Gang Zhou

General Chairs David Simplot-Ryl, IRCICA/LIFL, Univ. Lille 1, France Ivan Stojmenovic, SITE, University of Ottawa, Canada ... Program Co-Chairs Vojislav B. Mišić, Ryerson University, Canada Kui Wu, University of Victoria, Canada ... Program Committee Habib M. Ammari, Hofstra University, USA Claudia Campolo, Università Mediterranea di Reggio Calabria, Italy Ling-Jyh Chen, Academia Sinica, Taiwan Yuanzhu Peter Chen, Memorial University of Newfoundland, Canada Junzhao Du, Xidian University, China Hannes Frey, ...

ABSTRACT Automatically recognizing human activities in a body sensor network (BSN) enables many human-centric applications. Many current works recognize human activities through collecting and analyzing sensor readings from on-body sensor nodes. These sensing-based solutions face a dilemma. On one hand, to guarantee data availability and recognition accuracy, sensing-based solutions have to either utilize a high transmission power or involve a packet retransmission mechanism. On the other hand, enhancing the transmission power increases a sensor node's energy overheads and communication range. The enlarged communication range in consequence increases privacy risks. A packet retransmission mechanism complicates on-body sensor nodes' MAC layer and hence increases energy overheads. In contrast to the sensing-based solutions, we build Radio Sense, a prototype system that exploits wireless communication patterns for BSN activity recognition. Using Radio Sense, we benchmark three system parameters (transmission (TX) power, packet sending rate, and smoothing window size) to design algorithms for system parameter selection. The algorithms aim to balance accuracy, latency, and energy overheads. In addition, we investigate the minimal amount of training data needed for reliable performance. We evaluate our Radio Sense system with multiple subjects' data collected over a two-week period and demonstrate that Radio Sense achieves reliable performance in terms of accuracy, latency, and battery lifetime.

ABSTRACT The increasing availability of inexpensive off-the-shelf 802.11 hardware has made it possible to deploy access points (APs) densely to ensure the coverage of complex enterprise environments such as business and college campuses. However, dense AP deployment often leads to increased level of wireless contention, resulting in low system throughput. A promising approach to address this issue is to enable the transmission concurrency of exposed terminals in which two senders lie in the range of one another but do not interfere each other's receiver. However, existing solutions ignore the rate diversity of 802.11 and hence cannot fully exploit concurrent transmission opportunities in a WLAN. In this paper, we present TRACK - Transmission Rate Adaptation for Colliding linKs, a novel protocol for harnessing exposed terminals with a rate adaptation approach in enterprise WLANs. Using measurement-based channel models, TRACK can optimize the bit rates of concurrent links to improve system throughput while maintaining link fairness. Our extensive experiments on a testbed of 17 nodes show that TRACK improves system throughput by up to 67% and 35% over 802.11 CSMA and conventional approaches of harnessing exposed terminals.

... of Virginia †{jl3aq,stankovic}@cs.virginia.edu ‡ Intel Corporation ‡{chieh-yih.wan,mark.d ... in BodyQoS to make it radio-agnostic, allowing a BodyQoS to schedule wireless resources without ... When the effective bandwidth of the channel degrades due to RF interference or body ...

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most widespread and destructive wheat diseases worldwide. Growing resistant cultivars with adult-plant resistance (APR) is an effective approach for the control of the disease. In this study, 540 simple sequence repeat markers were screened to map quantitative trait loci (QTL) for APR to stripe rust in a doubled haploid (DH) population of 137 lines derived from the cross Pingyuan 50 x Mingxian 169. The DH lines were planted in randomized complete blocks with three replicates in Gansu and Sichuan provinces during the 2005-06, 2006-07, and 2007-08 cropping seasons, providing data for four environments. Artificial inoculations were carried out in Gansu and Sichuan with the prevalent Chinese race CYR32. Broad-sense heritability of resistance to stripe rust for maximum disease severity was 0.91, based on the mean value averaged across four environments. Inclusive composite interval mapping detected three QTL for AP...

ABSTRACT Extensive empirical results reveal that interference can cause link qualities to change quickly and dramatically. For such highly dynamic links, the short term link quality estimations widely used in existing protocols require frequent measurements and may not be accurate. As a result, when these links are selected, end-to-end communication quality varies significantly. Also, route changes occur frequently, introducing traffic oscillation and excessive overhead in network protocols. To achieve good and stable network performance, it is not enough to use short term link estimation. It is essential to characterize a link's capacity to perform well at a desired level in the presence of interference and environmental changes. Therefore, we propose a performance metric called competence. We have incorporated the competence metric into routing algorithm designs. We have also designed and implemented a maintenance framework that stabilizes performance at both link and network layers. This framework allocates the desired performance level among multiple links along an active route by using an end-to-end feedback loop, and enforces the performance level of each link through adaptive transmission power control and retransmission control. In real system evaluations with 48 TMotes, our solution outperforms previous protocols significantly and achieves end-to-end stable performance for more than 99% of the time over 24 hours.

ABSTRACT Query processing in mobile Wireless Sensor Networks (WSNs) is still a challenging problem because sensor mobility causes frequent changes of network topology. In this paper, we study the problem of processing Continuous Location Dependent Query (CLDQ) that retrieves the sampling data of the sensors within a specific area (i.e. query area) around a mobile sensor. Existing query processing approaches can not efficiently process CLDQs with continuously moving query areas. We propose scalable techniques to process CLDQs efficiently and accurately, including a dissemination approach, a Contention-based Distance-aware Message Scheduling scheme, in which each stationary sensor’s data transmissions are smartly scheduled according to its distance to the mobile sensor, and an optimization scheme for continuous processing of CLDQs. Extensive experiments indicate that our techniques demonstrate better efficiency of processing CLDQs over state-of-the-art techniques while achieving high accuracy and short query latency under various network settings.

Abstract—This paper describes the design of RESTORE, which is a framework for providing in-network event correlation and storage service for sensor environments. RESTORE uses a data-centric approach in which it partitions a sensor network into zones and maps every ...

RID: Radio Interference Detection in Wireless Sensor Networks Gang Zhou, Tian He, John A. Stankovic,Tarek Abdelzaher Department of Computer Science University of Virginia, Charlottesville 22903 {gzhou,tianhe.stankovic.zaher}@cs.virginia.edu Abstract—In wireless sensor ...

Abstract—This paper presents C-MAC, a new MAC protocol designed to achieve high-throughput bulk communication for data-intensive sensing applications. C-MAC exploits concurrent wireless channel access based on empirical power control and physical interference models. ...

Traditional fall detection is only based on acceleration analysis. In this work we present a novel fall detection method that also utilizes posture and context information. This information can help reduce both false positives and negatives. Our solution also strives for low computational cost and fast response.