438 research outputs found
The Triangle Metric: Fast Link Quality Estimation for Mobile Wireless Sensor Networks (Invited Paper)
ReSensesuppleCONE
Routing And Communication Path Mapping In VANETS
Vehicular ad-hoc network (VANET) has quickly become an important aspect of the intelligent transport system (ITS), which is a combination of information technology, and transport works to improve efficiency and safety through data gathering and dissemination. However, transmitting data over an ad-hoc network comes with several issues such as broadcast storms, hidden terminal problems and unreliability; these greatly reduce the efficiency of the network and hence the purpose for which it was developed. We therefore propose a system of utilising information gathered externally from the node or through the various layers of the network into the access layer of the ETSI communication stack for routing to improve the overall efficiency of data delivery, reduce hidden terminals and increase reliability. We divide route into segments and design a set of metric system to select a controlling node as well as procedure for data transfer. Furthermore we propose a system for faster data delivery based on priority of data and density of nodes from route information while developing a map to show the communication situation of an area. These metrics and algorithms will be simulated in further research using the NS-3 environment to demonstrate the effectiveness
Speed-Aware Routing for UAV Ad-Hoc Networks
In this paper we examine mobile ad-hoc networks (MANET) composed by unmanned
aerial vehicles (UAVs). Due to the high-mobility of the nodes, these networks
are very dynamic and the existing routing protocols partly fail to provide a
reliable communication. We present Predictive-OLSR an extension to the
Optimized Link-State Routing (OLSR) protocol: it enables efficient routing in
very dynamic conditions. The key idea is to exploit GPS information to aid the
routing protocol. Predictive-OLSR weights the expected transmission count (ETX)
metric, taking into account the relative speed between the nodes. We provide
numerical results obtained by a MAC-layer emulator that integrates a flight
simulator to reproduce realistic flight conditions. These numerical results
show that Predictive-OLSR significantly outperforms OLSR and BABEL, providing a
reliable communication even in very dynamic conditions.Comment: submitted to GlobeCom'13 Workshop - Wi-UA
On using Multiple Quality Link Metrics with Destination Sequenced Distance Vector Protocol for Wireless Multi-Hop Networks
In this paper, we compare and analyze performance of five quality link
metrics forWireless Multi-hop Networks (WMhNs). The metrics are based on loss
probability measurements; ETX, ETT, InvETX, ML and MD, in a distance vector
routing protocol; DSDV. Among these selected metrics, we have implemented ML,
MD, InvETX and ETT in DSDV which are previously implemented with different
protocols; ML, MD, InvETX are implemented with OLSR, while ETT is implemented
in MR-LQSR. For our comparison, we have selected Throughput, Normalized Routing
Load (NRL) and End-to-End Delay (E2ED) as performance parameters. Finally, we
deduce that InvETX due to low computational burden and link asymmetry
measurement outperforms among all metrics
On Link Estimation in Dense RPL Deployments
The Internet of Things vision foresees billions of
devices to connect the physical world to the digital world. Sensing
applications such as structural health monitoring, surveillance or
smart buildings employ multi-hop wireless networks with high
density to attain sufficient area coverage. Such applications need
networking stacks and routing protocols that can scale with
network size and density while remaining energy-efficient and
lightweight. To this end, the IETF RoLL working group has
designed the IPv6 Routing Protocol for Low-Power and Lossy
Networks (RPL). This paper discusses the problems of link quality
estimation and neighbor management policies when it comes
to handling high densities. We implement and evaluate different
neighbor management policies and link probing techniques in
Contikiβs RPL implementation. We report on our experience
with a 100-node testbed with average 40-degree density. We show
the sensitivity of high density routing with respect to cache sizes
and routing metric initialization. Finally, we devise guidelines for
design and implementation of density-scalable routing protocols
Reliable routing for low-power smart space communications
Smart Space (SS) communications has rapidly emerged as an exciting new paradigm that includes ubiquitous, grid, and pervasive computing to provide intelligence, insight, and vision for the emerging world of intelligent environments, products, services and human interaction. Dependable networking of a smart space environment can be ensured through reliable routing, efficient selection of error free links, rapid recovery from broken links and the avoidance of congested gateways. Since link failure and packet loss are inevitable in smart space wireless sensor networks, we have developed an efficient scheme to achieve a reliable data collection for smart spaces composed of low capacity wireless sensor nodes. Wireless Sensor Networks (WSNs) must tolerate a certain lack of reliability without a significant effect on packet delivery performance, data aggregation accuracy or energy consumption. In this paper we present an effective hybrid scheme that adaptively reduces control traffic with a metric that measures the reception success ratio of representative data packets. Based on this approach, our proposed routing scheme can achieve reduced energy consumption while ensuring minimal packet loss in environments featuring high link failure rates. The performance of our proposed routing scheme is experimentally investigated using both simulations and a test bed of TelosB motes. It is shown to be more robust and energy efficient than the network layer provided by TinyOS2.x. Our results show that the scheme is able to maintain better than 95% connectivity in an interference-prone medium while achieving a 35% energy saving
An enhanced Multipath Strategy in Mobile Ad hoc Routing Protocols
The various routing protocols in Mobile Ad hoc Networks follow different
strategies to send the information from one node to another. The nodes in the
network are non static and they move randomly and are prone to link failure
which makes always to find new routes to the destination. This research mainly
focused on the study of the characteristics of multipath routing protocols in
MANETS. Two of the multipath routing protocols were investigated and a
comparative study along with simulation using NS2 was done between DSR and AODV
to propose an enhanced approach to reach the destination maintaining the QoS. A
possible optimization to the DSR and AODV routing protocols was proposed to
make no node to be overburdened by distributing the load after finding the
alternate multipath routes which were discovered in the Route discovery
process. The simulation shows that the differences in the protocol highlighted
major differences with the protocol performance. These differences have been
analyzed with various network size, mobility, and network load. A new search
table named Search of Next Node Enquiry Table (SONNET) was proposed to find the
best neighbor node. Using SONNET the node selects the neighbor which can be
reached in less number of hops and with less time delay and maintaining the
QoS
Joint Channel Assignment and Opportunistic Routing for Maximizing Throughput in Cognitive Radio Networks
In this paper, we consider the joint opportunistic routing and channel
assignment problem in multi-channel multi-radio (MCMR) cognitive radio networks
(CRNs) for improving aggregate throughput of the secondary users. We first
present the nonlinear programming optimization model for this joint problem,
taking into account the feature of CRNs-channel uncertainty. Then considering
the queue state of a node, we propose a new scheme to select proper forwarding
candidates for opportunistic routing. Furthermore, a new algorithm for
calculating the forwarding probability of any packet at a node is proposed,
which is used to calculate how many packets a forwarder should send, so that
the duplicate transmission can be reduced compared with MAC-independent
opportunistic routing & encoding (MORE) [11]. Our numerical results show that
the proposed scheme performs significantly better that traditional routing and
opportunistic routing in which channel assignment strategy is employed.Comment: 5 pages, 4 figures, to appear in Proc. of IEEE GlobeCom 201
Π‘Π»ΠΎΠΆΠ½ΠΎΡΡΡ ΠΊΠ°ΠΊ Π³ΡΠ°Π½ΠΈΡΠ° ΡΠΏΡΠ°Π²Π»ΡΠ΅ΠΌΠΎΡΡΠΈ ΡΠ»ΠΎΠΆΠ½ΠΎΠΉ ΡΠΎΡΠΈΠΎΡΠ΅Ρ Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΠΎΠΉ
ΠΡΠ΄Π²ΠΈΠ½ΡΡΠ° Π³ΠΈΠΏΠΎΡΠ΅Π·Π° ΡΡΡΠ΅ΡΡΠ²ΠΎΠ²Π°Π½ΠΈΡ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΎ Π³ΡΠ°Π½ΠΈΡΠ°Ρ
ΡΠΏΡΠ°Π²Π»ΡΠ΅ΠΌΠΎΡΡΠΈ ΡΠΎΡΠΈΠΎΡΠ΅Ρ
Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ ΠΎΡ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ Π΅Π΅ ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ. ΠΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Ρ ΡΡΠΎΠ²Π½ΠΈ ΠΎΠΏΠΈΡΠ°Π½ΠΈΡ ΡΠΎΡΠΈΠΎΡΠ΅Ρ
Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ ΠΈ ΠΏΡΠΈΡΠΈΠ½Ρ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΡ Π΅Π΅ ΡΠ»ΠΎΠΆΠ½ΠΎΡΡΠΈ. ΠΠΏΠΈΡΠ°Π½Π° ΠΌΠΎΠ΄Π΅Π»Ρ ΡΠΎΡΠΈΠΎΡΠ΅Ρ
Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ Ρ ΡΠΎΡΠΊΠΈ Π·ΡΠ΅Π½ΠΈΡ ΡΠΎΠ²ΠΎΠΊΡΠΏΠ½ΠΎΡΡΠΈ ΡΡΡΡΠΊΡΡΡ ΡΠ΅Π°Π»ΠΈΠ·ΡΡΡΠΈΡ
ΡΠ΅Π»ΠΈ, ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΉ, ΡΠ°ΠΊΡΠΎΡΠΎΠ² Π²Π»ΠΈΡΡΡΠΈΡ
Π½Π° ΡΡΠ½ΠΊΡΠΈΠΎΠ½ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅.The article deals with a hypothesis of the existence depending information about the boundaries of socio-technical system of control on the effectiveness of its control. The author defines the levels of describing of socio-technical system and describes the reasons for increasing its complexity. The model of socio-technical system is made from the point of complex of structures realizing aims, technologies, factors which influence on the operation
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