scholarly journals Analysis of a framework implementation of the transceiver performances for integrating optical technologies and wireless LAN based on OFDM-RoF

Author(s):  
Adnan Hussein Ali ◽  
Alaa Desher Farhood ◽  
Maham Kamil Naji

The greatest advantages of optical fibers are the possibility of extending data rate transmission and propagation distances. Being a multi-carrier technique, the orthogonal frequency division multiplexing (OFDM) can be applicable in hybrid optical-wireless systems design owing to its best spectral efficiency for the interferences of radio frequency (RF) and minor multi-path distortion. An optical OFDM-RoF-based wireless local area network (W-LAN) system has been studied and evaluated in this work. The outline for integrating an optical technology and wireless in a single system was provided with the existence of OFDM-RoF technology and the microstrip patch antenna; these were applied in the Optisystem communication tool. The design of the proposed OFDM-RoF system is aimed at supporting mm-wave services and multi-standard operations. The proposed system can operate on different RF bands using different modulation schemes like 4,16 and 64QAM, that may be associated to OFDM and multidata rates up to 5 Gbps. The results demonstrate the robustness of the integrated optical wireless link in propagating OFDM-RoF-based WLAN signals across optical fibers.

Jurnal Teknik ◽  
2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Heru Abrianto

Microstrip antenna which designed with dual feeding at 2.4 GHz and 5.8 GHz can meet WLAN (Wireless Local Area Network) application.Antenna fabrication use PCB FR4 double layer with thickness 1.6 mm and dielectric constant value 4.4. The length of patch antenna according to calculation 28.63 mm, but to get needed parameter length of patch should be optimized to 53 mm. After examination, this antenna has VSWR 1.212 at 2.42 GHz and 1.502 at 5.8 GHz, RL -13.94 dB at 2.42 GHz and -20.357 dB at 5.8 GHz, gain of antenna 6.16 dB at 2.42 GHz and 6.91 dB at 5.8 GHz, the radiation pattern is bidirectional. Keywords : microstrip antenna, wireless LAN, dual polarization, single feeding technique


2013 ◽  
Vol 278-280 ◽  
pp. 582-585
Author(s):  
Rong Gao ◽  
Qi Sheng Wu ◽  
Lan Bai

A tms320dm642 and wireless fidelity based fire monitoring robot is designed. Flame features, both static and dynamic detecting algorithm, combine with long wave infrared (LWIR) is equipped to achieve the goal of monitoring fire. When the suspected fire event happens, Fire warning message will be sent to remote terminal through the wireless LAN automatically. Infrared image of the fire can be transmitted through the wireless network under the control of remote terminal. As LWIR camera can even look through the dense smoke of fire, fire source will be located accurately, rescuing and fire fighting work will carry on better and with less injury.


2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Chang-Seop Park ◽  
Hyun-Sun Kang ◽  
Jaijin Jung

A new key management and security scheme is proposed to integrate Layer Two (L2) and Layer Three (L3) keys for secure and fast Mobile IPv6 handover over IEEE 802.11 Wireless Local Area Network (WLAN). Unlike the original IEEE 802.11-based Mobile IPv6 Fast Handover (FMIPv6) that requires time-consuming IEEE 802.1x-based Extensible Authentication Protocol (EAP) authentication on each L3 handover, the newly proposed key management and security scheme requires only one 802.1x-EAP regardless of how many L3 handovers occur. Therefore, the proposed scheme reduces the handover latency that results from a lengthy 802.1x-based EAP. The proposed key management and security scheme is extensively analyzed in terms of security and performance, and the proposed security scheme is shown to be more secure than those that were previously proposed.


2014 ◽  
Vol 721 ◽  
pp. 728-731
Author(s):  
Da Wei Dong ◽  
Xiao Guo Liu ◽  
Tian Jing

To reduce the number of inter-disturb access points and the interference among access points in same channel, with research on interference issus and channel assignment algorithms of wireless local area network, a scheme suitable for centralized wireless local area network was proposed aiming to minimize the total interference among access points, which comprehensively considerate the number of neighbor and the received power. And then the algorithm with cases was simulated and analyzed, the result of NS2 simulation indicated that the algorithm was simple, effective and feasible, which could realize dynamic adjustment to the wireless LAN RF channel and had a better load balance effect among non-overlapping channels.


2012 ◽  
Vol 16 (6) ◽  
pp. 39-45
Author(s):  
A.V. Lazebnyi ◽  
Volodymyr Semenovych Lazebnyi

The concept of a virtual contention window for assessment of temporal and probabilistic characteristics of the processes occurring in the wireless LAN 802.11 is considered. The relations for determining the transmission time delay of the data package, the uneven of transmission time, throughput of wireless channel, the probability of packet loss for networks with saturated load are proposed in this paper.


T-Comm ◽  
2021 ◽  
Vol 15 (7) ◽  
pp. 28-33
Author(s):  
Albina Y. Sharifullina ◽  
◽  
Roman R. Galyamov ◽  
Rimma S. Zaripova ◽  
◽  
...  

This article discusses the stages of development, characteristics of a wireless local area network Wi-Fi, options for its topology and equipment used. Currently, there are such different types of wireless networks as Wireless Wide Area Network, Wireless Metropolitan Area Networks (Wireless Neighborhood Area Network), Wireless Local Area Network, Wireless Personal Area Network. Each of the listed wireless networks has its own specific range and application. Wireless LAN Wi-Fi refers to the Wireless Local Area Network. The first wireless LAN standard, Wi-Fi, was approved in 1997. From the moment of their appearance to the present day, the following standards of this network have appeared: 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ad, 802.11ax. For each standard, the speeds and frequency ranges at which the data transmission was carried out are indicated, and the technologies on which they are built are described. Wireless LAN Wi-Fi has three topologies: 1) Ad-Hoc (point-to-point) or Independent Basic Service Set; 2) Basic Service Set (“client / server”) and 3) Extended Service Set (“extended service areas”). To build a Wi-Fi network, network adapters, access points, routers, ADSL modems, Wi-Fi phones, Wi-Fi antennas, Wi-Fi repeaters are used. Wi-Fi adapters are used by devices that do not have a built-in Wi-Fi module. Wi-Fi access points are designed for organizing wireless access within a local network. Wi-Fi routers are designed to route traffic on a computer network. ADSL modems are used to access the Internet over a telephone line. Wi-Fi repeaters are used to expand the coverage of a wireless network using already installed equipment. Wi-Fi phones are wireless IP phones. Wi-Fi antennas are used to extend the range of a wireless network.


Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 290 ◽  
Author(s):  
Tomoki Murakami ◽  
Masahiko Miyazaki ◽  
Shigemi Ishida ◽  
Akira Fukuda

Sensing services for the detection of humans and animals by analyzing the environmental changes of wireless local area network (WLAN) signals have attracted attention in recent years. In object detection using WLAN signals, a widely known technique is the use of time changes in received signal strength indicators that are easily measured between WLAN devices. Utilizing channel response, including power and phase values per subcarrier on multiple input multiple output (MIMO), the orthogonal frequency division multiplexing transmission was researched as channel state information (CSI) to further improve detection accuracy. This paper describes a WLAN-based CSI monitoring system that efficiently acquires the CSI of multiple links in a target area where multiple CSI measuring stations are distributed. In the system, a novel CSI monitoring station captures wireless packets sent within the area and extracts CSI by analyzing the packets on the sounding protocol, specified by IEEE 802.11ac. The paper also describes the system configuration and shows that indoor experimental measurements confirmed the system’s feasibility.


Author(s):  
Rashmi SK ◽  
Swathi RN ◽  
Vaishnavi AS ◽  
Nekkanti Deepak

The Internet was initially used to transfer data packets between users and data sources with a specific IP address. Due to advancements, the Internet is being used to share data among different small, resource constrained devices connected in billions to constitute the (IOT) Internet of things .In addition, the paper discusses about wireless LAN Wi-Fi technology i.e. wireless local area network protocol and on a larger scale, mobile communication technology, that is used to provide connectivity to the internet, the wide area network. The paper draws an attention towards the background of IOT and its distinction with other technologies, discussion on network optimization in IOT. This paper not only reviews, compares and consolidates the recent related works, but also admires the author’s findings, solutions and discusses its usefulness towards network optimization in IOT. The uniqueness of this paper lies in the review of network optimization issues and challenges in IOT. In this paper, a comprehensive survey on the network optimization in IOT is presented.


Author(s):  
Mohamad Badra ◽  
Artur Hecker

The great promise of wireless LAN will never be realized unless there is an appropriate security level. From this point of view, various security protocols have been proposed to handle wireless local-area network (WLAN) security problems that are mostly due to the lack of physical protection in WLAN or because of the transmission on the radio link. The purpose of this chapter is (1) to provide the reader with a sample background in WLAN technologies and standards, (2) to give the reader a solid grounding in common security concepts and technologies, and (3) to identify the threats and vulnerabilities of WLAN communications.


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