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Combining wireless sensor networks (WSNs) with delay-tolerant networking (DTN) has the potential to extend their use in a multitude of previously impossible applications. However, and despite numerous proposed solutions, there is still wide debate as to how to best route messages in these networks and, more importantly, how to do it in an energy-ef...
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... have devised a simple scheme that uses two fields on the periodic beacons broadcast by each node and allows synchronization to the sink's clock. When two nodes meet, each processes the other's time reference as shown in Fig. 2. Sinks are considered to always have fresh references, that is, they have zero reference age. The stepPenalty parameter is only intended to reduce the number of average synchronization steps, as there is an error introduced with each one. Because there is no drift correction, the error will also tend to quickly increase with reference ...
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tenido, el conocimiento médico de los defectos del tubo neural (DTN) y el
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Citations
... Redundant data generation, which provides more reliable WSNs via higher data overhead, is mostly used in sparse networks (e.g., ARRIVE (Karlof, Li, & Polastre, 2003); PROPHET (Lindgren, Doria, & Schel en, 2003); CHARON (Soares & Rocha, 2009); Spray and Wait (Spyropoulos, Psounis, & Raghavendra, 2005); and Epidemic Routing (Vahdat & Becker, 2000)). Its motivation is to achieve WSN reliability by safeguarding against possible link and/ or node failures by sending extra copies of data to the BS. ...
... In multipath routing a source sensor can split its data packets into multiple sub packets and send them on different paths to the BS. Hence, it requires more effort for an outsider to retrieve a meaningful portion of a sensor's data unlike the single path routing case (Chang & Tassiulas, 2004;Incebacak, Bicakci, & Tavli, 2015;Karlof et al., 2003;Keskin, Altınel, & Aras, 2015;Paradis & Han, 2007;Soares & Rocha, 2009). On the other hand, balanced utilisation of sensors not only reduces the congestion risk but also avoids some sensors become too critical in network integrity since they possess a significant portion of all network's data. ...
A Wireless Sensor Network (WSN) is composed of tiny autonomous sensors with limited battery power. WSNs are employed to observe specific fields of interest. In this paper, we study the energy efficient and reliable network design problem using a mathematical programming framework. Energy efficiency is vital since battery replenishment is not always viable and the network lifetime is measured as the time until the first sensor exhausts its energy. Moreover, reliability is important since sensors are mostly deployed unattended and transmission of data fully and correctly is obviously critical. We develop a retransmission strategy originated from the Pareto principle and the scale-free property of complex networks. In our modified hop-by-hop reliability definition, sensors forwarding data directly to the central node must perform retransmission. Central node is the sensor with the highest data transmission load and our motivation is to secure the transmission of data passing through the central node against malicious attacks or technical failures. To this end, we present a mixed 0–1 integer programming model and an efficient heuristic. Our test results show an improvement of 80.5% in network lifetime and of 86.3% in redundant data overhead when compared with the classical conservative data redundancy approaches. We provide extensive test results, which reveal the contribution of our strategy in several other strategic design dimensions.
... In PRoPHET protocol, delivery predictability is obtained based on the contact history between nodes, and a message is forwarded to a node with higher delivery predictability. 3 Although the PRoPHET protocol was not originally proposed for wireless sensor networks but for general delay/disruption tolerant network, the PRoPHET protocol was widely used for data delivery in intermittently connected wireless sensor networks, such as the work in Kaur et al., 4 Rajpoot and Kushwah, 5 Agarwal and Bhadouria, 6 and Mezouary et al. 7 In Tao et al., 8 Lai et al., 9 and Soares and Rocha, 10 the PRoPHET protocol was used as a comparing protocol with the proposed protocol for wireless sensor network in intermittently connected networks. Furthermore, the PRoPHET protocol is the only routing protocol standardized as request for comment (RFC) in the Internet Research Task Force (IRTF), 3 and thus, it is regarded as a representative DTN protocol for intermittently connected networks, although it is not specialized for wireless sensor networks. ...
In delay-tolerant wireless sensor networks, messages for sensor data are delivered using opportunistic contacts between intermittently connected nodes. Since there is no stable end-to-end routing path like the Internet and mobile nodes operate on battery, an energy-efficient routing protocol is needed. In this article, we consider the probabilistic routing protocol using history of encounters and transitivity protocol as the base protocol. Then, we propose an energy-aware routing protocol in intermittently connected delay-tolerant wireless sensor networks, where messages are forwarded based on the node’s remaining battery, delivery predictability, and type of nodes. The performance of the proposed protocol is compared with that of probabilistic routing protocol using history of encounters and transitivity and probabilistic routing protocol using history of encounters and transitivity with periodic sleep in detail, from the aspects of delivery ratio, overhead ratio, delivery latency, and ratio of alive nodes. Simulation results show that the proposed protocol has better delivery probability, overhead ratio, and ratio of alive nodes, in most of the considered parameter settings, in spite of a small increase in delivery latency.
... There have been several propositions on how to route or share data in a delay or OSN. Here there exists both more straight forward routing techniques [7,11], as well as work on how to keep sensor data available in certain geographic locations [5,6]. These papers focus on the message transmission and relaying, and are complementary to our work. ...
Opportunistic sensor networks typically rely on node mobility to monitor an area by collecting samples at different locations. In this paper we show how the mobility in combination with the periodic sampling of nodes causes large differences in the sensor coverage. We address this issue by leveraging simple heuristics based on local knowledge, employing an adaptive sampling scheme. The main insight is that areas where over-sampling is prevalent exhibit a high correlation with node contacts. Results obtained from both synthetic and real-world traces show that a dramatic decrease in oversampling of affected areas is achievable alongside a smaller increase of samples in more sparse areas.
... This protocol adapts to the changing conditions of DTN and has reduced overhead compared to the existing protocol. In addition, few energy-preserving routing protocols do exist for opportunistic networks [20][21][22][23][24][25][26]. Locationbased routing [27] and directional routing [28] is also experimented for WSNs. ...
Wireless sensor networks face many threats which drain the energy. The performance of sensor network routing is much affected in the presence of selfish nodes with messages being delivered with a longer delay. Social network routing is a method in which the messages are selectively forwarded through the nodes where the encounters between these nodes are more likely to occur. Network reputations clearly speak about the quality of nodes involved in data forwarding. The idea is to utilise social network reputations of source or destinations for effective data forwarding in farmland sensor networks.
... Convergent Hybrid-replication Approach to Routing in Opportunistic Networks (CHARON): CHARON [35,36] aims to provide a simple but efficient solution to address the routing problem in highly mobile, sparse sensor networks where the future topologies of networks are unpredictable. It minimizes the number of messages exchanged and provides a way for urgent messages to be delivered quickly. ...
Intermittently Connected Delay-Tolerant Wireless Sensor Networks (ICDT-WSNs),
a branch of Wireless Sensor Networks (WSNs), have features of WSNs and the
intermittent connectivity of Delay-Tolerant Networks (DTNs). The applications
of ICDT-WSNs are increasing in recent years, however, the communication
protocols suitable for this category of networks often fall short. Most of the
existing communication protocols are designed for either WSNs or DTNs and tend
to be inadequate for direct use in ICDT-WSNs. This survey summarizes
characteristics of ICDT-WSNs and their communication protocol requirements, and
examines the communication protocols designed for WSNs and DTNs in recent years
from the perspective of ICDT-WSNs. Opportunities for future research in
ICDT-WSNs are also outlined.
... From the table, we can see that storage management is necessary for hop-by-hop transfer and in-network storage in WSNs. Although there are many routing protocols providing storage management such as CHARON [17,18], RED&FED [23] and TBR [15], they do not guarantee transmission reliability. In this paper, we propose a hop-by-hop transport protocol, Transport Protocol with Acknowledgement-assisted Storage Management (Acksis). ...
The benefits of hop-by-hop transport protocols and in-network storage in intermittently connected networks are well known. However, due to the extreme limitation on the storage capability of wireless sensor networks (WSNs), the hop-by-hop transport protocols that are based on in-network storage without storage management are inappropriate to apply directly to intermittently connected WSNs. The lack of storage management leads to mote storage overflow when using in-network storage, which in turn degrades the performance of the network.
In this paper, we propose a hop-by-hop transport protocol that provides not only end-to-end reliability and congestion control but also an innovative storage management mechanism. The proposed protocol enhances the network delivery rate without sacrificing the delivery speed even in high contention scenarios.
... Different techniques have been proposed for data gathering and forwarding. Researchers in those papers [8][9][10] have contributed some schemes for the data forwarding in the interrupted networks, but they failed to make contributions to the research on the mobility nodes deployed in CPS. ...
Cyber-physical system (CPS) cooperates with physical processes, computing, communication, and control (3C) into multiple levels of information processing and operation management to streamline and fortify the operation of physical systems. Due to the unique characteristics, such as unpredictable node mobility, low node density, lack of global information and network intermittent connectivity, an algorithm for data forwarding in CPS is a considerably difficult and challenging problem, and there is no good solution to it in existing works. In this paper, we propose a fully-fledged data forwarding algorithm tailored to the CPS environment. The proposed protocol, called data forwarding based on Delaunay triangulation (DFDT), takes into account the computational geometry based on Delaunay triangulation to form a few triangle communities according to nodes’ connectivity. Data in a community are forwarded to other nodes once a node comes into this community to increase the data delivery ratio. DFDT achieves a good performance by data gathering and sending data to other nodes with higher probability of meeting the link. An extensive simulation has been performed to validate the analytical results and to show the effectiveness of our approach compared with the three existing popular data forwarding algorithms.
... This paper proposes a solution that can be used to effectively and efficiently route messages in that scenario, without compromising its simplicity and, consequently, its feasibility. The proposed approach is named CHARON-Convergent Hybrid-replication Approach to Routing in Opportunistic Networks [6]. It uses an history-based collection algorithm, with delay as the main routing metric and aims to minimize the number of message exchanges, while still providing a way for urgent messages to be delivered quickly. ...
... It also features integrated time synchronization and radio power management, features seldom found but of critical importance to achieve good energy efficiency. In [6] an overview of CHARON, emphasizing its routing component and corresponding preliminary evaluation, was presented. Here, we provide a more exhaustive discussion on CHARON's design and evaluation, introduce a detailed description of the additional features and present a comprehensive experimental characterization of this opportunistic architecture, including the derivation of a simple analytical model that is able to accurately predict the opportunistic message delivery performance in a real-world test bed. ...
Opportunistic wireless sensor networks (WSNs) have recently been proposed as solutions for many remote monitoring problems. Many such problems, including environmental monitoring, involve large deployment scenarios with lower-than-average node density, as well as a long time scale and limited budgets. Traditional approaches designed for conventional situations, and thus not optimized for these scenarios, entail unnecessary complexity and larger costs. This article discusses the issues related with the design and test of opportunistic architectures, and presents one possible solution - CHARON (Convergent Hybrid-replication Approach to Routing in Opportunistic Networks). Both algorithm-specific and comparative simulation results are presented, as well as real-world tests using a reference implementation. A comprehensive experimental set-up was also used to seek a full characterization of the devised opportunistic approach including the derivation of a simple analytical model that is able to accurately predict the opportunistic message delivery performance in the used test bed.
... The criteria for forwarding message copies in the network are someway derived by statistics concerning previous inter-node contacts. CHARON (the reader can refer to [17], [18] for major details) can be considered to offer a hybrid approach. As in floodingbased protocols, it admits the existence of multiple copies by introducing the concept of " zombie " copies. ...
Low-power Wireless Personal Area Networks (LoW-PANs) solutions such as Wireless Sensor Networks (WSNs) can be deployed in scenarios characterized by partial node mobility and unreliable radio links. In such challenging conditions, normal ad-hoc networking approaches might result in unstable topologies and major data losses, thus hindering or limiting the validity of the solution. In case the application does not entail delay requirements, Delay Tolerant Networking (DTN) approaches could improve data delivery, thanks to cooperative nodes selectively storing and forwarding data to counter bad connectivity. In order to cope with such issues, this paper proposes 6LoWDTN, a DTN transport layer for WSNs built on-top the 6LoWPAN stack and derived from CHARON opportunistic networking solution. 6LoWDTN has been designed and implemented based on the μIPv6 stack provided by the Contiki operating system.
... Consequently, it does not support advanced mechanisms for quick contact detection. For a detailed description of CHARON, we refer the reader to [5]. ...
The use of opportunistic communications, while increasing in popularity, is still limited, due in part to some uncertainty that still exists regarding its performance in real-world conditions. This paper tries to assess the real performance of an opportunistic routing implementation in a physical setting, by comparing it with its expected performance, determined by a simplified theoretical model. For that purpose, we have deployed an experimental testbed combining static and mobile sensor nodes, and running two different applications in two different platforms in tandem. This allows us to obtain real contact traces from an unmodified application, while at the same time logging the messages transferred between participating nodes. The data collected was later analysed, mainly in what refers to the intra-contact and global communication patterns, as well as the end-to-end delay distributions for each sending node's messages. The results obtained show that the system behaviour can be predicted with high accuracy by our simple model.
