Wireless Local Area Networks Users Research Articles

Implementasi Authentication Captive Portal Pada Wireless Local Area Network di PT. St. Morita Industries

PT. St. Morita Industries has a Wireless Local Area Network (WLAN) which is used as a medium for exchanging data and information by utilizing wireless transmission media, WLAN currently uses WPA2-PSK as a security system to authenticate users to access the internet. However, the use of WPA2-PSK as WLAN security still has a weakness due to the use of the same 1 password for many users in order to connect to the WLAN hotspot will be an opportunity for cyber crime. This happens because it will be very easy for irresponsible users to enter the WLAN. Therefore, in this study, captive portal authentication will be applied as an effort to increase WLAN security replaces WPA2-PSK. This research process uses the Network Development Life Cycle (NDLC) method. All the configurations needed to build the captive portal authentication take advantage of the Winbox program. This research has resulted in a special user authentication limitation for users who have registered on the WLAN is permitted to access this company's internet. In addition, the Winbox program can also be used for monitoring all users connected to the WLAN, both active and inactive users. By setting up captive portal authentication on a WLAN network using a proxy routerboard device which comprises an IP address, DHCP server, hostpot setup, NAT firewall, and DNS server one can create a WPA2-PSK security system. This configuration is completed with the aid of the Winbox v3.37 software.

On optimization of resource allocation for LTE aided by WLAN networks with unlicensed frequency bands in internet of vehicles

AbstractDue to the explosive growth of communication devices and vehicles, the ever‐increasing communication data traffic is a challenge for mobile communication in the Internet of Vehicles (IoV). A practical solution is to offload the traffic from cellular networks to Wireless Local Area Network (WLAN), that is, WiFi, where the spectrum is license‐free. However, the coordination of unlicensed spectrum severely reduces the utilization rate on the spectrum. In this case, unlicensed networks assisted access is proposed to facilitate long‐term evolution technology in unlicensed spectrum (LTE‐U). To improve the data rate for LTE‐U and WLAN users, an allocation optimization scheme for the resources of the licensed and unlicensed spectrum is proposed. Accordingly, the data rate of LTE‐U users and WLAN users can be maximized by adjusting the transmit power and the frequency occupancy time ratio of the unlicensed spectrum for the small cell and WLAN users. Numerical results show that the proposed hybrid LTE networks with WLAN can improve the communication efficiency for the served users.

Two‐layer modelling of IEEE 802.11x channel occupancy

AbstractLow power IoT communication signals (e.g., Bluetooth and ZigBee) may seriously suffer from the presence of high‐power co‐channel interference like wireless local area network (WLAN) signal. They may effectively avoid WLAN interference by exploiting dynamic characteristics of WLAN traffic. Representing the arrival/departure of WLAN users using an M/M/m/m queueing structure, the characterization of large‐scale dynamics of WLAN channel occupancy is considered. The characterization of small‐scale dynamics of WLAN channel occupancy is also considered by generating WLAN signal using a two‐state semi‐Markovian process. Simulation results show that the proposed model generates WLAN signal having similar statistical characteristics to those of real WLAN signal.

Joint Radio Resource Management of Channel-Assignment and User-Association for Load Balancing in Dense WLAN Environment

IEEE 802.11-based wireless local area network (WLAN) is currently the most popular communication system and a lot of access points (APs) have been densely deployed over heavily populated areas. In such dense WLAN environment, the WLAN users can suffer from performance degradation due to high co-channel and adjacent-channel interference among APs. To tackling such user performance degradation problem, we propose a two-phase radio resource management (RRM) framework, of which the first phase is channel assignment (CA) and the second phase is user association for channel load balancing (UA-ChLB). In designing the RRM framework, we take account of typical WLAN environment where dual bands are supported and two types of APs coexist: controlled-APs, which are managed by a centralized controller, and stand-alone APs, which independently operate for themselves. The proposed CA method utilizes a channel bonding technique, which provides a high data rate by integrating multiple basic channels while reducing the interference among neighboring APs. The proposed hybrid UA-ChLB scheme, which is composed of distributed/centralized UA-ChLB, efficiently coordinates the channel load among neighboring APs and between two bands of 2.4 and 5 GHz, under consideration of the wireless channel quality, interference, and traffic conditions. We implement a prototype system in practice using the proposed RRM scheme. The experimental results show that the proposed RRM scheme greatly improves both throughput and fairness in dense WLAN environment, as compared with some existing schemes.

Detection and Prevention of De-authentication Attack in Real-time Scenario

Wireless Local Area Network (WLAN) is an infrastructure network in which nodes are connected to a centralized system to provide Internet access to mobile users by radio waves. But WLANs are vulnerable to Medium Access Control (MAC) layer Denial of Service (DoS) attacks due to the susceptibility of the management frames. An attacker can spoof the MAC address of the legitimate client and perform de-authentication attack to disconnect WLANs users from the access point. Many free tools are available in Kali Linux Operating System (OS) by which this attack can be performed and cause a security threat to WLAN users. The consequences of de-authentication DoS attack are frequent disconnection from Internet, traffic redirection, man-in-the-middle attack, and congestion. Despite enormous efforts in combating de-authentication DoS attack in the past decade, this attack is still a serious threat to the security of the cyber world. Medium Access Control Spoof Detection and Prevention (MAC SDP) DoS algorithm performs detection and prevention of de-authentication attack caused by spoofing MAC address. This algorithm is modified to make it more immune to the de-authentication attack and implemented in real-time scenario. The results show that the proposed technique increases the packet flow rate by 20.36%, reduces the packet loss by 95.71%, and reduces the down time and recovery time by 0.39 sec and 0.9 sec respectively as compared to MAC SDP DoS algorithm.

Energy-Efficient WLANs With Resource and Re-Association Scheduling Optimization

Recently, a number of WiFi access points (APs) have been densely deployed to provide widely available, high-performance Internet services. As such, an energy efficiency issue becomes crucial toward the design of green wireless local area networks (WLANs). In this paper, we propose a resource and re-association scheduling algorithm (referred to RAS) based on Benders’ decomposition to reduce the energy consumption. In particular, we endeavor to aggregate WLAN users on the small number of APs and turn off many APs without compromising users’ quality of experience (QoE) and system coverage. We conduct the analysis by using real trace data and formulate the energy minimization as the mixed integer nonlinear programming (MINLP) problem. We then transform and solve the original problem through the RAS algorithm. For practical implementation, we further propose the fast RAS (Fast-RAS) algorithm to relax the binary integer constraints and transform the MINLP problem into the nonlinear programming (NLP) problem. The relaxed problem then can be solved by using Feasible Pump algorithm with the reduced computational complexity. We evaluate the performance of RAS and Fast-RAS algorithms via extensive simulations. The results demonstrate that the Fast-RAS algorithm can achieve up to 20% improvement of energy saving comparing with existed methods.

Provisioning QoS in Wi-Fi Systems With Asymmetric Full-Duplex Communications

The traffic volume carried by wireless local area networks (WLANs) continues to increase at a rapid pace. Full-duplex communication is a key solution for satisfying the growing traffic demand, enhancing spectrum efficiency, and reducing latency for WLAN users. In this paper, we consider the application of asymmetric full-duplex (AFD) communications in WLANs, exemplified by a Wi-Fi system. Our system model relies on a full-duplex-enabled Wi-Fi access point to simultaneously transmit uplink and downlink to a pair of half-duplex Wi-Fi stations. Providing QoS guarantees in WLANs with AFD communication capabilities is challenging due to inter-node as well as residual self-interference. The heterogeneity of the QoS requirements between paired uplink and downlink stations further complicates the problem. To tackle these challenges, we introduce a framework called AFD-QoS, which incorporates AFD communications in WLANs and supports QoS. AFD-QoS consists of three components: 1) AFD-enabled uplink/downlink station-pair selection algorithm; 2) AFD-enabled block-acknowledgment session initiation/termination protocol; and 3) joint transmission rate/AFD communication mode adaptation scheme. Our adaptation scheme relies on intelligent and cognitive approaches to improve Wi-Fi networks awareness about channel dynamics as well as inter-node and self-interference. We introduce new intelligent MAC-layer procedures for supporting QoS services in AFD communications, and cast light on many challenges and their solutions. Our simulation results indicate that AFD-QoS outperforms classical half-duplex frameworks and achieves up to 90% of the optimal AFD performance.

Throughput performance of NOMA in WLANs with a CSMA MAC protocol

The existing medium access control (MAC) protocols are not able to utilize the full opportunities from power-domain non-orthogonal multiple access (NOMA) technique in wireless local area networks (WLANs). In this paper, we propose a carrier sense multiple access (CSMA) MAC protocol to increase downlink throughput by utilizing the opportunities offered by NOMA technique in downlink access of WLANs. For downlink transmission, an algorithm is developed to select an optimal user-set with appropriate power allocation from a randomly selected user-set. We then develop an analytical model to compute the uplink and downlink throughputs of a WLAN under the proposed MAC protocol by modelling the WLAN system as a discrete time Markov chain. The uplink and downlink throughputs of a WLAN under the proposed MAC protocol are determined by means of the analytical model and the accuracy of the analytical model is verified via extensive simulation. It is demonstrated that the proposed NOMA based MAC protocol improves the downlink throughput significantly compared to an orthogonal multiple access (OMA) based traditional CSMA MAC protocol without reducing the uplink throughput considerably. For a reasonable configuration, the downlink throughput gain is found to be more than 250%. We also study the throughput performance of the proposed MAC protocol for different transmit power levels, user medium access rates, data rates, path loss exponents and number of users in WLAN. We find that the throughput gain obtained by the proposed MAC protocol increases with increasing the transmit power and decreases with increasing the data rates and path loss. However, the change in the throughput gain obtained by the proposed MAC protocol is not significant for increasing the number of users and the user medium access rate.

Rogue Access Point Detection: Taxonomy, Challenges, and Future Directions

Wireless Local Area Networks (WLANs) are increasingly integrated into our daily lives. Access Points (APs) are an integral part of the WLAN infrastructure, as they are responsible for coordinating wireless users and connecting them to the wired side of the network and, eventually, to the Internet. APs are deployed everywhere, from airports and shopping malls to coffee shops and hospitals, to provide Internet connectivity. One of the most serious security problems encountered by WLAN users is the existence of Rogue Access Points (RAPs). This article classifies existing solutions, identifies vulnerabilities, and suggests future directions for research into these RAPs. The ultimate objective is to classify existing detection techniques and find new RAP types that have not been classified by the research community. The literature typically categorizes Evil-twin, Unauthorized, Compromised, and Improperly Configured RAPs. Two other types have largely been abandoned by researchers, but can be classified as Denial of Service RAP attacks. These are deauthentication/disassociation attacks targeting wireless users, and the forging of the first message in a four-way handshake.

A Threshold Based Handover Triggering Scheme in Heterogeneous Wireless Networks

The widespread popularity of Wireless Local Area Network (WLAN) is recognized as an effective approach to complementing cellular networks for the high data rate and cost effective connectivity delivered to mobile users. Efficient handover and offloading schemes for integrated WLAN and cellular networks, referred to as Heterogeneous Wireless Networks, have thus attracted lots of attentions from both academia and industry. This paper proposes a novel Multiple-Threshold based Triggering (MTT) scheme for Cellular-to-WLAN handover control. Aiming at minimizing the probability of handover failures and unnecessary handovers, three thresholds are calculated based on a variety of network parameters such as system performance requirements, radius of the WLAN coverage, user mobility and handover delays. The thresholds are then compared against the predicted user residence time and estimated channel holding time inside WLAN to make vertical handover decisions (VHDs). Simulations were carried out to evaluate the effectiveness of MTT and results show that MTT minimizes handover failures and avoids unnecessary handovers in integrated cellular and WLAN networks, thus providing satisfactory Quality of Service (QoS) to users and improving system resource utilization.

Security Analysis of 3G-WLAN Fusion

With development of wireless Internet, the interworking of the third generation (3G) and wireless Local Area Network (WLAN) has become a focus research. Fusion of 3GWLAN has complementary advantages. The background and scheme of 3G and WLAN Fusion are discussed. The security of Fusion was analysed. Presents two security Fusion schemes has given. The first is called a loose coupling, The second is called close coupling. Two schemes are complement each other, realize the 3G and WLAN user unified management and 3G signing based on user WAPI security mechanism of WLAN access, and protect the user privacy.

Network-Load Aware Adaptive Channel Access Control for WLAN

Wireless local area network (WLAN) brings us a low cost and high bandwidth experience and thus plays a critically important role in current/future networks to support high-rate transmissions. To better provide quality-of-service (QoS) for WLAN users, we in this paper propose an improved scheme called “A-EDCA”(adaptive EDCA), based on enhanced distributed channel access (EDCA) of IEEE 802.11e under the infrastructure mode. Our proposed scheme aims at efficiently adapting the transmission over WLAN to the time-varying network conditions and mitigating the competition ability unfairness between access point (AP) and non-AP stations (STAs). Specifically, all non-AP STAs adaptive-ly modify the contention window based on the network condition. Moreover, AP skips the backoff phase by setting its backoff counter as zero when non-AP STA completes transmission successfully to relieve the unfairness. At last, simulation results demonstrate the effectiveness of the proposed approach.

Intrusion Detection System for Misbehaving WLAN Users

Wireless networks in the lives of people at work, at home, and in public places, plays a decisive role. Given the widespread demand for wireless networks, providers deploy wireless local area networks (WLAN) to provide access to broadband Internet Within the range of a public wireless LAN hotspot such as in airports or hotels, users can access their e-mails and browse the Internet either for free or, most often, against a fee. However, as the number of users rises, so does the risk that users may misbehave. Misbehaving users can to a large extent increase their share of bandwidth at the expense of other paid users by slightly modifying the driver of the network adapter. As the use of such networks grows, users will demand secure yet efficient, low-latency communications. Intruders’ detection is one of the key techniques that can be used to protect a network against outsiders. Many Intrusion Detection Systems (IDSs) have been designed for wired networks. Unfortunately, most of these IDSs do not give the expected results when used with wireless networks and are especially poor at addressing the Media Access Control (MAC) layer problem. In this sheet, we present the design and implementation of an IDS tool that is chosen for WLANs and addresses misbehavior at the MAC layer properly. Keywords: IDS, WLAN, MAC layer, Misbehavior

Solving Nonlinear Covering Problems Arising in WLAN Design

Wireless local area networks (WLANs) are widely used for cable replacement and wireless Internet access. Because the medium access control (MAC) scheme of WLANs has a strong influence on network performance, it should be accounted for in WLAN design. This paper presents AP location models that optimize a network performance measure specifically for the MAC scheme of WLANs that represents the efficiency in sharing the wireless medium. For these models, we propose a solution framework based on an effective integer-linear programming Dantzig–Wolfe reformulation. This framework is applicable to any nonlinear covering problem where the objective function is a sum of contributions over the groundset elements (users in WLANs). Extensive computational results show that our solution strategy quickly yields optimal or near-optimal solutions for WLAN design instances of realistic size.

Secure fast WLAN handoff using time‐bound delegated authentication

AbstractTo support multimedia applications with good quality of services for roaming wireless local area network users, it is imperative to reduce the long re‐authentication latency that users experience during handoff among access points (APs). Athough a great deal of research resources have been put into the reduction of the re‐authentication latency, these schemes developed so far seem to either suffer from heavy overhead problems or have weak security. In this paper, we propose a novel approach to reducing the re‐authentication latency. With the authentication server (AS) periodically delegating its authentication authority to the authenticated APs, the APs can authenticate the roaming users on behalf of the AS. As our performance analysis and simulation results demonstrate, our new approach is capable of greatly reducing the latency and overhead while achieving a high security level. Furthermore, it does not increase the complexity on the AP side because only the already existing four‐way handshake with new keying mechanism is required. Copyright © 2008 John Wiley & Sons, Ltd.

Physical Security Perimeters for Wireless Local Area Networks

On a wired network, physical authentication is implicitly provided by access: if a user is able to plug a cable into a network socket, he must have cleared other security checks such as the receptionist and/or locked doors. In the case of a wireless local area network (WLAN), the signal propagation is not limited by a fixed boundary, and unauthorized access from outside the security perimeter is possible, and in many instances facile. In this paper, we present a probabilistic technique for localization of users in a WLAN. The presented technique is able to identify intruders based on their location, and thus successfully defend a “parking lot” attack. The approach relies on a probabilistic mapping from received signal strength (RSSI) to location. Calibration inside and around the security perimeter must precede the localization phase. During the localization phase, the RSSI of all the WLAN users is measured by multiple monitoring stations positioned to provide an overlapping coverage of the area (the access points needed to provide the WLAN coverage can double as monitoring stations). A Bayesian technique is used to estimate the location of the unsuspecting mobile user, and the position estimate of each user is updated with every new RSSI measurement at any of the monitoring stations. The presented approach is server-based, i.e., it works without the knowledge or cooperation of the user being tracked, thereby enabling the proposed security application, as well as location-aware services. Validation of the concepts was implemented using an experimental tested in an office environment. The results demonstrate the ability of the proposed technique to estimate the user location to a very high degree of accuracy.

Analysis of Sub-Carrier Multiplexed Radio Over Fiber Link for the Simultaneous Support of WLAN and WCDMA Systems

The present third generation (3G) wireless technology can provide data oriented applications. However, the bit rate is limited to around 2 Mbps with limited mobility. Today, more applications demand high data rate and reasonable mobility. Therefore, by integrating 3G cellular system and wireless local area network (WLAN), there is a potential to push the data rate higher. This integration means 3G cellular users can enjoy high data rate at a location that is within WLAN coverage area. Similarly, WLAN users also can have data services as long as they are under the coverage of the 3G cellular system. The 3G cellular system has a much larger coverage than the WLAN. In this paper, we present the first step toward an integration of the two systems. This paper presents a fiber-wireless architecture that simultaneously supports the wideband code division multiple access (WCDMA) system and the IEEE 802.11b WLAN. Our approach uses sub-carrier multiplexed (SCM) architecture to combine and transmit 2.4 GHz WLAN and 1.9 GHz WCDMA signals through an optical fiber from a central base station (CBS) to a radio access point (RAP, single antenna unit). After the fiber, the signals continue to propagate through the air interface to respective mobile stations. The WLAN access point is also located at the CBS. For the SCM architecture, we investigate three areas: i) the signal to noise ratio of the uplink and the downlink, ii) the cell coverage area for the WCDMA and WLAN systems, and iii) the throughput of the IEEE 802.11b WLAN. Our results show that with up to 2.5 km cell radius, better than 18 dB SNR is possible with 5 km fiber link for WLAN system. Simultaneously, the WCDMA system has at least 18 dB SNR for a cell coverage radius of 8 km. These numbers depend on the relative RF power of each system in the fiber.

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Outdoors we can easily acquire our accurate location by GPS. However, the GPS signal can't be acquired indoors because of its weak signal power level. Adequate positioning method is demanded for many indoor positioning applications. At present, wireless local area network (WLAN) is widely installed in various areas such as airport, campus, and park. This paper proposes a positioning algorithm using WLAN signal strength to provide the position of the WLAN user indoors. There are two methods for WLAN based positioning, the signal propagation method uses signal strength model over space and the empirical method uses RF power propagation database. The proposed method uses the probability distribution of the power propagation and the maximum likelihood estimation (MLE) algorithm based on power strength DB. Test results show that the proposed method can provide reasonably accurate position information.