Detection of selfish manipulation of carrier sensing in 802.11 networks

Recently, tuning the clear channel assessment (CCA) threshold in conjunction with power control has been considered for improving the performance of WLANs. However, we show that, CCA tuning can be exploited by selfish nodes to obtain an unfair share of the available bandwidth. Specifically, a selfish entity can manipulate the CCA threshold to ignore ongoing transmissions; this increases the probability of accessing the medium and provides the entity a higher, unfair share of the bandwidth. We experiment on our 802.11 testbed to characterize the effects of CCA tuning on both isolated links and in 802.11 WLAN configurations. We focus on AP-client(s) configurations, proposing a novel approach to detect this misbehavior. A misbehaving client is unlikely to recognize low power receptions as legitimate packets; by intelligently sending low power probe messages, an AP can efficiently detect a misbehaving node. Our key contributions are: 1) We are the first to quantify the impact of selfish CCA tuning via extensive experimentation on various 802.11 configurations. 2) We propose a lightweight scheme for detecting selfish nodes that inappropriately increase their CCAs. 3) We extensively evaluate our system on our testbed; its accuracy is 95 percent while the false positive rate is less than 5 percent. © 2012 IEEE

An Experimental Testbed and Methodology for Characterizing IEEE 802.11 Network Cards

It has been observed that IEEE 802.11 commercial cards produced by different vendors show a different behavior in terms of perceived throughput or access delay. Performance differences are evident both when the cards contend alone to the channel, and when heterogeneous cards contend together. Since the performance disaligment does not disappear by averaging the environmental factors (such as propagation conditions, laptop models, traffic generators, etc), it is evident that the well known throughput-fairness property of the DCF protocol is not guaranteed in actual networks. In this paper we propose a methodological approach devised to experimentally characterize the IEEE 802.11 commercial cards thus understanding and predicting their performances in different network scenarios. We set up some specific experiments using a custom test equipment, able to classify the card behavior not only in terms of figures which are evident to the user perspective (such as the throughput), but also in terms of low-level channel access operations and delays. Our approach is able to detect potential hardware limits or not-standard MAC implementations, which severely affect the contending card performance

M-Business: Economy Driver or a Mess?

Reports about mobile wireless technology in the media may be confusing. While we know that the telecommunication industry is in distress, we also observe a phenomenal, indeed unprecedented explosion of the use of mobile wireless devices and services all over the globe. This paper presents a balanced introduction to wireless technology including devices, mobile operating systems, and communication protocols. It discusses standardization efforts, technology evolution paths, and several new and potentially disruptive technologies, some still in the research stage. The paper lists leading global wireless service providers in terms of the number of domestic subscribers and presents an analysis of the six U.S. national operators including their strengths and weaknesses. Only four of them are profitable now. Although the consumer market currently dictates technology evolution, several examples of successful business applications of wireless mobile technology are presented. Finally, the question presented in the title is addressed

Concept and design of the hybrid distributed embedded systems testbed

Wireless mesh networks are an emerging and versatile communication technology. The most common application of these networks is to provide access of any number of users to the world wide Internet. They can be set up by Internet service providers or even individuals joined in communities. Due to the wireless medium that is shared by all participants, effects like short-time fading, or the multi-hop property of the network topology many issues are still in the focus of research. Testbeds are a powerful tool to study wireless mesh networks as close as possible to real world application scenarios. In this technical report we describe the design, architecture, and implementation of our work-in-progress wireless testbed at Freie Universität Berlin consisting of 100 mesh routers that span multiple buildings. The testbed is hybrid as it combines wireless mesh network routers with a wireless sensor network

Experimenting with commodity 802.11 hardware: overview and future directions

The huge adoption of 802.11 technologies has triggered a vast amount of experimentally-driven research works. These works range from performance analysis to protocol enhancements, including the proposal of novel applications and services. Due to the affordability of the technology, this experimental research is typically based on commercial off-the-shelf (COTS) devices, and, given the rate at which 802.11 releases new standards (which are adopted into new, affordable devices), the field is likely to continue to produce results. In this paper, we review and categorise the most prevalent works carried out with 802.11 COTS devices over the past 15 years, to present a timely snapshot of the areas that have attracted the most attention so far, through a taxonomy that distinguishes between performance studies, enhancements, services, and methodology. In this way, we provide a quick overview of the results achieved by the research community that enables prospective authors to identify potential areas of new research, some of which are discussed after the presentation of the survey.This work has been partly supported by the European Community through the CROWD project (FP7-ICT-318115) and by the Madrid Regional Government through the TIGRE5-CM program (S2013/ICE-2919).Publicad

The effect of people movement on Wi-Fi link throughput in indoor propagation environments

While various key performance limiting factors of IEEE 802.11-based Wi-Fi networks such as wireless protocols, radio propagation environment and signal interference have been studied by many network researchers, the effect of the movement of people (human) on Wi-Fi link throughput in indoor propagation environments has not been fully explored yet. This paper investigates the effect of people movement on Wi-Fi link throughput in six different indoor environments (i.e. lounge, bedroom, garage, common room, laboratory, and office space) using radio propagation measurements. Using a pair of wireless laptops we conducted various trials by considering both the straight line and random human movement in the above mentioned environments. Results obtained show that Wi-Fi link throughput degrades up to 20.4% as a result of people movement. The difference between the impact of straight line and random movement on Wi-Fi throughput is found to have insignificant. The research findings reported in this paper provide some insight into the impact of people movement on Wi-Fi link throughput in indoor environments

39P. Nature and Extent of Identity Crime through Wireless Technology Abuse and its Impact on Individual and Organisational Levels

Perpetrator(s) are stealing personal data abusing wireless networks to commit identity fraud and related crimes that is affecting us on individual, organisational and national levels. These threats affect national security also (Smith et al. 2010). There have been instances of identity and data theft crimes involving millions of debit and credit card numbers, which indicate the seriousness of this issue and reinforce the concerns of security professionals. These cases were taken from newspapers and recent research papers related to this field and analysed in this study. The objective of this research paper is to investigate the security weaknesses in the wireless protocols and examine how perpetrators are exploiting the wireless networks. The security limitations found in the commonly used types of wireless networks are also presented. The sharing of information on social networking services such as Facebook and Twitter also pose privacy and security threats. The current study presents guidelines and discusses approaches employed to safeguard and protect wireless networks in organisations. It is a study to create public awareness about the threats and related privacy issues in the use of wireless and hand held communication devices

An Open Management and Administration Platform for IEEE 802.11 Networks

The deployment of Wireless Local Area Network (WLAN) has greatly increased in past years. Due to the large deployment of the WLAN, the immediate need of management platforms has been recognized, which has a significant impact on the performance of a WLAN. Although there are various vendor-specific and proprietary solutions available in the market to cope with the management of wireless LAN, they have problems in interoperability and compatibility. To address this issues, IETF has come up with the interoperability standard of management of WLANs devices, Control And Provisioning of Wireless Access Points (CAPWAP) protocol, which is still in the draft phase. Commercial implementation of this draft protocol from WLAN equipment vendors is rather expensive. Open source community, therefore, tried to provide free management solutions. An open source project called openCAPWAP was initiated. However, it lacks a graphic user interface that makes it hard to implement for novice network administrators or regular customers. Therefore, the researcher designed and developed a web interface framework that encapsulates openCAPWAP at the bottom to provide user-friendly management experience. This application platform was designed to work with any remote web server in the public domain through which it can connect to access points or access controllers through a secure shell to configure them. This open platform is purely open source-based. It is operating system independent: it can be implemented on any open source environment such as regular Linux operating system or embedded operation system small form factor single board computers. The platform was designed and tested in a laboratory environment and a remote system. This development contributes to network administration in both network planning and operational management of the WLAN networks