With the prevalence of personal Bluetooth devices, potential breach of user privacy has been an increasing concern. To date, sniffing Bluetooth traffic has been widely considered an extremely intricate task due to Bluetooth’s indiscoverable mode, vendor-dependent adaptive hopping behavior, and the interference in the open 2.4 GHz band. In this paper, we present BlueEar –a practical Bluetooth traffic sniffer. BlueEar features a novel dual-radio architecture where two Bluetooth-compliant radios coordinate with each other on learning the hopping sequence of indiscoverable Bluetooth networks, predicting adaptive hopping behavior, and mitigating the impacts of RF interference. We built a prototype of BlueEar to sniff on Bluetooth classic traffic. Experiment results show that BlueEar can maintain a packet capture rate higher than 90% consistently in real-world environments, where the target Bluetooth network exhibits diverse hopping behaviors in the presence of dynamic interference from coexisting 802.11 devices. In addition, we discuss the privacy implications of the BlueEar system, and present a practical countermeasure that effectively reduces the packet capture rate of the sniffer to 20%. The proposed countermeasure can be easily implemented on Bluetooth master devices while requiring no modification to slave devices such as keyboards and headsets.

A Practical Bluetooth Traffic Sniffing System: Design, Implementation, and Countermeasure

IEEE 802.11 and Bluetooth, these two operating in the unlicensed 2.4 GHz frequency band are becoming more and more popular in the mobile computing world. The number of devices equipped with IEEE 802.11 and Bluetooth is growing drastically. Result is the number of co-located devices, say within 10 meters, grown to a limit, so that it may causes interference issues in the 2.4 GHz radio frequency spectrum. Bluetooth supports both voice synchronous connection oriented (SCO) data and asynchronous connection less (ACL) packets. In this paper, we investigate the interference issues of 2.4 GHz frequency band. In addition, this paper presents a new Bluetooth voice packet Synchronous Connection Oriented with Repeated Transmission (SCORT) scheme to optimize the performance of 2.4 GHz frequency band by minimizing the interference between Bluetooth and 802.11 wireless networks. For the sake of experimental verifications, we provide a comprehensive simulation results using Matlab Simulink.

/pdf/interference-of-802-11b-wlan-and-bluetooth-analysis-and-5cw2u9475h.pdf

Interference of 802.11B WLAN and Bluetooth: Analysis and Performance Evaluation

Modern mobile phones and laptops are equipped with multiple wireless communication interfaces, such as WiFi and Bluetooth (BT), enabling the creation of ad-hoc networks. These interfaces significantly differ from one another in their power requirements, transmission range, bandwidth, etc. For example, BT is an order of magnitude more power efficient than WiFi, but its transmission range is an order of magnitude shorter. This paper introduces a management middleware that establishes a power efficient overlay for such adhoc networks, in which most devices can shut down their long range power hungry wireless interface (e.g., WiFi). Yet, the resulting overlay is fully connected, and for capacity and latency needs, no message ever travels more than 2k short range (e.g., BT) hops, where k is an arbitrary parameter. The paper describes the architecture of the solution and the management protocol, as well as a detailed simulations based performance study. The simulations largely validate the ability of the management infrastructure to obtain considerable power savings while keeping the network connected and maintaining reasonable latency. The performance study covers both static and mobile networks.

/pdf/power-aware-management-middleware-for-multiple-radio-237go4b00g.pdf

Power aware management middleware for multiple radio interfaces

Die vorliegende Arbeit beschaftigt sich mit dem Management von Diensten im mobilen ad-hoc Netzwerken (MANETs). MANETs sind drahtlose Netzverbande mobiler Einheiten die sich dezentral ohne eine ubergeordnete Organisation selbst verwalten. Die Netztopologie eines MANET verandert sich dabei dynamisch mit der Bewegung der autonomen Teilnehmer. Sensor Netzwerke, Personal Area Networks und Satelliten Netzwerke sind typische Beispiele fur derartige MANETs. Mit der wachsenden Bedeutung der drahtlosen Vernetzung mobiler Gerate haben sich MANETs in den vergangenen Jahren zu einem wichtigen Forschungsgebiet entwickelt. Im Katastrophenmanagement, bei zivilen Rettungsfallen oder in militarischen Szenarien kann ihre infrastrukturlose Selbstorganisation MANETs zum einzig moglichen Kommunikationsmittel machen. Die mobilen Knoten eines MANETs kooperieren um essenzielle Netzwerkdienste wie das Routing und den Datentransport gemeinschaftlich zu gewahrleisten. Ressourcen wie die Bandbreite zwischen Knoten, die Rechenleistung der mobilen Gerate und ihre Batterieleistung sind dabei typischerweise stark begrenzt und zudem wechselnd. Das Teilen der verfugbaren Ressourcen ist daher eine Notwendigkeit fur das effiziente Funktionieren eines MANETs. Dienstorientierte Architekturen (SOAs) stellen ein geeignetes Paradigma dar, um geteilte Ressourcen zu verwalten. Wenn verfugbare Ressourcen als Dienst aufgefasst werden, lasst sich ihre Nutzung als Dienstabfrage bearbeiten. In diesem Zusammenhang ermoglichen SOAs Abstraktion, Kapselung, lose Koppelung, Auffindbarkeit von Ressourcen und dir fur MANETs essenzielle Autonomie. Die Anwendung von SOAs auf MANETs findet daher zunehmend Beachtung in der Forschung.

Service Replication in Wireless Mobile Ad Hoc Networks

802.11 Wireless Local Area Networks (WLANs) and Bluetooth are likely to be used within the same area. The two technologies operate in the 2.4 GHz band. This will result in mutual interference. The new emerging 802.11n Multi Input Multi Output (MIMO) devices implement different Physical and Medium Access Control (MAC) layers compared to legacy 802.11b/g devices. Through empirical experiments, this paper studies and presents results on the mutual impact of 802.11n and Bluetooth devices. The results show that coexistence mechanisms are crucial for the 802.11n to achieve the intended objective throughput.

Mutual interference between bluetooth and 802.11n MIMO devices

IEEE 802.11b wireless networks and Bluetooth networks provide complimentary services using the same unlicensed radio frequency band. As the benefits of utilizing these services become increasingly apparent, the likelihood of mutual interference also increases. The well-known frequency hopping algorithm and adaptive frequency hopping algorithm do not fully consider the interference level of the operating environment. In this paper an algorithm called interference-aware adaptive frequency hopping (IAFH) is presented and implemented on Bluetooth devices to mitigate the interference between IEEE 802.11b and Bluetooth wireless networks. An analytical model of IAFH is developed to evaluate the performance of 802.11b stations and Bluetooth devices in a mutual interference environment. The analysis comprises the collision probability, packet error rate, and throughput performance for both IEEE 802.11b and Bluetooth wireless networks. Simulation results confirm that 802.11b station and IAFH-enabled Bluetooth devices experience lower packet error rates and better throughput as compared to the frequency hopping and adaptive frequency hopping algorithms.

http://faculty.tnstate.edu/MovedToOU/sshetty/papers/p450-song.pdf

Coexistence of IEEE 802.11b and bluetooth: an integrated performance analysis

IEEE 802.11b Wireless Local Area Networks (WLAN) and Bluetooth Wireless Personal Area Networks (WPAN) provide complimentary services using the same unlicensed radio frequency band of operation. As the benefits of utilizing these services become increasingly apparent, the likelihood of mutual interference may also increase. In this paper an algorithm called Interference-Aware Adaptive Frequency Hopping (IAFH) is proposed and implemented on Bluetooth devices to mitigate the interference between WLAN and WPAN. An analytical channel model of IAFH based on the standard path loss-log normal shadowing-AWGN and Rayleigh multi-path fading channel model is developed to evaluate the performance of the 802.11b devices in the presence of Bluetooth devices. Numerical analysis of the model is done in MATLAB to calculate the throughput of the system using the existing algorithms and the proposed algorithm and the results are compared.

Deepthi Gopalpet

Papers

Coexistence of IEEE 802.11b and bluetooth: an integrated performance analysis

Performance analysis of 802.11b networks in the presence of interference-aware Bluetooth devices