Capacity planning of link restorable optical networks under dynamic change of traffic

Author(s):  
Kwok Shing Ho ◽  
Kwok Wai Cheung
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ashutosh Kumar Singh ◽  
Vanya Arun ◽  
Pallavi Singh ◽  
Kamal Kishore Upadhayay

AbstractAs technology advancing day by day, the data rate of optical network is moving towards Tb/s speed. The minimum capacity utilization and survivability are the crucial requirement in such high speed optical networks. This research work presents a new approach to calculate both working and spare capacity with the help of single mathematical programming model named as joint capacity planning model. The working traffic and restored traffic are routed jointly in proposed joint capacity planning model. Therefore the joint capacity planning model required minimum capacity in as compare to other optimization models. To evaluate our model, three example networks are proposed i.e., network A (6 node), network B (8 node) & National science foundation network (14 node). Results of these networks are analyzed and compared. The capacity utilization is optimized by increasing the backup paths of the optical networks. It has also been proved in this manuscript that capacity requirement is dependent on the backup path. The proposed joint capacity model provides fast restoration speed and guaranteed protection for optical network.


2014 ◽  
Vol 52 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Ori Gerstel ◽  
Clarence Filsfils ◽  
Thomas Telkamp ◽  
Matthias Gunkel ◽  
Martin Horneffer ◽  
...  

Respuestas ◽  
2015 ◽  
Vol 20 (2) ◽  
pp. 6 ◽  
Author(s):  
Jhon James Granada-Torres ◽  
Ana María Cárdenas-Soto ◽  
Neil Guerrero-González

ResumenEl tráfico en las redes de datos por fibra óptica ha tenido un crecimiento exponencial debido a la creciente demanda de información por parte de los usuarios finales, llevando a una saturación en la capacidad de las redes actuales. Proyectando los sistemas de transmisiones ópticos a tasas superiores a los 400 Gbps para redes de largo alcance, no será posible mantener la tecnología WDM de rejilla espectral fija de 50 GHz, la cual permite transmitir en la actualidad tasas hasta los 100 Gbps. Teniendo como limitación además del ancho espectral que ocuparía la información, la conmutación de los dispositivos para trabajar a altas frecuencias. En este contexto, surge el concepto de las redes ópticas elásticas, donde se emplea una rejilla de espectro flexible (flexi-grid) o sin rejilla (grid-less), con ancho espectral variable por canal según la demanda de ancho de banda, permitiendo una separación espectral flexible entre canales con el propósito de optimizar la eficiencia en el uso del espectro. Este artículo hace una revisión de los nuevos conceptos tecnológicos que conllevan el escenario de redes elásticas, y los posibles retos y limitaciones para el desarrollo de estas tecnologías. Recientes pruebas experimentales incorporan nuevos conceptos tecnológicos con relación a los ya comerciales sistemas de 100-G como: el diseño de transmisores multicanales, el uso de tecnologías como Nyquist-WDM y OFDM óptico flexible, receptores digitales coherentes reconfigurables, formatos de modulación m-arios e híbridos y asignación dinámica del espectro. No obstante, grandes limitantes como los efectos no lineales de la fibra óptica deben ser foco de investigación en este nuevo escenario, debido a sus efectos en la degradación de la señal. Finalmente, se muestra como las técnicas de procesamiento digital de señales desempeñarán un papel importante para lograr la reconfigurabilidad y elasticidad de las redes de alta capacidad.AbstractIn the last years, traffic on data optical networks has had an exponential growth due to the increasing demand of information by end users. This had lead to saturation of the current deployed networks in terms of capacity. Planning the optical transmission systems of long-reach to work with capacities above 400 Gbps, it will not be possible to keep the spectral fixed-grid of the WDM technology, which currently allows transmitting up to 100 Gbps. The principal limitation is due to the greater spectral bandwidth occupied by the data information and also due to the switching of electronics devices at high frequencies. In this context a new concept known as elastic optical network emerges, which proposes a flexible-grid or gridless, where the spectral width changes according to the bandwidth demand and allows optimizing the spectral efficiency with a minimum separation between adjacent channels. In this paper, we present a comprehensive survey of elastic optical networks, introducing new concepts and describing the challenges and the limitations in these networks. Recent experimental reports show new technological concepts related to the commercials 100-G systems such as: design of multichannels transmitters, gridless Nyquist-WDM and Optical-OFDM, reconfigurable digital coherent receivers, optical dynamic spectrum allocation and advanced modulation formats. Nevertheless, the nonlinearity effects of the optical fiber are a significant limitation that must be researched in detail in this new elastic scenario. Hence, it is shown how the digital signal processing techniques are going to play an important role in order to get high capacity in elastic and reconfigurable networksPalabras clave: Comunicaciones por Fibra Óptica, Enrutamiento, Interferencia Intercanal (ICI), Multiplexación por División de Longitud de Onda, Óptica No-Lineal, Procesamiento Digital de Señales (DSP), Redes Ópticas.


2013 ◽  
Vol E96.B (7) ◽  
pp. 1845-1856
Author(s):  
Xin WANG ◽  
Filippos BALASIS ◽  
Sugang XU ◽  
Yoshiaki TANAKA

2020 ◽  
Vol 28 (3) ◽  
pp. 323-333
Author(s):  
Sergej V. Ivanov ◽  
Ilya S. Ivanov ◽  
Evgenij G. Obyedkov ◽  
Liliya P. Popova

Aim. To study the influence of deproteinized dialysate from blood of milk-fed calves on the type of exudative discharge and dynamics of inflammatory reaction after hernia repair with plastics of the anterior abdominal wall with hernioendoprosthesis of polypropylene. Materials and Methods. The study involved 59 patients being on stationary treatment in the surgical department of Kursk Regional Clinical Hospital. Patients were hospitalized for the herniation of small or medium dimension. The patients were divided to two groups: the main (n=30) and control (n=29) groups. After endoprosthetics, the patients of the control group were given complex conservative treatment. The patients of the main group, besides standard treatment, were administered deproteinized dialysate from blood of milk-fed calves intravenously in drips 10 ml + 200 ml of 0.9% sodium chloride solution within 7 days. For cytological examination and determination of the type of cytograms, the traumatic discharge was collected and analyzed using the method of M.F. Kamaev and M.A. Palthsev. Results. Cytomorphometric examination was conducted on the third, fifth and seventh day after endoprosthetics with the aim of studying dynamic changes. Determination of cell composition and also of its changes characteristic of each studied period, was necessary for obtaining further information characterizing inflammatory process in the region of placement of the endoprosthesis. After endoprosthetics in patients who were administered hemodialysate, the inflammatory reaction was less pronounced than in patients who did not receive the preparation. This was associated with a more dynamic change of stages of the inflammatory process. In patients of the main group who received deproteinized dialysate, regenerative type of inflammation first appeared on the fifth day and made 6.9%; by the seventh day the share of patients with the regenerative type rose to 17.5%, while in the patients of the control group no regeneration stage was observed in both periods. Conclusion. Analysis of the efficiency of influence of hemodialysate on the inflammatory reaction in plastics of the anterior abdominal wall with polypropylene endoprosthesis evidences faster course of all stages of inflammation and reduction of its intensity by 10%.


Author(s):  
Rajbir Singh

Optical networks are bandwidth efficient networks are used for long haul communication providing seamless data transfer. For high speed data transmission in open space between different satellites, Inter-satellite Optical wireless communication (IsOWC) is widely used .In this paper we have evaluated the performance of IsOWC communication link for high speed data transmission .The performance of the system is evaluated on the basis of qualitative parameters such as Q-factor and BER using optisystem simulator.


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