LAN Network Research Articles

CoMoSy: a Flexible System-on-Chip Platform for Embedded Applications

Thanks to the rapid evolution of semiconduc-tor technology, System-on-Chip (SoC) paradigm has be-come one of the most common design methodologies for quickly developing embedded systems to meet the high demands of embedded applications. In this paper, we present the design and implementation on a SoC platform targeted to controlling and monitoring applications. This proposed platform is composed of a 32-bit processor and a dozen of common hardware interfaces, providing the programmability and connectivity to peripheral devices such as memories, Lan network, monitor, keyboard, ADC, DAC, or other I/O device. In addtion, to increase the flexibility of the system and to rapidly develop end-user applications, we also deploy an application-specific software framework with the robustness of a lightweight kernel and real-time applet management. The system model has finally been validated through the realization of a remote control camera system.

Instruments and Experiments Control Methodology Based on IVI and LXI Technologies

In this paper we present a new model to control the instruments and experiments in a remote laboratory. This model is based on LAN networks and a control methodology through reusable drivers. The objective is to obtain a software control architecture independent of the hardware of the laboratory, so each institution can use its own equipments and experiments based on its needs and with minimal restrictions regarding to the hardware of the lab.

Panoramic Vision Mine Safety Monitoring System Based on WLAN

For the requirements of complex environment and safe-management in the coal mine, this paper presents a new Panoramic Vision Mine Safety Monitoring System Based on WLAN. the monitoring system use a binocular omni-directional vision sensor(ODVS)[1] coordinated with the WLAN or LAN network to transmit images, information, commands or data. The system can also get the panoramic vision in the coal mine from any miner at any time. The miners’ identities will be binding with the ODVS and WLAN protocol. Then the monitoring system will use the binding information to position and track miners. This is a new reliable monitoring system which can monitor the coal mine environment security, the coal mine producing security, the coal mine transport security, the miner security at the same time, and these provide the system with expecting application value and market outlook.

Sistema SCADA UNAH para eficiencia energética

A SCADA system is a specialized software application to run on computers and field devices for monitoring and control of any system or distant installations. Therefore, the following is a proposal for the implementation of a SCADA system in the UNAH, which has as a main objective the reduction of electricity consumption costs, since the university currently has high energy consumption. In addition, the university has a fiber optic ring that is present on campus (where the entity responsible for managing the network is the Executive Director of Technology Management EDTM, DEGT in Spanish), which reduces the initial investment needed, and is a vital reason for conducting this project. The SCADA system will enable the user to monitor and control installed devices (data acquisition card, PC, PLC, and various motion and capacitive sensors), where these are interconnected to the network via a VLAN through a Switch and with the other buildings through fiber optic ring, which has its main server. It is important to mention that the same research led us to perform a REAL SCADA prototype of low cost, to demonstrate the performance of this type system and prove that it can be applied to the UNAH. The prototype was developed using a Data Acquisition Card, Project Board, and electronic devices, Performing the real-world data acquisition and control of these physical variables through remote computers via a wireless communication network, for simulation of a network LAN TCP / IP. The design and prototype were presented orally at the Research Seminar class and specifically to DEGT, where development and implementation of SCADA were explained, which must start with a pilot Building for the design and development of the system to carry all UNAH. The investment plan for the 25 buildings with high consumption of electrical power is 3,903,743.75 LPS, where funds could be acquired as follows, 30% own funds or from external sources (1,171,123.13 LPS), and 70% funded by one or more financial institutions (2,732,620.63 LPS). These investments include furniture, software and hardware only, these costs can vary considerably, because much of the network equipment already exist in university. The DEGT manages these resources, so it is important that, the detail of these must given by them and is itself which defines the final cost. The conditions in which the project arises, allows us to recover the investment in eighteen months. As shown in parallel the relationship between benefit and cost of project implementation, because the benefit is very profitable for more than five years. See Fig.8 Due to the magnitude of the project, it is extremely important to hire a professional engineer to work in DEGT full time, with extensive knowledge of electricity, software, automated systems and networks. Granting sufficient authority to coordinate and manage the implementation and development of this project and other energy saving projects in buildings of the National Autonomous University of Honduras. If the complete project is implemented, the economic savings that the UNAH would have is more than a million Lempiras annually. Key words: SCADA; Automation; Networks and Communication Protocols; Remote Control; Computer Systems for Automation and Control. DOI: http://dx.doi.org/10.5377/rct.v0i6.514 Revista Ciencia y Tecnología, No. 6, Segunda época, junio 2010: 97-109

Throughput and PER estimates harnessing link-layer measurements for indoor 802.11n WLAN

The research work reported in this paper investigates if a Markov chain can model the throughput and packet error rate (PER) performance of off-the-shelf IEEE 802.11n wireless LAN network interface cards (NICs). We draw together uplink -downlink information from the NIC with a Markov chain to examine the performance of 802.11n within an indoor environment. Site measurements and point-estimates are taken and compared with the model predictions. Errors of less than 4% were recorded for the Markov model estimates while point-estimates recorded average errors of 9% both compared to site-measured throughput.

Efficiency of Four Virtual LANs Switches with Equal Processing Times

Virtual LANs (VLANs) are introduced as some alternative switches to solve for the traffic problems of those LAN networks with Hubs. The idea is to create some collections in the whole LAN network, such collections are the so called VLANs. Appropriate switches (one switch or more of up to 24 ports) are designed to interconnect those VLANs. The design of such VLAN switches looks like the design of Look-Up tables to facilitate routing (similar to those used in CISCO networks). In this paper, an analytical model for such VLANs is proposed and then compared with single VLAN switch from the point of view of validity and speed characteristics.

Ubiquitous Health Monitoring System for Diagnosis of Sleep Apnea With Zigbee Network and Wireless LAN

The Greek word “apnea” literally means “without breath.” The three types of apnea are obstructive, central, and mixed. Obstructive is the most common type. Despite the difference in the root cause of the three types of apnea, people with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night and often for 1 min or longer. Sleep apnea can cause high blood pressure and other cardiovascular diseases, memory problems, weight gain, impotency, and headaches. Sleep apnea may be responsible for job impairment and motor vehicle accidents. Apart from the physical health risks, sleep apnea can lead to social problems when left undiagnosed or untreated such as a high amount of unnecessary health care cost. Sleep disorder is diagnosed with polysomnography, an overnight sleep study, by monitoring electrical activity of brain, heart, eye movement, muscle activity, breathing pattern, and other physiological signals. Because polysomnography requires overnight monitoring by a sleep technologist with full sleep staging, polysomnography is expensive, inconvenient, time consuming, and labor intensive. Although some systems provide home based diagnosis, most systems record the sleep data in a memory card. The patient must send the memory card to a medical center through the mail or internet. The real-time monitoring is not performed and a patient can experience life threatening episodes by not receiving proper feedback from a medical center or a physician. We propose a wireless health monitoring system to diagnose sleep apnea, which enables the global monitoring of biomedical signals. A patient does not need hospitalization and can be diagnosed and receive feedback at home. The system supports monitoring five different biomedical signals to diagnose sleep apnea: electrocardiogram with dry electrodes (no gel), body position, nasal airflow, abdomen/chest efforts and oxygen saturation. The system consists of three units: a wireless transmitter, a wireless receiver, and a monitoring unit. A wireless transmitter unit sends the measured signals from sensors to a receiver unit with Zigbee communication. The receiver unit, which has two wireless modules, Zigbee and Wi-Fi, receives signals from the transmitter unit and retransmits signals to the remote monitoring system with Zigbee and Wi-Fi communication, respectively. By using both the Zigbee network and wireless LAN, the system can achieve low power consumption in a local monitoring area with the feature of the Zigbee standard. The system also provides wide data coverage and easily extends its sensor network to the Internet with the Wi-Fi standard. The features of the system and the results of the continuous monitoring of vital signals are presented.

Virtual WiFi

As virtualization trend is moving towards "client virtualization", wireless virtualization remains to be one of the technology gaps that haven't been addressed satisfactorily. Today's approaches are mainly developed for wired network, and are not suitable for virtualizing wireless network interface due to the fundamental differences between wireless and wired LAN devices that we will elaborate in this paper. We propose a wireless LAN virtualization approach named virtual WiFi that addresses the technology gap. With our proposed solution, the full wireless LAN functionalities are supported inside virtual machines; each virtual machine can establish its own connection with self-supplied credentials; and multiple separate wireless LAN connections are supported through one physical wireless LAN network interface. We designed and implemented a prototype for our proposed virtual WiFi approach, and conducted detailed performance study. Our results show that with conventional virtualization overhead mitigation mechanisms, our proposed approach can support fully functional wireless functions inside VM, and achieve close to native performance of Wireless LAN with moderately increased CPU utilization.

A New Pre-authentication Scheme for IEEE 802.11i Wireless LAN Network

As 802.11 Wireless LAN network is vulnerable to many security attacks, a complicated authentication mechanism was developed in IEEE 802.11i to enhance the WLAN network security. Unfortunately, the original 802.11i authentication procedure takes some time to complete and it will significantly affect the quality of service offered to mobile users who may handover between several access points. The existing pre-authentication scheme can shorten the authentication time remarkably, but it suffers from the unnecessary signalling overhead which may be a heavy burden to the network. In this paper, we propose to improve the preauthentication mechanism via reducing the signalling overhead. In our scheme, the mobile user will initiate the pre-authentication with a neighbouring access point only when he is really approaching that particular access point. Therefore, many unnecessary preauthentication signalling overheads can be avoided. Preliminary simulation results show that signalling overhead can be reduced by 50% while still maintaining short authentication delay.

Cryptanalysis for RC4 and Breaking WEP/WPA-TKIP

In recent years, wireless LAN systems are widely used in campuses, offices, homes and so on. It is important to discuss the security aspect of wireless LAN networks in order to protect data confidentiality and integrity. The IEEE Standards Association formulated some security protocols, for example, Wired Equivalent Privacy (WEP) and Wi-Fi Protected Access Temporal Key Integrity Protocol (WPA-TKIP). However, these protocols have vulnerability for secure communication. In 2008, we proposed an efffective key recovery attack against WEP and it is called the TeAM-OK attack. In this paper, first, we present a different interpretation and the relation between other attacks and the TeAM-OK attack against WEP. Second, we present some existing attacks against WPA-TKIP and these attacks are not executable in a realistic environment. Then we propose an attack that is executable in a realistic environment against WPA-TKIP. This attack exploits the vulnerability implementation in the QoS packet processing feature of IEEE 802.11e. The receiver receives a falsification packet constructed as part of attack regardless of the setting of IEEE 802.11e. This vulnerability removes the attacker's condition that access points support IEEE 802.11e. We confirm that almost all wireless LAN implementations have this vulnerability. Therefore, almost all WPA-TKIP implementations cannot protect a system against the falsification attack in a realistic environment.

A Comprehensive Approach to Ensure Secure Data Communication in Cloud Environment

computing is an Internet based development, in concept, it is a paradigm shift whereby details are abstracted from the users who no longer need knowledge of, expertise in, or control over the technology infrastructure that supports them. According to a 2008 IEEE paper, ―Cloud Computing is a paradigm in which information is permanently stored in servers on the internet and cached temporarily on clients that include desktops, entertainment centers, table computers and notebooks etc.‖ Some examples of emerging Cloud computing infrastructures are Microsoft Azure, Amazon EC2, Google App Engine, and Aneka. Cloud service providers enable users to access and use the necessary resources via the internet. To provide these resources, providers often fall back upon other providers in the cloud, hence this raises security issues in Cloud Environment as Clouds have no borders and the data can be physically located anywhere in the world. So this phenomenon raises serious issues regarding user authentication and data confidentiality. Hence it is proposed to implement a simple Data Protection framework which performs authentication, verification and encrypted data transfer, thus maintaining data confidentiality. Programming is performed using JAVA platform, Cloud environment is created using wired and wireless LAN networks. And Advanced Encryption Standard security algorithm is implemented for ensuring security framework.

IP 네트워크를 기반으로 하는 무선망 통합 관리 시스템 설계 및 구현

The hand over between different radio access networks, especially where their coverage overlaps, suffers various complications since the different access networks provide different service characteristics. In this paper, it is about the system which can control the wireless LAN network management system and the wireless LAN access point of variety vendor which is in different areas. Successful development of mobile sink wireless LAN network management system which supports multi-vendor devices and have center-local interoperability structure. In proposed system, speed of the mobile station give about 10% improvement when the map domain size is 5 than the existing system. Through a data plane and management system of message way, it give a stability system and consistency network.

Evaluation of Ad Hoc on Demand Distance Vector Routing Protocol in HetMAN Architecture

Problem statement: Mobile Ad hoc Network (MANET), a type of network with special characteristics, needs a special mechanism to bear with its ad hoc behavior. Approach: The important issue in MANET is routing protocol. Routing protocol is a standard used to determine the route path taken during the transmission of data. Results: In this study we focused on the Ad hoc On demand Distance Vector (AODV) routing protocol for MANET. Simulation experiments were carried out using the OMNeT++ network simulator to study AODV performance in a HetMAN architecture, which models heterogeneous MANET that is MANET integrated with Internet through fixed and wireless networks. The four types of network in HetMAN architecture are MANET, wireless LAN, wired LAN and cellular network. The simulation results were analyzed using several metrics assigned to measure the routing protocol performance. Conclusion/Recommendations: We described three scenarios for HetMAN architecture. This study covered scenario I (communication entirely within MANET; Homogeneous MANET) and scenario II (communication between MANET and wireless LAN; Heterogeneous MANET). Analyzing the simulation results for these two scenarios, we compared the performance of AODV in homogeneous MANET and heterogeneous MANET. Throughput value for scenario I was found to be 16% higher than for scenario II, while packet delivery ratio in scenario I is between 26.5-36.6% higher than that for scenario II. Analysis showed that implementation of AODV performed better in homogeneous MANET than in heterogeneous MANET.

Application of Object-Oriented Languages and Private Principles of Steganography in Deconstructing Local-Area Networks

Object-oriented is an important feature of operating system, and it is not exclusive to its micro-kernel architecture but promoting it. Object-oriented technology embodies design and implementation, which makes idea and realization possible. Due to the openness of transmission medium, LAN communication requests higher and better steganography-keeping performance. Through the features of LAN network security, the LAN security framework and hierarchical network security technology are proposed. Based on the basic principles and common methods of steganography information and the commonly used methods, combined with steganography capacity and the distortion changes of statistical properties, the improved LSB steganography writing with anti-steganography is given. In conclusion, the method can write different amount of data in different regions.

WiFi and WiMAX Secure Deployments

Wireless Broadband offers incredibly fast, “always on” Internet similar to ADSL and sets the user free from the fixed access areas. In order to achieve these features standardisation was achieved for Wireless LAN (WLANs) and Wireless Metropolitan Area Networks (WMANs) with the advent of IEEE802.11 and IEEE802.16 family of standards, respectively. One serious concern in the rapidly developing wireless networking market has been the security of the deployments since the information is delivered freely in the air and therefore privacy and integrity of the transmitted information, along with the user-authentication procedures, become a very important issue. In this article, we present the security characteristics for the WiFi and the WiMAX networks. We thoroughly present the security mechanisms along with a threat analysis for both IEEE 802.11 and the 802.16 as well as their amendments. We summarise in a comparative manner the security characteristics and the possible residual threats for both standards. Finally focus on the necessary actions and configurations that are needed in order to deploy WiFi and WiMAX with increased levels of security and privacy.

Seamless Video Session Handoff between WLANs

Handoff in a distributed IEEE 802.11 Wireless LAN network is a source of significant amount of problems on the video transmission environment. The visual quality of video streaming applications is lowered when stations are in handoff status. In this paper, we introduce an architecture of a session proxy (SP), which tries to preserve the quality of the streaming video upon each handoff between access points. We have evaluated thresholds of RSSI and Loss Frame Rate (LFR) for deciding the moment when the handoff process shall begin. Our solution performance was evaluated in a testbed implementation for MPEG-4 video on demand with one video server (VLS) and two FreeBSD-based access points supporting Mobile IP, DHCP Server and IAPP approach.

A Hardware Approach for Detecting the ARP Attack

This paper describes Address Resolution Protocol (ARP) and the ARP cache poisoning (ARP SPOOFING) problem and presents a proposed architecture for detecting the ARP attacks. In addition, it discusses a set of techniques used to detect the ARP poisoning attacks on switched Ethernet networks. A new practical technique by adding external hardware element to the LAN network to work as sniffer is suggested. These external elements are combined in architecture for practical implementation in production network. Results from laboratory and real-world detection experiments using several popular attack tools are also presented. The obtained practical results illustrate that the practical board works successfully for detecting the ARP attack.

Seamless Handover of IPTV Streams in a Wireless LAN Network

A robust mechanism to enable seamless handover of streamed IPTV in a WLAN is presented. Handover in a wireless network is usually based on signal strength measurements, but that approach does not consider levels of congestion within the network. Here, the case of stationary nodes with varying levels of network congestion is considered. A scheme that analyzes the jitter is used to establish the relationship between congestion and loss in WLANs. This Moving Average of Negative Jitter is used as the basis of a handover scheme which can minimize loss. The handover scheme uses a client with two simultaneous connections to the same server through two separate WLANs, and it is shown that the client can compare the jitter in the two streams to determine which network delivers the best performance; this information is then used to determine when to perform a handover. The proposed scheme is implemented and results are presented that show the successful handover of an RTP over UDP stream in a live WLAN environment. The test scenario used is aimed at ldquoOver-The-Toprdquo service delivery, but the core algorithm is expected to be more broadly applicable.

Membangun Server Multicast Berbasis Streaming Menggunakan Centos

The development of IP-based technology contribute to the development of telecomunication and information technology. One of IP-based technology application is streaming multicast, as part of broadcasting. The streaming process is made by accessing Telkom-2 broadcast through AKATEL LAN network, then server forward it to clients using multicast IP system. Multicast IP is D-class IP, which is able to send data package in realtime. In multicast system, server only send one data package to some clients with same speed transmition. The Telkom-2 broadcast is already accessed before sent as data package. Server will access Telkom-2 broadcast using parabola antenna and Hughes modem, then forward it to clients through AKATEL LAN network. Clients must conect to server via AKATEL LAN network and already instaled VLC player, in order to be able to access the Telkom-2 broadcast

Distributed Proportional Fair Scheduling for IEEE802.11 Wireless LANs

In the time varying wireless channel, opportunistic scheduling is one of the important techniques to achieving the rich diversities inherent in wireless communications. However, most existing scheduling schemes require centralized scheduling and little work has been done on developing distributed algorithms The proportional fair scheduling is one of the representative opportunistic scheduling for centralized networks. In this paper, we propose distributed proportional fair scheduling (DPFS) scheme for wireless LAN network. In the proposed DPFS scheme, each receiver estimates channel condition and calculates independently its own priority with probabilistic manner, which can reduce excessive probing overhead required to gather the channel conditions of all receivers. We evaluate the proposed DPFS using extensive simulation and simulation results show that DPFS obtains higher network throughput than conventional scheduling schemes while maintaining fairness among users.