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Evaluating Next Cell Predictors With Extensive Wi-Fi Mobility Data, Libo Song, David Kotz, Ravi Jain, Xiaoning He
Evaluating Next Cell Predictors With Extensive Wi-Fi Mobility Data, Libo Song, David Kotz, Ravi Jain, Xiaoning He
Dartmouth Scholarship
Location is an important feature for many applications, and wireless networks can better serve their clients by anticipating client mobility. As a result, many location predictors have been proposed in the literature, though few have been evaluated with empirical evidence. This paper reports on the results of the first extensive empirical evaluation of location predictors, using a two-year trace of the mobility patterns of over 6,000 users on Dartmouth's campus-wide Wi-Fi wireless network. The surprising results provide critical evidence for anyone designing or using mobility predictors. \par We implemented and compared the prediction accuracy of several location predictors drawn from …
Mobicom Poster Abstract: Bandwidth Reservation Using Wlan Handoff Prediction, Libo Song, Udayan Deshpande, Ulaş C. Kozat, David Kotz, Ravi Jain
Mobicom Poster Abstract: Bandwidth Reservation Using Wlan Handoff Prediction, Libo Song, Udayan Deshpande, Ulaş C. Kozat, David Kotz, Ravi Jain
Dartmouth Scholarship
Many network services may be improved or enabled by successful predictions of users' future mobility. The success of predictions depend on how much accuracy can be achieved on real data and on the sensitivity of particular applications to this achievable accuracy. We investigate these issues for the case of advanced bandwidth reservation using real WLAN traces collected on the Dartmouth College campus.
Scalability In A Secure Distributed Proof System, Kazuhiro Minami, David Kotz
Scalability In A Secure Distributed Proof System, Kazuhiro Minami, David Kotz
Dartmouth Scholarship
A logic-based language is often adopted in systems for pervasive computing, because it provides a convenient way to define rules that change the behavior of the systems dynamically. Those systems might define rules that refer to the users' context information to provide context-aware services. For example, a smart-home application could define rules referring to the location of a user to control the light of a house automatically. In general, the context information is maintained in different administrative domains, and it is, therefore, desirable to construct a proof in a distributed way while preserving each domain's confidentiality policies. In this paper, …
Risks Of Using Ap Locations Discovered Through War Driving, Minkyong Kim, Jeffrey J. Fielding, David Kotz
Risks Of Using Ap Locations Discovered Through War Driving, Minkyong Kim, Jeffrey J. Fielding, David Kotz
Dartmouth Scholarship
Many pervasive-computing applications depend on knowledge of user location. Because most current location-sensing techniques work only either indoors or outdoors, researchers have started using 802.11 beacon frames from access points (APs) to provide broader coverage. To use 802.11 beacons, they need to know AP locations. Because the actual locations are often unavailable, they use estimated locations from \em war driving. But these estimated locations may be different from actual locations. In this paper, we analyzed the errors in these estimates and the effect of these errors on other applications that depend on them. We found that the estimated AP locations …
Extracting A Mobility Model From Real User Traces, Minkyong Kim, David Kotz, Songkuk Kim
Extracting A Mobility Model From Real User Traces, Minkyong Kim, David Kotz, Songkuk Kim
Dartmouth Scholarship
Understanding user mobility is critical for simulations of mobile devices in a wireless network, but current mobility models often do not reflect real user movements. In this paper, we provide a foundation for such work by exploring mobility characteristics in traces of mobile users. We present a method to estimate the physical location of users from a large trace of mobile devices associating with access points in a wireless network. Using this method, we extracted tracks of always-on Wi-Fi devices from a 13-month trace. We discovered that the speed and pause time each follow a log-normal distribution and that the …
Predictability Of Wlan Mobility And Its Effects On Bandwidth Provisioning, Libo Song, Udayan Deshpande, Ulaş C. Kozat, David Kotz, Ravi Jain
Predictability Of Wlan Mobility And Its Effects On Bandwidth Provisioning, Libo Song, Udayan Deshpande, Ulaş C. Kozat, David Kotz, Ravi Jain
Dartmouth Scholarship
Wireless local area networks (WLANs) are emerging as a popular technology for access to the Internet and enterprise networks. In the long term, the success of WLANs depends on services that support mobile network clients. \par Although other researchers have explored mobility prediction in hypothetical scenarios, evaluating their predictors analytically or with synthetic data, few studies have been able to evaluate their predictors with real user mobility data. As a first step towards filling this fundamental gap, we work with a large data set collected from the Dartmouth College campus-wide wireless network that hosts more than 500 access points and …