Local Area Network Communication Research Articles

A simple WDM-PON supporting LAN services by spectrum-sliced technology

A simple wavelength-division-multiplexing passive optical network is proposed in this paper. By simply designing the remote node, the virtual-ring local area network (LAN) services transmitted among optical network units are realized. And coupled with conventional broadband light source and spectrum-sliced technology, the network can support the LAN services in a cost-effective way. More particularly, the whole wavelength band of downstream services can also be reused for LAN services by selecting a special port of Arrayed Waveguide Grating. The simulation results indicate the 10 Gb/s LAN communication in this network can be achieved with the help of forward error correction.

A single feed dual-band (2.4 GHz/5 GHz) miniaturized patch antenna for wireless local area network (WLAN) communications

A single feed dual-band miniaturized microstrip patch antenna for Wireless Local Area Network (WLAN) communications has been proposed. The outer rectangular loop patch and inner modified E-shaped patch were used to resonate at 2.4 and 5 GHz, respectively. In order to separate the effect between two frequency bands, a shorting pin was set between two resonance cells. The simulated results show that it can operate at 2.4 and 5 GHz bands with 0.072 GHz (2.407–2.479 GHz) and 0.715 GHz (5.137–5.853 GHz) fractional bandwidth, respectively, which can cover the whole frequency band of WLAN. In addition, the antenna is miniaturized by 31% compared to the conventional rectangular patch without a slot. At last, the proposed microstrip patch antenna has been fabricated and measured for both impedance matching and radiation patterns. A comparison of the measurement and simulation results is given, which show reasonable good agreement.

Bandwidth Enhancement of a Monopolar Patch Antenna With V-Shaped Slot for Car-to-Car and WLAN Communications

A monopolar patch antenna with a V-shaped slot for car-to-car (C2C) and wireless local area network (WLAN) communications is presented in this paper. To widen the impedance bandwidth of the antenna, techniques for adding a shorting pin and a V-shaped slot are applied to an equilateral triangular patch. By properly placing the shorting pins on an equilateral triangular patch, two operating modes, i.e., TM10 and TM20, are obtained. The presence of the V-shaped slot can generate an additional TM11 mode. These three resonances found in the operating frequency bandwidth resulted in a wideband characteristic. The proposed antenna can operate from 4.82 to 6.67 GHz for the reflection coefficient $\le -$ 10 dB with the gain of around 5.0 dBi. In addition, an omnidirectional radiation pattern is yielded by a coaxial center-fed probe excitation. The antenna has a thickness of 0.09 $\boldsymbol{\lambda}_\mathbf{g}$ (at the center frequency of 5.5 GHz), which is easily hidden on the roof of a vehicle for C2C communication. This proposed design can also be used as indoor base-station antennas for WLAN communication.

The performance evaluation of IEEE 802.11 DCF using Markov chain model for wireless LANs

During the past few years the widespread use of the wireless local area networks (WLANs) communication technique is one of the most popular technologies in data telecommunications and networking. The IEEE 802.11 protocol has achieved worldwide acceptance with WLANs with minimum management and maintenance costs. The theoretical performance and numerical results in terms of saturation throughput and delay of distributed coordination function (DCF) were finished by Ziouva and Antonakopoulous. It took into account of the busy medium conditions and how they affected the use of the backoff mechanism. However, the definition of their proposed channel busy probability is not suitable for the operating system architecture. In this paper, the channel busy conditions is modified and the Ziouva and Antonakopoulous's (ZA's) model is improved, and the more accurate analyses of the DCF are presented. Our analysis is also extended to the computation of the delay performance of both the request-to-send/clear-to-send (RTS/CTS) and basic access mechanisms. The numerical results show that the modified model has better performance than the ZA's model under ideal channel scenario.

Instant Communication Method of Design and Development Based on Local Area Network in Linux

This document discusses an instant communication method of design and development based on Socket local area network. Based on the Socket local area network communication, software can provide for the original enterprise a good, safe, fast communication mechanism. It achieved without any changes for the original Local area network (LAN) hardware, and in the enterprise internal communication, discussion and other applications, it has a certain practical value.

Network Architecture of a High-Speed Visible Light Communication Local Area Network

A novel ultrahigh-speed LED visible light communication (VLC) local area network to provide beyond 10-Gb/s optical wireless access based on star topology architecture is proposed and experimentally demonstrated for massive users. Fiber link is used as the backbone of the bidirectional VLC network. The hybrid access protocol is utilized: 1) frequency division multiplexing for downlink and uplink fiber transmission and 2) time division multiplexing for bidirectional VLC transmission. A full-duplex VLC network for eight VLC access points (VAPs) has been successfully demonstrated with the total throughput of 8 Gb/s. Each VAP is offered 500-Mb/s downstream and 500-Mb/s upstream. The measured bit error rates of downlink and uplink for all the VAPs are under 7% FEC limit of $3.8\times 10^{-3}$ over 25-km standard single mode fiber and 65-cm free space, clearly validating the promising potential of the proposed VLC network architecture for future 40- and 100-Gb/s wireless access.

Design of a compact dual‐band‐notch ultra‐wideband bandpass filter based on wave cancellation method

In this study, a compact ultra-wideband (UWB) bandpass filter (BPF) with sharp roll-off, improved out-of-band performance and dual-band-notch operation is presented and its design procedure is discussed. In the proposed structure, in order to reject the unwanted harmonic pass bands, a pair of modified cross-shaped coupled lines (CCLs) is implemented along the ports of the filter. Moreover, a pair of half-circle-shaped stubs and a stepped-impedance stub are loaded on the main resonator in order to obtain additional transmission zeros (TZs) which are controllable separately. Implementation of the CCLs and the stub loaded resonator (SLR) reduce the total size of the presented microstrip BPF. Besides, by extending and folding the upper coupled line of each CCLs and also through an open stub which is protruded inside a slot on the main resonator, dual-band-notch operation is added to the performance of the presented filter. The fabricated prototype has a small size and is capable to cover frequency band of 2.8–10.69 GHz with two band-notch functions at 4.9–5.4 and 7.83–8.25 GHz which suppresses the interference between UWB spectrum with wireless local area network (WLAN) and satellite communication frequency bands, respectively. The proposed filter has a compact size while showing good return loss and insertion loss characteristic in the frequency band of interest.

New design of compact dual band‐notch ultra‐wideband bandpass filter based on coupled wave canceller inverted T‐shaped stubs

The procedure of attaining a compact bandpass filter (BPF) with dual band-notch function for ultra-wideband (UWB) applications is presented and discussed. In the proposed BPF, defected ground structure is used in order to improve the out-of-band performance of the filter. Also, four short-circuited bent stubs are employed in order to improve the selectivity of the filter at its cutoff frequencies. Dual band-notch function is added to the performance of the filter by coupling two short-circuited inverted T-shaped stubs to the filter main resonator. The fabricated filter satisfies well the demands of the Federal Communications Committee with two narrow band-notch functions at 5.5 and 8 GHz, which eliminates the interference of the UWB system with wireless local area network (WLAN) and satellite communication systems, respectively. The improved upper stop-band of the proposed filter with more than 20 dB attenuation level extends up to 20 GHz.

Underwater Image Gathering by Utilizing Stationary and Movable Sensor Nodes: Towards Observation of Symbiosis System in the Coral Reef of Okinawa

This paper describes the underwater data collection utilizing stationary sensor node and movable sensor node. We consider applying the system to investigate the conditions of marine ecosystem around the coral reef at Okinawa, Japan. The framework and fundamental design of our proposed underwater information gathering system under development are introduced. It is also reported the development of the prototypes of the sensory node and movable sensor node. Basic examinations utilizing such prototype at underwater environment are also described. This paper also describes experimental results of image gathering from via wireless local area network communication. Our future trials based on the current developmental situation are also discussed.

The Development of a Local Area Network Communication Software Based on Peer-to-Peer Mode

Compared with traditional client/server modes, peer-to-peer (P2P) mode has obvious advantages in eliminating the performance bottleneck of server and enhancing the utilization rate of network resources. Based on P2P technology, local area network (LAN) communication software was well designed in this paper. By using the support function of Java for multithreading technology and socket technology, P2P mode was adopted to realize various communication functions, such as LAN text message transmission, file transfer and voice transmission. Though processing multicast messages, the software can detect the login and logout status of LAN users. Proved by testing, this software can operate stably in a system environment installed with Java Virtual Machine (JVM).

Low-Profile Folded-Coupling Planar Inverted-F Antenna for 2.4/5 GHz WLAN Communications

A dual-band folded-coupling planar inverted-F antenna (FC-PIFA) is presented in this paper. By using the folded-coupling technique, the proposed antenna provides two distinct impedance bandwidths of 159 MHz (about 6.5% centered at 2.45 GHz) and 1512 MHz (about 27.5% centered at 5.5 GHz), which cover the required bandwidths for the 2.4/5 GHz wireless local area network (WLAN) communications. Moreover, the antenna shows a low profile of 5 mm and a small length of 20.5 mm in radiating area, making it easy to be installed in the casing of wireless handheld devices and laptops. Details of the design procedures and experimental results are discussed.

DUAL-BAND MIMO ANTENNA WITH HIGH ISOLATION APPLICATION BY USING NEUTRALIZING LINE

In this letter, a dual-band Multiple Input Multiple Output (MIMO) antenna system with high isolation is presented. This design consists of two dual-band monopole antennas and neutralizing transmission line. For each antenna element, the operating frequency band covers from 2.4 GHz to 2.6 GHz and 5.2 GHz to 6 GHz. To improve the isolation between these two antenna elements spacing only 0.1225λ0 at 2.45 GHz, a neutralization decoupling transmission line is introduced. The measured return loss results of these two antennas are better than 10-dB in operating frequency band. The measured isolation between the two antennas is better than 15 dB. The envelope correlation coefficient (ECC) is smaller than 0.01 of whole operating frequency band. The peak gain of this design is better than 2 dBi in operating bands. This configuration can be applied for Wireless local area network (WLAN), WiMAX and Bluetooth communication system.

Selection of VoIP CODECs for Different Networks based on QoS Analysis

Voice over Internet Protocol (VoIP) has been an interesting topic of research in the last decade. The engrossing increase in the use of VoIP services is resulting in the enormous growth of broadband network. The main objective of this paper is the selection of an appropriate voice compression and decompression (CODEC) schemes depending on the Quality of Service (QoS) of VoIP in different networks. Wired, Wireless Local Area Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX) and Universal Mobile Telecommunication System (UMTS) networks were implemented in OPNET Modeler. The quality is compared using different QoS parameters like end-to-end delay, MOS, throughput and jitter. The VoIP codecs used in the measurements of QoS are: GSM-FR, G.711, G.723.1 and G.729A. Simulations showed that G.711 and GSMFR are the best schemes that provide high quality of voice in Wireless Local Area Network (WLAN) communications. In WiMAX, G.729A gives the best quality of VoIP while in UMTS, GSMFR gives overall best results with respect to all the parameters. Wired model gives the best result irrespective of the codec being used. G.723.1 can be used in WiMAX and UMTS along with the wired network depending on conditions. The results analyzed and the performance evaluated will give network operators an opportunity to select the codec for better services of VoIP for customer satisfaction.

Design and Experiment of Underwater Monitoring System for Fish Domestication Equipment

The design of underwater monitoring system is an important component of fish domestication equipment for ocean ranching. In order to achieve the fish domestication effect so that to conduct feedback control of fish domestication device, this paper designs a wireless underwater camera monitoring system. The system includes local area network and GPRS network communication mode. The results of the underwater sealing experiment and the preliminary underwater camera test show the feasibility of the monitoring system. The effect monitored in Sparus macrocephalus domestication experiment in Xiangshan ocean area suggests that this camera system can not only meet the working requirements, but also be stable and reliable, which provides an effective means of monitoring for fish domestication on ocean ranching.

The model design and performance analysis of quantum signaling switch

This paper puts forward a quantum signaling switch model. The quantum signaling switch consists of a classical information control module, an exchange control module and a quantum exchange module. Classical control module transmits the initial entangled state information to the entanglement measurement and switching unit and updates the routing information. Exchange control module will choose the path, and is ready for the distribution channel of the entanglement photons. The quantum exchange module generates quantum entanglement pairs, measures the Bell state and achieves entanglement swapping. Quantum signaling switches can realize multi-user communication and local area network communication. Through the performance analysis and simulation of the switch, the results show that the switch is simple in structure, secure and easy to expand; also the time delay is small. This will be helpful for the construction of the quantum communication network.

Wideband Parameters Analysis and Validation for Indoor radio Channel at 60/70/80GHz for Gigabit Wireless Communication employing Isotropic, Horn and Omni directional Antenna

Recently, applications of millimeter (mm) waves for high-speed broadband wireless local area network communication systems in indoor environment are increasingly gaining recognition as it provides gigabit-speed wireless communications with carrier-class performances over distances of a mile or more due to spectrum availability and wider bandwidth requirements. Collectively referred to as E-Band, the millimeter wave wireless technology present the potential to offer bandwidth delivery comparable to that of fiber optic, but without the financial and logistic challenges of deploying fiber. This paper investigates the wideband parameters using the ray tracing technique for indoor propagation systems with rms delay spread for Omnidirectional and Horn Antennas for Bent Tunnel at 80GHz. The results obtained were 2.03 and 1.95 respectively, besides, the normalized received power with 0:55fix10^8 excess delay at 70GHz for Isotropic Antenna was at 0.97.

Broadband 57–64-GHz WLAN Communication System Integrated Into an Aircraft Cabin

This paper describes the specific development of a high-data-rate 57–64-GHz point-to-multipoint wireless local-area network communication system and the worldwide first installation of such a system into an aircraft cabin mock-up. All of the system components, from the RF-chip-set, the low-temperature cofired ceramic integrated antennas, and RF modules to the baseband processor, the medium access control, and the application software were purpose-designed for a wireless backbone for in-cabin communication. The integration aspects of these system components into a passenger aircraft cabin mock-up (ceiling and passenger seat-integration) as well as successful system performance tests were carried out and are reported here.

Controllable Band-Notched Slot Antenna for UWB Communication Systems

We propose a slot antenna consisting of a rectangular slot on the ground plane, fed by a microstrip line with a rectangular-ring-shaped tuning stub that can be deployed in ultra-wideband (UWB) communication systems to avoid interference with wireless local area network (WLAN) communication. Our antenna can achieve a single band-notched property from the 5 GHz frequency to the 6 GHz frequency owing to a controllable band notch that uses L- and J-shaped parasitic elements. The antenna characteristics can be modified to tune the band-notched property (4 GHz to 5 GHz or 6 GHz to 7 GHz) and the bandwidth of the band notch (1 GHz to 2 GHz). Furthermore, the shifted notch with enhanced width of the band notch from 1 GHz to 1.5 GHz is described in this paper. The UWB slot antenna and L- and J-shaped parasitic elements also provide the band-rejection function for reference in the WiMAX (3.5 GHz) and WLAN (5 GHz to 6 GHz) regions of the spectrum. Experiment results evidence the return loss performance, radiation patterns, and antenna gains at different operational frequencies.

A wavelength division multiplexer based on plastic surfacerelief grating applied to local area communication network

A plastic surface-relief grating as a wavelength division multiplexer is designed and fabricated with the conventional mould pressing technique using the transmission-type fused quartz phase grating as mask pattern and polycarbonate as basal material. The experiment results show that in an optimizing process, the plastic surface-relief grating has the highest firstorder diffraction efficiency under adequate groove depth and incident angle, and can be used as the best optical path for wavelength division multiplexing (WDM). We also establish the experiment setup for testing the WDM performance of the plastic surface-relief grating based wavelength division multiplexer. The results show that the proposed wavelength division multiplexer has the high-stability temperature characteristics, the low insertion loss of less than 5 dB, the large isolation of greater than 20 dB, the low polarization-dependent loss (PDL) of less than 0.4 dB and the relatively steep pass-band characteristics. It is a WDM device with good performance, which can be applied in short distance communication.

Virtual Optical Buffers: A Novel Interpretation of OCDMA in Packet Switch Networks

Among all proposed structures for optical networks, the optical packet switching (OPS) scheme, due to its practical implementation of IPs in an optical configuration and the consequent advantages, is a prizeworthy candidate for being employed in metropolitan area network and local area network communication levels. One of the few problems frequently met using the OPS structure in the fiber-optics realm is the lack of optical buffers, thus deteriorating the system's flexibility and quality of service. For example, optical label switching networks that have been developed recently based on the generalized multiprotocol label switching protocol, profoundly suffer from this setback which is considered as a great hurdle in their evolution. In this paper, we first introduce the input and output buffer switching models while deducing their blocking probability formulations. Then, by utilizing codes in the OPS structure, we closely examine the potential of code and/or wavelength switching in packet switching networks and also determine their blocking probability. Due to close similarities between different scenarios, we present the prospect of virtual optical buffers using codes, which have close performance to input and output buffers in sight of block probability. The most significant distinction in using virtual buffers is the fact that due to their substantial nature, they happen to exhibit some error probability. However, on account of the advantageous features of codes, the simulated and formulated error probability for both coherent and noncoherent optical code division multiple access (OCDMA), such as Spectrally phase encoded OCDMA and optical orthogonal codes, using virtual buffers, tends to be negligible. Two main code and wavelength switching schemes are also brought to attention in this work, the intelligent and random methods. These scenarios demonstrate an even greater behavioral performance to that of the mere code switching scenario, leading into a more reliable adaptation of virtual buffers. In addition, simulations results happen to provide clear verifications to our analytical approach.