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The hybrid system WDM Radiofrequency over free space optics\fiber optic (RoFSO\FO) is one of the modern technologies that support developing the 5th generation for the communication network. The WDM RoFSO\FO system is designed to transmit high data rates over a long distance under variable weather conditions (fog, dust, and rain). Where the attenuation caused by atmospheric changes is one of the most important obstacles faced the FSO channel. The spatial diversity technique is used by sending multiple copies across the free space to improve system performance. The hybrid design tested the performance of 16 channels optical transmission, each channel transmits 2.5Gbps data rate modulated by PSK modulator on a 20GHz radio frequency signal. Where 40 gigabits per second was transmitted via 4000m multi-channels FSO extending to 120 km optical fiber as a total distance, 80 km of which was amplified by Raman / EDFA hybrid optical amplifier. The bit error rate BER and the Q-factor monitored and compared with the standard Kim model. From the results obtained by using the OptiSystem simulation, an improvement in the system was found significantly by increasing the transmission capacity when using WDM technology and long-distance transmission under variable weather conditions without adding a light source.

In this paper, a hybrid system is proposed consisting of a radio-frequency (RF) over free space optic/fiber optic (RFOFSO/FO). A free-space communication system is an alternative to optical fibers if it fails in performance or if it is difficult to propagate. This hybrid system is an effective solution for developing new generation networks, by transmitting the optical signal over long distances within the C-band, and L-band. The proposed system sends the radio frequency signal through the optical free-space link then extends to 80 km of optical fiber, of which 40 km is amplified by the Raman/EDFA hybrid optical amplifier. This paper aims to test the performance of the free space optic link under different weather conditions. The atmospheric attenuation, which reduces visibility, was considered as the main challenge. Several copies were sent in different paths in FSO to meet this challenge. The submitted system was implemented in the case of transmission in a wavelength within the C-band and also in L-band. The results of the hybrid system were compared by measuring the bit error rate (BER) and Q-factor under dust and fog conditions relative to Kim’s standard model by using Optisystem. The results obtained showed an effective sensation at a long haul, inn addition to not using an additional light source when transmitting for such long distances.

In this paper hierarchical method of loadbalancing routing in MPLS network. Method identified tasks of two hierarchical levels: realization of source routing (lower level) and prevention of link overload in MPLS-network (upper level). Method oriented on procuring of Load-Balancing Routing in MPLS-network on principles of conceptions of Traffic Engineering. Modification of conditions of load balancing of links allows to reduce number of coordination iterations about 2 to 5 times which in practice will lead to a proportional decrease in the amount of service information circulating in the network associated with the implementation of hierarchical routing, as well as to increase the efficiency of network management in general.

In this paper the approach of the scalability improvement of the hierarchical queue management solutions on telecommunication network routers interfaces is presented. Decision is based on usage of hierarchical goal coordination method, in which was proposed usage of the quadratic optimality criterion. It allows ensuring a more balanced queues load that helped to reduce the number of coordination iterations introduced to prevent interface overloading.

In the research the load balancing routing model in Time-Sensitive Networks is proposed. The novelty of the solution is a type of optimality criterion, the use of which minimizes the circuit delays. The proposed solution is compromise in terms of computational implementation as compared to the previously known models, in which the equality of the circuit delays of packets were considered as limitations, rather than optimality criterion.

The paper presents the flow-based queue management model on telecommunication networks routers based on optimal flow aggregation and packets distribution in queues. The novelty of the model is that with flows distribution in queues it is carried out its aggregation based on flows and queues classes comparison within the analysis of the set of classification indicators.