Shortcomings of the existing IP technology, e.g. lack for mobility and multicast, have in practice not been successfully addressed. With the emergence of small personal networked devices, these shortcomings negatively...
Next to traditional communication systems like servers or routers at the backbone and personal computers or laptops acting as clients, the Future Internet will additionally comprise many so-called smart objects. Most ...
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Next to traditional communication systems like servers or routers at the backbone and personal computers or laptops acting as clients, the Future Internet will additionally comprise many so-called smart objects. Most of everyday devices like coffee machines, fridges, or light switches will participate in this Internet of Things (IoT).Small-sized computers will connect these devices to the network by establishing low power wireless links. To achieve this vision various kinds of wireless multi-hop networks (WMHNs) play an important role. During the last years, it has become clear that test bed-based research is mandatory in order to develop suitable protocol implementations and metrics for these networks. In this article, we review network configurations for wireless networks for the IoT. We describe the DES-Test bed at the Freie Universitat Berlin as an experimental facility to study these network configurations. In addition to the infrastructure and software provided by the test bed, we introduce μkleos as a micro kernel based operating system for embedded devices. We designed μkleos with a special focus on Wireless Sensor Networks (WSNs) to complement our approach to study WMHNs. μkleos provides an implementation of 6LoWPAN to interconnect WSNs to IP-based networks.
Routing is in fact a simple task, yet the implementation of routing protocols requires specific operating system related knowledge. The developer has to deal with particular kernel internals that might have severe sid...
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Routing is in fact a simple task, yet the implementation of routing protocols requires specific operating system related knowledge. The developer has to deal with particular kernel internals that might have severe side effects. Furthermore, novel routing protocols require features that are not provided by current operating systems. Thus, routing protocols for mobile ad-hoc networks and wireless mesh networks are often studied in simulation environments. However, simulations have limitations that can result in conclusions that do not hold in real networks. A framework for the implementation of routing protocols in operating systems is required to enable real world oriented research. We introduce the DES Simple and Extensible Routing-Framework for Testbeds (DES-SERT). It supports the implementation, experimentation, and evaluation of routing protocols in a testbed environment. A structured protocol implementation is advocated by transmitting data in extensions attached to packets and by its pipeline based architecture. Several steps are elaborated how to derive an implementation from a routing protocol specification. A gossip implementation is presented as a simple example.
Motivated by our experience from previous testbed-based studies, we discuss the performance of flooding based route discovery schemes. Based on an empirical case study, the limits of routing in IEEE 802.11 wireless mu...
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Motivated by our experience from previous testbed-based studies, we discuss the performance of flooding based route discovery schemes. Based on an empirical case study, the limits of routing in IEEE 802.11 wireless multi-hop networks are highlighted. We show that the route discovery itself can already lead to problems even when there are no or few data flows.
Dynamic Source Routing (DSR) was one of the first proposed protocols for routing in Mobile Ad-hoc Networks and is among the few that were ratified by the IETF. Despite its source routing overhead, the protocol exhibit...
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Dynamic Source Routing (DSR) was one of the first proposed protocols for routing in Mobile Ad-hoc Networks and is among the few that were ratified by the IETF. Despite its source routing overhead, the protocol exhibits particular properties that make it an optimal choice for multi-path routing where multiple paths are discovered for each destination. The alternative paths can either be stored for error recovery situations or used in parallel to improve the throughput. In this paper we present a study of 10 uni- and multi-path DSR variants in a wireless mesh network testbed. A modified ETX metric is proposed for an improved link quality measurement. The experiments are evaluated considering the routing-overhead and packet delivery ratio with focus on the route discovery.
Gossip routing is an approach to reduce the redundancy of flooding in wireless networks. A study by Haas et al. evaluated different gossip routing variants in simulations on regular and random network topologies. Usin...
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Gossip routing is an approach to reduce the redundancy of flooding in wireless networks. A study by Haas et al. evaluated different gossip routing variants in simulations on regular and random network topologies. Using the DES-Testbed, a wireless mesh network, we tried to replicate their experiments to evaluate whether the findings hold in real world scenarios. Four different gossip routing variants and the experiment setup are elaborated as well as issues regarding the replication of the experiments discussed. With this study we demonstrate that even small wireless network deployments show a bimodal behavior when a certain probability threshold is passed.
Routing is a general task, yet the implementation of routing protocols requires specific operating system related knowledge. The developer has to deal with particular kernel internals that might have severe side effec...
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ISBN:
(纸本)9781424456604;9781424456611
Routing is a general task, yet the implementation of routing protocols requires specific operating system related knowledge. The developer has to deal with particular kernel internals that might have severe side effects. This is especially true for reactive and hybrid protocols where routing and forwarding are heavily intermixed. Furthermore, novel routing protocols require features that are not provided by current operating systems or have to be customized. Thus routing protocols for mobile ad-hoc networks and wireless mesh networks are often studied in simulation environments. However, simulations have limitations that can result in conclusions that do not hold in real networks. A framework for the implementation of routing protocols in operating systems is required to enable real world oriented research. We introduce the DES Simple and Extensible Routing-Framework for Testbeds (DES-SERT). The framework supports the implementation and evaluation of routing protocols in a testbed environment. A structured protocol implementation is advocated by transmitting data in extensions attached to packets and by its pipeline based architecture. Several steps are elaborated how to derive an implementation from a routing protocol specification.
Electricity theft is one of the major issues in developing countries which is affecting their economy *** with the introduction of emerging technologies,this issue became more *** many new energy theft detection(ETD)t...
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Electricity theft is one of the major issues in developing countries which is affecting their economy *** with the introduction of emerging technologies,this issue became more *** many new energy theft detection(ETD)techniques have been proposed by utilising different data mining(DM)techniques,state&network(S&N)based techniques,and game theory(GT)***,a detailed survey is presented where many state-of-the-art ETD techniques are studied and analysed for their strengths and *** levels of taxonomy are presented to classify state-of-the-art ETD *** types and ways of energy theft and their consequences are studied and summarised and different parameters to benchmark the performance of proposed techniques are extracted from *** challenges of different ETD techniques and their mitigation are suggested for future *** is observed that the literature on ETD lacks knowledge management techniques that can be more effective,not only for ETD but also for theft *** can help in the prevention of energy theft,in the future,as well as for ETD.
BioPortal is a leading repository of biomedical ontologies developed in different formats such as OWL and OBO. There is an increasing number of ontologies as well as an increasing number of concepts available via this...
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