279,762 research outputs found

    Robust Path Construction for Reliable Data Transmissions in Node Disjoint Multipath Routing

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    Wireless Sensor Networks (WSNs) are prone to node breakdowns due to energy constraints, which contribute to frequent topology changes. Moreover, since sensor nodes have restricted transmission range, multiple hops are needed by the node in order to forward the packets from one node to the other and this raises very challenging issues when designing routing protocols. Most of the proposed single path routing schemes use a periodic low-rate flooding of data in order to recover from path failures, which causes higher consumption in sensor node resources. So multipath routing is an optimal approach to enhance the network lifetime. In this paper, a robust path construction for a reliable data transmission in node-disjoint multipath routing (RNDMR) is proposed for WSNs. The proposed RNDMR has the ability to provide a low overhead path construction as well as provide data transmission reliability by using XOR-based coding algorithm, which entails low utilization of resources, such as low storage space and lesser computing power. In the proposed RNDMR, the procedure involves the splitting up of all transmitted messages into many different segments of equal size, before adding the XOR-based error correction codes and distributing it among multiple paths simultaneously in order to boost reliable data transmission and to be assured that the essential fragment of the packet arrives at the sink node without any additional consumption of energy and undue delay. By using simulations, the performance of RNDMR was assessed and compares it with ReInForm routing. The results illustrate that RNDMR attains low energy consumption, records low average delay and routing overhead, as well as increased packet delivery ratio when compared with ReInForm Routing

    PERFORMANCE EVALUATION OF WIRELESS SENSOR NETWORK ROUTING PROTOCOL FOR VOLCANO ACTIVITY MONITORIN

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    As a country with the most volcanoes in the world, the Indonesian government must provide accurate and up-to-date information on the activity of active volcanoes. Until 2021, only 59% of mountains were directly monitored. Monitoring volcanic activity is not an easy thing to do. Visual observation alone is not enough, and instrumental comment is needed. Wireless Sensor Network (WSN) is a new opportunity to conduct a real-time and low-cost monitoring system for volcanic activity. However, the placement of independent WSN sensors in locations that are difficult to access creates new reliability and energy consumption problems. Therefore, we need a reliable communication line design for data transmission and path determination that does not drain sensor energy. This study specifically evaluates the performance of several routing protocols on WSN (proactive, reactive, and hybrid) to provide recommendations for the best routing design for volcanic activity monitoring needs. The simulation results of 6 WSN routing protocols using the NS-2 simulator show that the proactive protocol provides the smallest delay value, and the reactive protocol shows the highest data transmission success ratio but with the best residual energy. In contrast, the hybrid protocol could maintain a stable throughput value during data transmission

    Radio-wave propagation for space communications systems

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    The most recent information on the effects of Earth's atmosphere on space communications systems is reviewed. The design and reliable operation of satellite systems that provide the many applications in space which rely on the transmission of radio waves for communications and scientific purposes are dependent on the propagation characteristics of the transmission path. The presence of atmospheric gases, clouds, fog, precipitation, and turbulence causes uncontrolled variations in the signal characteristics. These variations can result in a reduction of the quality and reliability of the transmitted information. Models and other techniques are used in the prediction of atmospheric effects as influenced by frequency, geography, elevation angle, and type of transmission. Recent data on performance characteristics obtained from direct measurements on satellite links operating to above 30 GHz have been reviewed. Particular emphasis has been placed on the effects of precipitation on the Earth/space path, including rain attenuation, and ice particle depolarization. Other factors are sky noise, antenna gain degradation, scintillations, and bandwidth coherence. Each of the various propagation factors has an effect on design criteria for communications systems. These criteria include link reliability, power margins, noise contribution, modulation and polarization factors, channel cross talk, error rate, and bandwidth limitations

    A Power Estimation Method for Energy Efficient Wireless Sensor Network

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    Wireless sensor networks (WSN) are composed of large number of sensor node with restricted energy. The energy is one of the most important terms in wireless sensor networks problem. Sensor node of WSN consists of processor unit, memory unit and power supply. Wireless sensor node is battery operated, therefore the biggest challenge in field of wireless sensor is the lifetimes of WSN node which can be improve by achieving communication with low power consumption. So in this proposed work, a path metric that accurately captures the expected number of link layer transmission required for reliable end to end packet delivery with minimum number of retransmission are considered; we analytically computed estimated cost with direct data transmission within the node and with shortest path between those nodes. Power is analyzed in terms of minimum cost which is the function of distance, number of packets used for transmission along with numbers of permissible hops. Comparative results are shown between time v/s delay, time v/s direct estimated cost and estimation with shortest minimum retransmission path, with variable data packets rate and number of hops. So, with the proper selection of data packet rate and number of hops for end to end transmission considerable reduction in power consumption can be obtained

    Reliable and Low-Latency Fronthaul for Tactile Internet Applications

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    With the emergence of Cloud-RAN as one of the dominant architectural solutions for next-generation mobile networks, the reliability and latency on the fronthaul (FH) segment become critical performance metrics for applications such as the Tactile Internet. Ensuring FH performance is further complicated by the switch from point-to-point dedicated FH links to packet-based multi-hop FH networks. This change is largely justified by the fact that packet-based fronthauling allows the deployment of FH networks on the existing Ethernet infrastructure. This paper proposes to improve reliability and latency of packet-based fronthauling by means of multi-path diversity and erasure coding of the MAC frames transported by the FH network. Under a probabilistic model that assumes a single service, the average latency required to obtain reliable FH transport and the reliability-latency trade-off are first investigated. The analytical results are then validated and complemented by a numerical study that accounts for the coexistence of enhanced Mobile BroadBand (eMBB) and Ultra-Reliable Low-Latency (URLLC) services in 5G networks by comparing orthogonal and non-orthogonal sharing of FH resources.Comment: 11pages, 13 figures, 3 bio photo

    Optimal Constrained Wireless Emergency Network Antennae Placement

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    With increasing number of mobile devices, newly introduced smart devices, and the Internet of things (IoT) sensors, the current microwave frequency spectrum is getting rapidly congested. The obvious solution to this frequency spectrum congestion is to use millimeter wave spectrum ranging from 6 GHz to 300 GHz. With the use of millimeter waves, we can enjoy very high communication speeds and very low latency. But, this technology also introduces some challenges that we hardly faced before. The most important one among these challenges is the Line of Sight (LOS) requirement. In the emergent concept of smart cities, the wireless emergency network is set to use millimeter waves. We have worked on the problem of efficiently finding a line of sight for such wireless emergency network antennae in minimal time. We devised two algorithms, Sequential Line of Sight (SLOS) and Tiled Line of Sight (TLOS), both perform better than traditional algorithms in terms of execution time. The tiled line of sight algorithm reduces the time required for a single line of sight query from 200 ms for traditional algorithms to mere 1.7 ms on average

    eCMT-SCTP: Improving Performance of Multipath SCTP with Erasure Coding Over Lossy Links

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    Performance of transport protocols on lossy links is a well-researched topic, however there are only a few proposals making use of the opportunities of erasure coding within the multipath transport protocol context. In this paper, we investigate performance improvements of multipath CMT-SCTP with the novel integration of the on-the-fly erasure code within congestion control and reliability mechanisms. Our contributions include: integration of transport protocol and erasure codes with regards to congestion control; proposal for a variable retransmission delay parameter (aRTX) adjustment; performance evaluation of CMT-SCTP with erasure coding with simulations. We have implemented the explicit congestion notification (ECN) and erasure coding schemes in NS-2, evaluated and demonstrated results of improvement both for application goodput and decline of spurious retransmission. Our results show that we can achieve from 10% to 80% improvements in goodput under lossy network conditions without a significant penalty and minimal overhead due to the encoding-decoding process
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