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In this work we implement features for IEEE 802.11ac in the NS-3 simulator, in particular wider channels and bit-error calculations for higher modulation coding schemes. We also implement four wireless LAN deployment scenarios from the 802.11ax working group scenario document, and evaluate their performance under different operating conditions. Our simulation results demonstrate that many nodes in...
We consider a collocated WLAN with Nac 802.11ac users using dynamic 20/40 MHz channel access and Nl 802.11a/n legacy users operating in the secondary 20 MHz channel. Under ideal channel conditions, we seek to characterise the saturation throughput performance of the 802.11ac users and the legacy users. We propose an analytical model based on a decoupling approximation for saturation throughput analysis...
We conduct in this work a comparative study betweena greedy versus limited proposals for resource aggregationin the backhaul of wireless local area networks. We consider asetting with several access points, some with excess backhaulcapacity (providers), and others in shortage of it (beneficiaries) and investigate two approaches for the distribution of resourcesbetween them: a greedy one wherein each...
A novel modified-design of Hilbert curve is presented, which has stable frequency response for both TE and TM polarizations. Furthermore, a frequency selective surface (FSS) based on this modified-Hilbert curve is proposed for shielding against dual-band WLAN. It has an insertion loss of more than 15 dB with the bandwidths of 220 MHz at 2.45 GHz and 160 MHz at 5.78 GHz. The proposed FSS provides an...
In this paper, an antenna for 4G and WLAN devices is proposed. The proposed antenna is designed using Planar Inverted F Antenna (PIFA) structure. The antenna uses Rogers Duroid 5880 as a dielectric substrate and metallic ground plane. The dimensions of the top patch are 18.5 mm × 18.5 mm and thus making it a low profile antenna. The designed antenna covers WLAN (2.4–2.48 GHz) & 4G LTE (2300–2400...
A novel differential wide-slot ultrawideband(UWB) antenna with band-notched selectivity is proposed and investigated in this paper. The antenna consists of a rectangle ground with a wide slot and a stepped differential feeding line. In order to realize controllable notched bands characteristics, a pair of half-wave-length slits are utilized in ground and feeding structure. Moreover, the notched bands...
Inadequate telecommunication infrastructure is one of the main reason of drawback on telecardiology implementation in developing countries. A new network selection algorithm is proposed to overcome this problem by providing adaptive heterogeneous networks. The proposed algorithm finds the most suitable wireless network according to user's health condition and service requirements. This algorithm adaptively...
Compact multiband cross slot rectangular microstrip patch antenna is introduced in this paper. Here one close ended rectangular slot in ground plane and one cross slot in patch are given to excite different resonant frequencies. The correct probe feed location along with the exact slot position gave the promising result. The proposed antenna meets the requirement of impedance bandwidth, return loss...
Channel bonding enables a transmitting device to form a wide channel in order to facilitate high data rate. From IEEE 802.11n, which is the most generally deployed wireless local area network standard, channel bonding feature has been widely applied. However, prior studies have reported that the wide channel does not always guarantee high data rate since a node using wide channel width might deprive...
A user in IEEE 802.11(Wi-Fi) system must associate to a particular Access Point (AP) to communicate through the Internet. According to the current association method which is based on Receive Signal Strength Index(RSSI), the user first identify its convenient APs and associate with the strongest AP, excluding the fact whether that AP is overloaded or not. In current scenario, the wireless network...
In this paper, a coaxially excited dual band triangular dielectric resonator antenna (DRA) for WLAN application is presented. Two equilateral triangle shaped DRA, having εr=10.2 are excited simultaneously using a coaxial cable to resonate at 2.4–2.5GHz and 5.75–5.85 GHz bandwidth. The height of coaxial cable is varied and appropriately fine tuned to bring proper impedance matching. The performance...
A tri-polarized wideband antenna is presented for wireless local networks (WLANs) application. The antenna consists of 2 printed dipoles and a monopole with size around 100mm × 100mm. Three antennas are put orthogonally to realize tri-polarization. The antenna bandwidth for three ports is around 1GHz under the condition of voltage standing wave ratio (VSWR) less than 2. The measured gains are around...
In an interconnected power system, all the generators must run at an appropriate capacity to meet the demand in power. Loss of synchronism between the generators and/or too much frequency fluctuations may cause protective equipment to trip. Load frequency control (LFC) is necessary to balance the power generation and the load, by monitoring frequency and power changes between interconnected power...
Previous attempts in addressing Access Point (AP) association at overlapping zone of IEEE 802.11 networks have shown some issues. They work passively and estimate load from different network metrics such as frame delay, packet loss, number of users etc. that may not always true. Further the user behaviour is selfish i.e. illegitimate user consume high network resources. This adversely affect existing...
This paper presents the analysis of CPW-fed trapezoidal monopole antenna added with parasitic elements and slots. From previous work, the proposed antenna altered by adding parasitic elements to enhance the operation bandwidth and achieved frequencies from 3.2GHz to 11.5GHz which covered Ultra Wide Bandwidth. This antenna is fabricated on FR4 for real measurement. Next experiment continues with slots...
In this paper, a compact omnidirectional circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) is presented. The DRA is excited in its TM01δ mode by a probe located at the center, giving linearly polarized (LP) omnidirectional radiation patterns. Four interleaved strips serving as a wave polarizer are placed on the top of the DRA. By tuning the strips, the LP fields can be changed...
In this paper, we present a planar unidirectional printed Dual-Band antenna for wireless communications. The first band covers global system for mobile communication (GSM), universal mobile telecommunication system (UMTS), wirless local area network (WLAN) and long term evaluation (LTE), while the second one covers the Worldwide Interoperability for Microwave Access (Wi-MAX) band. The antenna is composed...
A dual band CPW-fed Koch fractal antenna, suitable for WLAN and WiMAX operations, is proposed in this paper. The antenna has been designed by increasing the perimeters of right angled isosceles triangular shape patch by using self-similarity property. The proposed antenna is fed by a 50Ω Microstrip line and fabricated on a low-cost FR4 substrate having dimensions 40 (L) × 40 (W) × 1.59(H) mm3. The...
Wireless communication systems beyond 3G are characterized by variety of applications which have the requirement of simultaneous transmission/reception of low data rate voice and high data rate video streaming content. Wireless applications such as live video chat requires more bandwidth for transmitting/receiving with high quality. The civilian/COTS cellular wireless systems are very promising and...
To meet the ever increasing demand for wireless local area network (WLAN) connectivity, we propose to use the frequency range allocated for ultra-wideband (UWB) radios as an alternative spectral resource for conventional WLAN systems. Since the maximum permitted emission of UWB radios is 50-dB smaller than that of conventional WLAN devices, aerial communication range will be shortened to less than...
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