Available Online at www.ijcsmc.com International Journal of Computer Science and Mobile Computing A Monthly Journal of Computer Science and Information Technology ISSN 2320 088X IMPACT FACTOR: 6.017 IJCSMC, Vol. 8, Issue. 4, April 2019, pg.35 50 Design and Simulation of Fiber to the Home (FTTH) Network Saed Thuneibat Department of Electrical Engineering, Al-Balqa Applied University, Jordan Saed1970@bau.edu.jo Abstract: In this paper, we study and analysis Fiber To The Home network. This system will replace the ADSL technology in providing Internet to home users. We discuss the line coding techniques in optical digital communication system.we simulate the FTTH and compare between line codes to choose the suitable line code for the Jordanian FTTH. Keywords: Optical network, FTTH, Line Code, Simulation. I. INTRODUCTION FTTH is the delivery of a communication services by sending pulses of light through an optical fiber link from the Internet service provider to a home, thereby replacing existing copper infrastructure such as ADSL based on telephone wires and CATV based on coaxial cable. FTTH is fast growing method of providing optical THz bandwidth to consumers. Many telecommunication companies in Jordan use optical fiber to transmit Internet communication signals via FTTH. Different research papers on FTTH network design and implementation are published [1]. To improve service reliability, efficiency and monitoring capabilities in FTTH-PON network, MATLAB based Online Central Fault Monitoring System (CFDS) is proposed [2]. A design and implementation of GPON based FTTH access network serving 1000 users, in order to validate the design, the power budgets analysis is performed [3]. An Optical CDMA (OCDMA) as a configuration solution for FTTH networks to improve the performance of network have been proposed [4]. In this paper we simulate FTTH with different parameters of input power, transmitter wavelength, data rate, distance, channel wavelength, modulation scheme, line encoding. For different types of filters, we developed the eye diagrams, BER analyzers and Quality factors that are used for the comparison between line codes, NRZ and RZ. 2019, IJCSMC All Rights Reserved 35
Section two presents digital optical communication system, FTTX and FTTH are introduced in the third section. Simulation system elements are defined in section 4. Simulation Results for NRZ and RZ encoding are discussed in section 5. II. DIGITAL OPTICAL COMMUNICATION SYSTEM Like all other communication systems, the primary objective of FTTH network is to provide an access to Internet and transfer the signal containing information (voice, data and video) from the source to the destination. The general block diagram of optical fiber communication system is shown in figure 1 [5]. Figure 1. Block diagram of optical communication system. The information source generates and provides an electrical signal to the transmitter. The electrical stage of the transmitter drives an optical source to produce modulated light wave carrier. Semiconductor LASERs or LEDs are usually used as optical sources. The information carrying light wave then passes through optical fiber cables in this system. Now it reaches to the receiver stage where the optical detector demodulates the optical carrier and gives an electrical output signal to the electrical stage. The common types of optical detectors used are pin and avalanche photodiodes. Finally, the electrical stage gets the real information back and gives it to the concerned destination. Figure 2 shows the major elements used in an optical fiber communication system. Additional components like optical amplifier, connectors, splices and couplers are also there. The regenerator section is a key part of the system as it amplifies and reshapes the distorted signals for long distance links. 2019, IJCSMC All Rights Reserved 36
Figure 2. Optical communication system [6]. In present days, for longer repeater spacing, the use of single mode fibers and LASERs seem to be essential whereas the earlier transmitters operated within 0.8µm to 0.9µm wavelength range, used double hetero structure LASER or LED as optical sources [7]. III. BLOCK DIAGRAM OF FTTX AND FTTH In this section we will show in figure 3 the difference between Fiber To The Neighborhood (FTTN), Fiber To The Curb (FTTC), Fiber To The Building (FTTB) and as well as, in figure 4, the block diagram of FTTH. Figure 3. FTTx optical network. 2019, IJCSMC All Rights Reserved 37
Figure 4. FTTH block diagram. IV. OPTICAL SIMULATION SYSTEM Under my superposition, my students: Mohammad Abu-Zubiedah and Manar Aljawarneh has developed a FTTH simulation system in their graduation project at AL-Huson university college, BAU, Jordan. We analyzed and compared RZ and NRZ encoding formats by varying different parameters using the designated system. In literature, such approach is performed by Mandeep Kaur and Gurpreet Bharti, where the system performance is evaluated in terms of eye diagram, BER, receiver sensitivity, and limitations on the fiber length. Duobinary modulation provides better results as compared to NRZ and RZ modulation format as the distance is crucial factor for measuring the system performance [8]. This is not the case of FTTH, where the distance is not large. The FTTH network is simulated using Optisystem which is a simulation system used for designing, testing and performance measuring the optical network by compensate minimum bit error and improve quality factor of the network [9], [10], [11]. 4.1 Elements of optical simulation tools Figure 5 shows the blocks that used in the transmission part of simulation system Figure 5. Transmission part blocks 2019, IJCSMC All Rights Reserved 38
Figure 6 and 7 shows the blocks that represent the transmission media Figure 6.Transmission media and Mux blocks Loop control replaces repetition of fiber spans and EDFA, for example if you are working on 10000 km long fiber link containing EDFA at each 1000 km then it is better to use loop control, you set loop control=10 giving 10*1000 where the signal pass 10 times from 1000 km fiber and one EDFA. Wave Division Multiplexer, that combine more than one optical frequency together. Figure 7.Transmission media blocks, amplifier and demux Wave Division Demultiplexer separates different optical wavelengths. Figure 8 shows the reception Part. 2019, IJCSMC All Rights Reserved 39
Figure 8. Reception Part blocks Figure 9 shows the electrical Visualizer elements. Figure 9. Electrical Visualizer elements Figure 10 shows Optical Visualizer elements. Figure 10. Optical Visualize elements 4.2 System specifications The modeled system has been configured for a specific set of parameters at the transmitter, channel as well as the receiver side. The parameters are selected either based on their type or mathematical value according to the simulation system requirements. The various parameters like input power of the transmitter, input wavelength, distance covered, type of amplifiers used, multiplexing scheme, are described for the proposed simulation set-up. The proposed system specifications have been summarized in Table 1. 2019, IJCSMC All Rights Reserved 40
Parameter TABLE 1. THE PROPOSED SYSTEM SPECIFICATIONS Value/Type Input power(in dbm) -16 to -20 Transmitter wavelength (in nm) 1552 to 1550 Data rate(in Gbps) 2.5 Distance(in kilometers) 100 Channelwavelength(in nm) 1550 Modulation scheme NRZ,RZ V. SIMULATION RESULTS AND DISCUSSIONS In this chapter, we provide the results of several runs of the designated optical communication simulation system. Discussion of these results is following each graph. 5.1 optical communication simulation system for NRZ encoding In figure 11, we show optical communication simulation system for 100 kilometers using NRZ encoding format. Figure 11. optical communication simulation system with NRZ encoding In this section we see results of BER analyzer; quality factor, min BER, threshold and eye height for different types of filters. Figure 12 shows eye diagram with Bessel filter. 2019, IJCSMC All Rights Reserved 41
Figure 12. Eye diagram with Bessel filter The above figure shows the eye diagram for an input power of -19.1dBm at 100 kilometers using NRZ modulation format. Figure 13 shows the results of BER analyzer. Figure 13. BER analyzer Figure (a) shows Quality factor as 5.97, figure (b) shows Min BER as 1.13e-9, figure (c) shows threshold as 4.81e-6 and figure (d) shows eye height as 6.18e-6. Figure 14 shows eye diagram with low pass Gaussian filter. 2019, IJCSMC All Rights Reserved 42
Figure 14.Eye diagramwith low pass Gaussian filter The above figure shows the eye diagram for an input power of -18.4dBm at 100 kilometers using NRZ modulation format. Figure 15 shows the results of BER analyzer. Figure 15. BER analyzer Figure (a) shows Quality factor as 5.92, figure (b) shows Min BER as 1.53e-9, figure (c) shows threshold as 5.54e-6 and figure (d) shows eye height as 7.005e-6. Figure 16 shows eye diagram with low pass Rectangle filter. 2019, IJCSMC All Rights Reserved 43
Figure 16.Eye diagram low pass Rectangle filter The previous figure shows the eye diagram for an input power of -16 dbm at 100 kilometers using NRZ modulation format. Figure 17 shows the results of BER analyzer. Figure 17. BER analyzer Figure (a) shows Quality factor as 5.89, figure (b) shows Min BER as 1.80e-9, figure (c) shows threshold as 1.01e-5 and figure (d) shows eye height as 1.32e-5. Figure 18 shows eye diagram with low pass Butterworth filter. 2019, IJCSMC All Rights Reserved 44
Figure 18. Eye diagram The above figure shows the eye diagram for an input power of -17.7 dbm at 100 kilometers using NRZ encoding format. Figure 19 shows the results of BER analyzer. Figure 19. BER analyzer Figure (a) shows Quality factor as 5.95, figure (b) shows Min BER as 1.24e-9, figure (c) shows threshold as 6.20e-6 and figure (d) shows eye height as 8.14e-6. 2019, IJCSMC All Rights Reserved 45
5.2 optical communication simulation system for NRZ encoding The following figure 20 shows optical communication system for 100 kilometers using RZ encoding format. Figure 20 optical communication simulation system for RZ encoding In this section we see.results of BER analyzer; quality factor, min BER, threshold and eye height for different types of filters. Figure 21 shows eye diagram with low pass Bessel filter. Figure 21.Eye diagramwith low pass Bessel filter The previous figure shows the eye diagram for an input power of -16.6 dbm at 100 kilometers using RZ modulation format. Figure 22 shows the results of BER analyzer. 2019, IJCSMC All Rights Reserved 46
Figure 22. BER analyzer Figure (a) shows Quality factor as 5.90, figure (b) shows Min BER as 1.55e-9, figure (c) shows threshold as 4.49e-6 and figure (d) shows eye height as 7.05e-6. Figure 23 shows eye diagram with low pass Gaussian filter. Figure 23.Eye diagramwith low pass Gaussian filter The previous figure shows the eye diagram for an input power of -17.3 dbm at 100 kilometers using RZ modulation format. Figure 24 shows the results of BER analyzer. 2019, IJCSMC All Rights Reserved 47
Figure 24. BER analyzer Figure (a) shows Quality factor as 5.93, figure (b) shows Min BER as 1.39e-9, figure (c) shows threshold as 4.34e-6 and figure (d) shows eye height as 6.27e-6. Figure 25 shows eye diagram with low pass Butterworth filter. Figure 25.Eye diagramwith low pass Butterworth filter. The previous figure shows the eye diagram for an input power of -16 dbm at 100 kilometers using RZ modulation format. Figure 26 shows the results of BER analyzer. 2019, IJCSMC All Rights Reserved 48
Figure 26. BER analyzer Figure (a) shows Quality factor as 5.95, figure (b) shows Min BER as 1.22e-9, figure (c) shows threshold is 5.71e-6 and figure (d) shows eye height as 8.98e-6. VI. CONCLUSION In this paper, we simulated FTTH system using NRZ, RZ encoding formats. We found that the NRZ provides better simulation results in the quality factor, Min BER, threshold and eye height. From the simulation of three filter types we found that the quality factor for low pass Bessel filter is higher. It is upon to the designer of optical communication system in choosing the required parameters. REFERENCES [1] Dheyaa Jasim Kadhim, Nahla Abdul-Rahman Hussain, Design and Implementation of a Practical FTTH Network International Journal of Computer Applications (0975 8887) Volume 72 No.12, June 2013, pp. 50-56. [2] T.Venkateswarlu, R. Renuka, Design of Fiber to the Home (FTTH) Access Network and Implementing Online Monitoring to Increase Efficiency, International Journal of Innovative Research in Computer and Communication Engineering, Vol. 5, Issue 2, February 2017, pp. 2338-2346. [3] Mahmoud M. Al-Quzwini, Design and Implementation of a Fiber to the Home FTTH Access Network based on GPON, International Journal of Computer Applications (0975 8887) Volume 92 No.6, April 2014, pp. 30-42. [4] Bouregaa Mouweffeq, Chikh-Bled Mohammed El Kebir etc., Optical Code Division Multiple Access for a FTTH system, PHOTONICS LETTERS OF POLAND, VOL.10 (4), 2018, pp. 121-123 [5] Hecht J, Long L, Understanding fiber optics, Prentice Hall, 1993 [6] Gerd Keiser Optical fiber communications 3rd edition. [7] B. Voisiat, et al. "Laser processing for precise fabrication of the THz optics", Proc. SPIE vol. 10091, LAMOM XXII; 100910F (2017); 2019, IJCSMC All Rights Reserved 49
[8] Mandeep Kaur, Er. Gurpreet Bharti, Performance Analysis of Optical Fiber Communication Systems For NRZ, RZ and Duobinary Formats, International Journal of Advanced Engineering Research and Science (IJAERS), Vol-1, Issue-5, Oct.- 2014, pp. 81-84. [9] W Awalia, A B Pantjawati, Performance Simulation of Fiber to the Home (FTTH) Devices Based on Optisystem, International Symposium on Materials and Electrical Engineering 2017, IOP Conf. Series: Materials Science and Engineering 384 (2018) 012051 doi:10.1088/1757-899x/384/1/012051. [10] Wang Y and Guan Y, Performance simulations for a high-speed optical transmission system based on Optisystem Image and Signal Processing, 7th International Congress 4 Oct 14, pp. 907-911. [11] Verma S, Kakati A and Bhulania P, Performance analysis of Q-factor and polarization for GPON network using Optisystem, Information Technology-The Next Generation IT Summit on the Theme- Internet of Things: Oct 6, pp. 138-141. 2019, IJCSMC All Rights Reserved 50