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82
The pothole patrol: Using a mobile sensor network for road surface monitoring
- in ACM MobiSys
, 2008
"... This paper investigates an application of mobile sensing: detecting and reporting the surface conditions of roads. We describe a system and associated algorithms to monitor this important civil infrastructure using a collection of sensor-equipped vehicles. This system, which we call the Pothole Patr ..."
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Cited by 151 (4 self)
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This paper investigates an application of mobile sensing: detecting and reporting the surface conditions of roads. We describe a system and associated algorithms to monitor this important civil infrastructure using a collection of sensor-equipped vehicles. This system, which we call the Pothole Patrol (P 2), uses the inherent mobility of the participating vehicles, opportunistically gathering data from vibration and GPS sensors, and processing the data to assess road surface conditions. We have deployed P 2 on 7 taxis running in the Boston area. Using a simple machine-learning approach, we show that we are able to identify potholes and other severe road surface anomalies from accelerometer data. Via careful selection of training data and signal features, we have been able to build a detector that misidentifies good road segments as having potholes less than 0.2 % of the time. We evaluate our system on data from thousands of kilometers of taxi drives, and show that it can successfully detect a number of real potholes in and around the Boston area. After clustering to further reduce spurious detections, manual inspection of reported potholes shows that over 90 % contain road anomalies in need of repair.
Cabernet: Vehicular Content Delivery Using WiFi
"... Cabernet is a system for delivering data to and from moving vehicles using open 802.11 (WiFi) access points encountered opportunistically during travel. Using open WiFi access from the road can be challenging. Network connectivity in Cabernet is both fleeting (access points are typically within rang ..."
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Cited by 123 (3 self)
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Cabernet is a system for delivering data to and from moving vehicles using open 802.11 (WiFi) access points encountered opportunistically during travel. Using open WiFi access from the road can be challenging. Network connectivity in Cabernet is both fleeting (access points are typically within range for a few seconds) and intermittent (because the access points do not provide continuous coverage), and suffers from high packet loss rates over the wireless channel. On the positive side, WiFi data transfers, when available, can occur at broadband speeds. In this paper, we introduce two new components for improving open WiFi data delivery to moving vehicles: The first, QuickWiFi, is a streamlined client-side process to establish end-to-end connectivity, reducing mean connection time to less than 400 ms, from over 10 seconds when using standard wireless networking software. The second part, CTP, is a transport protocol that distinguishes congestion on the wired portion of the path from losses over the wireless link, resulting in a 2 × throughput improvement over TCP. To characterize the amount of open WiFi capacity available to vehicular users, we deployed Cabernet on a fleet of 10 taxis in the Boston area. The long-term average transfer rate achieved was approximately 38 Mbytes/hour per car (86 kbit/s), making Cabernet a viable system for a number of non-interactive applications.
Dissemination and Harvesting of Urban Data using Vehicular Sensing Platforms
, 2007
"... Abstract — Recent advances in vehicular communications make it possible to realize vehicular sensor networks, i.e., collaborative environments where mobile vehicles equipped with sensors of different nature (from toxic detectors to still/video cameras) inter-work to implement monitoring applications ..."
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Cited by 54 (2 self)
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Abstract — Recent advances in vehicular communications make it possible to realize vehicular sensor networks, i.e., collaborative environments where mobile vehicles equipped with sensors of different nature (from toxic detectors to still/video cameras) inter-work to implement monitoring applications. In particular, there is an increasing interest in proactive urban monitoring where vehicles continuously sense events from urban streets, autonomously process sensed data, e.g., recognizing license plates, and possibly route messages to vehicles in their vicinity to achieve a common goal, e.g., to permit police agents to track the movements of specified cars. This challenging environment requires novel solutions, with respect to those of more traditional wireless sensor nodes. In fact, different from conventional sensor nodes, vehicles exhibit constrained mobility, have no strict limits on processing power and storage capabilities, and host
A graph-based model for disconnected ad hoc networks
- PROCEEDINGS OF THE 26TH IEEE CONFERENCE ON COMPUTER COMMUNICATIONS (INFOCOM
, 2007
"... Recently, research on disconnected networks has been fostered by several studies on delay-tolerant networks, which are designed in order to sustain disconnected operations. We focus on the emerging notion of connectivity which exists in such networks, where the message exchange between nodes is enfo ..."
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Cited by 26 (2 self)
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Recently, research on disconnected networks has been fostered by several studies on delay-tolerant networks, which are designed in order to sustain disconnected operations. We focus on the emerging notion of connectivity which exists in such networks, where the message exchange between nodes is enforced by leveraging storage capabilities at intermediate relays, with the aim of achieving connectivity over time. The problem, under the constraint of intermittent connectivity, is hence to devise efficient mechanisms for message delivery, and evaluate the performance thereof. In this paper, we introduce a graph-based model able to capture the evolution of the connectivity properties of such systems over time. We show that, for most networks of interest, such connectivity graphs can be modeled as Erdös-Renyi random graphs. Furthermore, we show that, under a uniformity assumption, the time taken for the connectivity graph to become connected scales n log n as Θ ( ) with the number of nodes in the network. Hence λ we found that, using epidemic routing techniques, message delay is O ( n log2 n). The model is validated by numerical simulations λ log log n and by a comparison with the connectivity patterns emerging from real experiments.
An Efficient Identity-based Batch Verification Scheme for Vehicular Sensor Networks
"... Abstract—With the adoption of state-of-the-art telecommu-nication technologies for sensing and collecting traffic related information, Vehicular Sensor Networks (VSNs) have emerged as a new application scenario that is envisioned to revolutionize the human driving experiences and traffic flow contro ..."
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Cited by 26 (3 self)
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Abstract—With the adoption of state-of-the-art telecommu-nication technologies for sensing and collecting traffic related information, Vehicular Sensor Networks (VSNs) have emerged as a new application scenario that is envisioned to revolutionize the human driving experiences and traffic flow control systems. To avoid any possible malicious attack and resource abuse, employing a digital signature scheme is widely recognized as the most effective approach for VSNs to achieve authentication, integrity, and validity. However, when the number of signatures received by a Roadside Unit (RSU) becomes large, a scalability problem emerges immediately, where the RSU could be diffi-cult to sequentially verify each received signature within 300 ms interval according to the current Dedicated Short Range Communications (DSRC) broadcast protocol. In this paper, we introduce an efficient batch signature verification scheme for communications between vehicles and RSUs (or termed vehicle-to-Infrastructure (V2I) communications), in which an RSU can verify multiple received signatures at the same time such that the total verification time can be dramatically reduced. We demonstrate that the proposed scheme can achieve conditional privacy preservation that is essential in VSNs, where each mes-sage launched by a vehicle is mapped to a distinct pseudo identity, while a trust authority can always retrieve the real identity of a vehicle from any pseudo identity. With the proposed scheme, since identity-based cryptography is employed in generating private keys for pseudo identities, certificates are not needed and thus transmission overhead can be significantly reduced. I.
Automatic Collection of Fuel Prices from a Network of Mobile Cameras
- In Proceedings of the Distributed Computing in Sensor Systems
, 2008
"... Abstract. It is an undeniable fact that people want information. Unfortunately, even in today’s highly automated society, a lot of the information we desire is still manually collected. An example is fuel prices where websites providing fuel price information either send their workers out to manuall ..."
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Cited by 20 (10 self)
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Abstract. It is an undeniable fact that people want information. Unfortunately, even in today’s highly automated society, a lot of the information we desire is still manually collected. An example is fuel prices where websites providing fuel price information either send their workers out to manually collect the prices or depend on volunteers manually relaying the information. This paper proposes a novel application of wireless sensor networks to automatically collect fuel prices from camera images of road-side price board (billboard) of service (or gas) stations. Our system exploits the ubiquity of mobile phones that have cameras as well as users contributing and sharing data. In our proposed system, cameras of contributing users will be automatically triggered when they get close to a service station. These images will then be processed by computer vision algorithms to extract the fuel prices. In this paper, we will describe the system architecture and present results from our computer vision algorithms. Based on 52 images, our system achieves a hit rate of 92.3 % for correctly detecting the fuel price board from the image background and reads the prices correctly in 87.7 % of them. To the best of our knowledge, this is the first instance of a sensor network being used for collecting consumer pricing information. Key words: Automatic data collection, Computer-vision-based sensing, Consumer pricing information gathering, Participatory sensor networks, Vehicular sensor networks 1
Down the block and around the corner – the impact of radio propagation on inter-vehicle wireless communication
- in Proc. of IEEE International Conference on Distributed Computing Systems (ICDCS
, 2009
"... Vehicular networks are emerging as a new distributed system environment with myriad possible applications. Most studies on vehicular networks are carried out via simulation, given the logistical and economical problems with large-scale deployments. This paper investigates the impact of realistic rad ..."
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Cited by 10 (2 self)
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Vehicular networks are emerging as a new distributed system environment with myriad possible applications. Most studies on vehicular networks are carried out via simulation, given the logistical and economical problems with large-scale deployments. This paper investigates the impact of realistic radio propagation settings on the evaluation of VANET-based systems. Using a set of instrumented cars, we collected IEEE 802.11b signal propagation measure-ments between vehicles in a variety of urban and suburban environments. We found that signal propagation between vehicles varies in different settings, especially between line-of-sight (“down the block”) and non line-of-sight (“around the corner”) communication in the same setting. Using a probabilistic shadowing model, we evaluate the impact of different parameter settings on the performance of an epidemic data dissemination protocol and discuss the im-plications of our findings. We also suggest a variation of a basic signal propagation model that incorporates additional realism without sacrificing scalability by taking advantage of environmental information, including node locations and street information. 1.
Review A Comprehensive Approach to WSN-Based ITS Applications: A Survey
, 2011
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An Integrated Network of Roadside Sensors and Vehicles for Driving Safety: Concept, Design and Experiments,” PerCom ’10
"... Abstract—One major goal of the vehicular ad hoc network (VANET) is to improve driving safety. However, the VANET may not guarantee timely detection of dangerous road conditions or maintain communication connectivity when the network density is low (e.g., in rural highways), which may pose as a big t ..."
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Cited by 8 (1 self)
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Abstract—One major goal of the vehicular ad hoc network (VANET) is to improve driving safety. However, the VANET may not guarantee timely detection of dangerous road conditions or maintain communication connectivity when the network density is low (e.g., in rural highways), which may pose as a big threat to driving safety. Towards addressing the problem, we propose to integrate the VANET with the inexpensive wireless sensor network (WSN). That is, sensor nodes are deployed along the roadside to sense road conditions, and to buffer and deliver information about dangerous conditions to vehicles regardless of the density or connectivity of the VANET. Along with the concept of VANET-WSN integration, new challenges arise and should be addressed. In this paper, we investigate these challenges and propose schemes for effective and efficient vehicle-sensor and sensor-sensor interactions. Prototype of the designed system has been implemented and tested in the field. Extensive simulations have also been conducted to evaluate the designed schemes. The results demonstrate various design tradeoffs, and indicate that satisfactory safety and energy efficiency can be achieved simultaneously when system parameters are appropriately chosen.
Vehicular Grid Communications: The Role of the Internet Infrastructure
- Proc of the 1st International Conference on Genetic Algorithms and their Applications
, 2006
"... Vehicle communications are becoming a reality, driven by navigation safety requirements and by the investments of car manufacturers and Public Transport Authorities. As a consequence many of the essential vehicle grid components (radios, Access Points, spectrum, standards, etc.) will soon be in plac ..."
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Cited by 7 (3 self)
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Vehicle communications are becoming a reality, driven by navigation safety requirements and by the investments of car manufacturers and Public Transport Authorities. As a consequence many of the essential vehicle grid components (radios, Access Points, spectrum, standards, etc.) will soon be in place (and paid for) paving the way to unlimited opportunities for other car-to-car applications beyond safe navigation, for example, from news to entertainment, mobile network games and civic defense. In this study, we take a visionary look at these future applications, the emerging “Vehicular Grid ” that will support them and the interplay between the grid and the communications infrastructure. In essence, the Vehicular Grid is a large scale ad hoc network. However, an important feature of the Vehicular Grid, which sets it apart from most instantly-deployed ad hoc networks, is the ubiquitous presence of the infrastructure (and the opportunity to use it). While the Vehicular Grid must be entirely self-supporting for emergency operations (natural disaster, terrorist attack, etc), it should exploit the infrastructure (when present) during normal operations. In this paper we address the interaction between vehicles and Internet servers through Virtual Grid and Internet Infrastructure. This includes transparent geo-route provisioning across the Internet, mobile resource monitoring, and mobility management (using back up services in case of infrastructure failure). We then focus on routing and show the importance of Infrastructure cooperation and feedback for efficient, congestion free routing.
