Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
This paper presents a technique for extending the bandwidth of chirped active sonar signals. Bandwidth synthesis (BWS) results in improved range resolution, increased signal-to-noise ratio (SNR) and reduced fading due to delay-spread multipath. The approach demonstrated uses a low-order autoregressive (AR) process to model de-chirped segments of the received signal, which are then extrapolated using...
In order to manage Quality of Service (QoS) and energy efficiency in the optical access network, an online Dynamic Bandwidth Allocation (DBA) algorithm with adaptive sleep cycle is presented. This DBA algorithm has the ability to allocate an additional bandwidth to the end user within a single sleep cycle whose duration changes depending on the current buffers occupancy. The purpose of this DBA algorithm...
Current Network Function Virtualization (NFV) with Virtualized Network Functions (VNFs) running as virtual machines on commodity servers enables flexibility to Service Function Chaining (SFC). Specific applications may require Quality of Service (QoS) on end-to-end latency. However, the processing delay and the queuing delay of VNFs varies with virtual resource configurations (vCPU and vMemory), as...
The traditional world has transformed into a digital society where almost anything can be accessed from anywhere. However, this digital society is responsible for an explosive growth of high-volume, high-velocity and high-variety information assets, with high demand for “Big Data”. A Software Defined Connectivity (SDC) is an emerging paradigm, which promises to simplify network management, to provide...
In a wireless body area networks (WBAN) with integrated sensor hubs, the proposed MAC protocol is a TDMA-based schedule used in active superframe interleaving and beacon shifting defined by the IEEE 802.15.6 standard. It considers the human dynamics and traffic information to meet the different QoS requirements of each sensor, improve bandwidth utilization and reduces packet collisions within networks...
A MANET or Mobile Ad-Hoc Network is decentralized in nature and it is basically a collection of heterogeneous mobile nodes which are autonomous and can communicate among themselves over the wireless link. In this infrastructure-less network, all the nodes dynamically route the packets by themselves with help of some protocols for sending or receiving the packet information. The ZRP or Zone Routing...
With compact folded method, a kind of folded crossed dipole ultra wideband antenna is proposed with omnidirectional radiation characteristics on the horizontal direction in this paper. The antenna is comprised of orthogonal crossed semicircular metal discs with twice 90° folded on both ends. Horizontal size is reduced obviously compared with original crossed semicircular disc antenna. This antenna...
In this work, we address the problem of reducing the vibrations in the case of a thin flexible beam, with an Euler-Bernoulli configuration thanks to a new type of feedback controller based on a delayed proportional action. The flexible structure is equipped with two piezoelectric patches: one of them works as a sensor and the other as an actuator. Each one of them is bonded on one side of the beam...
This paper examines the accuracy of the zero-order hold (ZOH) model of the digital pulsewidth modulator (DPWM). The influence of the computational delay on the precision of this equivalent DPWM model is discussed in detail. A compensation method is proposed to compensate the deviation of this DPWM model for accurately calculating the stability region with different computational delay and duty-cycle...
The main theme of this paper is to propose a self-commissioning technique for high bandwidth servo drives. The presented self-commissioning technique include auto-identification of servo motor parameters and on-line calculation of controller gains of servo drives. The electrical parameters required for current controller, including stator resistance and inductance are identified under standstill....
Increasing use of online backup services, as well as the popularity of user-generated content, has increased the demand for bandwidth. However, traffic generated by these applications can impact on the responsiveness of delay-sensitive applications if they receive a 'fair-share' of the available bandwidth. Less-than-Best-Effort TCP congestion control mechanisms aim to allow lower-priority applications...
A variety of wireless communication links today, such as HSPA+ access in high speed trains, balloon-based aerial wireless networks and satellite Internet connections have high loss rates. In such environments, Multipath TCP (MPTCP) offers a robust solution compared to regular TCP. However, MPTCP and existing schedulers suffer from performance degradation for both constant bit rate (CBR) and bulk traffic...
Conventional resonant controllers (RCs) are commonly used in the current control of grid-tied converters with LCL filter due to their advantages, such as zero steady-state error at both fundamental sequences, easy design process, and straightforward implementation. Nevertheless, these traditional solutions do not permit to place the closed-loop poles of the system in convenient locations when dealing...
The quality of service multicast routing problem (QoSMRP) is a very interesting research issue for transmission in communication networks. It is known to be an NP-hard problem, so many heuristic algorithms have been employed for solving this problem. This paper proposes two hybrid approaches based on the hybridization of Firefly algorithm (FA) with Quantum Evolutionary algorithm (QEA) to solve the...
This paper investigates the network function virtualization (NFV)-enabled multicast problem, and proposes a steiner tree-based algorithm to reduce the cost of virtual network function (VNF) deployment and routing. In the algorithm, to minimize the bandwidth consumption, the Steiner tree is constructed by taking all the destination nodes as the terminals. Then a interconnection node of the tree is...
QoS of applications in an edge node of mobile edge computing (MEC) could degrade due to congestion of wireless access or short of mobile edge computing resource. In order to improve QoS such as TCP throughput, we propose a VM migration method, which takes a VM from congested node to another node in a mobile edge. Users can choose a far but less-congested node, instead of a near but congested node...
BBR is a recently proposed congestion control. Instead of using packet loss as congestion signal, like many currently used congestion controls, it uses an estimate of the available bottleneck link bandwidth to determine its sending rate. BBR tries to provide high link utilization while avoiding to create queues in bottleneck buffers. The original publication of BBR shows that it can deliver superior...
Network performance is one of the most important entities in today’s long-distance networks. TCP congestion control mechanisms play an important role in these networks. Most of the current TCP congestion control mechanisms which are also known as TCP variants, detect congestion and slow down the packets transmission to avoid further congestion in the network. In this paper, three classes...
Due to improvements in defensive systems, network threats are becoming increasingly sophisticated and complex as cybercriminals are using various methods to cloak their actions. This, among others, includes the application of network steganography e.g. to hide the communication between an infected host and a malicious control server by embedding commands into innocent-looking traffic. Currently, a...
Low Extra Delay Background Transport (LEDBAT) is defined in RFC6817 as a congestion control algorithm for lower than best effort transport service that reacts to both delay and loss congestion signals. LEDBAT allows bulk transfer applications (such peer-to-peer file transfer and software updates) to utilize available capacity in the background while limiting additional forward queuing delays at network...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.