scholarly journals Investigation and Evaluation of IEEE 802.11n WLANs Link Features Performance Under Single Host and Concurrent Communication

2021 ◽  
Vol 11 (1) ◽  
pp. 1-13
Author(s):  
Sumon Kumar Debnath ◽  
Prodip Kumar Sarker ◽  
Md. Manowarul Islam ◽  
Ileas Pramanik

For an efficient design of wireless local-area networks (WLANs), the simulation tools are important to accurately estimate the IEEE 802.11n/ac link features for WLANs. However, this true simulation of network behavior is critical in designing high-performance WLANs. Through testing, analysis, and modeling of the proposed scheme repetitively, the design of the WLAN can be enhanced with a small budget before making its practical implementation. Many network simulation tools have been established to give solutions for this request and ns-3 is the most widely used tools among them by the research industry as an open-source network simulator. In this paper, we examine the various link features of the 802.11n WLANs under several conditions. We investigate the effects of 802.11n WLAN modulation and coding schemes (MCSs), 20MHz single channel or 40 MHz bonded channel, guard intervals (GI), frame aggregation, data encoding, number of antennas and their data rate, and link distance features of 802.11n WLAN in ns-3 when only a unique host connects with the access point (AP) and generates data traffic. Besides, the performance for an enterprise scenario proposed by the IEEE 802.11ax study group is evaluated when several hosts are simultaneously creating traffic with their associated APs. The results demonstrate that ns-3 support most of the link features of the 802.11n protocol with significant accuracy.

SIMULATION ◽  
2020 ◽  
Vol 96 (12) ◽  
pp. 939-956 ◽  
Author(s):  
Anisa Allahdadi ◽  
Ricardo Morla ◽  
Jaime S Cardoso

Despite the growing popularity of 802.11 wireless networks, users often suffer from connectivity problems and performance issues due to unstable radio conditions and dynamic user behavior, among other reasons. Anomaly detection and distinction are in the thick of major challenges that network managers encounter. The difficulty of monitoring broad and complex Wireless Local Area Networks, that often requires heavy instrumentation of the user devices, makes anomaly detection analysis even harder. In this paper we exploit 802.11 access point usage data and propose an anomaly detection technique based on Hidden Markov Model (HMM) and Universal Background Model (UBM) on data that is inexpensive to obtain. We then generate a number of network anomalous scenarios in OMNeT++/INET network simulator and compare the detection outcomes with those in baseline approaches—RawData and Principal Component Analysis. The experimental results show the superiority of HMM and HMM-UBM models in detection precision and sensitivity.


Author(s):  
T.N. Narytnik ◽  
P. G. Akopyan ◽  
V.G. Saiko ◽  
V.I. Korsun ◽  
S.V. Sarapulov

At present, there is an exponential increase in the total data traffic of mobile networks. Implementation of new technologies, implementation of innovative infrastructure solutions, as well as optimization and increase of efficiency of use of existing networks are necessary to prevent failures and congestion. The most promising way, from a mobile operator's perspective, is to develop a macro level and use Wi-Fi to offload LTE-A (Wi-Fi Offloading). However, the efficiency of the conflict resolution algorithms used in modern Wi-Fi systems is significantly reduced with increasing number of subscribers. Features of the family of the latest Wi-Fi standards (IEEE 802.11n, IEEE 802.11ac, IEEE 802.11ax), which are intended for unloading mobile networks and quality provision of Internet of Things, are considered in the article. A review and comparison of the protocols of the latest IEEE 802.11 standards showed that, technically, Wi-Fi 6 has a data rate that is 37% faster than 802.11ac, but more importantly, the updated specification offers 4 times more bandwidth per user in crowded places, as well as higher energy efficiency, which should increase the battery life of the devices. To achieve these improvements, 802.11ax has made many changes, including several multi-user technologies borrowed from the cellular industry, namely MU-MIMO and OFDMA technologies, which greatly increase bandwidth and productivity through more concurrent connections and more careful use of the spectrum. The results of simulation modeling of the delay in packet transmission, average access point bandwidth and data loss values ​​using different modes of collective access to the IEEE 802.11n network channels: distributed (DCF) and centralized (PCF) access coordination functions. OPNET Modeler, which is radio-oriented and allows you to build models without programming, has been selected to develop the network simulation model.


2021 ◽  
Vol 3 (11) ◽  
pp. 144-154
Author(s):  
Roman Korolkov

One of the most serious security threats to wireless local area networks (WLANs) in recent years is rogue access points that intruders use to spy on and attack. Due to the open nature of the wireless transmission medium, an attacker can easily detect the MAC addresses of other devices, commonly used as unique identifiers for all nodes in the network, and implement a spoofing attack, creating a rogue access point, the so-called "Evil Twin". The attacker goal is to connect legitimate users to a rogue access point and gain access to confidential information. This article discusses the concept, demonstrates the practical implementation and analysis of the “Evil Twin” attack. The algorithm of the intruder's actions, the scenario of attack on the client, and also procedure for setting up the program-implemented rogue access point is shown. It has been proven that the implementation of the attack is possible due to the existence of several access points with the same service set identifier and MAC address in the same area, allowed by 802.11 standard. The reasons for failure operation of the network and possible interception of information as a result of the attack are identified, methods of detecting rogue access points are analyzed. During the experiment, observations of the 802.11 frames showed that there were deviations in the behavior of beacon frames at the time of the "Evil Twin" attack. First, the number of beacon frames coming from the access point which succumbed to the attack is increasing. Secondly, the traffic analyzer detected significant fluctuations in the values of the received signal level, which simultaneously come from a legitimate and rogue access point, which allows to distinguish two groups of beacon frames. The "Evil Twin" attack was implemented and researched using Aircrack-ng – a package of software for auditing wireless networks, and Wireshark – network traffic analyzer. In the future, the results obtained can be used to improve methods of protection against intrusion into wireless networks, in order to develop effective systems for detecting and preventing intrusions into WLAN.


Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1880 ◽  
Author(s):  
Kristián Košťál ◽  
Rastislav Bencel ◽  
Michal Ries ◽  
Peter Trúchly ◽  
Ivan Kotuliak

Wireless Local Area Network (WLAN) infrastructure is a dominant technology for direct access to the Internet and for cellular mobile data traffic offloading to WLANs. Additionally, the enterprise infrastructure can be used to provide functionality for the Internet of Things and Machine to Machine scenarios. This work is focused on improvements of radio resources control scalability similar to mobile networks via handover between cells. We introduce an improved IEEE 802.11 architecture utilizing Software-Defined Networks (SDNs). The proposed architecture allows communications during device movements without losing a quality of service (QoS). The fast seamless handover with QoS enables efficient usage of radio resources in large networks. Our improvements consist of integrating wireless management to OpenFlow protocol, separating encryption and decryption from an access point. In parallel, this feature as a side effect unloads processing at the Access Points (APs). Finally, the functionality of architecture design and scalability was proven by Colored Petri Nets (CPNs). The second proof of our concept was performed on two scenarios. The first scenario was applied to a delay sensitive use case. The second scenario considers a network congestion in real world conditions. Client’s mobility was integrated into both scenarios. The design was developed to demonstrate SDN WLAN architecture efficiency.


2019 ◽  
Vol 12 (2) ◽  
pp. 135-141
Author(s):  
Dharm Singh Jat ◽  
Lal Chand Bishnoi ◽  
Shoopala Nambahu

Background: In just last two-years most of the world’s video data has been created by the digital devices like smartphone, surveillance cameras, and wireless sensor networks. These days the IEEE 802.11n enabled devices for Wireless Local Area Networks (WLANs) are being used to achieve higher throughput at the Medium Access Control (MAC) layer. </p><p> Methods: In this research, the Dynamic Aggregation Mechanism (DAM) algorithm is proposed for H.264/SVC video transmission over IEEE 802.11n WLANs. The modified Network Simulator (NS2) was used to examine the quality of received H.264/SVC video over 802.11n WLAN. For quality measurement, PSNR was used for all nine H.264/SVC video traffic. </p><p> Results: The proposed mechanism improved the PSNR for received video.


Author(s):  
Chaithra. H. U ◽  
Vani H.R

Now a days in Wireless Local Area Networks (WLANs) used in different fields because its well-suited simulator and higher flexibility. The concept of WLAN  with  advanced 5th Generation technologies, related to a Internet-of-Thing (IOT). In this project, representing the Network Simulator (NS-2) used linked-level simulators for Wireless Local Area Networks and still utilized IEEE 802.11g/n/ac with advanced IEEE 802.11ah/af technology. Realization of the whole Wireless Local Area Networking linked-level simulators inspired by the recognized Vienna Long Term Evolution- simulators. As a outcome, this is achieved to link together that simulator to detailed performances of Wireless Local Area Networking with Long Term Evolution, operated in the similar RF bands. From the advanced 5th Generation support cellular networking, such explore is main because different coexistences scenario can arise linking wireless communicating system to the ISM and UHF bands.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yehe Liu ◽  
Andrew M. Rollins ◽  
Richard M. Levenson ◽  
Farzad Fereidouni ◽  
Michael W. Jenkins

AbstractSmartphone microscopes can be useful tools for a broad range of imaging applications. This manuscript demonstrates the first practical implementation of Microscopy with Ultraviolet Surface Excitation (MUSE) in a compact smartphone microscope called Pocket MUSE, resulting in a remarkably effective design. Fabricated with parts from consumer electronics that are readily available at low cost, the small optical module attaches directly over the rear lens in a smartphone. It enables high-quality multichannel fluorescence microscopy with submicron resolution over a 10× equivalent field of view. In addition to the novel optical configuration, Pocket MUSE is compatible with a series of simple, portable, and user-friendly sample preparation strategies that can be directly implemented for various microscopy applications for point-of-care diagnostics, at-home health monitoring, plant biology, STEM education, environmental studies, etc.


2013 ◽  
Vol 397-400 ◽  
pp. 2090-2093
Author(s):  
An Hong Tian ◽  
Cheng Biao Fu

Due to the problem of network structure, security, redundant path in traditional network, this can be solved by Virtual Local Area Network (VLAN) technology. As the network laboratory in colleges and universities is not perfect because of high cost, a virtual simulation tools named Packet Tracer has been introduced to computer network experimental curriculum, this paper put forwards the detail design scheme by the example of VLAN with three switches, and provides the experiment and theoretical analysis and simulation verification .The practice has proved this method not only deepens students comprehension of network, but also cultivates the students' actual comprehensive ability.


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