of the basic equations and also based on the set of the assumed of affecting operating parameters on the system model. Two type of AWG devices have been studied deeply and have been employed over wide range of the affecting parameters in order to upgrade network performance, and efficiency. UThe first typeU is the conventional multiplexer/demultiplexer (Mux/Demux) AWG, Uthe second typeU is a thermal AWG which resolve the problem of occurrence of shifting in the output channels center wavelengths of the conventional AWG which result from a rise in temperature.
Moreover two other devices have been studied, Uthe first oneU was the optical add DROP multiplexers (OADM), where it has been studied deeply with UW-DWDM multiplexing technique, OADMs have been modeled and have been parametrically investigated over wide range of affecting parameters. Also the performance characteristics of the OADMs have been taken as the major interest in optical communication networks to handle large number of channels to increase the number of supported users. UThe second deviceU was the optical distributed Raman amplifier (DRA), where it has been modeled and has been parametrically investigated, based on the coupled differential equations of first order, and also based on a set of affecting operating parameters on the system model in the transmission signal power and pump power within Raman amplification technique in co-pumped, counter-pumped, and bi-directional pumping direction configurations through different types of fiber cable media, to boost a weak signal in the communication systems.
Finally, all of the previous devices (conventional, a thermal Mux/Demux AWG, OADMs, and DRAs) have been employed with the assistant of two multiplexing techniques, wavelength division multiplexing (WDM) and space division multiplexing (SDM), in order to obtain the best performance and efficiency of optical communication networks as in the following results:
i) Increasing the number of input/output (I/O) wavelength channels in both conventional and a thermal AWG and then increasing the number of supported subscribers.
ii) Management wavelengths by enabling the selective add and DROP of optical channels.
iii) Improvement of optical signal to noise ratio (OSNR) and then to decrease bit error rate (BER) in optical fiber data transmission.
iv) Boost a weak signal in optical communication networks (OCNs).