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A Survey of Context Data Distribution for Mobile Ubiquitous Systems
, 2013
"... The capacity to gather and timely deliver to the service level any relevant information that can characterize service-provisioning environment, such as computing resources/capabilities, physical device location, user preferences, and time constraints, usually defined as context-awareness, is widely ..."
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Cited by 23 (0 self)
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The capacity to gather and timely deliver to the service level any relevant information that can characterize service-provisioning environment, such as computing resources/capabilities, physical device location, user preferences, and time constraints, usually defined as context-awareness, is widely recognized as a core function for the development of modern ubiquitous and mobile systems. Much work has been done to enable contextawareness and to ease the diffusion of context-aware services; at the same time, several middleware solutions have been designed to transparently implement context management and provisioning in the mobile system. However, to the best of our knowledge, an in-depth analysis of the context data distribution, namely the function in charge of distributing context data to interested entities, is still missing. Starting from the core assumption that only effective and efficient context data distribution can pave the way to the deployment of truly context-aware services, this paper aims at putting together current research efforts to derive an original and holistic view of the existing literature. We present a unified architectural model and a new taxonomy for context data distribution, by considering and comparing a large number of solutions. Finally, based on our analysis, we
Gossiping on MANETs: The Beauty and the Beast
- ACM Operating Systems Review
"... Gossip protocols have emerged as a powerful technique for implementing highly scalable and robust services, such as information dissemination and aggregation. The fact that gossip protocols require very little or no structure to operate makes them particularly appealing to apply in dynamic systems, ..."
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Cited by 19 (2 self)
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Gossip protocols have emerged as a powerful technique for implementing highly scalable and robust services, such as information dissemination and aggregation. The fact that gossip protocols require very little or no structure to operate makes them particularly appealing to apply in dynamic systems, where topology changes are common (for instance, due to frequent faults or high churn rates). Therefore, gossip protocols seem particularly well fit to operate in wireless self-organizing networks. Unfortunately, these networks have a number of characteristics that impede the deployment of gossip protocols designed for wired networks. In this work we identify the inherent differences in communication between wired and wireless networks and their impact on the design and implementation of gossip protocols. In particular, our comparison includes drawing a distinction between the gossiping primitives suitable for each of these environments. In the context of this analysis, we conclude by presenting a list of open research questions. 1.
A Probabilistic Replication and Storage Scheme for Large Wireless Networks of Small Devices
"... Nodes in wireless ad hoc networks are often limited in terms of resources, such as storage, power, and bandwidth. A downside of this is the fact that local storage at one node cannot accommodate the vast amount of data contained in the network. In this paper, we present Shared-State, a scheme for st ..."
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Cited by 13 (1 self)
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Nodes in wireless ad hoc networks are often limited in terms of resources, such as storage, power, and bandwidth. A downside of this is the fact that local storage at one node cannot accommodate the vast amount of data contained in the network. In this paper, we present Shared-State, a scheme for storage, replication, and distribution of common-interest data in wireless networks of resourceconstrained devices (e.g. sensor nodes or embedded devices). SharedState works under the assumption that individual nodes would greatly benefit from having access to the wealth of information in the network, but are unable to store it locally at once. SharedState strives to make data available to every node by providing local access to a subset of the whole collection of data items in the network at any moment in time and ensuring that this subset is updated periodically. This is accomplished by probabilistic propagation and replication of data items, ensuring the availability and persistence of information in the face of changing network conditions. We evaluate the performance of SharedState by studying the effectiveness with which nodes can gather information from the network. In addition, we optimize the bandwidth usage of our proposed solution by minimizing unnecessary communication based on feedback from the local neighborhood. 1.
Replacing the Stop Sign: Unmanaged Intersection Control for Autonomous Vehicles
, 2008
"... As computers inevitably begin to replace humans as the drivers of automobiles, our current human-centric traffic management mechanisms will give way to hyper-efficient systems and protocols specifically designed to exploit the capabilities of fully autonomous vehicles. We have introduced such a syst ..."
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Cited by 7 (3 self)
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As computers inevitably begin to replace humans as the drivers of automobiles, our current human-centric traffic management mechanisms will give way to hyper-efficient systems and protocols specifically designed to exploit the capabilities of fully autonomous vehicles. We have introduced such a system for coordinating large numbers of autonomous vehicles at intersections [4, 5]. Our experiments suggest that this system could alleviate many of the dangers and delays associated with intersections by allowing vehicles to “call ahead” to an agent stationed at the intersection and reserve time and space for their traversal. Unfortunately, such a system is not cost-effective at small intersections, as it requires the installation of specialized infrastructure. In this paper, we propose an intersection control mechanism for autonomous vehicles designed specifically for low-traffic intersections where the previous system would not be practical, just as inexpensive stop signs are used at intersections that do not warrant a full traffic light installation. Our mechanism is based on purely peer-to-peer communication and thus requires no infrastructure at the intersection. We present experimental results demonstrating that our system, while not suited to large, busy intersections, can significantly outperform traditional stop signs at small intersections: vehicles spend less time waiting and consume less fuel.
Vehicular networks for collision avoidance at intersections
- SAE World Congress
, 2011
"... Copyright © 2011 SAE International A substantial fraction of automotive collisions occur at intersections. Statistics collected by the Federal Highway Administration (FHWA) show that more than 2.8 million intersection-related crashes occur in the United States each year, with such crashes constituti ..."
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Cited by 6 (1 self)
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Copyright © 2011 SAE International A substantial fraction of automotive collisions occur at intersections. Statistics collected by the Federal Highway Administration (FHWA) show that more than 2.8 million intersection-related crashes occur in the United States each year, with such crashes constituting more than 44 percent of all reported crashes [12]. In addition, there is a desire to increase throughput at intersections by reducing the delay introduced by stop signs and traffic signals. In the future, when dealing with autonomous vehicles, some form of co-operative driving is also necessary at intersections to address safety and throughput concerns. In this paper, we investigate the use of vehicle-to-vehicle (V2V) communications to enable the navigation of traffic intersections, to mitigate collision risks, and to increase intersection throughput significantly. Specifically, we design a vehicular network protocol that integrates with mobile wireless radio communication standards such as Dedicated Short Range Communications (DSRC) and Wireless Access in a Vehicular Environment (WAVE). This protocol relies primarily on using V2V communications, GPS and other automotive sensors to safely navigate intersections and also to enable autonomous vehicle control. Vehicles use DSRC/WAVE wireless media to periodically broadcast their position information along with the driving intentions as they approach intersections. We used the hybrid simulator called GrooveNet [1, 2] in order to study different driving scenarios at intersections using simulated vehicles interacting with each other. Our simulation results indicate that very reasonable improvements in safe throughput are possible across many practical traffic scenarios.
GOSSIP: Gossip Over Storage Systems Is Practical
"... Gossip-based mechanisms are touted for their simplicity, limited resource usage, robustness to failures, and tunable system behavior. These qualities make gossiping an ideal mechanism for storage systems that are responsible for maintaining and updating data in a mist of failures and limited resourc ..."
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Cited by 4 (0 self)
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Gossip-based mechanisms are touted for their simplicity, limited resource usage, robustness to failures, and tunable system behavior. These qualities make gossiping an ideal mechanism for storage systems that are responsible for maintaining and updating data in a mist of failures and limited resources (e.g., intermittent network connectivity, limited bandwidth, constrained communication range, or limited battery power). We focus on persistent storage systems that, unlike mere caches, are responsible for the durability and consistency of data. Examples of such systems may be encountered in many different environments, in particular: wide-area networks (limited bandwidth), wireless sensor networks (limited resources), and mobile ad hoc networks (intermittent connectivity). In this paper, we demonstrate the qualities of gossiping in these three respective environments. 1.
Gossiping Components for Cyber-Physical Systems
"... © Springer, (2014). This is the authors ’ preliminary version of the work. It is posted here for ..."
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Cited by 2 (2 self)
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© Springer, (2014). This is the authors ’ preliminary version of the work. It is posted here for
Intersection management using vehicular networks, society for automotive engineers (SAE) world congress
, 2012
"... Driving through intersections can be potentially dangerous because nearly 23 percent of the total automotive related fatalities and almost 1 million injury-causing crashes occur at or within intersections every year [1]. The impact of traffic intersections on trip delays also leads to waste of human ..."
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Cited by 1 (0 self)
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Driving through intersections can be potentially dangerous because nearly 23 percent of the total automotive related fatalities and almost 1 million injury-causing crashes occur at or within intersections every year [1]. The impact of traffic intersections on trip delays also leads to waste of human and natural resources. Our goal is to increase the safety and throughput of traffic intersections using co-operative driving. In earlier work [2], we have proposed a family of vehicular network protocols, which use Dedicated Short Range Communications (DSRC) and Wireless Access in Vehicular Environment (WAVE) technologies to manage a vehicle’s movement at intersections Specifically, we have provided a collision detection algorithm at intersections (CDAI) to avoid potential crashes at or near intersections and improve safety. We have shown that vehicle-to-vehicle (V2V) communications can be used to significantly decrease the trip delays introduced by traffic lights and stop signs. In this paper, we investigate the use of more realistic controller models and higher concurrency to improve V2V intersection protocols for autonomous driving at intersections. We quantify the throughput enhancements due to the use of V2V under various driving conditions, while maintaining safe passage through intersections. 1.
H (2012) PAMPA in the wild: a real-life evaluation of a lightweight ad-hoc broadcasting family
- In: Proceedings of the 7th International Workshop on Middleware Tools, Services
"... PAMPA is a family of broadcast algorithms for adhoc and wireless networks that are both lightweight and robust. PAMPA variants have shown promising performance results in sim-ulations. Simulations can however be misleading, as they often poorly reflect reality. This paper seeks to further our unders ..."
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Cited by 1 (1 self)
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PAMPA is a family of broadcast algorithms for adhoc and wireless networks that are both lightweight and robust. PAMPA variants have shown promising performance results in sim-ulations. Simulations can however be misleading, as they often poorly reflect reality. This paper seeks to further our understanding of PAMPA beyond simulations, and reports on the first ever characterisation of the PAMPA family on a real deployment. We use this opportunity to reflect on our findings and lessons learnt when moving from simulations to actual experiments. Categories and Subject Descriptors C.2.1 [Network architecture and design]: Wireless com-munication
