下一代SONET/SDH对网络部署的冲击

面对电信业的低迷,运营商和设备制造商都捏紧了钱袋,想方设法少花钱多办事。这就意味着,必须改进现有传输网(见图1),使话音和数据传输效率更高。从网络部署的角度来看,运营商需要:用一些有效的方法,将多协议数据转换到SONET/SDH信道上;用一种灵活的带宽适应机制,使SONET/SDH信道大小与在其中传输的数据的需求相一致;用一种机制,灵活并以理想的动态方式改变整个SONET/SDH网络的信道带宽。这就要求集成电路供应商提供有助于在SONET/SDH上有效传输数据的芯片。虽然现在有多种SONET/SDH信息包(PoS)产品,但是它们的转换效率都太…     

A new finite-difference-based method for wide-angle beam propagation

A novel split-step finite-difference method for wide-angle beam propagation is presented. The formulation allows solution of the second-order scalar wave equation without having to make the slowly varying envelope and one-way propagation approximations. The method is highly accurate and numerically efficient requiring only simple matrix multiplication for propagation.     

Shared hardware,high throughput implementation of 2D 4 × 4 and 8 × 8 integer transform for H.264/AVC high-profile coders

Two-dimensional discrete cosine transforms are used in the core transformations in all profiles of the H.264/Advanced video coding (AVC) standard. In this paper, implementing the resource sharing of high throughput 4 × 4 and 8 × 8 forward and inverse integer transforms for high definition H.264 is presented. It is shown that the 4 × 4 forward/inverse transform can be obtained from 8 × 8 forward/inverse transform using selective data input and data arrangement at intermediate stages. Fast 8 × 8 forward and inverse transform is implemented using matrix decomposition and matrix operation such as Kronecker product and direct sum. The proposed implementation does not require any transpose memory and has a dual clocked pipeline structure. Compared with existing designs, the gate count is reduced by 27.7% in the proposed design. The maximum operating frequency of the proposed system is approx. 1.3 GHz, while the throughput is 7 G and 18.7 G pixels/s for 4 × 4 and 8 × 8 forward integer transforms, respectively. The proposed design can be used for real time H.264/AVC high definition processing owing to its high throughput and low hardware cost.     

VLC Enabled Hybrid Wireless Network for B5G/6G Communications

Wireless Personal Communications - In the present scenario, there is a boom in the demand of the users to achieve increased capacity, high data, low latency, and high-performance rates. 5G New...     

Intrusion Detection System in Wireless Sensor Network Using Conditional Generative Adversarial Network

Wireless communication networks have much data to sense, process, and transmit. It tends to develop a security mechanism to care for these needs for such modern-day systems. An intrusion detection system (IDS) is a solution that has recently gained the researcher’s attention with the application of deep learning techniques in IDS. In this paper, we propose an IDS model that uses a deep learning algorithm, conditional generative adversarial network (CGAN), enabling unsupervised learning in the model and adding an eXtreme gradient boosting (XGBoost) classifier for faster comparison and visualization of results. The proposed method can reduce the need to deploy extra sensors to generate fake data to fool the intruder 1.2–2.6%, as the proposed system generates this fake data. The parameters were selected to give optimal results to our model without significant alterations and complications. The model learns from its dataset samples with the multiple-layer network for a refined training process. We aimed that the proposed model could improve the accuracy and thus, decrease the false detection rate and obtain good precision in the cases of both the datasets, NSL-KDD and the CICIDS2017, which can be used as a detector for cyber intrusions. The false alarm rate of the proposed model decreases by about 1.827%.

     

An Adaptive Transmission Mode Selection Scheme for Cellular Underlaid D2D Communication

In this paper, we propose to use Artificial Bee Colony (ABC) optimization to solve the joint mode selection, channel assignment, and power allocation (JMSCPA) problem to maximize system throughput and spectral efficiency. JMSCPA is a problem where the allocation of channel and power depends on the mode selection. Such problems require two step solution and are called bi-level optimization problems. As bi-level optimization increases the complexity and computational time, we propose a modified version of single-level ABC algorithm aided with the adaptive transmission mode selection algorithm to allocate the cellular, reuse, and dedicated modes to the DUs along with channel and power allocation based on the network traffic load scenarios. A single variable, represented by the users (CUs and DUs) is used to allocate mode selection, and channel allocation to solve the JMSCPA problem, leading to a simpler solution with faster convergence, and significant reduction in the computational complexity which scales linearly with the number of users. Further, the proposed solution avoids premature stagnation of conventional ABC into local minima by incorporating a modification in its update procedure. The efficacy of the ABC-aided approach, as compared to the results reported in the literature, is validated by extensive numerical investigations under different simulation scenarios.

     

Nitrogen Plasma Processing of SiO2/4H-SiC Interfaces

A nitrogen plasma annealing process for gate dielectric applications in 4H-SiC metal oxide semiconductor (MOS) technology has been investigated. This process results in substantially greater interfacial N coverage at the SiO₂/4H-SiC interface and lower interface trap densities than the state-of-the-art nitric oxide (NO) annealing process. Despite these exciting results, the field-effect mobility of MOS field-effect transistors (MOSFETs) fabricated by use of this process is very similar to that of NO-annealed MOSFETs. These results emphasize the importance of understanding mobility-limiting mechanisms in addition to charge trapping in next-generation 4H-SiC MOSFETs.     

Bacteria-Responsive Multidrug Delivery Nanosystem for Combating Long-Term Biofilm-Associated Infections

Microbial biofilm formation on implantable devices causes chronic infections that cannot be treated with existing antimicrobials. Quorum sensing inhibitors (QSIs) have recently emerged as novel antimicrobials for the prevention of biofilm formation. But blocking QS alone is insufficient to inhibit biofilm-associated chronic infections. Herein, chitosan hollow nanospheres are capped by bacteria-responsive β-casein to form a synergistic antifouling nanosystem consisting of a QSI and bactericide. β-casein is degraded by protease in a bacteria-colonized microenvironment in situ thus, QSI and bactericide are released sequentially. The release of QSI sensitises bacteria effectively through reduction of surface hydrophobicity, eDNA content, and lipopolysaccharide production in biofilms, amplifying the chemotherapeutic action of the bactericide. Compared to the uncoated surface, the coated surface inhibits biofilm formation and removes preformed biofilms of Pseudomonas aeruginosa PAO1 and methicillin-resistant Staphylococcus aureus by 1.8 logs and 1.9 logs of biomass inhibition, respectively. The coated catheters are found to stay clean for 30 days under artificial urine flow, while the uncoated catheters are clogged by bacterial biofilms within 5 days. Finally, the long term antifouling activity in vivo is confirmed. Overall, the nanosystem is devoted to making urinary catheters resistant to bacterial biofilm formation for the long term.     

DC and analog/RF performance optimisation of source pocket dual work function TFET

We investigate a systematic study of source pocket tunnel field-effect transistor (SP TFET) with dual work function of single gate material by using uniform and Gaussian doping profile in the drain region for ultra-low power high frequency high speed applications. For this, a n⁺ doped region is created near the source/channel junction to decrease the depletion width results in improvement of ON-state current. However, the dual work function of the double gate is used for enhancement of the device performance in terms of DC and analog/RF parameters. Further, to improve the high frequency performance of the device, Gaussian doping profile is considered in the drain region with different characteristic lengths which decreases the gate to drain capacitance and leads to drastic improvement in analog/RF figures of merit. Furthermore, the optimisation is performed with different concentrations for uniform and Gaussian drain doping profile and for various sectional length of lower work function of the gate electrode. Finally, the effect of temperature variation on the device performance is demonstrated.     

Analysis of diffused planar and channel waveguides

A simple analytical method is presented which improves upon the Hermite-Gauss field proposed by S.K. Korotky et al. (1982) for diffused waveguides by taking into account the evanescent field in the cover region. The method is used to analyze the propagation characteristics of diffused planar and channel waveguides