| 301. |
- Seceleanu, Tiberiu, et al.
(författare)
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On-Chip Distributed Architectures
- 2006
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Ingår i: 2006 IEEE International Systems-on-Chip Conference, SOC. - : IEEE. - 0780397819 - 9780780397811 ; , s. 329-330
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Konferensbidrag (refereegranskat)
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| 302. |
- Shallari, Irida, et al.
(författare)
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Design space exploration for an IoT node : Trade-offs in processing and communication
- 2021
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Ingår i: IEEE Access. - 2169-3536. ; 9, s. 65078-65090
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Tidskriftsartikel (refereegranskat)abstract
- Optimising the energy consumption of IoT nodes can be tedious due to the due to complex trade-offs involved between processing and communication. In this article, we investigate the partitioning of processing between the sensor node and a server and study the energy trade-offs involved. We propose a method that provides a trade-off analysis for a given set of constraints and allows for exploring several intelligence partitioning configurations. Furthermore, we demonstrate how this method can be used for the analysis of four design examples with traditional and CNN-based image processing systems, and we also provide an implementation of it on Matlab. CCBY
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| 303. |
- Shaoteng, Liu, 1984-
(författare)
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New circuit switching techniques in on-chip networks
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Network on Chip (NoC) is proposed as a promising technology to address the communication challenges in deep sub-micron era. NoC brings network-based communication into the on-chip environment and tackles the problems like long wire complexities, bandwidth scaling and so on. After more than a decade's evolution and development, there are many NoC architectures and solutions available. Nevertheless, NoCs can be classi_ed into two categories: packet switched NoC and circuit switched NoC. In this thesis, targeting circuit switched NoC, we present our innovations and considerations on circuit switched NoCs in three areas, namely, connection setup method, time division multiplexing (TDM) technology and spatial division multiplexing (SDM) technology.Connection setup technique deeply inuences the architecture and performance of a circuit switched NoC, since circuit switched NoC requires to set up connections before launching data transfer. We propose a novel parallel probe based method for dynamic distributed connection setup. This setup method on one hand searches all the possible minimal paths in parallel. On the other hand, it also has a mechanism to reduce resource occupation during the path search process by reclaiming redundant paths. With this setup method, connections are more likely to be established because of the exploration on the path diversity.TDM based NoC constitutes a sub-category of circuit switched NoC. We propose a double time-wheel technique to facilitate a probe based connection setup in TDM NoCs. With this technique, path search algorithms used in connection setup are no longer limited to deterministic routing algorithms. Moreover, the hardware cost can be reduced, since setup requests and data flows can co-exist in one network. Apart from the double time-wheel technique for connection setup, we also propose a highway technique that can enhance the slot utilization during data transfer. This technique can accelerate the transfer of a data flow while maintaining the throughput guarantee and the packet order.SDM based NoC constitutes another sub-category of circuit switched NoC. SDM NoC can benefit from high clock frequency and simple synchronization efforts. To better support the dynamic connection setup in SDM NoCs, we design a single cycle allocator for channel allocation inside each router. This allocator can guarantee both strong fairness and maximal matching quality. We also build up a circuit switched NoC, which can support multiple channels and multiple networks, to study different ways of organizing channels and setting up connections. Finally, we make a comparison between circuit switched NoC and packet switched NoC. We show the strengths and weaknesses on each of them by analysis and evaluation.
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| 304. |
- She, Huimin, et al.
(författare)
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A Network-based System Architecture for Remote Medical Applications
- 2007
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Ingår i: Proceedings of the Asia-Pacific Advanced Network Meeting.
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Konferensbidrag (refereegranskat)abstract
- Nowadays, the evolution of wireless communication and networktechnologies enables remote medical services to be availableeverywhere in the world. In this paper, a network-based systemarchitecture adopting wireless personal area network (WPAN)protocol IEEE 802.15.4/Zigbee standard and 3G communicationnetworks for remote medical applications is proposed. In theproposed system, the number and type of medical sensors arescalable depending on individual needs. This feature allows thesystem to be flexibly applied in several medical applications.Furthermore, a differentiated service using priority scheduling anddata compression is introduced. This scheme can not only reducetransmission delay for critical physiological signals and enhancebandwidth utilization at the same time, but also decrease powerconsumption of the hand-held personal server which uses batteryas the energy source.
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| 305. |
- She, Huimin, et al.
(författare)
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Analysis of Traffic Splitting Mechanisms for 2D Mesh Sensor Networks
- 2008
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Ingår i: International Journal of Software Engineering and Its Applications. - 1738-9984. ; 2:3
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Tidskriftsartikel (refereegranskat)abstract
- For many applications of sensor networks, it is essential to ensure that messages aretransmitted to their destinations within delay bounds and the buffer size of each sensor nodeis as small as possible. In this paper, we firstly introduce the system model of a mesh sensornetwork. Based on this system model, the expressions for deriving the delay bound and bufferrequirement bound are presented using network calculus theory. In order to balance trafficload and improve resource utilization, three traffic splitting mechanisms are proposed. Andthe two bounds are derived in these traffic splitting mechanisms. To show how our methodapplies to real applications, we conduct a case study on a fresh food tracking application,which monitors the food freshness status in real-time during transportation. The numericalresults show that the delay bound and buffer requirement bound are reduced while applyingtraffic splitting mechanisms. Thus the performance of the whole sensor network is improvedwith less cost.
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| 306. |
- She, Huimin, et al.
(författare)
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Analytical Evaluation of Retransmission Schemes in Wireless Sensor Networks
- 2009
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Ingår i: 2009 IEEE VEHICULAR TECHNOLOGY CONFERENCE. - 9781424425167 ; , s. 38-42
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Konferensbidrag (refereegranskat)abstract
- Retransmission has been adopted as one of the most popular schemes for improving transmission reliability in wireless sensor networks. Many previous works have been done on reliable transmission issues in experimental ways, however, there still lack of analytical techniques to evaluate these solutions. Based on the traffic model, service model and energy model, we propose an analytical method to analyze the delay and energy metrics of two categories of retransmission schemes: hop-by-hop retransmission (HBH) and end-to-end retransmission (ETE). With the experiment results, the maximum packet transfer delay and energy efficiency of these two scheme are compared in several scenarios. Moreover, the analytical results of transfer delay are validated through simulations. Our experiments demonstrate that HBH has less energy consumption at the cost of lager transfer delay compared with ETE. With the same target success probability, ETE is superior on the delay metric for low bit-error-rate (BER) cases, while HBH is superior for high BER cases.
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| 307. |
- She, Huimin, et al.
(författare)
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Deterministic Worst-case Performance Analysis for Wireless Sensor Networks
- 2008
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Ingår i: Proceedings of the International Wireless Communications and Mobile Computing Conference. - 9781424422029 ; , s. 1081-1086
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Konferensbidrag (refereegranskat)abstract
- Dimensioning wireless sensor networks requires formal methods to guarantee network performance and cost in any conditions. Based on network calculus, this paper presents a deterministic analysis method for evaluating the worst-case performance and buffer cost of sensor networks. To this end, we introduce three general traffic flow operators and derive their delay and buffer bounds. These operators are general because they can be used in combination to model any complex traffic flowing scenarios in sensor networks. Furthermore, our method integrates variable duty cycle to allow the sensor nodes to operate at lower rates thus saving power. Moreover, it incorporates traffic splitting mechanisms in order to balance network workload and nodes' buffers. To show how our method applies to real applications, we conduct a case study on a fresh food tracking application, which monitors the food freshness in realtime. The experimental results demonstrate that our method can be either used to perform network planning before deployment, or to conduct network reconfiguration after deployment.
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| 308. |
- She, Huimin, et al.
(författare)
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Modeling and Analysis of Rayleigh Fading Channels using Stochastic Network Calculus
- 2011
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Konferensbidrag (refereegranskat)abstract
- Deterministic network calculus (DNC) is not suitable for deriving performance guarantees for wireless networks due to their inherently random behaviors. In this paper, we develop a method for Quality of Service (QoS) analysis of wireless channels subject to Rayleigh fading based on stochastic network calculus. We provide closed-form stochastic service curve for the Rayleigh fading channel. With this service curve, we derive stochastic delay and backlog bounds. Simulation results verify that the bounds are reasonably tight. Moreover, through numerical experiments, we show the method is not only capable of deriving stochastic performance bounds, but also can provide guidelines for designing transmission strategies in wireless networks.
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| 309. |
- She, Huimin, 1982-
(författare)
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Network-Calculus-based Performance Analysis for Wireless Sensor Networks
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Recently, wireless sensor network (WSN) has become a promising technologywith a wide range of applications such as supply chain monitoringand environment surveillance. It is typically composed of multiple tiny devicesequipped with limited sensing, computing and wireless communicationcapabilities. Design of such networks presents several technique challengeswhile dealing with various requirements and diverse constraints. Performanceanalysis techniques are required to provide insight on design parametersand system behaviors. Based on network calculus, we present a deterministic analysis methodfor evaluating the worst-case delay and buffer cost of sensor networks. Tothis end, three general traffic flow operators are proposed and their delayand buffer bounds are derived. These operators can be used in combinationto model any complex traffic flowing scenarios. Furthermore, the methodintegrates a variable duty cycle to allow the sensor nodes to operate at lowrates thus saving power. In an attempt to balance traffic load and improveresource utilization and performance, traffic splitting mechanisms areintroduced for mesh sensor networks. Based on network calculus, the delayand buffer bounds are derived in non-splitting and splitting scenarios.In addition, analysis of traffic splitting mechanisms are extended to sensornetworks with general topologies. To provide reliable data delivery in sensornetworks, retransmission has been adopted as one of the most popularschemes. We propose an analytical method to evaluate the maximum datatransmission delay and energy consumption of two types of retransmissionschemes: hop-by-hop retransmission and end-to-end retransmission. We perform a case study of using sensor networks for a fresh food trackingsystem. Several experiments are carried out in the Omnet++ simulationenvironment. In order to validate the tightness of the two bounds obtainedby the analysis method, the simulation results and analytical results arecompared in the chain and mesh scenarios with various input traffic loads.From the results, we show that the analytic bounds are correct and tight.Therefore, network calculus is useful and accurate for performance analysisof wireless sensor network.
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| 310. |
- She, Huimin, et al.
(författare)
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Performance Analysis of Flow-Based Traffic Splitting Strategy on Cluster-Mesh Sensor Networks
- 2012
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Ingår i: International Journal of Distributed Sensor Networks. - : Hindawi Publishing Corporation. - 1550-1329 .- 1550-1477. ; , s. 232937-
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Tidskriftsartikel (refereegranskat)abstract
- Performance analysis is crucial for designing predictable and cost-efficient sensor networks. Based on the network calculus theory, we propose a flow-based traffic splitting strategy and its analytical method for worst-case performance analysis on cluster-mesh sensor networks. The traffic splitting strategy can be used to alleviate the problem of uneven network traffic load. The analytical method is able to derive close-form formulas for the worst-case performance in terms of the end-to-end least upper delay bounds for individual flows, the least upper backlog bounds, and power consumptions for individual nodes. Numerical results and simulations are conducted to show benefits of the splitting strategy as well as validate the analytical method. The numerical results show that the splitting strategy enables much better balance on network traffic load and power consumption. Moreover, the simulation results verify that the theoretic bounds are fairly tight.
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