O. Chipara, C. Brooks, Sangeeta Bhattacharya, Chenyang Lu, R. Chamberlain, G. Roman, T. Bailey
Real-time patient monitoring is critical to early detection of clinical patient deterioration in general hospital wards. A key challenge in such applications is to reliably deliver sensor data from mobile patients. We present an empirical analysis on the reliability of data collection from wireless pulse oximeters attached to users. We observe that most packet loss occur from mobile users to their first-hop relays. Based on this insight we developed the Dynamic Relay Association Protocol (DRAP), a simple and effective mechanism for dynamically discovering the right relays to be used for forwarding data from mobile users.
{"title":"Poster abstract: Reliable data collection from mobile users for real-time clinical monitoring","authors":"O. Chipara, C. Brooks, Sangeeta Bhattacharya, Chenyang Lu, R. Chamberlain, G. Roman, T. Bailey","doi":"10.7936/K7RV0KXT","DOIUrl":"https://doi.org/10.7936/K7RV0KXT","url":null,"abstract":"Real-time patient monitoring is critical to early detection of clinical patient deterioration in general hospital wards. A key challenge in such applications is to reliably deliver sensor data from mobile patients. We present an empirical analysis on the reliability of data collection from wireless pulse oximeters attached to users. We observe that most packet loss occur from mobile users to their first-hop relays. Based on this insight we developed the Dynamic Relay Association Protocol (DRAP), a simple and effective mechanism for dynamically discovering the right relays to be used for forwarding data from mobile users.","PeriodicalId":259491,"journal":{"name":"2009 International Conference on Information Processing in Sensor Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122072706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andreas Krause, R. Rajagopal, Anupam Gupta, Carlos Guestrin
We consider the problem of monitoring spatial phenomena, such as road speeds on a highway, using wireless sensors with limited battery life. A central question is to decide where to locate these sensors to best predict the phenomenon at the unsensed locations. However, given the power constraints, we also need to determine when to selectively activate these sensors in order to maximize the performance while satisfying lifetime requirements. Traditionally, these two problems of sensor placement and scheduling have been considered separately from each other; one first decides where to place the sensors, and then when to activate them. In this paper, we present an efficient algorithm, ESPASS, that simultaneously optimizes the placement and the schedule. We prove that ESPASS provides a constant-factor approximation to the optimal solution of this NP-hard optimization problem. A salient feature of our approach is that it obtains “balanced” schedules that perform uniformly well over time, rather than only on average. We then extend the algorithm to allow for a smooth power-accuracy tradeoff. Our algorithm applies to complex settings where the sensing quality of a set of sensors is measured, e.g., in the improvement of prediction accuracy (more formally, to situations where the sensing quality function is submodular). We present extensive empirical studies on several sensing tasks, and our results show that simultaneously placing and scheduling gives drastically improved performance compared to separate placement and scheduling (e.g., a 33% improvement in network lifetime on the traffic prediction task).
{"title":"Simultaneous placement and scheduling of sensors","authors":"Andreas Krause, R. Rajagopal, Anupam Gupta, Carlos Guestrin","doi":"10.5555/1602165.1602183","DOIUrl":"https://doi.org/10.5555/1602165.1602183","url":null,"abstract":"We consider the problem of monitoring spatial phenomena, such as road speeds on a highway, using wireless sensors with limited battery life. A central question is to decide where to locate these sensors to best predict the phenomenon at the unsensed locations. However, given the power constraints, we also need to determine when to selectively activate these sensors in order to maximize the performance while satisfying lifetime requirements. Traditionally, these two problems of sensor placement and scheduling have been considered separately from each other; one first decides where to place the sensors, and then when to activate them. In this paper, we present an efficient algorithm, ESPASS, that simultaneously optimizes the placement and the schedule. We prove that ESPASS provides a constant-factor approximation to the optimal solution of this NP-hard optimization problem. A salient feature of our approach is that it obtains “balanced” schedules that perform uniformly well over time, rather than only on average. We then extend the algorithm to allow for a smooth power-accuracy tradeoff. Our algorithm applies to complex settings where the sensing quality of a set of sensors is measured, e.g., in the improvement of prediction accuracy (more formally, to situations where the sensing quality function is submodular). We present extensive empirical studies on several sensing tasks, and our results show that simultaneously placing and scheduling gives drastically improved performance compared to separate placement and scheduling (e.g., a 33% improvement in network lifetime on the traffic prediction task).","PeriodicalId":259491,"journal":{"name":"2009 International Conference on Information Processing in Sensor Networks","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121637060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Beutel, S. Gruber, A. Hasler, R. Lim, A. Meier, Christian Plessl, I. Talzi, L. Thiele, C. Tschudin, M. Woehrle, M. Yuecel
The PermaSense project has set the ambitious goal of gathering real-time environmental data for high-mountain permafrost in unattended operation over multiple years. This paper discusses the specialized sensing and data recovery architecture tailored to meet the precision, reliability and durability requirements of scientists utilizing the data for model validation. We present a custom sensor interface board including specialized sensors and redundancy features for end-to-end data validation. Aspects of high-quality data acquisition, design for reliability by strict separation of operating phases and analysis of energy efficiency are discussed. The system integration using the Dozer protocol scheme achieves a best-in-class average power consumption of 148µA considerably exceeding the lifetime requirement.
{"title":"PermaDAQ: A scientific instrument for precision sensing and data recovery in environmental extremes","authors":"J. Beutel, S. Gruber, A. Hasler, R. Lim, A. Meier, Christian Plessl, I. Talzi, L. Thiele, C. Tschudin, M. Woehrle, M. Yuecel","doi":"10.5167/UZH-31231","DOIUrl":"https://doi.org/10.5167/UZH-31231","url":null,"abstract":"The PermaSense project has set the ambitious goal of gathering real-time environmental data for high-mountain permafrost in unattended operation over multiple years. This paper discusses the specialized sensing and data recovery architecture tailored to meet the precision, reliability and durability requirements of scientists utilizing the data for model validation. We present a custom sensor interface board including specialized sensors and redundancy features for end-to-end data validation. Aspects of high-quality data acquisition, design for reliability by strict separation of operating phases and analysis of energy efficiency are discussed. The system integration using the Dozer protocol scheme achieves a best-in-class average power consumption of 148µA considerably exceeding the lifetime requirement.","PeriodicalId":259491,"journal":{"name":"2009 International Conference on Information Processing in Sensor Networks","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115469165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Boano, T. Voigt, A. Dunkels, Fredrik Österlind, N. Tsiftes, L. Mottola, Pablo Suarez
Communicating over a reliable radio channel is vital for an efficient resource usage in sensor networks: a bad radio channel can lead to poor application performance and higher energy consumption. Previous research has shown that the LQI mean value is a good estimator of the link quality. Nevertheless, due to its high variance, many packets are needed to obtain a reliable estimation. Based on experimental results, we show instead that the LQI variance is not a limitation. We show that the variance of the LQI can be used as a metric for a rapid channel quality assessment. Our initial results indicate that identifying good channels using the LQI variance requires an order of magnitude fewer packets than when using the mean LQI.
{"title":"Poster abstract: Exploiting the LQI variance for rapid channel quality assessment","authors":"C. Boano, T. Voigt, A. Dunkels, Fredrik Österlind, N. Tsiftes, L. Mottola, Pablo Suarez","doi":"10.5555/1602165.1602202","DOIUrl":"https://doi.org/10.5555/1602165.1602202","url":null,"abstract":"Communicating over a reliable radio channel is vital for an efficient resource usage in sensor networks: a bad radio channel can lead to poor application performance and higher energy consumption. Previous research has shown that the LQI mean value is a good estimator of the link quality. Nevertheless, due to its high variance, many packets are needed to obtain a reliable estimation. Based on experimental results, we show instead that the LQI variance is not a limitation. We show that the variance of the LQI can be used as a metric for a rapid channel quality assessment. Our initial results indicate that identifying good channels using the LQI variance requires an order of magnitude fewer packets than when using the mean LQI.","PeriodicalId":259491,"journal":{"name":"2009 International Conference on Information Processing in Sensor Networks","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121575124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spatial skyline queries can be used in wireless sensor networks for collaborative positioning of multiple objects. However, designing a distributed spatial skyline algorithm in resource constrained wireless environments introduces several research challenges: how to combine multi-dimensional data, (e.g. distances to multiple events) to compute the skylines efficiently, accurately, quickly, progressively, and concurrently while dealing with the network and event dynamics. We address this challenge by designing Distributed Spatial Skyline (DSS) algorithm. DSS is the first distributed algorithm to compute spatial skylines. In a network of 554 nodes, DSS reduces the communication overhead by up to 91% over a centralized algorithm with 100% accuracy.
{"title":"Poster abstract: A distributed algorithm to compute spatial skyline in wireless sensor networks","authors":"Sunhee Yoon, C. Shahabi","doi":"10.5555/1602165.1602205","DOIUrl":"https://doi.org/10.5555/1602165.1602205","url":null,"abstract":"Spatial skyline queries can be used in wireless sensor networks for collaborative positioning of multiple objects. However, designing a distributed spatial skyline algorithm in resource constrained wireless environments introduces several research challenges: how to combine multi-dimensional data, (e.g. distances to multiple events) to compute the skylines efficiently, accurately, quickly, progressively, and concurrently while dealing with the network and event dynamics. We address this challenge by designing Distributed Spatial Skyline (DSS) algorithm. DSS is the first distributed algorithm to compute spatial skylines. In a network of 554 nodes, DSS reduces the communication overhead by up to 91% over a centralized algorithm with 100% accuracy.","PeriodicalId":259491,"journal":{"name":"2009 International Conference on Information Processing in Sensor Networks","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129996409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hierarchical routing is a promising approach for point-to-point routing with very small routing state. While there are many theoretical analyses and high-level simulations demonstrating its benefits, there has been little work to evaluate it in a realistic wireless sensor network setting. Based on numerous proposed hierarchical routing infrastructures, we develop a framework that captures the common characteristics of the infrastructures and identifies design points where the infrastructures differ. We then evaluate the implementation of the framework in TOSSIM and on a 60-node testbed. We demonstrate that from the practical perspective hierarchical routing is also an appealing routing approach for sensor networks. Despite only logarithmic routing state, it can offer low routing stretch: the average of ∼1.25 and the 99-th percentile of 2. Moreover, a hierarchical routing infrastructure can be autonomously bootstrapped and maintained by the nodes. By exploring the design points within our framework, the hierarchy maintenance protocol can optimize different metrics, such as the latency of bootstrapping and repairing the hierarchy after failures or the traffic volume, depending on the application requirements. Finally, we also identify a number of practical issues which we believe the applications employing hierarchical routing should be aware of.
{"title":"On hierarchical routing in wireless sensor networks","authors":"K. Iwanicki, M. Steen","doi":"10.5555/1602165.1602179","DOIUrl":"https://doi.org/10.5555/1602165.1602179","url":null,"abstract":"Hierarchical routing is a promising approach for point-to-point routing with very small routing state. While there are many theoretical analyses and high-level simulations demonstrating its benefits, there has been little work to evaluate it in a realistic wireless sensor network setting. Based on numerous proposed hierarchical routing infrastructures, we develop a framework that captures the common characteristics of the infrastructures and identifies design points where the infrastructures differ. We then evaluate the implementation of the framework in TOSSIM and on a 60-node testbed. We demonstrate that from the practical perspective hierarchical routing is also an appealing routing approach for sensor networks. Despite only logarithmic routing state, it can offer low routing stretch: the average of ∼1.25 and the 99-th percentile of 2. Moreover, a hierarchical routing infrastructure can be autonomously bootstrapped and maintained by the nodes. By exploring the design points within our framework, the hierarchy maintenance protocol can optimize different metrics, such as the latency of bootstrapping and repairing the hierarchy after failures or the traffic volume, depending on the application requirements. Finally, we also identify a number of practical issues which we believe the applications employing hierarchical routing should be aware of.","PeriodicalId":259491,"journal":{"name":"2009 International Conference on Information Processing in Sensor Networks","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127935760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}