Showing papers in "Photonic Network Communications in 2019"
TL;DR: A new single-bit QCA-based RAM is proposed to overcome weaknesses in the consumption area, and the circuit complexity, and it is confirmed that the proposed design improves cell numbers and wasted area.
Abstract: The use of modern quantum dot cellular automata (QCA) on the nanoscale gives better results than complementary metal–oxide–semiconductor (CMOS) technology such as diminution power consumption, augmentation clock frequency and device density enhancement. Thereupon, it becomes a substantial technology for forming whole varieties of memory. Random access memory (RAM) is an essential element of any computer set where the operating system, application programs and data can be kept to rapidly admonition via the main processor. The RAM is extremely swifter to read from and write into other kinds of the computer storages. There are some QCA cells for memory structures, wherein their specifications are used to design more optimized structures than CMOS. The offered techniques in the previous studies lead to extend in the consumption area, and the circuit complexity. So, in this paper a new single-bit QCA-based RAM is proposed to overcome these weaknesses. Ultimately, 4 × 1 RAM is designed by applying the single-bit memory. The operational authenticity of the offered layouts is demonstrated utilizing QCADesigner. Also, the QCAPro tool is utilized for calculating the dissipated energy of the circuit. The obtained results have indicated that the offered design has a smaller number of cells, low complexity and low wire crossing. Also, the wasted area has optimized based on the one-level loop-based structure. The suggested D-latch has 24 QCA cells, and the wasted area is 0.02 μm2. Each memory structure in RAM layout has the wasted area of 0.06 μm2 and 55 QCA cells. Finally, the obtained results have confirmed that the proposed design improves cell numbers and wasted area.
59 citations
TL;DR: A novel structure for realizing an all-optical comparator, which can compare two 1-bit binary codes is proposed, which used three nonlinear resonant rings for this purpose.
Abstract: All-optical comparators play crucial roles in all-optical data processing systems. In this paper, we proposed a novel structure for realizing an all-optical comparator, which can compare two 1-bit binary codes. For this purpose, we used three nonlinear resonant rings. The final structure has two input and three output ports. The maximum rise and fall times for the proposed structure are about 1.5 and 2 ps, respectively.
49 citations
TL;DR: The obtained results show that the proposed fiber reduces the confinement loss as well as DMD over the entire range of the C-band, leading to the possibility of using this type of fibers as temperature sensors.
Abstract: In this paper, a novel fiber is proposed to support few linearly polarized (LP) modes, with the feature of a circular ring-shaped core filled by liquid. This fiber supports four LP modes: LP01, LP02, LP31 and LP11. The properties of all spatial modes are numerically analyzed by considering the different optical parameters such as confinement loss, dispersion and differential modal delay (DMD) at different temperatures. The obtained results show that the proposed fiber reduces the confinement loss as well as DMD over the entire range of the C-band. The same characteristics are also investigated and optimized at 1.55 μm in the temperature range 20–80 °C. Both confinement loss and DMD evidently decrease with temperature leading to the possibility of using this type of fibers as temperature sensors.
47 citations
TL;DR: The future FON features including 3T, 3M and 3S are introduced in detail, and the key issues in the ultra-large-capacity FON (e.g., 400G FON) are analyzed including transmission distance, flexible connecting and performance monitoring.
Abstract: All-optical signal processing has always been critical assistance for the flexible optical networks (FONs) development which realizes various signal processing functions in all-optical domain avoiding electronic bottlenecks. The sustained demands for the transmission capacity and network functions drive the optical networks to enlarge the bandwidth, extend formats and increase network structures. The optical vectors are multiplexed in four domains at least in practical which are amplitude, phase, polarization and wavelength, and more multiplexing technologies are under researching. Moreover, various kinds of optical networks are employed to fulfill the constantly emerging applications such as core, metro and access networks. Facing the higher-order modulation formats, multiple multiplexing technologies and more and more complicated network structure, the future FON needs to have the feature of modulation format transparency, bandwidth transparency, wavelength transparency (3T), multi-function, multi-channel, multi-network (3M), self-perceiving, self-learning, self-adapting (3S). The transmission capacity, network flexibility and efficiency will always be the critical index for the whole network performance. The all-optical signal processing technologies have great potential in realizing the FON with the feature of 3T, 3M and 3S to process the multiple multiplexing optical signals and the problems among various optical networks. In this paper, the future FON features including 3T, 3M and 3S are introduced in detail, and the key issues in the ultra-large-capacity FON (e.g., 400G FON) are analyzed including transmission distance, flexible connecting and performance monitoring. Then, the crucial all-optical signal processing technologies and the principle and important applications of the phase-sensitive amplifier are introduced. Finally, the current existing problems and future developing trend for the all-optical signal processing technologies are discussed.
36 citations
TL;DR: The proposed RoFSO transmission system incorporating 4-QAM modulation demonstrates a successful transmission of 2 × 20 Gbit/s–40 GHz information over 104 km link range under clear weather conditions.
Abstract: This work is focused on the modeling and performance investigation of a 2 × 20 Gbit/s–40 GHz hybrid mode division multiplexing–orthogonal frequency division multiplexing-based radio over free space optics (RoFSO) transmission system under the influence of different weather conditions. The performance of the proposed system has been compared for 4-quadrature amplitude modulation (QAM), differential quadrature phase-shift keying, 16-QAM, and 32-QAM modulation schemes using error vector magnitude, optical signal-to-noise ratio requirement, and maximum link reach as the performance metrics. The results show that 4-QAM scheme demonstrates the best performance. The proposed RoFSO transmission system incorporating 4-QAM modulation demonstrates a successful transmission of 2 × 20 Gbit/s–40 GHz information over 104 km link range under clear weather conditions. Also, the maximum link range using the proposed system is reported as 4.52 km under light fog, 2.78 km under moderate fog, and 2.11 km under heavy fog conditions. Further, the performance of the proposed system has been compared with the previously reported literature which shows that the proposed system has a better figure of merit (information rate × transmission distance). The presented work can be used to implement a spectrum efficient, high-speed, long-haul information transmission system for future wireless networks.
31 citations
TL;DR: Low-power operation of the structure avoids the occurrence of nonlinear effects and neither resonant cavity nor resonant ring is employed in the structure which makes possible to operate at a wide range of photonic bandgaps.
Abstract: In this paper, we propose an all-optical 8-to-3 encoder based on photonic crystal. The structure includes 17 waveguides to make the appropriate connections between the input and the output ports. Interference at cross-connects of the waveguides results in light propagation in the desired paths. This issue reduces the needed optical intensity at input ports as well as 100 mW/μm2. Low-power operation of the structure avoids the occurrence of nonlinear effects. Also, neither resonant cavity nor resonant ring is employed in the structure which makes possible to operate at a wide range of photonic bandgaps. The maximum delay time for the presented device is obtained about 5 ps. The total footprint of the proposed structure is 510 μm2, which means it can be employed in optical integrated circuits.
30 citations
TL;DR: A novel node deployment scheme, which is based on evidence theory approach and caters for 3D USWNs, which implements sonar probability perception and an enhanced data fusion model to improve prior probability deployment algorithm of D–S evidence theory.
Abstract: Underwater wireless sensor networks (UWSNs) applications for ocean monitoring, deep sea surveillance, and locating natural resources are gaining more and more popularity. To monitor the underwater environment or any object within a certain area of interest, these applications are required to deploy underwater node sensors connected for obtaining useful data. For thriving UWSNs, it is essential that an efficient and secure node deployment mechanism is in place. This paper presents a novel node deployment scheme, which is based on evidence theory approach and caters for 3D USWNs. This scheme implements sonar probability perception and an enhanced data fusion model to improve prior probability deployment algorithm of D–S evidence theory. The viability of our algorithm is verified by performing multiple simulation experiments. The simulation results reveal that our algorithm deploys fewer nodes with enhanced network judgment criteria and expanded detection capabilities for a relatively large coverage area compared to other schemes. In addition, the generated nodes are also less resource intensive, i.e., low-power sensor nodes.
26 citations
TL;DR: Performance analysis of the NZCC code employing SAC-OCDMA using the direct detection scheme is simulated and the efficiency with the other existing codes is compared.
Abstract: Recently, a new code structure, zero cross-correlation (ZCC) using anti-diagonal type-identity-column block matrices for spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system, was proposed by K.S. Nisar. The new ZCC code (NZCC) is available for each natural number and has satisfactory code lengths. An effective OCDMA system must have efficient address codes to encode the source with almost zero correlation properties. ZCC eliminates phase-induced intensity noise that consequently improves the bit error rate. In this paper, performance analysis of the NZCC code employing SAC-OCDMA using the direct detection scheme is simulated and compared the efficiency with the other existing codes. The results show that for shorter ranges more number of users accommodated with high data rate by using NZCC code.
26 citations
TL;DR: Results indicate that placing the DI in series with the SOA-MZI renders acceptable QF of the XOR outcome at the target data rate, as opposed to the case without the DI, where the achievement of the same goal is not possible.
Abstract: All-optical exclusive OR (XOR) gate with semiconductor optical amplifier (SOA)-Mach–Zehnder interferometer (MZI) and delayed interferometer (DI) is demonstrated at 320 Gb/s through numerical simulation and analysis. The performance of the XOR gate is investigated and evaluated against the quality factor (QF). The obtained results indicate that placing the DI in series with the SOA-MZI renders acceptable QF of the XOR outcome at the target data rate, as opposed to the case without the DI, where the achievement of the same goal is not possible.
23 citations
TL;DR: The distributed approach, differently from the centralized one, is shown to be able to cope with the evolution of the C-RAN topology with limited incremental changes in the original placement and the limits of the centralized approach in terms of scalability are shown.
Abstract: Cloud radio access networks (C-RANs), relying on network function virtualization and software-defined networking (SDN), require a proper placement of baseband functionalities (BBUs) to reach full coverage of served areas and service continuity. In this context, network resources can be shared and orchestrated to meet the flexibility required by a dynamically evolving environment. Different methodologies, based on analytical formulation or heuristic algorithms, can be applied to achieve suitable trade-offs among cost components. This paper considers both centralized and distributed algorithms to obtain BBU hotel placement in C-RAN and compares their performance, scalability and adaptability to evolving scenarios. As expected, the results obtained with the distributed approach are sub-optimal, but very close, in most cases, to the optimal solutions obtained with a centralized algorithm based on integer linear programming. In addition to off-loading the SDN orchestrator, the distributed approach, differently from the centralized one, is shown to be able to cope with the evolution of the C-RAN topology with limited incremental changes in the original placement. The limits of the centralized approach in terms of scalability that the distributed approach is able to overcome are also evidenced.
21 citations
TL;DR: A brief discussion on the major pillars of 5G which are millimeter wave technology, massive MIMO, ultra-dense network, beamforming and full-duplex transmission are presented and the role of optics in 5G technology, sometimes commonly referred to as microwave photonics, an interdisciplinary research platform is focused.
Abstract: A new generation of mobile communications has been evolving for every 10 years, keeping in mind the enormous data traffic, huge capacity requirements, excellent quality of service with minimal latency; there is a shift in paradigm toward the upcoming 5G technology which is expected to be rolled out by 2020 that promises to meet the requirements stated above. 5G is envisaged to be a merged framework of wide range of applications ranging from device-to-device communications, smart grid to Internet of Things and many more. In this survey paper, a brief discussion on the major pillars of 5G which are millimeter wave technology, massive MIMO, ultra-dense network, beamforming and full-duplex transmission are presented. This survey paper also focuses on the role of optics in 5G technology, sometimes commonly referred to as microwave photonics, an interdisciplinary research platform. Due to huge bandwidth and enormous capacity upgrade, optical fibers are considered to be ideal backhaul and fronthaul media rather than copper cables in order to support small cells and next-generation networks. These advantages of optical fiber technology enable integrated optical and wireless access technologies for 5G wireless communications an interdisciplinary area of research.
TL;DR: In this study, the plane wave expansion and finite difference time domain methods are used, to characterize the photonic band gap and to investigate the optical behavior of the structures.
Abstract: In this research, using photonic crystal dielectric rods with a triangular lattice constant, a photonic crystal ring resonator (PhCRR) has been designed in order to be used in optical add/drop filters (ADF).Query Using the proposed hexagonal PhCRR with four different dropping waveguides, new ADFs have been designed and simulated. At a central wavelength of 1550.5 nm, the four proposed ADFs have an average transmission coefficient, a bandwidth, and a quality factor of 100%, 1.2 nm and 1330, respectively. The results obtained from these structures indicate the high flexibility of the proposed PhCRR and ADFs and their applicability in optical communication systems. Using the ADFs, two multi-channel drop filters have been designed in order to be used as optical MUX/DeMUX with a channel spacing of 4 nm which are suitable for wavelength division multiplexing systems. In this study, the plane wave expansion and finite difference time domain methods are, respectively, used, to characterize the photonic band gap and to investigate the optical behavior of the structures.
TL;DR: The proposed circuits compared with the previous structure improve delay by 90–75–35% in generator and checker structures of parity and their reversibility of nano-communication system, respectively and are used in nano-transmitters and nano-receivers.
Abstract: Complementary metal-oxide semiconductor (CMOS) technology may face so much problems in future due to the smaller size of transistors and increase in circuits’ volume and chips temperature. A new technology that can be a good alternative to CMOS circuits is quantum-dot cellular automata (QCA). These technologies have features such as a very low power consumption, high speed and small dimensions. In nano-communication system, error detection and correction in a receiver message are major factors. In addition, circuit reversibility in QCA helps designs a lot. In this research, generator and checker circuit of the reversible parity and eventually their nano-communication system are designed reversible using odd parity bit. The proposed circuits and the theoretical values are tested by QCADesigner 2.0.3 simulator to show the correct operation of the circuits. According to the simulation results, the proposed circuits compared with the previous structure improve delay by 90–75–35% in generator and checker structures of parity and their reversibility of nano-communication system, respectively. The proposed circuits are used in nano-transmitters and nano-receivers.
TL;DR: A new switching scheme is proposed for the hybrid FSO/RF system, in which both FSO and RF links are emphatically activated or deactivated according to the channel conditions, with closed-form analytical expressions obtained for the bit error rate and outage probability.
Abstract: Hybrid FSO/RF communication systems make use of an RF link with OWC link to achieve higher reliability along with high data rate communication. Both these (OWC and RF) channels are complementary in nature. We propose and analyze a new switching scheme for the hybrid FSO/RF system, in which both FSO and RF links are emphatically activated or deactivated according to the channel conditions. A single threshold level is decided for the Rayleigh-faded RF link, and two threshold levels are defined for FSO link under strong atmospheric turbulence conditions. Closed-form analytical expressions have been obtained for the bit error rate and outage probability for the proposed system.
TL;DR: It is observed that when link is subjected to strong turbulence along with adverse weather conditions, the DSP-aided coherent DWDM-FSO receiver achieves target bit error rate (BER) of 10−4 at signal-to-noise ratio (SNR) of 36.4 dB.
Abstract: In this paper, 1.28 Tbps (32 × 40 Gbps) high-capacity DWDM-FSO link has been investigated for performance enhancement using coherent detection and digital signal processing (DSP). The DP-16QAM-modulated proposed DWDM-FSO link has been analyzed for both adverse weather and turbulent atmospheric conditions. It is observed that when link is subjected to strong turbulence along with adverse weather conditions, the DSP-aided coherent DWDM-FSO receiver achieves target bit error rate (BER) of 10−4 at signal-to-noise ratio (SNR) of 36.4 dB, while for similar conditions, the SNR requirements for IM/DD-based DWDM-FSO link shoots by 12.8 dB to 49.2 dB. Also, in terms of operational link range, the proposed link even under strong turbulent conditions serves 1.88 km, whereas IM/DD link was restricted to mere 1.12 km for target of BER of 10−4, thus producing a decent range increment of 760 m. The proposed link has been designed and investigated using OptiSystem™ 14.2.
TL;DR: This paper proposes a RSA algorithm named Min-PCR-LCR, which always chooses a spectrum block with the minimum path contiguity reduction to a connection request, and if there is a tie, the one with theminimum sum of link Contiguity reductions is finally chosen.
Abstract: Elastic optical network, due to its flexibility of spectrum assignment, has been the most promising technology in the next generation of backbone transport network. Routing and spectrum assignment (RSA) is one of its key issues. Several RSA algorithms have been proposed in recent years. In the spectrum assignment process, the more contiguous the idle frequency slices, the more likely it is to find available spectrum blocks for connection requests. Therefore, in this paper, we first give the concept of link/path contiguity reduction (LCR/PCR) to express the change of spectrum contiguity on a link/path after a spectrum block is used. Then, we propose a RSA algorithm named Min-PCR-LCR, which always chooses a spectrum block with the minimum path contiguity reduction to a connection request, and if there is a tie, the one with the minimum sum of link contiguity reductions is finally chosen. Simulation results show that the Min-PCR-LCR algorithm can get lower blocking probability than the existing well-performed RSA algorithms.
TL;DR: A structure which is capable of separating eight optical channels with transmission efficiencies very close to 100% is proposed, and eight cavities with different sizes for the reduced rods are proposed.
Abstract: In order to improve the transmission efficiency in eight-channel optical demultiplexers, we are going to use novel resonant cavities for performing the wavelength selecting function in photonic crystal demultiplexers. These resonant cavities will be created by removing one rod and reducing the radius of four rods. By incorporating eight cavities with different sizes for the reduced rods, we proposed a structure which is capable of separating eight optical channels with transmission efficiencies very close to 100%. The average channel spacing is about 3 nm. Crosstalk values vary between − 40 and − 16 dB.
TL;DR: Considering the cost, the scheme of 3/2-way PWM-solenoid valve is the most suitable choice for the system with multi-channel soft actuators, and the research achievement is providing a valuable suggestion on balancing the performance and cost for different soft robotic system applications.
Abstract: Pneumatic soft actuator is a crucial component of soft robot. This paper proposes several pneumatic control schemes implemented with proportional and PWM-solenoid valves to achieve optimal control for pneumatic soft actuators adapted to different soft robots, such as soft gripper and soft humanoid hand. The schemes include: proportional valve; 3/2-way PWM-solenoid valve; 2/2-way PWM-solenoid valve. The control framework of these schemes contains human–machine interface in upper computer and control algorithm in lower computer. Sinusoidal and multi-step signals are served as reference input to draw a comparison of pressure tracking precision, steady-state accuracy and responsibility of these proposed schemes. The experimental results show that the scheme of proportional valve is more excellent than those of the PWM-solenoid valves, and the scheme of 3/2-way is superior to that of 2/2-way with regard to PWM-solenoid valve. Considering the cost, the scheme of 3/2-way PWM-solenoid valve is the most suitable choice for the system with multi-channel soft actuators. Therefore, the research achievement of this paper is providing a valuable suggestion on balancing the performance and cost for different soft robotic system applications.
TL;DR: Three different approaches for the survivable BBU pool placement problem and traffic routing in C-RAN deployment over a 5G optical aggregation network are proposed and the trade-off between the centralization degree and the tight latency requirements are shown.
Abstract: The huge data demand envisioned for the 5G requires radical changes in the mobile network architecture and technology. Centralized radio access network (C-RAN) is introduced as a novel mobile network architecture, designed to effectively support the challenging requirements of the future 5G mobile networks. In C-RAN, BaseBand Units (BBUs) are physically separated from their corresponding radio remote heads (RRHs) and located in a central single physical location called BBU pool. The RRHs are connected to the BBU pool via the so-called fronthaul network.
The “centralization” demonstrates remarkable benefits in terms of computational resources as well as power savings. Following this centralization, designing a survivable C-RAN becomes crucial as BBU pool and link failures might cause service outage for large number of users. In this paper, we propose three different approaches for the survivable BBU pool placement problem and traffic routing in C-RAN deployment over a 5G optical aggregation network. Namely, we define the following protection scenarios: (1) dedicated path protection, (2) dedicated BBU protection and (3) dedicated BBU and path protection. The three approaches are formalized as integer linear programming (ILP) problems. The ILPs objectives are to minimize the number of BBU pools, the number of used wavelengths and the baseband processing computational resources, in terms of giga operations per second. We provide numerical results to compare the aforementioned protection strategies considering different network topologies. The results show the effect of the latency and the transport–network capacity on the BBU placement. We show the trade-off between the centralization degree and the tight latency requirements. Moreover, we discuss important insights about considering the different objective functions for each protection approach.
TL;DR: The proposed 2-channel and 4-channel demultiplexers can be used in WDM systems, especially DWDM systems and the simplicity of the structure and the small size are among the characteristics of these designs.
Abstract: In this paper, 2-channel and 4-channel optical demultiplexers have been designed based on photonic crystal nano-ring resonator. The structure of both demultiplexers is based on the use of a photonic crystal filter. The mean quality factor of 2828, mean transfer factor of 95%, mean cross-talk of − 25.07 dB, and an inter-channel distance of 7.4 nm are among the structural advantages of the 2-channel demultiplexer. The advantages of the 4-channel demultiplexer include the mean quality factor of 4525, mean channel power transfer factor of 95%, and maximum and minimum channel cross-talk of − 19.6 and − 40.4, respectively. Also, the inter-channel difference is 7.8 nm and mean channel width is 0.375 nm. Moreover, the simplicity of the structure and the small size are among the characteristics of these designs. The proposed 2-channel and 4-channel demultiplexers can be used in WDM systems, especially DWDM systems.
TL;DR: The PSO-optimized antenna has been attained and its performance has been compared with both initial conventional ‘T’-shape slot loaded antenna and manually optimized antenna.
Abstract: This paper illustrates optimization and comparative analysis for rectangular microstrip patch antenna loaded with ‘T’-shape slot utilizing manual (conventional) optimization and particle swarm optimization (PSO) with curve fitting. Initially, a conventional antenna has been designed by cutting ‘T’-shape slot in rectangular radiating patch and manually optimized by selecting some parameters of patch as variable. The bandwidth and resonant frequency data obtained from IE3D simulation tool by varying distinct parameters of the conventional ‘T’-shape slot loaded antenna have been used for generating the curve in Graphmatica (curve fitting software) and developing the PSO program in MATLAB for optimization purpose. Finally, the PSO-optimized antenna has been attained and its performance has been compared with both initial conventional ‘T’-shape slot loaded antenna and manually optimized antenna. Fragmentary bandwidth of PSO-optimized ‘T’-shape slot loaded antenna has been increased by 16.86% as compared to initial conventional ‘T’-shape slot loaded antenna and kept the resonant frequency at 2.477 GHz near the desired frequency of 2.45 GHz.
TL;DR: There is no statistical difference in the characteristic parameters of EMG signals calculated from the start/end points obtained by the segmentation algorithm and the manual segmentation method, and this study lays the foundation for the application of surface electromyography in the field of rehabilitation analysis and control.
Abstract: Surface electromyography (SEMG) is an important tool for analyzing gait movements. Effective segmentation of electromyography (EMG) start/end points is an important step in the analysis of EMG signals. This paper presents a SEMG segmentation algorithm based on signal envelope and integral electromyography. Compared with manual segmentation, the coincidence rate is more than 90%. There is no statistical difference in the characteristic parameters of EMG signals calculated from the start/end points obtained by the segmentation algorithm and the manual segmentation method (P > 0.05). Based on this segmentation algorithm, quantitative analysis and comparison of the force situation of the iliopsoas, musculus gracilis, soleus and tibialis anterior muscles during the complete gait cycle are performed. This study lays the foundation for the application of surface electromyography in the field of rehabilitation analysis and control, such as rehabilitation training and rehabilitation robots.
TL;DR: This paper focuses on the entire resource consumption of a single cell for the multicast-service beam-forming in next-generation RAN and proposes a flexible wavelength-division-multiplexing-based fronthaul to support the high-capacity and resilient transport.
Abstract: Massive MIMO (mMIMO) is a technology with high potential in future 5G radio access networks (RAN). As a crucial feature in mMIMO, beam-forming provides a remarkable enhancement for the wireless transmission. However, beam-forming introduces extra wireless resource and fronthaul bandwidth consumption for utilizing multiple antennas to transmit the same data. Moreover, this problem will be highlighted in the multicast-service beam-forming because more identical data will be transmitted in networks. In this paper, we focus on the entire resource consumption of a single cell for the multicast-service beam-forming in next-generation RAN and propose a flexible wavelength-division-multiplexing-based fronthaul to support the high-capacity and resilient transport. A mixed-integer nonlinear programming formulation and two heuristic algorithms are developed to minimize the utilized optical bandwidth, radio resource blocks and antennas. Simulation comparisons are performed among different resource allocation strategies. Numerical results demonstrate that our strategies can efficiently reduce the total resource consumption.
TL;DR: A minimal and optimal design of the circuit-switched network is presented at a single level in QCA and is studied and compared with existing designs in terms of fault tolerant under stuck-at 0 and 1.
Abstract: Quantum-dot cellular automata (QCA) is a nanoscale technology to design digital circuits in nano-measure which acts based on electron’s interaction. The technology of collecting, processing and distributing information is growing rapidly, but the growth in demand for advanced methods in data processing has always been greater than the speed of growth of these technologies. Hence, computer networks play an important role in providing a resource sharing and facilitating user communications. The circuit-switched network is one of the main components for sending input signals between different users within the network. In this paper, a minimal and optimal design of the circuit-switched network is presented at a single level in QCA. The proposed design is studied and compared with existing designs in terms of fault tolerant under stuck-at 0 and 1. There is also a physical analysis for the proposed circuit-switched network.
TL;DR: The positive and negative impacts of the SDN paradigm profoundly affects the architecture of networks in favor of more adaptability to the needs for new value-added services are examined.
Abstract: The SDN paradigm profoundly affects the architecture of networks in favor of more adaptability to the needs for new value-added services. This article examines the positive and negative impacts of such a change on network security. While few in-depth studies have attempted to cover this issue in a comprehensive way, we first tried to define the most relevant axes of analyses with regard to this concept, namely availability, access control and application services oriented security. In relation to these axes as well as to the state of the art of security, a number of researches and studies that have addressed this issue by proposing solutions through the OpenFlow specification are analyzed with the aim to highlight the real opportunities and the real challenges brought by this new concept for the network security.
TL;DR: Simulation results show that mirror-aided non- Los channels outperform purely diffuse non-LOS links regardless of the link configuration, and the effect of concentration and directionality of non-Los VLC channels is shown and discussed.
Abstract: The emerging cost-efficient visible light communication (VLC)-based indoor wireless network requires an economical solution for backhaul transmission. Non-line-of-sight (non-LOS) VLC links are generally applicable candidates to set up a backhaul network without rearrangement of existing lighting fixtures. Here, we describe non-LOS channels aided by the first-order specular reflection from mirrors, which can be used to overcome the multipath effect of purely diffuse non-LOS channels. Characterizations of purely diffuse and mirror-aided non-LOS channels are conducted with a time-efficient simulation model based on an iterative algorithm. Any bounce of reflections combined with specular and diffuse reflections can be simulated using the proposed iterative VLC model in polynomial time. Simulation results show that mirror-aided non-LOS channels outperform purely diffuse non-LOS links regardless of the link configuration. The effect of concentration and directionality of non-LOS VLC channels is also shown and discussed.
TL;DR: A new hybrid intrusion detection model which combines the distributed and centralized strategies is proposed, and results show that the proposed method has better performance than the traditional Sinkhole attacks detection method.
Abstract: In this paper, a new hybrid intrusion detection model which combines the distributed and centralized strategies is proposed in this paper as follows. Firstly, considering the network anomalies, situation cannot be captured in real time on the base station; by introducing the CUSUM (cumulative summation) GLR (generalized likelihood ratio), an anomaly detection model which runs on the node is given. It can conduct real-time network monitoring. Based on the “link quality” and “majority rule,” a new algorithm to detect the “Sinkhole attack” in the base station is proposed, and a new model CUSUM_MV to detect intrusion is given. Secondly, the evidence theory is introduced to detect intrusion in wireless sensor network. We give the redundant information process mechanism in the relay node, an evidence-based intrusion detection model deployed on the base station and the intrusion detection model CUSUM_HDST. The hybrid model can detect not only Sinkhole and DoS attacks, but also other specific vulnerabilities. A simulation experiment on Castalia simulator is carried out, and results show that the proposed method has better performance than the traditional Sinkhole attacks detection method.
TL;DR: An optimization approach that is a combination of advanced scalable (heuristics) and large-scale optimization approaches for solving the routing and spectrum allocation with transceiver and regeneration allocation problem in elastic optical networks is developed.
Abstract: In view of determining the optimal solutions to large problem cases of the routing and spectrum allocation with transceiver and regeneration allocation problem in elastic optical networks, the optimization proves to be challenging in terms of the (i) size of the network, (ii) demand(s) amount, and (ii) width of the spectrum. In the current work, we develop an optimization approach that is a combination of advanced scalable (heuristics) and large-scale optimization approaches. The routing and spectrum allocation with transceiver and regeneration allocation problem is formulated as a mixed integer program, and to solve it efficiently, the branch and price algorithm is upgraded with the following methods: (i) relaxation(s) of the problem and cuts to improve the optimal objective value’s lower bounds and (ii) formulation of a heuristic to improve the upper bounds, and finally, the aforementioned elements are mixed to form an effective optimization method. The simulation conducted for (i) realistic topologies characterized by different node(s) numbers and link distances, and (ii) large sets of demands demonstrate that the developed algorithm’s performance is efficient, and it is also applicable to problem cases for which determining the solution(s) proves to be difficult by using commercially available solvers (e.g. CPLEX) in the market.
TL;DR: A succinct outline of the smart antenna, an analysis and the comparison of different architectures of optical signal processing beamforming network (OSPBFN) is presented and can enhance the understanding of the ongoing research work in the area of OSPBFN.
Abstract: Forthcoming wireless systems are developed to support greater data rate and extra coverage area. This can be achieved with the help of multiple input multiple output and smart antenna techniques. One of the major rapidly emerging areas of communication is the smart antenna system which aids in attaining better coverage by increasing the signal strength only in the chosen direction. With effective optical beamforming techniques, the smart antenna systems demonstrate to be more competent in terms of excellence of signals in wireless communication.
In this paper, a succinct outline of the smart antenna, an analysis and the comparison of different architectures of optical signal processing beamforming network (OSPBFN) is presented. The performance of OSPBFN is analyzed and the comparison is done for different architectures with the antenna radiation parameters. This paper can enhance the understanding of the ongoing research work in the area of OSPBFN.
TL;DR: This paper will study the HWSN reliability evaluation based on IoV perception layer and utilizes the object-oriented colored Petri net as the modeling tool for HWSN, and proposes a new approach to HW SN reliability evaluation quantification.
Abstract: Internet of vehicles (IoV) is a typical application of internet of things in the field of traffic. Heterogeneous wireless sensor network (HWSN) offers the technical support for perceiving and collecting the information on the internet of vehicles, but this technology faces tremendous challenges regarding the guarantee for data transmission reliability. This paper will study the HWSN reliability evaluation based on IoV perception layer and utilizes the object-oriented colored Petri net as the modeling tool for HWSN. On the basis of this model, this paper further explores the definition of HWSN reliability evaluation quantification and proposes a new approach to HWSN reliability evaluation quantification. At last, a simulation platform of HWSN is constructed to verify the effectiveness and feasibility of the proposed model and approach.