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Free Space Optical Networks: Applications, Challenges and Research Directions

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Abstract

Free Space Optics (FSO) is an optical communication technique which disseminates light in free space such as air, vacuum or celestial space, to wirelessly transfer data. FSO communication offers high data rates up to 2.5 Gbps over a range of 100 m to a few kilometers and has the potential to replace the traditional means of communications in a wide variety of applications. Despite advantages such as high bandwidth and unlicensed spectrum, its widespread use has been inhibited by factors including interference and atmospheric turbulences. Many of these challenges have been addressed by researchers who have proposed modulation techniques, channel coding, diversity, hybrid systems and physical implementation of hardware. There is a need for a comprehensive review of contemporary research in FSO in order to examine the significant contributions and to identify open challenges and potential directions for future research endeavors. This paper presents a state-of-the-art review of the use of FSO in important indoor and outdoor applications and identifies some of the open research problems. We indicate the following open research problems: (a) the future FSO systems would offer both illumination and communication which necessitates modulation and coding techniques for a better dimming control along with efficient data communication, (b) security threats at the physical layer are a major concern to be addressed, (c) FSO transceiver design for future 5G systems faces a challenge of optimizing bit-error-rate and signal-to-noise ratio at the receiver, and (d) cost-effective hybrid RF/FSO solutions are needed to combine the benefits of RF and FSO.

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References

  1. Huurdeman, A. A. (2003). The worldwide history of telecommunications. New York: Wiley.

    Book  Google Scholar 

  2. Groth, M. (2005, April 7). Photophones revisited. Retrieved June 8, 2019, from http://www.bluehaze.com.au/modlight/GrothArticle1.htm.

  3. Begley, D. L. (2002). Free-space laser communications: A historical perspective. In 15th annual meeting of the IEEE lasers and electro-optics society (LEOS) (pp. 391–392). IEEE.

  4. Ciaramella, E., Arimoto, Y., Contestabile, G., Presi, M., D’Errico, A., Guarino, V., & Matsumoto, M. (2009). 1.28 terabit/s (32 × 40 gbit/s) WDM transmission system for free space optical communications. IEEE Journal on Selected Areas in Communications, 27(9), 1639–1645. https://doi.org/10.1109/JSAC.2009.091213.

    Article  Google Scholar 

  5. Messier, D. (2016). DLR Researchers Set World Record in Freespace Optical Communications. Retrieved July 10, 2019, from http://www.parabolicarc.com/2016/11/05/dlrresearchers-set-world-record-freespace-optical-communications/.

  6. Schutz, A. (2018). DLR and ADVA set a new world record in optical free-space data transmission. Retrieved July 10, 2019, from https://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10989/1769_read-27323/#/gallery/30516.

  7. IEEE Standard for Local and Metropolitan Area Networks–Part 15.7: Short-Range Wireless Optical Communication Using Visible Light. In IEEE Std. 802.15.7, (pp. 1-309) (2011).

  8. IEEE Approved Draft Standard for Short-Range Wireless Optical Communication Using Visible Light.  In IEEE P802.15.7/D8 (pp.1-306) (2011).

  9. Roberts, R., Rajagopal, S., & Lim, S. K. (2011). IEEE 802.15.7 physical layer summary. In IEEE GLOBECOM Workshops, (GLOBECOM) (pp. 772–776). IEEE.

  10. Pathak, P., Feng, X., Hu, P., & Mohapatra, P. (2015). Visible light communication, networking, and sensing: A survey, potential and challenges. IEEE Communications Surveys & Tutorials, 17(4), 343–345. https://doi.org/10.1109/COMST.2015.2476474.

    Article  Google Scholar 

  11. Le, N. T., & Jang, Y. M. (2013). Broadcasting MAC protocol for IEEE 802.15.7 visible light communication. In Fifth international conference on ubiquitous and future networks (ICUFN) (pp. 667–671). KICS.

  12. pureLiFi. (2015). Retrieved July 20, 2019, from https://purelifi.com/company/#history.

  13. Cuthbertson, A. (2018). LiFi Internet breakthrough: 224 Gbps connection broadcast with an LED bulb. Retrieved July 31, 2019, from http://www.ibtimes.co.uk/lifi-internetbreakthrough-224gbps-connection-broadcast-led-bulb-1488204.

  14. Azhar, A. H., Tran, T. A., & O’Brien, D. (2013). A Gigabit/s indoor wireless transmission using MIMO-OFDM visible-light communications. IEEE Photonics Technology Letters, 25(2), 171–174. https://doi.org/10.1109/LPT.2012.2231857.

    Article  Google Scholar 

  15. Khalid, A. M., Cossu, G., Corsini, R., Choudhury, P., & Ciaramella, E. (2012). 1-Gb/s transmission over a phosphorescent white LED by using rate-adaptive discrete multitone modulation. IEEE Photonics Journal, 4(5), 1465–1473. https://doi.org/10.1109/JPHOT.2012.2210397.

    Article  Google Scholar 

  16. Cossu, G., Khalid, A. M., Choudhury, P., Corsini, R., & Ciaramella, E. (2012). 3.4 Gbit/s visible optical wireless transmission based on RGB LED. Optics Express, 20(26), B501–B506. https://doi.org/10.1364/OE.20.00B501.

    Article  Google Scholar 

  17. Tsonev, D., Videv, S., & Hass, H. (2014). Light fidelity (Li-Fi): Towards all-optical networking. In Proceedings of the International Society for Optical Engineering, (SPIE) vol. 900702. SPIE.

  18. Zeng, Z., Soltani, M. D., Wang, Y., Wu, X., & Haas, H. (2020). Realistic indoor hybrid WiFi and OFDMA-based LiFi networks. IEEE Transactions on Communications, 68, 2978–2991. https://doi.org/10.1109/TCOMM.2020.2974458.

    Article  Google Scholar 

  19. Ullah, S., Rehman, S. U., & Chong, P. H. J. (2021). A comprehensive open-source simulation framework for LiFi communication. Sensors (Basel, Switzerland), 21(7), 2485. https://doi.org/10.3390/s21072485.

    Article  Google Scholar 

  20. Ng, X. W., & Chung, W. Y. (2012). VLC-based medical healthcare information system. Biomedical Engineering: Applications, Basis and Communications, 24(2), 155–163. https://doi.org/10.4015/S1016237212500123.

    Article  Google Scholar 

  21. Khalid, H., Waris, F., & Asif, H. M. (2018). Design of an integrated power line communication (PLC)-visible light communication (VLC) system for data communication. Lasers in Engineering, 40(1–3), 107–125.

    Google Scholar 

  22. Komine, T., & Nakagawa, M. (2003). Integrated system of white LED visible light communication and power-line communication. IEEE Transactions on Consumer Electronics, 49(1), 71–79. https://doi.org/10.1109/TCE.2003.1205458.

    Article  Google Scholar 

  23. Murai, R., Sakai, T., Kawano, H., Matsukawa, Y., Honda, Y., & Campbell, K. (2012). A novel visible light communication system for enhanced control of autonomous delivery robots in a hospital. In Proceedings of the IEEE/SICE International Symposium on System Integration (SII) (pp. 510–516).

  24. Lv, H., Feng, L., Yang, A., Guo, P., Huang, H., & Chen, S. (2017). High accuracy VLC indoor positioning system with differential detection. IEEE Photonics Journal, 9(3), Art no. 7903713. https://doi.org/10.1109/JPHOT.2017.2698240.

  25. Ganti, D., Zhang, W., & Kaverhrad, M. (2014). VLC-based indoor positioning system with tracking capability using Kalman and particle filters. In Proceedings of IEEE international conference on consumer electronics (ICCE) (pp. 476–477). IEEE.

  26. Yasir, M., Ho, S. W., & Vellambi, B. N. (2014). Indoor positioning system using visible light and accelerometer. Journal of Lightwave Technology, 32(19), 3306–3316. https://doi.org/10.1109/JLT.2014.2344772.

    Article  Google Scholar 

  27. Perez-Jimenez, R., Rufo, J., Quintana, C., Rabadan, J., & LopezHernandez, F. J. (2011). Visible light communication systems for passenger in-flight data networking. In IEEE International Conference on Consumer Electronics (ICCE) (pp. 445–446). IEEE.

  28. Sui, M., Xia, Z., Zhu, W., Shen, J., & Chen, J. (2015). A visible light communication based aircraft cabin wireless network demo system. In Asia communications and photonics conference (ACP) (paper AM1E.1).

  29. Brazda, V., Fiser, O., Pek, V., Pesice, P., & Schejbal, V. (2014). Meteorological measurement of atmospheric turbulence and FSO link attenuation - preliminary results. In The 8th European conference on antennas and propagation (EuCAP) (pp. 1046–1048).

  30. Pernice, R., Ando, A., Cardinale, M., Curcio, L., Stivala, S., & Parisi, A. (2015). Indoor free space optics link under the weak turbulence regime: Measurements and model validation. IET Communications, 9(1), 62–70. https://doi.org/10.1049/iet-com.2014.0432.

    Article  Google Scholar 

  31. Vavoulas, A., Sandalidis, H. G., & Varoutas, D. (2012). Weather effects on FSO network connectivity. Journal of Optical Communications and Networking, 4(10), 734–740. https://doi.org/10.1364/JOCN.4.000734.

    Article  Google Scholar 

  32. Shaikh, M. N., Waqas, A., Chowdhry, B. S., & Umrani, F. A. (2012). Performance and analysis of FSO link availability under different weather conditions in Pakistan. New Horizons Journal of the Institution of Electrical & Electronics Engineers Pakistan, 76, 3–8.

    Google Scholar 

  33. Sheikh, M. S., Kohldorfer, P., & Leitgeb, E. (2005). Channel modeling for terrestrial free space optical links. In Proceedings of 7th IEEE international conference on transparent optical networks (ICTON) (pp. 407–410). IEEE.

  34. Navidpour, S. M., Uysal, M., & Kavehrad, M. (2007). BER performance of free-space optical transmission with spatial diversity. IEEE Transactions on Wireless Communications, 6(8), 2813–2819. https://doi.org/10.1109/TWC.2007.06109.

    Article  Google Scholar 

  35. Moradi, H., Falahpour, M., Refai, H. H., LoPresti, P. G., & Atiquzzaman, M. (2010). On the capacity of hybrid FSO/RF links. In IEEE global telecommunications conference (GLOBECOM) (pp. 1–5). IEEE.

  36. Usman, M., Yang, H. C., & Alouini, M. S. (2014). Practical switching-based hybrid FSO/RF transmission and its performance analysis. IEEE Photonics Journal, 6(5), 1–13. https://doi.org/10.1109/JPHOT.2014.2352629.

    Article  Google Scholar 

  37. Rakia, T., Yang, H. C., Alouini, M. S., & Gebali, F. (2015). Outage analysis of practical FSO/RF hybrid system with adaptive combining. IEEE Communication Letters, 19(8), 1366–1369. https://doi.org/10.1109/LCOMM.2015.2443771.

    Article  Google Scholar 

  38. Makki, B., Svensson, T., Pearce, M. B., & Alouini, M. S. (2017). Performance analysis of RF-FSO multi-hop networks. In IEEE wireless communications and networking conference (WCNC) (pp. 1–6). IEEE.

  39. Chowdhury, M. Z., Hasan, M. K., Shahjalal, M., Hossan, M. T., & Jang, Y. M. (2020). Optical wireless hybrid networks: Trends, opportunities, challenges, and research directions. IEEE Communications Surveys & Tutorials, 22(2), 930–966. https://doi.org/10.1109/COMST.2020.2966855.

    Article  Google Scholar 

  40. Vehicle Safety Communications Consortium. Vehicle safety communications project: Task 3 final report: identify intelligent vehicle safety applications enabled by DSRC (2005, July). Retrieved August 5, 2019 from https://trid.trb.org/view/757708.

  41. Shen, W. H., & Tsai, H. M. (2017). Testing vehicle-to-vehicle visible light communications in real-world driving scenarios. In IEEE vehicular networking conference (VNC) (pp. 187–194). IEEE.

  42. Marabissi, D., Mucchi, L., Caputo, S., Nizzi, F., Pecorella, T., Fantacci, R., Nawaz, T., Seminara, M., & Catani, J. (2020). Experimental measurements of a joint 5G-VLC communication for future vehicular networks. Journal of Sensor and Actuator Networks, 9(3), 32. https://doi.org/10.3390/jsan9030032.

    Article  Google Scholar 

  43. Iwasaki, S., Premachandra, C., Endo, T., Fujii, T., Tanimoto, M., & Kimura, Y. (2008). Visible light road-to-vehicle communication using highspeed camera. In Proceedings of IEEE intelligent vehicles symposium (IV’08) (pp. 13–18). IEEE.

  44. Chow, R., & Tsai, H. M. (2018). Securing the visual channel: How my car saw the light and stopped learning. In 52nd annual conference on information sciences and systems (CISS) (pp. 1–6). IEEE.

  45. Ndjiongue, A. R., & Ferreira, H. C. (2018). An overview of outdoor visible light communications. Transactions on Emerging Telecommunications Technologies, 29(7), 1–13. https://doi.org/10.1002/ett.3448.

    Article  Google Scholar 

  46. Wang, Z., Tsonev, D., Videv, S., & Haas, H. (2015). On the design of a solar-panel receiver for optical wireless communications with simultaneous energy harvesting. IEEE Journal on Selected Areas in Communications, 33(8), 1612–1623. https://doi.org/10.1109/JSAC.2015.2391811.

    Article  Google Scholar 

  47. Keller, J. (2010). Aircraft optical communications networking using free-space lasers to be demonstrated by AOptix for DARPA. Retrieved August 6, 2019 from https://www.militaryaerospace.com/articles/2010/12/aircraft-optical-communications.html.

  48. Fletcher, G. D., Hicks, T. R., & Laurent, B. (1991). The SILEX optical interorbit link experiment. Electronics & Communication Engineering Journal, 3(6), 273–279. https://doi.org/10.1049/ecej:19910045.

    Article  Google Scholar 

  49. Baister, G., Kudielka, K., Dreischer, T., & Tüchler, M. (2009). Results from the DOLCE (Deep Space Optical Link Communications Experiment) project. In Proceedings of SPIE, free-space laser communication technologies XXI, vol. 7199. SPIE.

  50. Sodnik, Z., Lutz, H., Furch, B., & Meyer, R. (2010). Optical satellite communications in Europe. In Proceedings of SPIE, free space laser communication technologies XXII, vol. 7587. SPIE.

  51. Pribil, K., & Flemmig, J. (1994). Solid state laser communications in space (SOLACOS) high data rate satellite communication system verification program. In Proceedings of SPIE, space instrumentation and spacecraft optics, vol. 2210(39). SPIE.

  52. Perlot, N., Knapek, M., Giggenbach, D., Horwath, J., Brechtelsbauer, M., Takayama, Y., & Jono, T. (2007). Results of the optical downlink experiment KIODO from OICETS satellite to optical ground station oberpfaffenhofen (OGS-OP). In Proceedings of SPIE, free-space laser communication technologies XIX and atmospheric propagation of electromagnetic waves, vol. 6457, (pp. 645704-1-645704–8). SPIE.

  53. Nakamaru, K., Kondo, K., Katagi, T., Kitahara, H., & Tanaka, M. (1989). An overview of Japan’s Engineering Test Satellite VI (ETS-VI) project. In Proceedings of IEEE communications, international conference on communications, world prosperity through communications (ICC) (pp. 1582 – 1586). IEEE.

  54. Dreischer, T., Tuechler, M., Weigel, T., Baister, G., Regnier, P., Sembely, X., & Panzeca, R. (2009). Integrated RF-optical TT & C for a deep space mission. Acta Astronautica, 65(11), 1772–1782. https://doi.org/10.1016/j.actaastro.2009.05.006.

    Article  Google Scholar 

  55. Wilson, K. E., & Lesh, J. R. (1993, August 15). An overview of galileo optical experiment (GOPEX). The telecommunications and data acquisition report, Communication Systems Research Section, NASA. Retrieved August 15, 2019, from https://ntrs.nasa.gov/citations/19940009913.

  56. Boroson, D. M., Biswas, A., & Edward, B. L. (2004). MLCD: Overview of NASA’s mars laser communications demonstration system. In Proceedings of SPIE, free space laser communication technologies XVI, vol. 5338. SPIE.

  57. Rausch, C. (2012, September 12). GA-ASI and TESAT partner to develop RPA-to-spacecraft lasercom link. Retrieved September 5, 2019, from https://www.ga-asi.com/ga-asi-and-tesat-partner-to-develop-rpa-to-spacecraft-lasercom-link.

  58. Cazaubiel, V., Planche, G., Chorvalli, V., Hors, L., Roy, B., Giraud, E., Vaillon, L., Carré, F., & Decourbey, E. (2006). LOLA: A 40,000 km optical link between an aircraft and a geostationary satellite. In Proceedings of international conference on space optics (ESA/CNES ICSO) (pp. 87.1–87.6). SPIE.

  59. Padhy, J. B., & Patnaik, B. (2019). 100 Gbps multiplexed inter-satellite optical wireless communication system. Optical and Quantum Electronics, 51, 213. https://doi.org/10.1007/s11082-019-1932-7.

    Article  Google Scholar 

  60. Nguyen, N. D., Pham, H. T. T., Mai, V. V., & Dang, N. T. (2020). Comprehensive performance analysis of satellite-to-ground FSO/QKD systems using key retransmission. Optical Engineering, 59(12), 126102–126101. https://doi.org/10.1117/1.OE.59.12.126102.

    Article  Google Scholar 

  61. Simpson, J. A., Hughes, B. L., & Muth, J. (2012). Smart transmitters and receivers for underwater free-space optical communication. IEEE Journal on Selected Areas in Communications, 30(5), 964–974. https://doi.org/10.1109/JSAC.2012.120611.

    Article  Google Scholar 

  62. Muth, J. (2017, May 10) Free-space optical communications: Building a ‘deeper’ understanding of underwater optical communications. Retrieved September 10, 2019 from https://www.laserfocusworld.com/articles/print/volume-53/issue-05/features/free-space-optical-communications-building-a-deeper-understanding-of-underwater-optical-communications.html.

  63. Doniec, M., Angermann, M., & Rus, D. (2013). An end-to-end signal strength model for underwater optical communications. IEEE Journal of Oceanic Engineering, 38(4), 743–757. https://doi.org/10.1109/JOE.2013.2278932.

    Article  Google Scholar 

  64. Peppas, K. P., Boucouvalas, A. C., & Ghassemloy, Z. (2017). Performance of underwater optical wireless communication with multi-pulse pulse-position modulation receivers and spatial diversity. IET Optoelectronics, 11(5), 180–185. https://doi.org/10.1049/iet-opt.2016.0130.

    Article  Google Scholar 

  65. Vali, Z., Gholami, A., Michelson, D. G., Ghassemloy, Z., Omoomi, M., & Noori, H. (2017). Use of Gaussian beam divergence to compensate for misalignment of underwater wireless optical communication links. IET Optoelectronics, 11(5), 171–175. https://doi.org/10.1049/iet-opt.2016.0132.

    Article  Google Scholar 

  66. Oubei, H. M., Li, C., Park, K. H., Ng, T. K., Alouini, M. S., & Ooi, B. S. (2015). 2.3 Gbit/s underwater wireless optical communications using directly modulated 520 nm laser diode. Optical Express, 23(16), 20743–20748. https://doi.org/10.1364/OE.23.020743.

    Article  Google Scholar 

  67. Oubei, H. M., Duran, J. R., Janjua, B., Wang, H. Y., Tsai, C. T., Chi, Y. C., Ng, T. K., Kuo, H. C., He, J. H., Alouini, M. S., Lin, G. R., & Ooi, B. S. (2015). 4.8 Gbit/s 16-QAM-OFDM transmission based on compact 450-nm laser for underwater wireless optical communication. Optical Express, 23(18), 23302–23309. https://doi.org/10.1364/OE.23.023302.

    Article  Google Scholar 

  68. Huang, X. H., Li, C. Y., Lu, H. H., Su, C. W., Wu, Y. R., Wang, Z. H., & Chen, Y. N. (2018). 6-m/10-Gbps underwater wireless red-light laser transmission system. Optical Engineering, 57(6), 066110. https://doi.org/10.1117/1.OE.57.6.066110.

    Article  Google Scholar 

  69. Nasir, S., Celik, A., Al-Naffouri, T. Y., & Alouini, M. S. (2019). Underwater optical wireless communications, networking, and localization: A survey. Ad Hoc Networks, 94, 101935. https://doi.org/10.1016/j.adhoc.2019.101935.

    Article  Google Scholar 

  70. Nguyen, C. T., Nguyen, M. T., & Mai, V. V. (2020). Underwater optical wireless communication-based IoUT networks: MAC performance analysis and improvement. Optical Switching and Networking, 37(100570), 1–9. https://doi.org/10.1016/j.osn.2020.100570.

    Article  Google Scholar 

  71. Nguyen, C. T., Mai, V. V., & Nguyen, C. T. (2021). Probing packet retransmission scheme in underwater optical wireless communication with energy harvesting. IEEE access : practical innovations, open solutions, 9(1), 34287–34297. https://doi.org/10.1109/ACCESS.2021.3061647.

    Article  Google Scholar 

  72. Lee, S. H., Kwon, J. K., & Jung, S. Y. (2015). Modulation and coding for dimmable visible light communication. IEEE Communications Magazine, 53(2), 136–143. https://doi.org/10.1109/MCOM.2015.7045402.

    Article  Google Scholar 

  73. Zuo, Y., Zhang, Y. Y., Zhang, J., & Ruhan, C. (2018). Weight threshold check coding for dimmable indoor visible light communication systems. IEEE Photonics Journal, 10(3), 1–11. https://doi.org/10.1109/JPHOT.2018.2844858.

    Article  Google Scholar 

  74. Kim, S., & Jung, S. Y. (2013). Modified Reed-Muller coding scheme made from the bent function for dimmable visible light communications. IEEE Photonics Technology Letters, 25(1), 11–13. https://doi.org/10.1109/LPT.2012.2226210.

    Article  MathSciNet  Google Scholar 

  75. Thummaluri, U., Natarajn, L., & Kumar, A. (2019). MIMO codes for uniform illumination across space and time in VLC with dimming control. IEEE Photonics Journal, 11(3), 1–21. https://doi.org/10.1109/JPHOT.2019.2918063.

    Article  Google Scholar 

  76. Pathak, P. H., Feng, X., Hu, P., & Mohapatra, P. (2015). Visible light communication, networking and sensing: A survey, potential and challenges. IEEE Communications Surveys & Tutorials, 17(4), 2047–2077. https://doi.org/10.1109/COMST.2015.2476474.

    Article  Google Scholar 

  77. Arain, S., Shaikh, M. N., Waqas, A., Chowdhry, B. S., & Themistos, C. (2016). Performance analysis of advance modulation schemes for free-space optical networks. In Proceedings of 18th international conference on transparent optical networks (ICTON) (pp. 1–4). IEEE.

  78. Arain, S., Shaikh, M. N., Waqas, A., Ali, Q., Chowdhry, B. S., & Themistos, C. (2017). Comparative study and packet error rate analysis of advance modulation schemes for optical wireless communication networks. Wireless Personal Communications, 95(2), 593–606. https://doi.org/10.1007/s11277-016-3912-6.

    Article  Google Scholar 

  79. Wilkins, A., Veitch, J., & Lehman, B. (2010). LED lighting flicker and potential health concerns: IEEE standard par1789 update. In Proceedings of IEEE Energy Conversion Congress and Exposition (ECCE) (pp. 171–178). IEEE.

  80. Rajagopal, S., Roberts, R. D., & Lim, S. K. (2012). IEEE 802.15.7 visible light communication: Modulation schemes and dimming support. IEEE Communications Magazine, 50(3), 72–82. https://doi.org/10.1109/MCOM.2012.6163585.

    Article  Google Scholar 

  81. Rehman, S. U., Ullah, S., Chong, P. H. J., Yongchareon, S., & Komosny, D. (2019). Visible light communication: A system perspective—overview and challenges. Sensors (Basel, Switzerland), 19(5), 1153. https://doi.org/10.3390/s19051153.

    Article  Google Scholar 

  82. Mejia, C. E., Georghiades, C. N., Abdallah, M. M., & Albadarneh, Y. (2017). Code design for flicker mitigation in visible light communications using finite state machines. IEEE Transactions on Communications, 65(5), 2091–2100. https://doi.org/10.1109/TCOMM.2017.2657518.

    Article  Google Scholar 

  83. Yang, Y., Wang, C., Feng, C., Guo, C., Cheng, J., & Zeng, Z. (2021). A generalized dimming control scheme for visible light communications. IEEE Transactions on Communications, 69(3), 1845–1857. https://doi.org/10.1109/TCOMM.2021.3051692.

    Article  Google Scholar 

  84. Obeed, M., Salhab, A. M., Alouini, M. S., & Zummo, S. A. (2018). Survey on physical layer security in optical wireless communication systems. In Proceedings of 7th international conference on communications and networking (ComNet) (pp. 1–5). IEEE.

  85. Lopez-Martinez, F. J., Gomez, G., & Garrido-Balsells, J. M. (2015). Physical-layer security in free-space optical communications. IEEE Photonics Journal, 7(2), 1–14. https://doi.org/10.1109/JPHOT.2015.2402158.

    Article  Google Scholar 

  86. Mostafa, A., & Lampe, L. (2014). Securing visible light communications via friendly jamming. In Proceedings of global communications conference (GLOBECOM) (pp. 524–529). IEEE.

  87. Mostafa, A., & Lampe, L. (2016). Optimal and robust beamforming for secure transmission in MISO visible-light communication links. IEEE Transactions on Signal Processing, 64(24), 6501–6516. https://doi.org/10.1109/TSP.2016.2603964.

    Article  MathSciNet  MATH  Google Scholar 

  88. Mostafa, A., & Lampe, L. (2015). Physical-layer security for MISO visible light communication channels. IEEE Journal on Selected Areas in Communications, 33(9), 1806–1818. https://doi.org/10.1109/JSAC.2015.2432513.

    Article  Google Scholar 

  89. Lei, H., Dai, Z., Ansari, I. S., Park, K. H., Pan, G., & Alouini, M. S. (2017). On secrecy performance of mixed RF-FSO systems. IEEE Photonics Journal, 9(4), 1–14. https://doi.org/10.1109/JPHOT.2017.2723422.

    Article  Google Scholar 

  90. Lei, H., Luo, H., Park, K., Ren, Z., Pan, G., & Alouini, M. S. (2018). Secrecy outage analysis of mixed RF-FSO systems with channel imperfection. IEEE Photonics Journal, 10(3), 1–13. https://doi.org/10.1109/JPHOT.2018.2835562.

    Article  Google Scholar 

  91. Blinowski, G. (2019). Security of Visible Light Communication systems - a survey. Physical Communication, 34, 246–260. https://doi.org/10.1016/j.phycom.2019.04.003.

    Article  Google Scholar 

  92. Arfaoui, M. A., Soltani, M. D., Tavakkolnia, I., Ghrayeb, A., Safari, M., Assi, C. M., & Haas, H. (2020). Physical layer security for visible light communication systems: A survey. IEEE Communications Surveys & Tutorials, 22(3), 1887–1908. https://doi.org/10.1109/COMST.2020.2988615.

    Article  Google Scholar 

  93. Ai, Y., Mathur, A., Verma, G. D., Kong, L., & Cheffena, M. (2020). Comprehensive physical layer security analysis of FSO communications over málaga channels. IEEE Photonics Journal, 12(6), 1–17. https://doi.org/10.1109/JPHOT.2020.3036244.

    Article  Google Scholar 

  94. Trinh, P. V., Carrasco-Casado, A., Pham, A. T., & Toyoshima, M. (2020). Secrecy analysis of FSO systems considering misalignments and eavesdropper’s location. IEEE Transactions on Communications, 68(12), 7810–7823. https://doi.org/10.1109/TCOMM.2020.3023465.

    Article  Google Scholar 

  95. Wu, L., Zhang, Z., & Liu, H. (2014). Transmit beamforming for MIMO optical wireless communication systems. Wireless Personal Communications, 78(1), 615–628. https://doi.org/10.1007/s11277-014-1774-3.

    Article  Google Scholar 

  96. Butala, P. M., Elgala, H., & Little, T. D. C. (2013). SVD-VLC: A novel capacity maximizing VLC MIMO system architecture under illumination constraints. In Proceedings of IEEE global communications conference (GLOBECOM) (pp. 1087–1092). IEEE.

  97. Kim, S. M., Baek, M. W., & Nahm, S. H. (2017). Visible light communication using TDMA optical beamforming. EURASIP Journal on Wireless Communications and Networking, 56(2017). https://doi.org/10.1186/s13638-017-0841-3.

  98. Murugan, K. H. S., & Sumathi, M. (2019). Design and analysis of 5G optical communication system for various filtering operations using wireless optical transmission. Results in Physics, 12, 460–468. https://doi.org/10.1016/j.rinp.2018.10.064.

    Article  Google Scholar 

  99. Mai, V. V., & Kim, H. (2021). Airborne free-space optical communications for fronthaul/backhaul networks of 5G and beyond. IEEE Future Networks Tech Focus, 4(2), 1–5.

    Google Scholar 

  100. Llana, P. N. D. L., Haq, A. F. M. S., & Yuksel, M. (2021). Design of a multi-element FSO transceiver array for mobile communication links. In Proceedings of SPIE 11678, free-space laser communications XXXIII, 1167805.

  101. Dahrouj, H., Douik, A., Rayal, F., Al-Naffouri, T. Y., & Alouini, M. S. (2015). Cost-effective hybrid RF/FSO backhaul solution for next generation wireless systems. IEEE Wireless Communications, 22(5), 98–104. https://doi.org/10.1109/MWC.2015.7306543.

    Article  Google Scholar 

  102. Douik, A., Dahrouj, H., Al-Naffouri, T. Y., & Alouini, M. S. (2015). Hybrid radio/free-space optical design for next generation backhaul systems. IEEE Transactions on Communications, 64(6), 2563–2577. https://doi.org/10.1109/TCOMM.2016.2557789.

    Article  Google Scholar 

  103. Bag, B., Das, A., Ansari, I. S., Prokes, A., Bose, C., & Chandra, A. (2018). Performance analysis of hybrid FSO systems using FSO/RF-FSO link adaptation. IEEE Photonics Journal, 10(3), 7904417. https://doi.org/10.1109/JPHOT.2018.2837356.

    Article  Google Scholar 

  104. Yasir, S. M., Abas, N., Rahman, A., & Saleem, M. S. (2021). Simulation analysis of adaptive FSO/RF hybrid link under diverse weather conditions of Lahore, Pakistan. Results in Optics, 2, 100047. https://doi.org/10.1016/j.rio.2020.100047.

    Article  Google Scholar 

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The authors confirm contribution to the paper as follows: Saima Zafar drafted the final version, critically analyzed and revised the article, sketched figures/illustrations, and analyzed and interpreted the study. Hira Khalid conceived the idea and the initial design of the study. Both authors contributed in data collection, literature review and drafting the manuscript. Both authors reviewed and approved the final version of the manuscript.

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Zafar, S., Khalid, H. Free Space Optical Networks: Applications, Challenges and Research Directions. Wireless Pers Commun 121, 429–457 (2021). https://doi.org/10.1007/s11277-021-08644-4

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