This paper develops a novel distributed iterative event-triggered control scheme for a master-slave-organized dc microgrid network with limited communication bandwidth. The proposed scheme can ...synchronize the voltage of multiple distributed energy resources (DER) to their desired value. Moreover, the optimal load sharing for their economic operation (e.g., minimize the total generation cost) can be achieved through a low bandwidth communication network. The designed controllers are fully distributed and only triggered at their own event time, which effectively reduces the frequency of controller updates compared with continuous-time feedback control. Eventually, each DER only requires the local voltage and current measurement from its own and some nearest (but not all) neighbors at given event-triggered time through limited-bandwidth communication links. The Lyapunov technique is employed to derive the event-triggered conditions that guarantee the stability. Furthermore, the lower bound of the interevent intervals is captured by the proposed iterative algorithm to exclude Zeno behaviors. Different cases in MATLAB/SimPowerSystems are investigated and results demonstrate the effectiveness and the performance of the proposed approach.
Improper Gaussian signaling (IGS) has shown its capability of improving the rate of interference-limited networks by exploiting the additional degrees of freedom in signal processing. This article ...considers a system of a multiple-input single-output (MISO) cellular network coexisting with device-to-device (D2D) communication, where the former employs proper Gaussian signaling (PGS) but the latter employs IGS to improve D2D's rate and also to mitigate interference to the former. Both non-orthogonal and orthogonal bandwidth sharing between cellular users (CUs) and D2D pairs are considered. The problems of joint bandwidth allocation and signal beamforming to maximize the minimum CUs' rate subject to the transmit power budget and D2D's rate threshold are addressed, which pose critical computational challenges. Path-following algorithms of low complexity are developed for computational solutions. Two distinct scenarios, i.e., unmanned aerial vehicle (UAV)-enabled networks, and MISO cellular networks are simulated to give insight into the superiority of using IGS over PGS. Our results reveal that in UAV-enabled networks, orthogonal sharing produces a higher D2D's rate, while non-orthogonal sharing offers better CUs' rate under practical levels of D2D's rate. In MISO systems, IGS is a game-changer, which enables the orthogonal sharing to uniformly outperform the non-orthogonal sharing in terms of CUs' rate.
Wireless sensor networks (WSN) is formed by autonomous nodes with partial memory, communication range, power, and bandwidth. Their occupation depends on inspecting corporal and environmental ...conditions, and communing through a system and performing data processing. The application field is vast, comprising military, ecology, healthcare, home or commercial and require a highly secured communication. This article analyses different types of attacks and counterattacks, and provides solutions for the WSN threats.
As a key technology of enabling Artificial Intelligence (AI) applications in 5G era, Deep Neural Networks (DNNs) have quickly attracted widespread attention. However, it is challenging to run ...computation-intensive DNN-based tasks on mobile devices due to the limited computation resources. What's worse, traditional cloud-assisted DNN inference is heavily hindered by the significant wide-area network latency, leading to poor real-time performance as well as low quality of user experience. To address these challenges, in this paper, we propose Edgent, a framework that leverages edge computing for DNN collaborative inference through device-edge synergy. Edgent exploits two design knobs: (1) DNN partitioning that adaptively partitions computation between device and edge for purpose of coordinating the powerful cloud resource and the proximal edge resource for real-time DNN inference; (2) DNN right-sizing that further reduces computing latency via early exiting inference at an appropriate intermediate DNN layer. In addition, considering the potential network fluctuation in real-world deployment, Edgent is properly design to specialize for both static and dynamic network environment. Specifically, in a static environment where the bandwidth changes slowly, Edgent derives the best configurations with the assist of regression-based prediction models, while in a dynamic environment where the bandwidth varies dramatically, Edgent generates the best execution plan through the online change point detection algorithm that maps the current bandwidth state to the optimal configuration. We implement Edgent prototype based on the Raspberry Pi and the desktop PC and the extensive experimental evaluations demonstrate Edgent's effectiveness in enabling on-demand low-latency edge intelligence.
This paper studies a federated learning (FL) system, where multiple FL services co-exist in a wireless network and share common wireless resources. It fills the void of wireless resource allocation ...for multiple simultaneous FL services in the existing literature. Our method designs a two-level resource allocation framework comprising intra-service resource allocation and inter-service resource allocation. The intra-service resource allocation problem aims to minimize the length of FL rounds by optimizing the bandwidth allocation among the clients of each FL service. Based on this, an inter-service resource allocation problem is further considered, which distributes bandwidth resources among multiple simultaneous FL services. We consider both cooperative and selfish providers of the FL services. For cooperative FL service providers, we design a distributed bandwidth allocation algorithm to optimize the overall performance of multiple FL services, meanwhile catering it to the fairness among FL services and the privacy of clients. For selfish FL service providers, a new auction scheme is designed with the FL service providers as the bidders and the network operator as the auctioneer. The designed auction scheme strikes a balance between the overall FL performance and fairness. Our simulation results show that the proposed algorithms outperform other benchmarks under various network conditions.
A novel wide-bandwidth wearable all-textile planar inverted-F antenna (PIFA), designed for 5 GHz wireless local area network (WLAN) applications (5.15-5.825 GHz), is proposed in this communication. ...By using hollow copper rivets, nylon conductive fabric, and wool felt, a PIFA with a compact structure and flexible fabrication is realized. Additional wide bandwidth is achieved by adding a pair of shorting pins and etching a slot to manipulate the dual resonances of the TM 0,1/2 and TM 0,3/2 modes. The variation in the electric field distributions qualitatively explains the effects of the shorting pins and the slot for these two modes. As a result, the antenna has a good performance with a measured fractional bandwidth of 18.0%, a peak gain of 5.9 dBi, and an average efficiency up to 74.1%. In addition, stable performance on a human body is obtained such that the operating bandwidth on different human tissues and under different bending conditions can cover the design band. The calculated specific absorption rate (SAR) values are 0.9307 and 0.4016 W/kg under 1 g average and 10 g average, respectively. These properties make the proposed antenna suitable for wearable systems.
Motivated by a broad range of potential applications in event-driven signal processing inference, we examine a class of spectral moments estimators derived from multiple level-crossings of a ...stationary Gaussian stochastic signal as well as non-Gaussian signals being monotone transformations of the Gaussian signal. The established spectral moments estimators are used to obtain estimates of the stochastic signal bandwidth. Both the mean-squared bandwidth and the absolute bandwidth are taken into account. Also the notion of the power bandwidth is introduced and its estimation is examined. We prove that the proposed estimates are consistent as the length of the observed time interval is increasing. The accuracy of the proposed bandwidth estimation methods from multiple level-crossings is assessed in simulation studies.
The bandwidth (BW) of a broadband dual-polarized antenna is enhanced for 2G/3G/4G systems and international mobile telecommunications services. The broadband dual-polarized element is a four-leaf ...clover antenna. By introducing a U-shaped slot to each leaf of the four-leaf clover and a parasitic element of four disks above the dual-polarized element, the BW enhancement is achieved. It is shown by simulation and experiment that the BW enhanced dual-polarized antenna achieves a BW of 67% (1.39-2.8 GHz) for reflection coefficients <−15 dB with an isolation (ISO) of 30 dB. An eight-element antenna array is developed for base station applications. The antenna array has a BW of about 70% (1.32-2.74 GHz) with an ISO of 25 dB. The antenna array achieves an average gain of ~17 dBi and a half-power beamwidth of 65 ± 5°, suitable for base station applications.
Traditional in-vehicle networks are statically deployed and configured during the car manufacturing process. However, the growing need for supporting new in-car traffic flows, e.g., to add new ...camera-based Advanced Driver Assistant Systems (ADAS) or infotainment applications, generates an increasing demand for bandwidth and requires the ability for re-configuring the bandwidth allocation among flows during the vehicle lifecycle. For this reason, this work proposes a partitioning system for Time-Sensitive Networking (TSN) that allows introducing new flows in the in-vehicle network without affecting the already existing ones. Moreover, the letter presents a simulative assessment of the proposed approach in a realistic automotive scenario.
Empowered by the optical orthogonal frequency-division multiplexing (O-OFDM) technology, flexible online service provisioning can be realized with dynamic routing, modulation, and spectrum assignment ...(RMSA). In this paper, we propose several online service provisioning algorithms that incorporate dynamic RMSA with a hybrid single-/multi-path routing (HSMR) scheme. We investigate two types of HSMR schemes, namely HSMR using online path computation (HSMR-OPC) and HSMR using fixed path sets (HSMR-FPS). Moreover, for HSMR-FPS, we analyze several path selection policies to optimize the design. We evaluate the proposed algorithms with numerical simulations using a Poisson traffic model and two mesh network topologies. The simulation results have demonstrated that the proposed HSMR schemes can effectively reduce the bandwidth blocking probability (BBP) of dynamic RMSA, as compared to two benchmark algorithms that use single-path routing and split spectrum. Our simulation results suggest that HSMR-OPC can achieve the lowest BBP among all HSMR schemes. This is attributed to the fact that HSMR-OPC optimizes routing paths for each request on the fly with considerations of both bandwidth utilizations and lengths of links. Our simulation results also indicate that the HSMR-FPS scheme that use the largest slots-over-square-of-hops first path-selection policy obtains the lowest BBP among all HSMR-FPS schemes. We then investigate the proposed algorithms' impacts on other network performance metrics, including network throughput and network bandwidth fragmentation ratio. To the best of our knowledge, this is the first attempt to consider dynamic RMSA based on both online path computation and offline path computation with various path selection policies for multipath provisioning in O-OFDM networks.
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