High-capacity Transmission Research Articles

Securing Ethernet-based Optical Fronthaul for 5G Network

In 5G networks, an optical fronthaul transports massive user data from remote radio heads (RRH) to the core network (CO) with high throughput and low latency. eCPRI is a new standard interface for the Ethernet-based optical fronthaul network to enhance the efficiency and performance. However, if fronthaul networks are deployed in an unsafe domain, an end-to-end security system should be implemented over the data flow, which requires additional overhead and processing time. This redundancy may cause unexpected latency and performance degradation in the data transport for 5G networks. According to the specification of eCPRI, vendors may optionally implement either IPsec or MACsec for the secure transmission. In this paper, we investigate security solutions suitable for the Ethernet-based optical fronthaul network. We analyse the standard security protocols such as IPsec and MACsec. Alternatively, we propose WireGuard as an replacement of IPsec for secure fronthaul networks. According to our analysis, the extended overhead for three security protocols has negligible impact on the latency. However, the encryption and decryption of transmission packets may cause additional latency on the eCPRI processing time and eventually reduce the maximum transmission distance between RRH and CO. To verify our analysis, we simulated an eCPRI traffic on our test platform with the WireGuard protocol enabled. Our test results showed that the latency caused by encryption and decryption process could be significant. We also point out that a re-key interval should be carefully selected not to compromise the security of the high capacity transmission link such as 5G fronthaul networks. Our analysis is further extended with quantum-resistant cryptographic solutions for the long-term security of fronthaul networks.

Deep learning and hierarchical graph-assisted crosstalk-aware fragmentation avoidance strategy in space division multiplexing elastic optical networks.

Space division multiplexing elastic optical networks (SDM-EONs) with multi-core fiber (MCF) are the promising candidate for future optical networks due to their high transmission capacity and high flexibility. However, the inherent defects of inter-core crosstalk and spectrum fragmentation may have some negative impact on the performance of SDM-EONs. A deep learning and hierarchical graph-assisted crosstalk-aware fragmentation avoidance (DLHGA) strategy is proposed in this paper. Firstly, we introduce a deep learning (DL) model to predict future requests, so as to achieve reasonable scheduling of resource in advance. Then, considering the inter-core crosstalk of MCF, we abstract the core, spectrum and time resource as a three-dimensional (3D) model with the hierarchical graphs. Therefore, the resource allocation process is simplified to be mitigating the crosstalk and fragmentation from the perspective of inter-core and intra-core, respectively. Finally, based on DL traffic prediction and different characteristics of hierarchical graph, we present an adaptive resource allocation algorithm considering relieving core adjacency and downgrading modulation format to achieve efficient resource scheduling. We evaluate our DLHGA strategy in different topologies, and the results show that our strategy can efficiently improve network performance in terms to inter-core crosstalk and bandwidth blocking probability compared to earlier approaches.

Upgrading Physical Layer of Multi-Carrier OGFDM Waveform for Improving Wireless Channel Capacity of 5G Mobile Networks and Beyond

On the brink of sophisticated generations of mobile starting with the fifth-generation (5G) and moving on to the future mobile technologies, the necessity for developing the wireless telecommunications waveform is extremely required. The main reason beyond this is to support the future digital lifestyle that tends principally to maximize wireless channel capacity and number of connected users. In this paper, the upgraded design of the multi-carrier orthogonal generalized frequency division multiplexing (OGFDM) that aims to enlarge the number of mobile subscribers yet sustaining each one with a high transmission capacity is presented, explored, and evaluated. The expanded multi-carrier OGFDM can improve the performance of the future wireless network that targets equally the broad sharing operation (scalability) and elevated transmission rate. From a spectrum perspective, the upgraded OGFDM can manipulate the side effect of the increased number of network subscribers on the transmission bit-rate for each frequency subcarrier. This primarily can be achieved by utilizing the developed OGFDM features, like acceleration ability, filter orthogonality, interference avoidance, subcarrier scalability, and flexible bit loading. Consequently, the introduced OGFDM can supply lower latency, better BW efficiency, higher robustness, wider sharing, and more resilient bit loading than the current waveform. To highlight the main advantages of the proposed OGFDM, the system performance is compared with the initial design of the multicarrier OGFDM side by side with the 5G waveform generalized frequency division multiplexing (GFDM). The experimented results show that by moving from both the conventional OGFDM and GFDM with 4 GHz to the advanced OGFDM with 6 GHz, the gained channel capacity is improved. Because of the efficient use of Hilbert filters and improved rate of sampling acceleration, the upgraded system can gain about 3 dB and 1.5 dB increments in relative to the OGFDM and GFDM respectively. This, as a result, can maximize mainly the overall channel capacity of the enhanced OGFDM, which in turn can raise the bit-rate of each user in the mobile network. In addition, by employing the OGFDM with the dual oversampling, the achieved channel capacity in worst transmission condition is increased to around six and twelve times relative to the OGFDM and GFDM with the normal oversampling. Furthermore, applying the promoted OGFDM with the adaptive modulation comes up with maximizing the overall channel capacity up to around 1.66 dB and 3.32 dB compared to the initial OGFDM and GFDM respectively. A MATLAB simulation is applied to evaluate the transmission performance in terms of the channel capacity and the bit error rate (BER) in an electrical back-to-back wireless transmission system.

SPECIFICATIONS OF THE COVID-19 INFECTION IN CHILDREN

First encountered in the 2019 COVID-19 virus has a high transmission capacity, and children are not spared. Therefore, we set a goal, referring to the experience of the countries in which the infection spread the earliest and widest, to make a summary of the characteristics of COVID-19 in the pediatric population. Of course, the most significant thing is the variation in the clinical manifestation, the correct assessment of the clinical risk of lung damage, as well as the laboratory and imaging methods of examination that support a reliable diagnosis. The therapy section of the article describes all the possible strategies for therapeutic behavior. Despite the rapidly growing theoretical information and shared clinical experience, the article could be a foundation on which to add and expand theoretical and practical knowledge.

A study of optical modulation and higher transmission capacity

A study of optical modulation and higher transmission capacity

Research and implementation on high-speed transmission performance optimization technology of ten gigabit firewall UDP multicast

Under the development trend of high throughput, large capacity and strong time effective data security transmission of the second generation data relay system in China, the high-performance processing requirements for the firewall of the backbone network security protection equipment are constantly improving. Focusing on the characteristics of the second generation data relay system, the key technologies of the transmission processing of the 10 Gigabit firewall based on the x86 architecture for different data flows are researched, the optimization design of the CPU allocation and scheduling mode, the function judgment mechanism of the network card characteristics and the kernel state write operation function of the 10 Gigabit firewall are completed. The test results show that the optimized 10 Gigabit firewall gives full play to its maximum transmission performance, and provides a better security transmission service guarantee for the integrated data relay users.

A 448-Gb/s PAM4 FSO Communication With Polarization-Multiplexing Injection-Locked VCSELs Through 600 M Free-Space Link

A 448-Gb/s four-level pulse amplitude modulation (PAM4) free-space optical (FSO) communication through 600 m free-space link was constructed, utilizing polarization-multiplexing injection-locked vertical-cavity surface-emitting lasers (VCSELs) for presentation. When uniting four-wavelength polarization-multiplexing and PAM4 modulation schemes, the transmission capacity of FSO communications is substantially multiplied, with an aggregate transmission rate of 448 Gb/s [56 Gb/s PAM4/wavelength × 4 wavelengths × 2 polarizations (xand y-polarizations)]. The results show that four 1.55 μm VCSEL transmitters with injection locking technique are sufficiently powerful for 448 Gb/s PAM4 signal transmission. Adopting a tunable optical band-pass filter and a polarization beam splitter for wavelength filtering and polarization de-multiplexing, the polarized wavelengths are effectually filtered and de-multiplexed in each polarized state. As the polarization state is well preserved in the scenario over 600 m free-space transmission, a sophisticated polarization tracker is not required in this proposed FSO communication. High bit error rate performance and accepted PAM4 eye diagrams are attained through 600 m free-space transmission. The four-wavelength polarization-multiplexing PAM4 FSO communication established here reveals the prominent benefits of high aggregate transmission capacity and long-distance free-space link.

Performance analysis of 80 channels hybrid optical time division dense multiplexing system with the support of different orthogonal modulation techniques

High spectral transmission capacity signals are the prime requirement of today’s dense communication system to enhance the quality of different users services, which have been analyzed and resolved with the support of 80 channels hybrid optical time division dense multiplexing system with different orthogonal modulation techniques (return to zero (RZ), differential quadrature phase shift keying (DQPSK), non-return-to-zero (NRZ), polarization shift keying (PoISK), and differential phase shift keying (DPSK)). Further, evaluation has also been proceeded to receive the best rating results in terms of bit error rate (BER) and quality factor (38 dB to 20 dB) with attainable rating power amplification from Erbium-Doped fiber amplifier (EDFA). Furthermore, final examine has recommended that orthogonal DPSK modulation is the best choice to attain the data rate of 1.80 Tbps from the recommended system for 200 km optical communication with acceptable rating from 10-24 to 10-10.

Increased Horizontal Transmission of Recombinant Marek's Disease Virus Due to Reticuloendotheliosis Virus Long Terminal Repeat Is the Major Competitive Advantage of the Virus Being a Prevalent Strain.

GX0101 is the first field Marek’s disease virus (MDV) recombinant with an REV LTR insert isolated in China. We speculated that there was a selective advantage of GX0101 becoming the more prevalent field strain from a very low percentage of recombinant virus. In the study, dual fluorescence quantitative real-time PCR (DF-qPCR) that detects GX0101 and GX0101ΔLTR simultaneously was established based on the genomic difference of GX0101 and its LTR deletion strain GX0101ΔLTR. MDV natural transmission was simulated in specific-pathogen-free (SPF) chicks, and continuous tracking of GX0101 and GX0101ΔLTR in chicks was carried out. The results showed that GX0101 possessed high horizontal transmission capacity, which could infect SPF chicks by contact in a short time and became the predominant strain following contact infections in chicken flocks. GX0101 still had a more significant advantage of horizontal transmission than GX0101ΔLTR after continuous passage even if the initially infectious dose was significantly lower. There were 72 differentially expressed MDV genes between GX0101 and GX0101ΔLTR, with the genes and gene products mainly involved in virus replication, tegument protein, glycoprotein, nucleocapsid protein, immune evasion, tumor development and/or pathogenesis, and hypothetical protein. Sixteen genes related to virus replication and transmission were significantly up-regulated. This is the first study to illuminate that increased horizontal transmission of recombinant MDV due to REV LTR was the competitive advantage of the virus being a prevalent strain and define the differential transcription profile of viral genes between GX0101 and GX0101ΔLTR. This will be helpful for in-depth study on the molecular mechanism of increased horizontal transmission of MDV by REV LTR.

Phase Uniformly Distributed Circular MQAM Combined With Probabilistic Shaping for PM-CO-OFDM Systems in Satellite-to-Ground Optical Communications

Due to the rapid growth of high-resolution services, low earth orbit satellite-to-ground (LEO-StG) optical communications are expected to provide higher speed and better receiver sensitivity transmission. Here, we propose a phase uniformly distributed circular m-ary quadrature amplitude modulation (MQAM) combined with probabilistic shaping (PS) scheme for polarization multiplexing coherent optical orthogonal frequency-division multiplexing (PM-CO-OFDM) systems in LEO-StG communications to achieve high capacity transmission and improve receiver sensitivity as well as linewidth tolerance. In such scheme, the radius ratio of the circular 16/32QAM is optimized to maximize the minimum Euclidean distance (MED), and the constellation points of each ring are uniformly distributed to maximize the phase space of adjacent constellation points. Besides, the circular 16/32QAM is combined with probabilistic shaping (PS) to further increase the MED under the constraint of average transmit power. Simulation results of such circular 16/32QAM combined with PS scheme under different turbulence channels not only demonstrate its feasibility, but also show the improvements in receiver sensitivity and linewidth tolerance compared with regular 16/32QAM under same entropy. The improvement of receiver sensitivity is also experimentally validated. The superiorities of such scheme make it highly desirable for potential application in long-reach, non-relay, and high capacity LEO-StG optical communications .

Big Data for Transportations and Mobility- Recent Trend, Advance and Challenge

In extensive scale Internet applications running on topographically disseminated datacenter's, for example, video gushing, it is critical to productively apportion demands among datacenters. To the best of our insight, existing methodologies, be that as it may, either exclusively center on limiting all out expense for supplier, or ensuring QOS for end-clients. In this task, we apply the product characterized organize (SDN) controller to empower the focal control of the whole system and propose a joint improvement model to consider high transfer speed use for supplier and low postponement for clients. We present the Nash bartering arrangement (NBS) based technique to show the two necessities of supplier's high transmission capacity use and end-clients' low postponement. In particular, we detail the plan of solicitation distribution under those necessities as an improvement issue, which is NP-hard. To take care of such hard improvement issue, we build up a proficient calculation mixing the upsides of Logarithmic Smoothing system and the assistant variable strategy. As per the hypothetical investigation, we confirm the presence and uniqueness of our answer and the union of our calculation. We direct a lot of trials dependent on certifiable remaining burden follows and exhibit the effectiveness of our calculation contrasted with both insatiable and area calculations.

Optimal design of a single-mode trench-assisted homogeneous multicore fibre with a minimum crosstalk level

We have proposed an optimal design of five different core structures (St1 – St5) for a seven-core trench-assisted multicore fibre, whose core radius and relative core/cladding refractive index difference Δ1 are optimal for single-mode propagation. The crosstalk performance and its reduction (in dB) with respect to variations in fibre design parameters, such as cladding/trench (Δ2) depth and trench width Wt are investigated. It is shown that some fibre operational parameters, like, fibre bending radius, operating wavelength and fibre length, affect the crosstalk performance. It is found that the crosstalk and its reduction amount are extremely dependent on the values of Δ1 and Δ2. The dispersion characteristics of the cores are investigated for all the proposed core structures and the observed dispersion is found to be about – 6 ps nm−1 km−1 at an operating wavelength of 1550 nm. An ultralow crosstalk (less than –100 dB per 100 km) can be achieved mainly with two proposed core structures (St4 and St5) having a suitably higher values of Δ1 along with a small core radius for single-mode propagation. The multicore fibre design with many cores (up to 55) is demonstrated to ensure a high transmission capacity.

Modelling and Simulation of Mho Type Distance Relay for High Voltage Transmission Line Protection Using MATLAB Software

Transmission lines are an important part of a power system. Transmission lines have high power transmission capacity and they are prone to faults of larger magnitudes. Various faults occur in transmission lines. Therefore, protection relays are necessary to protect transmission lines. The purpose of protection system is to interrupt the faulty section from the healthy section because the fault currents may damage the electrical equipments. One of the protection relays is distance relay and it is mainly used in transmission line. Sometimes these relay are used for backup protection. Distance relays for determining the impedance need the voltage and current. Transmission lines are typically protected by distance protection relay. Distance relays are considered of high speed class and can provide transmission lines. Nowadays, numerical distance relays have been used instead of using electromechanical and static distance relays. The proposed model was verified under different tests such as single line to ground (L-G) fault, double line to ground (L-L-G) fault, line to line (L-L) fault and three phase (L-L-L) fault. SimPower System was used for modelling and simulation of distance relay, transmission lines and faults. The simulation results were obtained from MATLAB software shows the feasibility of analysis of transmission line protection with mho type distance relay for single line to ground fault, double line to ground fault, line to line fault and three phase fault at different location of transmission lines. The difficulties understanding on operation of distance relay can be cleared by using MATLAB/SIMULINK software.

Sharing Large Datasets b etween Hadoop Clusters

The real information in other hand for large generous datasets either is direct data oriented stores or circulated license frameworks, in Hadoop being the prevailing open-source lifetime for 'Huge Data'. Real complete clamber stockpiling beginnings, be stroll as it may, bid urge for the competent allotment of expansive datasets over the Internet. Those frameworks that are generally utilized for the spread of extensive records, similar to Bit Torrent, should be adjusted to deal with difficulties, for example, organize joins with both high dormancy and high data transfer capacity, and versatile stockpiling backends wind are streamlined for gushing what's more, not unpredictable access. In this paper, we genuine Dela, a be awarded pounce on lead order supervision structural into the Hops Hadoop stage depart gives a start to finish answer for dataset sharing. Dela is intentional for colossal emerge amassing back ends and counsel trades that are both non-interfering to physical TCP change house and give predominant encipher throughput than TCP on high latency, high transmission capacity organize joins, for example, transoceanic system joins.

A machine learning method for green energy saving in space division multiplexing elastic optical networks

Abstract Elastic optical networks (EONs) and space division multiplexing (SDM) are promising technologies for future core optical networks with high transmission capacity. However, energy consumption and crosstalk are two inevitable problems of practical application of space division multiplexing elastic optical networks (SDM-EONs). In this paper, we leverage machine learning techniques to decrease the energy consumption and crosstalk of SDM-EONs. Specifically, we use an online sequence extreme learning machine to forecast traffic load on the lightpath, and reconstruct an energy model containing energy-consumption components in the whole network so as to reduce energy consumption. We also present a suitable scheme to decrease crosstalk. Numerical results show that the proposed algorithm is effective in achieving substantial savings in energy consumption while maintaining blocking probability and crosstalk at levels comparable to those of earlier algorithms.

Intelligent Massive MIMO Antenna Selection Using Monte Carlo Tree Search

Antenna selection is a promising technology to achieve a good balance between high transmission capacity and low hardware complexity for massive multiple-input multiple-output (MIMO) systems. However, the design of a near-optimal antenna selection algorithm with low searching complexity is still a challenge. In this paper, we describe a self-supervised learning based Monte Carlo Tree Search (MCTS) method to solve the antenna selection problem for a massive MIMO system. The search process for selecting antennas with maximal channel capacity is converted to a decision-making based problem. Based on the system model of antenna selection, we map the components of a MIMO system to the basic elements of MCTS such as action, tree state, and reward. To improve the search efficiency of the MCTS, we employ a linear regression module to extract the channel features from the channel state information (CSI) and output the prediction to MCTS as prior probability. Since the data and label are generated by the MCTS process itself, the entire process can be considered as a self-supervised learning process. According to the simulation results, the proposed self-supervised learning MCTS-based antenna search method exhibits a high searching efficiency with near-optimal performance, which archives 40% and 15% outage capacity compared with random selection and greedy search selection, respectively. The bit error rate (BER) performance of the proposed method has about 1-dB gain compared to the greedy search selection method.

High Data-Rate and Long Distance MCF Transmission With 19-Core C+L band Cladding-Pumped EDFA

We describe a series of optical transmission experiments based around single-mode, multi-core fiber (MCF) amplified with 19-core, C+L band erbium-doped fiber amplifier (EDFA). The cladding-pumped amplifier uses two multi-mode pumps in each of C and L band to provide gain bandwidth over more than 75 nm. For recirculating transmission of PDM-16QAM signals on 345 wavelength carriers between 1530.52 nm and 1605.52 nm, we measure 0.715 Pb/s transmission over a distance of 2009 km (64 recirculations), equivalent to a throughput-distance product of 1.44 exabit/s x km. Next, using PDM-QPSK modulation, we investigate trans-oceanic transmission distances, measuring throughputs of 18.6 Tb/s and 14.5 Tb/s in 2 cores after 255 recirculations, a distance of 8007 km. Further, we evaluate the combined EDFA and fiber crosstalk penalties showing a core and wavelength dependence in agreement with previous MCF crosstalk measurements. These results demonstrate the potential of high core-count EDFAs to combine both high capacity transmission over transoceanic distances with benefits of SDM integration.

An optical backhaul solution for LiFi-based access networks

The light fidelity (Li-Fi) technology is being considered as one of the most promising solutions that can achieve a dramatic increase in communication capacity and a significant reduction in transmission latency especially when it is deployed in the indoor scenario. This technique can enable fully networking capabilities by exploiting the high speed transmission of visible light communication (VLC) technique and supporting massive deployment of LiFi access points to create a network of attocells. In this paper, we investigate the design of an optical backhaul network architecture that can provide efficient interconnection for LiFi access points. Specifically, we propose a LiFi access-point structure implementing orthogonal frequency division multiplexing (OFDM) and optical encoding technique to provide multi-users access and allow all-optical processing and transmission in the backhaul network. A tunable optical encoding/decoding technique based on delaying optical pulses in a vector of optical delay line (ODLs) loops is designed to allow efficient mapping of the OFDM based access and data forwarding in the optical backhaul network. In this encoding scheme, optical codewords can be easily modified by dynamically changing the number of rounds that must be performed by the optical pulse in the ODL. This feature was exploited in the backhaul architecture to enable appropriate mobility management schemes and allow seamless handover between attocells. Performance evaluation using simulation was performed to show that the proposed optical backhaul solution can achieve high transmission capacity with reduced latency.

Upgrading superior operation performance efficiency of submarine transceiver optical communication systems toward multi tera bit per second

This paper shows the enhancement of performance operation efficiency of submarine optical communication systems toward multi Tb/s. The performance and cost optimization within transceiver submarine communication system requires careful balancing of single mode fiber attributes. Commercial single mode optical fibers are employed for this task, which that are namely Vascade® L1000 fiber, Vascade® LS+ fiber, Vascade® LEAF® fiber, Vascade® S1000 fiber, Vascade® EX 1000 fiber, and Vascade® EX 3000 fiber. High transmission capacity and long distance repeated submarine systems are achieved with attenuation and dispersion managed solutions as well as the effects of water depth, water pressure, and water temperature are taken into account in this study. The importance of minimizing dispersion slope within choosing suitable hybrid commercial submarine optical fibers to ensure good channel performance and wide system bandwidth. Vascade® R1000 fiber (mixed Vascade® L1000 fiber plus Vascade® S1000 fiber) that is namely dispersion managed fiber (DMF) offers a solution for high submarine system capacity. The figure of merit, cost planning budget, average repeater spacing, and possible transmission bit rate are the key solution for the trade off different commercial submarine optical fibers.

Coalitional Game Theoretical Approach for VANET Clustering to Improve SNR

Clustering is considered as the potential approach for network management in vehicular ad hoc network (VANET). The performance of clustering is often assessed based on the stability of the clusters. Hence, most of the clustering methods aim to establish stable clusters. However, besides the stability of cluster, good link quality must be provided, especially when reliable and high-capacity transmission is demanded. Therefore, this paper proposes a clustering method based on coalitional game theory with the purpose to improve the average of vehicle-to-vehicle (V2V) signal-to-noise ratio (SNR) and channel capacity while maintaining the stability of the cluster. In the proposed method, each vehicle attempts to form a cluster with other vehicles according to coalition value. To attain the purpose of clustering, the value of coalition is formulated based on the V2V SNR, connection lifetime, and speed difference between vehicles. In fast-changing network topology, the higher average of SNR can be achieved but the stability of cluster becomes hard to be maintained. Based on the simulation results, SNR improvement can be adjusted in order to balance with the cluster stability by setting the parameters in the proposed method accordingly. Further simulation results show that the proposed method can obtain a higher average of V2V SNR and channel capacity than other relevant methods.