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With the development of mobile Internet, more and more readers search for book information through mobile phones and other devices, so how to optimize the efficiency and accuracy of book information search has become an important issue of intelligent library system management. This paper presents a book information search algorithm based on cellular network, which can effectively improve the efficiency and accuracy of book information search. Based on the existing problems of book information search in the intelligent library system, this paper proposes a book information search algorithm based on cellular network. By assigning the book information to multiple search nodes, the algorithm makes use of the advantages of cellular network to realize efficient search and transmission. At the same time, the improved text similarity algorithm is introduced, which can improve the search efficiency and accuracy by analyzing and processing the keywords searched by users, and can match the readers' search requests and book information records more accurately. The experimental results show that this scheme can improve the search efficiency and data transmission rate of intelligent library system, and provide a new idea and method for the management optimization of intelligent library system. [ABSTRACT FROM AUTHOR]

Many researchers over the years studied how logic gates work on the basis of electrical signals. Here, we proposed to create a brand-new, COMPARATOR-focused idea for optical logic design. Being able to keep their shape as well as potential intact even after propagating through a long distance, optical soliton is a well-established phenomenon in digital communication system. Though we have a previous concept of electrical logic gates, at this stage we can design a new technique of logic gates where the light signal can be used instead of electrical signal. An optical signal having a very high data communication speed, there is not an unwanted gate delay time. Here we use hyper secant optical soliton pulse (HOSP)-based logic GATES from numerical aspects. This paper proposes a new method to perform all-optical COMPARATOR using HOSP. An optical comparator using soliton pulse superposition is very fast and systematic process to compare the data with a proper simulation using MATLAB simulation. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive analysis of free space optical (FSO) communication that incorporates the orthogonal frequency division modulation (OFDM) system with differential quadrature phase shift keying (DQPSK) modulation scheme. FSO has become a significant area of research in the optical communication field due to efficient communication systems with higher data transmission rates and lower energy requirements. While transmitting signals through free space, the efficiency of the system is constantly compromised by atmospheric turbulence. In this research, the Gamma-Gamma fading model is considered to incorporate atmospheric turbulence which offers better protection against signal fading and scintillation. Convolutional coding is introduced as the forward error correction (FEC) code with the OFDM technique to ensure better and easier encoding of the signal. The system performance is evaluated in terms of bit error rate (BER). All complex calculations and final result are computed with the help of a hyper-geometrical function, Meijer G. Final results are obtained in graphical form with the help of MATLAB software. System performance is analyzed in terms of BER by varying different system's parameters including the number of OFDM sub-carrier and link distance. Significant amount of coding gain almost 32 dB was found at a BER of 10–9, when the system link length is 2000 m and the refractive index structure parameter is 10–14 m−2/3. [ABSTRACT FROM AUTHOR]

This paper dedicates to study the optical soliton solutions for the time-fractional perturbed Fokas-Lenells equation using the novel modified Sardar sub-equation approach. Several novel optical solutions include a class of categories, comprising mixed dark-bright, bell-shape, singular, and wave optical solutions are constructed. Further, the magnitude of the time-fractional perturbed Fokas-Lenells model by investigating the impact of the conformable fractional parameter and the effect of the time parameter on the novel optical solutions is analyzed. The current type of Sardar sub-equation approach is a general form of several approachs, such as the tanh-function extension approach, the modified Kudryashov approach, the improved Sardar sub-equation method, and others. It can be claimed that the current optical soliton solutions are novel and have not existed in the literature. The results of this study are expected to shed light on the field of soliton theory in nonlinear optics. Time-fractional perturbed Fokas–Lenells soliton solutions could be applied to model and understand the behavior of signals in optical communication systems and potentially improving data transmission. [ABSTRACT FROM AUTHOR]

In this paper, we have proposed and demonstrated a 100 Gbps data transmission system over hybrid single mode fiber (SMF)-free space optics (FSO) link using optical comb lines in wavelength-division-multiplexing technique. A continuous wave laser, two dual drive Mach-Zehnder modulators and four electrical attenuators are employed to generate optical frequency comb lines (OFCL). The OFCL generator generates 52 comb lines by optimizing biasing voltages. The OFCL lines with a side mode suppression ratio of ∼ 50dB and flatness ∼∼ 0.01dB are generated and used as an optical carrier in the proposed system. The performance of the system is investigated in different weather conditions, such as clear weather, hazy weather, heavy rain, light fog, moderate fog, and heavy fog. [ABSTRACT FROM AUTHOR]

This paper presents the design and investigation of a two-element MIMO antenna using a series-fed microstrip antenna array for next-generation (Next-gen) communications in the THz regime. The antenna array is developed on an ultra-thin substrate material with graphene patterning to obtain quad-band radiation. Concentric split rings of various radii are used in the development of each element and three sections are used to construct each of the series-fed antenna array within a footprint of 50 × 16 μm. The series-fed configuration is chosen to maximize the antenna radiation making it suitable for low-power applications. The proposed series-fed antenna works at 3.4, 3.6, 4.96 and 5.6 THz with a return loss greater than 25 dB. The estimated bandwidth of the series-fed antenna array is 128, 142, 145 and 176 GHz making it suitable for high-speed data communication. The peak simulated gain is greater than 6 dBi while the total efficiency is above 80% in the four operating bands. Further, to enhance the antenna performance for a highly cluttered environment, a two-element Multiple-Input Multiple-Output (MIMO) array is constructed with an element spacing of 22 μm with an inherent isolation of 20 dB. The MIMO performance parameters are evaluated and presented. [ABSTRACT FROM AUTHOR]

In this paper, a high-speed transmission system that combines a multimode fiber (MMF) with Free Space Optics (FSO) is proposed to accommodate the rapid growth of traffic. As Orbital Angular Beams Multiplexing (OAM) plays a crucial role in 6G networks by enhancing transmission capacity, four OAM beams ( LG 0 , 0 , LG 0 , 20 , LG 0 , 40 , and LG 0 , 40 ) are utilized in this study. Additionally, the Optical Code Division Multiple Access (OCDMA) technique is employed, known for its high level of confidentiality and the ability to allow multiple channels to transmit data simultaneously. To ensure ubiquitous data transmission, two channels: MMF and FSO are used. Accordingly, in our proposed MMF/FSO system, we employ four OAM beams, with each carrying four OCDMA channels assigned distinct Permutation Vector (PV) codes. With a data transmission rate of 10 Gbps on each OCDMA channel, the overall capacity of the system amounts to 160 Gbps (10 Gbps × 4 OCDMA channels × 4 OAM beams). Moreover, the performance is investigated and evaluated using two scenarios. The first assumes an FSO range of 5 km and Clear Air (CA) weather conditions, with a variable MMF length. In contrast, the second scenario maintains a fixed MMF length of 1 km while altering the FSO span. Weather conditions like CA and rain conditions; Light Rain (LR), Medium Rain (MR), and Heavy Rain (HR) are considered while evaluating the system performance in the second case. The bit error rate (BER), travelling distances in the channel either MMF or FSO, and eye diagrams are among the metrics used for evaluation. They all provide information about the received signal performance. Finally, the obtained results for the proposed MMF/FSO system, utilizing OAM beams and PV codes, indicate that in the first scenario, the system can support a total capacity of 160 Gbps across all channels. The performance is noteworthy, with a BER below 10 - 5 and a wide eye opening, enabling successful transmission over 6.2 km (1.2 km MMF length + fixed 5 km FSO span). For the second scenario, the achievable distance is decreased due to the attenuation caused by rain. It becomes 2.62 km (1 km MMF + 1.62 km FSO span), 5.2 km (1 km MMF + 1.2 km FSO span), and 1.77 km (1 km MMF + 0.77 km FSO span), under LR, MR, and HR, respectively. [ABSTRACT FROM AUTHOR]

The Smart Grid AMI is at the forefront of modernizing energy management for efficient energy distribution and maintaining grid reliability. However, the seamless flow of data within AMI introduces critical security challenges, necessitating innovative approaches to ensure secure data transmission. This paper addresses these challenges by proposing a Quantum Key Distribution (QKD) based on Multi-Objective Optimization (MOO) and Reinforcement Learning (RL) framework for secure data transmission within the Smart Grid AMI. Primarily, we formulate the routing problem as a MOO challenge with four primary objectives namely, energy efficiency, latency minimization, reliability, and security to capture the essence of efficient and secure data transmission. Further, we introduce an RL agent based on the Proximal Policy Optimization (PPO) algorithm for robust policy learning. The RL agent by exploring diverse routing actions and receiving rewards optimizes the routing decisions within the network environment based on the objectives specified in the multi-objective function (MOF). A novel MOF quantifies trade-offs between security and performance metrics, integrating QKD-based security metrics with traditional optimization objectives. This function guides the RL agent in making informed routing decisions. Through extensive simulations using the NS-2 simulator in a realistic Smart Grid AMI environment, the proposed approach obtained energy consumption of 750 J, latency of 55 ms, and security level of 96% and also revealed significant improvements compared to conventional techniques widely employed for secured communication in AMI networks. Overall, the simulation results exhibited that the proposed method showed outstanding performance by achieving energy efficiency of 0.95, latency reduction of 0.92, reliability improvement of 0.94, and security enhancement of 0.96. Overall, this integration offers a pioneering solution to address the evolving security challenges in the Smart Grid landscape and contributes to the advancement of secure data transmission in Smart Grid AMI networks, fostering a resilient and secure energy ecosystem. [ABSTRACT FROM AUTHOR]

Visible light communication (VLC) is a technology of wireless optical communication, which combines lighting and communication simultaneously. In indoor VLC system, both data communication and lighting quality plays an important role and must be considered. Thus, to achieve the desired levels of illumination, dimming control in VLC is an efficient technology. In this paper, the authors have designed and implemented a dimming control VLC system employing multi header-hybrid pulse position modulation (MH-HPPM) to achieve dimming functionality. MH-HPPM supports various dimming levels and also doesn't have flicker problems. In this paper, the authors present the implementation of MH-HPPM based VLC system using Raspberry Pi. The prototype is designed using low-cost commodity hardware. Comprehensive experiments are carried out to evaluate the performance of MH-HPPM based VLC under dimming levels 0.25, 0.5 and 0.75. The results demonstrate that designed prototype supports a communication distance up to 3 m for dimming level 0.25 and 3.5 m for dimming level 0.5 and 0.75. It is also observed that MH-HPPM based VLC system also achieves and maintains better throughput for different incidence angle. [ABSTRACT FROM AUTHOR]

In this paper, the generalized nonautonomous Hirota equation was investigated with the help of symbolic computation. Using Darboux transformation method three soliton and four soliton solutions were developed based on Lax pair construction. The corresponding figures are plotted to show the properties of the constructed soliton solutions. By manipulating autonomous and nonautonomous profile, various soliton systems are investigated. These solitons systems have potential applications in the design of soliton compressor, soliton amplification, and high-speed optical devices in ultra large data transmission systems. In future experiments, the findings of this study are expected to be demonstrated. [ABSTRACT FROM AUTHOR]

In this paper, a high-speed short-reach free space optical (FSO) transmission system is proposed for data center interconnect (DCI). This system supports the transmission of 400 Gbps over a single wavelength by employing spatial vertical cavity surface emitting lasers. Space division multiplexing along with polarization division multiplexing of the Laguerre–Gaussian (LG) modes (LG 00 and LG 01 ) are exploited to achieve higher capacity over FSO channel. Intensity modulation direct detection scheme is used in the proposed system for cost-efficiency. Least mean square equalization is applied to the received data signals to mitigate the FSO channel's impairments. The performance of the proposed system is evaluated by observing the bit error ratio (BER) for weak, moderate and strong turbulences at different weather dynamics. The effects of polarization induced crosstalk and aperture misalignment induced crosstalk on BER degradation are also investigated. FSO channel lengths of 700 m, 500 m and 150 m are achieved for weak, moderate and strong turbulences, respectively. The receiver sensitivities at forward error correction limit of 3.8 × 10 - 3 for each FSO channel length are compared with back to back configuration. A penalty of 2.5 dB is observed for strong turbulence whereas 2 dB and 0.6 dB penalties are obtained for moderate and weak turbulences, respectively. The proposed FSO-DCI could be used to provide high aggregate transmission capacity of 800 Gbps and 1.6 Tbps for future DCI by adding more LG modes or other wavelengths. [ABSTRACT FROM AUTHOR]

In this paper, using the Hirota bilinear method, we investigate the perturbed Gerdjikov–Ivanov equation (PGIE) for lump soliton, rogue wave, periodic and kink cross rational solutions, homoclinic breathers, M-shaped and many other interactions. All these solutions have so many real life applications for example lump wave help to study the behavior of vortices and eddies in the ocean, which are used for climate modeling and fisheries management. Rogue waves are used in maritime safety, M-shaped solitons are used in optical fiber communications to transmit data over long distances without distortion, improving the efficiency and reliability of high-speed data transmission. Breathers can be used in fiber optic systems to generate ultrafast optical pulses, which have applications in telecommunications and laser technology. We also discuss the dynamical behaviour of our solutions in various dimensions. [ABSTRACT FROM AUTHOR]

The growing need for high-speed services, coupled with data-intensive technologies like the Internet of Things (IoT), is expected to exacerbate congestion within existing Radio Frequency (RF) communication systems. As a result, Free Space Optics (FSO) has emerged as a promising alternative to RF, offering superior data transmission capabilities. Additionally, ensuring security has become a crucial concern to safeguard sensitive information. Accordingly, in this paper, an FSO system is proposed that uses an Identity Column Shift Matrix (ICSM) code for higher and confidential data transformation. The ICSM code is one of the Spectral-Amplitude-Optical-Code-Division-Multiple Access (SAC-OCDMA) codes which is characterized by easy construction due to zero cross-correlation property. Moreover, the effectiveness of clear, haze, fog and rain conditions are considered while examining the proposed model performance in addition to real meteorological data for two cities (Alexandria, Egypt, and Pune, India). Eye diagrams, received power, and Bit Error Rate (BER) are the evaluation parameters used for the proposed model performance. The simulation results reveal that as weather becomes severe, the FSO span decreases, and the performance becomes worst. As for clear weather, an FSO link of 26 km is obtained which is decreased to 1.1 km under the dense level of fog. Regarding the two cities, the distance covered by the information signal during rainy weather in Pune is 6.7 km, which is smaller than that in Alexandria due to Pune's higher attenuation value. These transmission ranges are obtained with an overall capacity of 3 × 10 Gbps, received power < − 22.8 dBm, and BER below 10–5.6. [ABSTRACT FROM AUTHOR]

Water represents 71% of the globe, of which 95% reserved by oceans and the rest is made out of seas and other water bodies. Communication among entities floating and diving underwater is not typically available or meets the acceptable level in most areas of water bodies, even though many underwater communication systems exist nowadays. However, the main issue of underwater acoustic and radio frequency (RF) wireless communication systems is the short communication distance between the transmitter and receiver without repeater due to the frequency dependence. Where in the optical wireless communication (OWC) the distance depends on the operating wavelength of the used light source. Recently, many researches have appeared in the field of underwater communication using visible light communications (VLC) and invisible OWC. Underwater optical wireless communication (UOWC) at 450 nm wavelength has proven to be better than at 680 nm and 860 nm due to the attenuation and dispersion mechanisms. In this paper, we will present a new design for a passive optical wireless code division multiple access (OW-CDMA) network based on a M-arry differential pulse position modulation (M-DPPM) with a new spreading code called double length modified prime code (DL-MPC) with distinct correlation characteristics to enhance the transmission distance, minimize the system latency, security of data transmission through the network, enhance the data rate per user, network capacity, improve the system signal to noise ratio (SNR) and consequently enhance BER performance at long transmission distance. The simulation results proved that the proposed system can accommodate about 500 users at a BER equals 10–9 using the proposed DL-MPC sequence at a transmission distance of 880 m under pure water. [ABSTRACT FROM AUTHOR]

Due to the advancement of high definition, 5G technologies, the Internet of Things, and Artificial Intelligence, the demand for optical networks has increased widely. Optical communication networks offer various metrics, including high transmission capacity, efficient anti-interference, minimum transmission loss and robustness, and so on, that offer opportunities for communication networks. To satisfy the optical network demands, effective network resource utilization is essential. Therefore, developing a tool with improved Quality of Transmission (QoT) accuracy in optical networks is necessary. Recently, Artificial intelligence (AI) approaches have provided various opportunities to resolve these issues and the deep learning (DL) algorithms offer improved performance over the conventional methods. This paper developed a novel DL-based cognitive QoT prediction model for Quantum optical communication networks. This proposed model predicts the QoT for the QoS (Quality of Service) setup using the DL model with the transmission computation. The proposed model utilized an optimized DL model called CNN-LSTM for the prediction process using the signal and link characteristics as input features. The DL model is trained using the transmission equations. The hyperparameters of the neural network are optimized using frog leap optimization to improve the predictive performance. The experimental results highlight the enhanced and improved version of the proposed model, and the results are compared with the conventional systems in terms of performance measures. [ABSTRACT FROM AUTHOR]

The demand for fault protection transmission link with high-speed, high security and long-reach in an optical access network is growing at an exponential rate. It is quite difficult to accommodate huge number of users with several connected devices in different geographical locations without deteriorating the quality of service at low cost. So, strong communication technique is needed that can offers high-speed, long-reach transmission and high data security along with multiple connected users or devices. In this paper, a ring-topology based hybrid passive optical network free space optics system using optical add/drop multiplexer with fault protection optical access network has been proposed. It is a promising network with fault-protection link for enhanced survivability and reliability of the network especially for the remote areas when the primary fiber link is broken or cut in the network. The results show that generated signal can propagate through a hybrid 10 km fiber along with FSO link of 35 km in downstream and 40 km in upstream transmission at symmetric 1 Tbps data rate considering turbulence effects and atmospheric conditions. Also, using single weight zero-cross correlation code in the proposed system offers the received optical power from − 5 to – 25 dBm under different atmospheric conditions. For hybrid fiber-FSO link, the maximum power penalties of 3 and 5 dB among 50 users can be achieved with respect to back-to-back and fiber links respectively, under 10–9 BER. The comparison of the obtained results with literature, show that the hybrid fiber-FSO link offers cost-effective long-reach, high transmission rate and security. [ABSTRACT FROM AUTHOR]

Underwater optical wireless communication (UOWC) has been a promising high data rate communication system. The performance of UOWC has numerous constraints in terms of maximum attainable distance, absorption, and scattering of the intensity, which vary depending on the quality of the water environment. This paper proposes a UOWC system based on filtered orthogonal frequency division multiplexing (F-OFDM). It has achieved large bandwidth while also addressing the issue of intersymbol interference (ISI). F-OFDM has attained lower out-of-band emission (OOB) while preserving bit error rate (BER) performance. Furthermore, to permit many users to share the entire UOWC system, non-orthogonal multiple access (NOMA) is adopted with F-OFDM, taking advantage of filtering subcarriers that reduce user interference. NOMA F-OFDM has been examined across harbor water channels under different power coefficients and modulation. Simulations have shown that F-OFDM is better than DC-biased optical OFDM (DCO-OFDM), with an OOB improvement of about 120 dB and a signal-to-noise ratio (SNR) gain of about 13 dB for BER = 10–3 using 4-QAM modulation. As well, NOMA F-OFDM has better BER performance than NOMA DCO-OFDM. [ABSTRACT FROM AUTHOR]

This paper demonstrates a four-level pulse amplitude modulated (PAM4) signal without any digital to analog conversion by controlling the polarization of the continuous-wave laser signal applied to the two parallel placed Mach–Zehnder modulators. In this way, up to 200 Gbps, the PAM4 signal has been successfully generated and transmitted over an 80 km distance with a quality factor of 23.9 dB. The dispersion in optical fiber limits the data-transmission distance, which is reduced by controlling the chromatic dispersion using a dispersion compensated fiber. For long-distance transmission, polarization mode dispersion also comes into the picture due to its polarization dependency and degrades the signal's quality, which is reduced by controlling the polarization rotator just before the DCF fiber. The proposed system is also suitable for inter data-center communication due to its 80 km distance data transmission with such a high bit rate and Q-factor. [ABSTRACT FROM AUTHOR]

Secure communication is a critical aspect of modern networks, especially in optically designed networks where sensitive data is transmitted. This paper presents a novel secure communication method based on probabilistic sensing to enhance the security of data transmission in such networks. The proposed method exploits the unique characteristics of optical signals to ensure secure and reliable communication. In the proposed method, probabilistic sensing techniques are employed to detect and prevent unauthorized access and eavesdropping in the network. By analyzing the probability distribution of optical signals, the method can identify any potential security threats or anomalies in the communication channel. This enables the network to dynamically adapt its security measures and protocols to counteract unauthorized access attempts. To evaluate the effectiveness of the proposed method, extensive simulations and experiments are conducted on optically designed networks. The results demonstrate that the method provides enhanced security, robustness, and confidentiality in data transmission. It effectively mitigates the risk of data breaches and unauthorized interception, ensuring the integrity and privacy of sensitive information. The secure communication method based on probabilistic sensing contributes to the field of network security by providing a reliable solution for AI and IoT enabled networks. By using the unique properties of optical signals, the method offers an additional layer of security to protect against potential threats as demonstrated in the results. This research has implications for various domains, including telecommunications, data centers, and critical infrastructure, where secure and confidential communication is of utmost importance. [ABSTRACT FROM AUTHOR]

Novel coding and modulation methods are required for fulfilling the demands of 5G and beyond cellular communication systems. In this paper, an innovative time diversity non-orthogonal multiple access (TD-NOMA) approach is proposed for 5G applications. The suggested system uses time diversity (TD) in conjunction with NOMA to improve the system bit error rate (BER) performance. The NOMA technique basically employes data transmission based on non-orthogonal basis functions. The data pass through the channel, and the desired signal can be obtained by a successive interference cancelation (SIC) receiver. Using different subcarriers and channel models, different modulation schemes such as QPSK and BPSK are investigated. When compared to conventional methodologies, the simulation results reveal that the proposed system outperforms them; it reduces the effect of fading for the multipath channel and enhances the BER. [ABSTRACT FROM AUTHOR]

Adaptability of an effective access network in optical code division multiple access domain requires an efficient coding scheme which has the abilitiy to provide required communication capacity in terms of cardinality, reach, and data rates. In this paper, an extensive study and investigation has been carried out for adaptability study of a well-known coding scheme diagonal eigenvalue unity (DEU) code at various date rates in passive optical network (PON) environment. DEU code design is based on Jordan block matrix with ideal in-phase cross correlation (IPCC) properties. The numerical and simulation results show the ability of DEU code in supporting synchronized transmissions at different data rates that suits triple play services of video, audio and data (VAD). An algorithm is developed to determine the required chip duration that matches a particular service. It shows that data rate is more influential than code length on pulse duration especially for video applications. In support of the proposed algorithm, 5 Gb/s, 2.5 Gb/s, and 1.25 Gb/s data rate transmissions have been validated for various simultaneous users. In addition, a Poisson's distribution analysis is carried out aiming to study different bit rate scenarios with ad hoc population network. Results have concluded that higher value of average rate of simultaneous users (σ) is preferable for low data rate whereas the lower value of σ is suitable to the higher data rates in accordance with network population. In particular, for video streaming, the traffic running in a continuous fashion requires the highest transmission priority and small value of σ. [ABSTRACT FROM AUTHOR]

Visible Light Communication (VLC) concurrently affords illumination and communication. VLC emerged to overcome the demerits of Radio Frequency communication and the congestion of spectrum. The incorporation of dimming in Light Emitting Diodes (LEDs) endows energy saving and increases the alluring value of the spot. While dimming the LEDs the problem faced is flickering. The flickering can be mitigated using Variable Delta Sigma Modulation (vDSM). The Non Return to Zero (NRZ) encoded data and Optical-Orthogonal Frequency Division Multiplexing (O-OFDM) symbols are transmitted over vDSM digital dimming signals. The transmission of O-OFDM signal, Enhanced Reverse Polarity Optical OFDM (ERPO-OFDM) assures enhanced bit rate, better spectral and optical power efficiency than the transmitted NRZ encoded data through the dimming signal. The paper makes us to look onto the performance analysis of data transmission over various digital dimming modulation techniques. The ERPO-OFDM technique supports high speed communication with efficient energy saving capability in indoors under flicker avoidance while data transmission through dimmed LEDs. [ABSTRACT FROM AUTHOR]

Optical network serves as a core network with huge capacity and a multitude of high-speed data transmission. Natural disasters and physical attacks showed significant impacts on the optical networks such as damages the network nodes and optical links. Network survivability attempts to provide uninterrupted services when network component ceases to function or malfunctioned either in the event of a disaster or due to human intervention. In this paper, two polynomial-time algorithms have been proposed to select an optimal pair of link-disjoint lightpaths between two network nodes such that (1) their minimum spatial distance (MSD) is maximized, and (2) the path length of the primary lightpath is minimized such that backup lightpath has some particular MSD from the primary lightpath while disregarding safe regions around the source and destination nodes. Through extensive simulations, it is shown that, in case of disaster event, the first algorithm (DPMMSD) computes the backup path with maximum survivability in case of multiple link failures of spatially close nodes, whereas second algorithm (CMMSD) computes the shortest backup lightpath while adhering to the target survivability requirements. DPMMSD, CMMSD and the benchmark EKSP enables the evaluation and comparison of the performance. EKSP computes more pairs hence takes more computing time whereas DPMMSD and CMMSD modestly discard the computation of self and repeating pairs, enabling quick computations. [ABSTRACT FROM AUTHOR]

Secure medical data transfer technologies have advanced as a result of the brisk growth of telehealth services. This study provides a thorough review of the most up-to-date research on using optical steganography to conceal medical records from prying eyes. Data concealing capacity has been increased without sacrificing picture quality using new techniques that make it difficult for unauthorised parties to access hidden information. Using adaptive steganography methods, medical data may be encoded in images in a way that makes it impossible to detect or extract by prying eyes. By concealing information over many picture layers, multi-layer steganography adds an extra degree of protection from prying eyes. The development of steganographic techniques has been spurred on by the use of machine learning and artificial intelligence to enhance steganalysis and the use of quantum characteristics to offer an extra layer of security in quantum steganography. Combining this with cryptographic safeguards like encryption provides an additional layer of security. In order to successfully safeguard sensitive medical data during transmission, standardisation and compliance in optical steganography are becoming more important as telehealth systems become more widespread. [ABSTRACT FROM AUTHOR]

Free space optics (FSO) communication is a very recent mechanism. It is mainly needed when physical connection between the transmitter and the receiver is practically impossible and when high bandwidth data transmission is expected. This paper walks through the investigation of the performance of FSO communication adopting spectral amplitude coding optical code division multiple access (SAC-OCDMA) systems at different weather scenarios. The suggested system uses enhanced double weight codes as signature codes by 3 clients, simultaneously. To eliminate multiple access interference and phase induced intensity noise, two different detection schemes are used; single photodiode (SPD) and modified-AND subtraction detection schemes. Furthermore, a comparison between PIN and APD detectors is performed. The performance is evaluated through its propagation distance, received power, Q-factor and bit error rate (BER). The obtained numerical results reveal both Q-factor and BER are modified by 30%. Accordingly, the system performance is enhanced by 30%, when using SAC-OCDMA-FSO with SPD detection technique compared with modified-AND subtraction technique. [ABSTRACT FROM AUTHOR]

To handle the massive high-speed internet traffic, free space optics (FSO) or single-mode fiber (SMF) based fiber optic communication is being used everywhere across the world. These technologies are capable of providing huge bandwidth and transmitting the data at very high speed with low energy consumption. FSO is a very convenient technology to quickly expand the legacy network in the adverse geographical areas. However, its link performance is highly dependent of inconsistent weather conditions. SMF based fiber optic link has a very low loss and its performance is almost independent on the weather conditions. Though, the installation and maintenance of fibers are quite complex and costly. Individually, FSO or SMF links have their limitations and have to be integrated to leverage their benefits. In this paper, we integrated FSO/SMF links and compared the performance of the proposed architecture which is capable of providing high-speed dual-rate data transmission. The proposed architecture transmits data over either FSO or SMF or both links simultaneously and has 100% more reliability against any one of the link failures. In case of operational link failure (FSO/SMF), data may be switched to the alternative working link (SMF/FSO), simply by tuning the transmitted signal by 50 GHz. The proposed architecture is also reliable against the optical line terminal transceiver (TRx) failure as each user located in the network can be served by two transceivers (1 Gbps and 10 Gbps). The proposed architecture also supports the wavelength division multiplexing overlay transmission for broadcasting the common signal to all the available users in the networks. The architecture reduces ~ 27% of the energy consumption by utilizing the appropriate link of hybrid architecture and TRx according to weather conditions and traffic load. The integrated architecture looks attractive for providing energy-efficient, high speed, and reliable internet coverage to the areas where there is a difficulty of laying fibers and has frequent fiber faults. The architecture is useful for strengthening and boosting rural and urban development. [ABSTRACT FROM AUTHOR]

This study offers the most recent network architecture employing the CWDM/DWDM/5G millimeter wave system over the Free-Space Optical Communication (or FSOC) channel with performance analysis of the Refractive Index Structural Parameter (or RISP), from weak turbulence 10 - 20 m−2/3 to strong turbulence 10 - 10 m−2/3. The hybrid CWDM/DWDM system and the 5G millimeter Wave (or mm Wave) transmission technology are the two major components that the proposed system would unite under a single FSOC channel. To assess the effectiveness of the proposed system at 500 m transmission data distance, the Min Bit Error Rate (or BER), the Max Q-factor, the Received Electrical Signal Power (or RESP), the Received signal-to-noise ratio (or RSNR), the Communication Capacity (or CC), and the Total Communication Capacity (or TCC) are investigated. The effectiveness analysis of the proposed system indicates that the FSOC transmission channel may be impacted by the RISP variance, which may lead to a decline in system performance. To get around this, the receiver side of the proposed system performs better thanks to the usage of the SQuare RooT (or SQRT) and Electrical Rescale (or ER) blocks. However, to correct the photodiode's square law characteristics and enhance the received signal quality, the SQRT block has been used. Moreover, the ER block has been included to scale the electrical signal input's minimum and maximum values to those previously set in the electrical pulse generator. The results of the simulation are successful, particularly when the SQRT and ER blocks are incorporated into the suggested system. For each result, the predicted RISP value and the estimated RESP, RSNR, CC, and TCC values have been achieved for the tolerable Min BER and Max Q-factor values of approximately 1e-09 and 6, respectively. [ABSTRACT FROM AUTHOR]

Space-division multiplexing (SDM) has emerged as a crucial transmission technique for meeting the high-capacity demands of the end users in next-generation information transmission links. In this work, we propose a SDM transmission system enabled by linear polarized (LP) spatial modes in an integrated multimode fibre (MMF)/free-space-optics (FSO) link. 2-Independent 10 Gbps data signals are transmitted over distinct LP modes to generate 20 Gbps transmission. The information is transmitted over 10 km MMF and varying FSO range for providing last-mile connectivity in remote areas. The system performance is evaluated under varying external weather and the received signal quality factor (Q factor), bit-error-rate (BER), and eye diagrams are used as the performance evaluators. We achieve an effective transportation of both the channels over 10 km MMF and 6 km FSO range under clear sky weather with BER ≤ 10−9 and Q Factor ~ 6 dB to achieve 20 Gbps data transmission. Further, under the adverse heavy foggy conditions, FSO range of 580 m is achieved with good system performance for both the modal channels. [ABSTRACT FROM AUTHOR]

An OFDM based radio over FSO (RoFSO) transmission system with 3-level multiplexing using RF subcarrier multiplexing (SCM), mode division multiplexing (MDM) and polarization division multiplexing (PDM) is proposed. Eight information channels, each having 20 Gbps data rate are combined through multiplexing at SCM level with subcarrier frequency i.e. 40 GHz and 60 GHz, MDM level with optical modes i.e. HG00 and LG10 and PDM level via horizontal and vertical polarization before being transmitted through RoFSO link. Thus, a total of 160 Gbps data is transmitted through RoFSO link. The proposed system is simulated and its performance is analysed for receiver parameters such as total received power, SNR, bit error rate (BER), Q-factor, and channel crosstalk under different atmospheric turbulence conditions. It has been observed that the proposed system is bandwidth efficient and achieves higher transmission capacity in comparison to 1-level (SCM) and 2-level (SCM-MDM) multiplexing. Further, no significant interference from adjacent channels is observed as the channel crosstalk is within the specified limits. [ABSTRACT FROM AUTHOR]

In the face of rising needs for exchanging different types of information nowadays, a growing demand for higher transmission rates, channel bandwidth, and spectral-efficiency in optical communication links are witnessed. Space division multiplexing (SDM) has garnered significant attention because it adds another dimension to information transmission. Orbital angular momentum (OAM) multiplexing, which is a subset of SDM technologies, can be deployed in free-space optical (FSO) links to achieve high-speed spectral-efficient links. The present work reports an OAM multiplexing-based FSO link that implements 4-level pulse amplitude modulated signals. 4-distinct OAM beams L G 0 0 , L G 13 0 , L G 40 0 , and L G 80 0 , each transporting independent 50 Gbps four-level pulse amplitude modulation (PAM-4) signals are multiplexed to realize a net transmission rate of 200 Gbps. The FSO link performance is assessed for clear weather, achieved decent bit error rate (BER) performance, and shows clear eye diagrams over a 345 m range. Further, the system is analyzed for varying rain, haze, and fog channel conditions. The reported results demonstrate reliable transmission over a link range of 250–320 m for varying haze conditions, 205–270 m for varying rain conditions, and 197–257 m for varying fog conditions with acceptable BER. The proposed 200 Gbps OAM multiplexing-based FSO transmission employing PAM-4 signals is a promising solution for providing spectral-efficient high-speed information transmission systems used in the last-mile access networks. [ABSTRACT FROM AUTHOR]

Orbital angular momentum (OAM) beams, containing helical phase structures are extensively used as data carriers due to their additional degree of freedom. OAM beam containing different modes with different l-values are always mutually orthogonal to each other. The orthogonal property of the OAM-modes reduces the intermodal crosstalk. A 10 Tbps free-space data transmission system enabled with self-injection locked quantum dash-laser diode (QDLD) and successive multiplexing of different wavelengths, OAM modes, and polarisation states of light-wave are proposed and analysed using simulation. Self-injection locked QDLD is used to generate 10 optical carriers, which results in significant reduction in cost and complexity of the system. Combination of wavelength division multiplexing, OAM multiplexing, polarisation multiplexing enhances the number of data channels up to 200. The parallel generation and detection of OAM modes have been performed employing Dammann optical vortex gratings. (10 × 10 × 2 × 50) Gbps data has been successfully transmitted over a 10 m free-space optics link. Open eye and clear constellation diagrams with a very low power penalty of 2.1 dB at a bit-error-rate value of 2.2 × 10–3 have been achieved in our proposed architecture, which authenticates the feasibility of the system. [ABSTRACT FROM AUTHOR]

with regarding to the development of technology and the use of polymeric composites in the telecommunications industry, there has been a tremendous advancement in data exchange over long distances. consequently, optical fiber telecommunications emerged which is able to response to communication need of data in high bit rate conditions. But, one of the remarkable drawbacks with polymeric optical fibers is their limited bandwidth. Hence to overcome this problem, we reporte a novel design of hollow ring core polymeric optical fiber with polystyrene core and ethylene propylene florin cladding which can provide stable support for high bandwidth data transmission. The simulation results demonstrate that the hollow ring core polymeric optical fiber has a high potential for data transferring at high speed and low latency.moreover, the results show new reported design of polymeric optical fiber at low wavelength has a larger and flatter negative dispersion than glass-based ring fibers. additionally it has been found that the dispersion index range in the range of wavelengths between 1.11 and 1.369 µm is negative, which reduces the slope delay. [ABSTRACT FROM AUTHOR]

Many sensor notes are disseminated over the network in a topographical region. The sensors existed in the environment are clustered together, that enhance the lifetime and energy of the nodes in the networks. The multi-hop routing approach is introduced through clustering, which joins one cluster with another and passes the data to the base station. The several hierarchical routing techniques has been proposed based on clustering methods. Each cluster head receives the message from the cluster member, aggregate the data together send the information to the base station via the cluster heads. In the proposed system, the Ordered Transmission Paradigm-Effective Routing (OTP-ER) protocol used the fitness function, f(x) for the selection of the Cluster Head. The fitness function is based on energy of the node and the quality of the link for data transmission. The system extends the network lifetime by utilizing the optimal energy required for effective functioning of the network when compared with other existing system. [ABSTRACT FROM AUTHOR]

The Internet of Things is made up of a set of embedded devices such as light detection sensors, ranging (LiDAR) sensors, and millimetre-wave sensors. These sensors generate a massive amount of data in which limited communication capacity is available to share a massive amount of data to Fog-based Roadside Units (RSU) for data process and analysis service. Fog-based RSU has become an emerging paradigm in intelligent transportation but needs research attention to design intelligent decision-making methods for data communication and computation at Fog-based RSU. To address these issues, we design a two-level Quantum based D2D Computation, Communication ( Q D C 2 ) approach. First, design a bandwidth allocation strategy based on spatial importance score factors to resolve embedded devices' data transmission issues. Second, design an adaptive equilibrium service offloading strategy based on device-centric measurements to assess the computation capacity and performance rate for resolving Fog-node computation consistency issues. Additionally, Fog-based RSU is interconnected with LAN helps to optimize service latency. Simulation results show that our approach achieved a high service reliability rate (79.56%), low error rate (0.9%), and an execution delay of 22.5 s for 15 devices compared to state-of-the-art approaches. [ABSTRACT FROM AUTHOR]

Orbital angular momentum (OAM) beams are basically twisted beams with infinite number of possible orthogonal OAM states. A 640 Gbps (4 × 16 × 10 Gbps) data transmission over 180 m FSO link, implemented by multiplexing of 4 OAM modes, each containing 16 wavelength channels has been proposed and demonstrated. An optical frequency comb generator, containing a single laser source is used as broadband laser source. Low power penalty of 2.91 dB at a BER value < 10–9 with very good Q-value (> 5.5) and open eye diagrams have been achieved, which reveal the potential of the proposed system for free space communication. [ABSTRACT FROM AUTHOR]

Free space optics (FSO) is considered as one of the emerging technologies in wireless communication system. In this work, real time data analysis of fog weather condition has been performed for hilly regions of north west region (Nainital, Uttarakhand) and north east region (Imphal, Manipur) of India. Different models have been considered for calculation of fog attenuation considering two specific months (January and February) for six consecutive years from 2016 to 2021. Quality of received signal has been analysed in terms of internal system parameters of an FSO link by incorporating amplitude shift keying, phase shift keying and duobinary return-to-zero modulation techniques at a data rate and transmission wavelength of 40 Gbps and 1550 nm respectively. It has been studied that PSK modulation scheme performs better as compared to other modulation techniques and received signal quality deteriorates below an unacceptable value in case of fog beyond the propagation range of 9000 m. [ABSTRACT FROM AUTHOR]