Resilient wireless network planning using mixed optical fiber cabling and free space optical technologies

Free space optical (FSO) communication technology, also known as optical wireless communications, has regained a great interest over the last few years. In some cases, FSO is seen as an alternative to existing technologies, such as radio frequency. In other cases, FSO is considered as a strong candidate to complement and integrate with next-generation technologies, such as 5G wireless networks. Accordingly, FSO technology is being widely deployed in various indoor (e.g., data centers), terrestrial (e.g., mobile networks), space (e.g., inter-satellite and deep space communication), and underwater systems (e.g., underwater sensing). As the application portfolio of FSO technology grows, so does the need for a clear classification for FSO link configurations. Most existing surveys and classifications are single-level classifications, and thus not inclusive enough to accommodate recent and emerging changes and developments of different FSO link configurations and systems. In this paper, we propose a multi-level classification framework to classify existing and future indoor, terrestrial, space, underwater, and heterogenous FSO links and systems using common and simple unified notation. We use the proposed classification to review and summarize major experimental work and systems in the area until 2017. Using the proposed classification and survey, we aim to give researchers a jump-start to tap into the growing and expanding realm of the FSO technology in different environments. The proposed classification can also help organize and systematically present the progress in the research on FSO technology. This makes the identification of the market needs for standards an easier task. Moreover, different entities involved in the standardization process including academic, industry, and regulatory organizations can use the proposed classification as a unified language to communicate during the early stages of standard development which require ambiguity-free discussions and exchange of ideas between different standardization entities. We use the proposed classification to review existing standards and recommendations in the field of FSO. It is also envisioned that the proposed classification can be used as a unified framework to define different FSO channel models for simulation tools.

Free Space Optics (FSO) technology transmits information using free space optical signals similar to those that travel through optical fibers. The capacity of FSO to connect buildings close together is covered in this paper. Four optical wireless links between three buildings of a fictitious company, considering a building that obstructs the sight line between two of them, are designed here. As part of the design process, several issues such as distance between the equipment, weather conditions, some features of the FSO equipment, and system losses were addressed; moreover, an application that performs the calculations and displays the results of the most important aspects in the design was implemented. The importance of such links is given by their flexibility, low implementation costs, mobility, rapid deployment, high throughput, great bandwidth, reliability, and high security level due to their operating principles, among others; therefore, this type of links are an ideal option to implement a backbone for the proposed network.

The increasing number of mobile devices and high-speed services accelerate the growth of traffic in cellular backhaul networks. The traditional technologies used in the backhaul, copper, radio links and optical fibers, either cannot offer high data-rate, or are expensive. In this paper, we propose mixed integer programming models to facilitate upgrading the cellular backhaul using the free space optical (FSO) technology, a cost-effective and high-bandwidth solution. Since the optical signal is transmitted along line-of-sight and FSO links are sensitive to weather conditions, we incorporate mirrors in the models to provide alternative paths for pairs of FSO nodes without line-of-sight, and increase the path diversity to enhance the resilience. Optical fibers existing in the backhaul are considered in the models and reused to decrease the upgrading cost and improve reliability. The presented models can deliver topologies for various requirements on cost and resilience. They can also be used to develop topology planning and optimization tools.

Free Space Optics (FSO) Technology is the advanced wireless communication system that provides higher bandwidth with a higher data rate transmission over higher link range. The major challenge on free space optics technology is atmospheric attenuation that hampers data transmission of the system by increasing bit error rate. Fog is the atmospheric condition which causes highest amount of signal attenuation. Travelling wave semiconductor optical amplifier is a functional device that can eliminate the effect of fog on free space optical communication link. Multiple TX/RX system architecture with the existence of this efficient device is capable of improving the performance under fog atmospheric effect by ensuring higher received power and lower bit error rate. Our paper implements the architecture of multiple TX/RX system with travelling wave semiconductor optical amplifier under fog atmospheric condition using simulation tool Optisystem 7. The effort in this paper is to overcome the effect of fog attenuation on free space optics link by the evaluation of performance through simulated results of the implemented model in terms of Q factor, bit error rate, received power and eye height.

In this paper, a techno-economic evaluation of the business prospects of Free Space Optical (KSO) technology as an alternative last mile solution is carried out and compared to Fiber-to-the-Home/Office (FTTH) and Fiber-to-the-Cabinet (FFTC). The analysis is based on the results from the TONIC tool which takes into account network topology, area characteristics, service demand and price evolution forecasting and calculates key economic figures-of-merits. The results reveal that FSO technology could provide a viable alternative in cases where the existing duct availability is limited and scenarios with either FTTH or FFTC have negative or less favourable business prospects.

A technoeconomic evaluation of the business prospects of a wide-scale deployment of free space optical (FSO) technology as a last-mile solution is carried out. The evaluation is based on a technoeconomic tool that taking into account network topology, area characteristics, service demand, and price evolution forecasts, estimates key economic figures-of-merit. It is shown that FSO technology could provide a viable alternative in situations where the duct availability is limited, and fiber-to-the-home/office or fiber-to-the-cabinet scenarios have negative or less favorable business prospects. Hybrid fiber/FSO scenarios are also investigated taking into account different FSO coverage conditions.

In this paper, a techno-economic evaluation of the business prospects of a wide scale deployment of Free Space Optical (FSO) technology as a last mile solution is carried out. The evaluation is based on the TONIC tool which takes into account network topology, area characteristics, service demand and price evolution forecasting and calculates key economic figures-of-merits. It is shown that FSO technology could provide a viable alternative in situations where the duct availability is limited and Fiber-to-the-Home/Office or Fiber- to-the-Cabinet scenarios have negative or less favorable business prospects.

PurposeThe purpose of this paper is to carry out a techno‐economic evaluation of the business prospects of Free Space Optical (FSO) technology as an alternative last mile solutionDesign/methodology/approachThe analysis is based on the results from the TONIC tool that takes into account parameters such as network topology, area characteristics, service demand, price evolution forecasting and calculates several economic figures‐of‐merits. Furthermore in order to analyze market and technologies uncertainties a thorough risk analysis has been performedFindingsThe results reveal that FSO technology could provide a viable alternative in cases where the existing duct availability is limited especially compared to the Fiber‐to‐the‐Home (FFTH) solutions.Originality/valueThis paper studies two alternative last mile broadband technologies FSO and FTTH

Free space optics (FSO) technology is gaining attention for 6G and beyond networks due to its ability to provide secure data transmission, operate without the need for licensed spectrum, and support significantly higher data rates. Although the FSO system has various advantages, long-distance communication transmissions are inadequate. The dependability of FSO technology is predominantly influenced by various weather factors. This paper’s results seek to enhance the efficiency of FSO technology for long-distance communication. The present work utilised a combined methodology that mixes multi-beam combinations and self-homodyne direct-detection (SHDD) approaches inside a wavelength division multiplexed (WDM) FSO technology. The system is assessed through several implementations of single beam (SB), 4 multiple beams (MB4), and 8 multiple beams (MB8). This paper utilises the gamma–gamma (GG) channel model. The findings show that MB provided the best performance throughout a range of 1.6–12 km, with all lengths depending on the surrounding conditions. The link quality is determined by calculating the bit error rate (BER), Q factor and Eye height.

Due to the limitation of the radio frequency (RF) spectrum, it is increasingly more difficult to support billions of wireless devices in the age of Internet-of-Things. Consequently, many recent wireless indoor communication systems have been developed using free space optical (FSO) communication technologies that exploit the extremely large light spectrum to transmit data. However, FSO technologies, especially when using On-Off Keying(OOK) modulation, the Light-Emitting-Diode (LED) transmitters produce an inherent non-linear distortion in the output. Effectively, the LED acts as a band-limited channel between the inputs and outputs. In this paper, we utilize a mathematical model to capture the distortion of the output for a given input. Based on the mathematical model, we developed a technique called Memory Decoding Algorithm (MDA) used at a receiver and effectively reduces the bit error rates via maximum likelihood decoding principle when On-Off Keying(OOK) modulation is used. Both theoretical analyses and simulation results show that the proposed technique outperforms the conventional methods such as linear equalization.

The demand for large bandwidth and high data rates in communication systems has become the main cause of the upgrade of traditional networks into free space optical (FSO) technology. FSO technology has gained significant popularity due to its easy deployment, high data rates, abundant bandwidth, enhanced security, and license-free spectrum utilization. However, the performance of FSO communication systems can be affected by certain limiting factors, such as changes in weather conditions during data transmission. To overcome these challenges and improve FSO performance, various modulation techniques are employed. This article presents a concise overview of the FSO communication system, highlighting different modulation techniques used to enhance its performance, as well as discussing its advantages, applications, and existing challenges. Some advanced modulation formats which are recently introduced in the field of FSO communication such as QPSK, DP-QPSK, QAM, and OFDM are also made part of this paper.

Free space optical (FSO) technology is a quick-to-deploy and economical way of getting access to the fiber optic network. FSO technology not only offers fiber-quality connections, but it also offers the sector’s cheapest transmission capacity. FSO systems complement legacy network commitments and function in harmony with any protocol, saving significant up-front investments as a completely protocol-independent broadband gateway. An FSO link may be purchased and deployed at a fraction of the cost of installing fiber cable and for roughly half the cost of equivalent microwave/RF wireless systems. With exception of RF wireless technologies, FSO does not need the purchase of expensive spectrum licenses or the fulfillment of additional regulatory criteria. The purpose of this study is to examine the performance of FSO-based optical access networks. Analysis of the performance in detail, with a focus on BER is also described.

This paper presents a novel approach of establishing a multichannel optical communication link, combining optical fiber cable (OFC) and free space optics (FSO) technology. By leveraging multiple lengths of optical fiber and FSO links, along with optical amplifiers to counteract attenuation, our proposed hybrid system incorporates four channels operating within the 1550 nm window. This model is specifically designed to address communication challenges in scenarios such as unplanned urban layouts, multistory buildings, or rugged terrains where traditional optical fiber deployment is impractical. By integrating FSO for the fronthaul and optical fiber for the backhaul, our system enhances transmission capacity, thereby supporting the requirements of next-generation networks and alleviating bottlenecks and connectivity issues at the last or first mile. This innovative approach holds promise for internet service providers, enterprises, and industrial networks operating in demanding environments. Furthermore, it can serve as a vital tool for restoring emergency communication links in the aftermath of disasters such as earthquakes or floods, where traditional wired optical infrastructure may be compromised.

The transport capabilities of optical communication systems have increased tremendously in the past two decades, primarily due to advances in optical devices and technologies, and have enabled the Internet as we know it today with all its impacts on the modern society. Future internet technologies should be able to support a wide range of services containing a large amount of multimedia over different network types at high transmission speeds. The future optical networks should allow the interoperability of radio frequency (RF), fiber-optic and free-space optical (FSO) technologies. However, the incompatibility of RF/microwave and fiber-optics technologies is an important limiting factor in efforts to further increase future transport capabilities of such hybrid networks. Because of its flexibility, FSO communication is a technology that can potentially solve the incompatibility problems between RF and optical technologies. Moreover, FSO technologies can address any type of connectivity needs in optical networks. To elaborate, in metropolitan area networks (MANs), FSO communications can be used to extend the existing MAN rings; in enterprise networks, FSO can be used to enable local area network (LAN)-to-LAN connectivity and intercampus connectivity; and, last but not the least, FSO is an excellent candidate for the last-mile connectivity.

We propose a free-space optical system for the current network topology of university campus buildings and the Astronomical Observatory, at Quito, Ecuador. Using wireless optical communication provides the advantages of a wireless environment and faster data transfer rate. The Free Space Optics (FSO) design considers the worst atmospheric condition (torrential rain and fog) where the visibility value is 770 meters. The obtained atmospheric-attenuation coefficient is 3.84 dB/Km. Link margin values calculated between 4.74 dB to 43.99 dB allow validating the FSO network design. The FSO cost implementation is almost equal than a fiber optic alternative, which makes this technology very attractive for Optical Wireless Communications (OWC) in the 5G/5GB/6G network environment.