| 301. |
- 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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| 302. |
- 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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| 303. |
- 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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| 304. |
- She, Huimin, et al.
(författare)
-
Stochastic Coverage in Event-Driven Sensor Networks
- 2011
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Ingår i: 2011 IEEE 22nd International Symposium On Personal Indoor And Mobile Radio Communications (PIMRC). - New York : IEEE. - 9781457713484 ; , s. 915-919
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Konferensbidrag (refereegranskat)abstract
- One of the primary tasks of sensor networks is to detect events in a field of interest (FoI). To quantify how well events are detected in such networks, coverage of events is a fundamental problem to be studied. However, traditional studies mostly focus on analyzing the coverage of the FoI, which is usually called are a coverage. In this paper, we propose an analytic method to evaluate the performance of event coverage in sensor networks with randomly deployed sensor nodes and stochastic event occurrences. We provide formulas to calculate the probabilities of event coverage and event missing. The numerical results show how these two probabilities change with the sensor and event densities. Moreover, simulations are conducted to validate the analytic method. This method can provide guidelines for determining the amount of sensor nodes to achieve a certain level of coverage in event-driven sensor networks.
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| 305. |
- She, Huimin, et al.
(författare)
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System-level evaluation of sensor networks deployment strategies : Coverage, lifetime and cost
- 2012
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Ingår i: 2012 8th International Wireless Communications And Mobile Computing Conference (IWCMC). - : IEEE. - 9781457713798 ; , s. 549-554
-
Konferensbidrag (refereegranskat)abstract
- In wireless sensor networks, sensor nodes can be organized either randomly or deterministically according to regular deployment patterns. Due to the trade-offs between performance and cost, evaluating the advantages and disadvantages of node deployment strategies are fundamental issues to be solved. In this paper, we present a framework for analyzing node deployment schemes in terms of three performance metrics: coverage, lifetime, and cost. Based on the proposed coverage analysis model, energy model and cost model, we compare the performance of two node deployment schemes: rectangle mesh and uniformly random. The results show that the rectangle mesh scheme is generally better than the uniformly random scheme in terms of coverage and network lifetime. Our method can be used to evaluate the benefits of different deployment schemes and thus provide guidelines for network designers.
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| 306. |
- She, Huimin, et al.
(författare)
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Traffic splitting with network calculus for mesh sensor networks
- 2007
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Ingår i: Proceedings of Future Generation Communication and Networking, FGCN 2007. - : IEEE Computer Society. - 9780769530482 ; , s. 371-376
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Konferensbidrag (refereegranskat)abstract
- In many applications of sensor networks, it is essential to ensure that messages are transmitted to their destinations as early as possible and the buffer size of each sensor node is as small as possible. In this paper, we firstly propose a mesh sensor network system model. Based on this system model, the expressions for deriving the delay bound and buffer requirement bound are presented using network calculus. In order to balance traffic load and improve resource utilization, three traffic splitting mechanisms are proposed The numerical results show that the delay bound and buffer requirement bound are lowered while applying those traffic splitting mechanisms. And thus the performance of the whole sensor network is improved.
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| 307. |
- Soininen, Juha-Pekka, et al.
(författare)
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Extending Platform-Based Design to Network on Chip Systems
- 2003
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Ingår i: Proceedings of the International Conference on VLSI Design.
-
Konferensbidrag (refereegranskat)abstract
- Exploitation of silicon capacity will require improvements in design productivity and more scalable system paradigms. Asynchronous message passing networks on chip (NOC) have been proposed as backbones for billion-transistor ASICs. We present a novel layered backbone-platform-system (BPS) design methodology for development of network-on-chip based products. It combines and extends the distributed, parallel, embedded and platform-based design concepts in order to manage the diversity and complexity of NOCbased-systems. The reuse of communication principles in various platforms, the reuse of platforms in product differentiation, and system-level decision-support methods are the cornerstones of our methodology. The presented mappability estimation and workload simulations demonstrate the feasibility of such methods.
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| 308. |
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| 309. |
- Svantesson, Bengt, et al.
(författare)
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A Novell Allocation Strategy for Control and Memory Intensive Telecommunication Circiuts
- 1996
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Konferensbidrag (refereegranskat)abstract
- Communication sub-systems that deal with switching, routing and protocol implementation often have their functionality dominated by control logic and interaction with memory. Synthesis of such Control and Memory Intensive Systems (hereafter abbreviated to CMISTs) poses demands that in the past have not been met satisfactorily by general purpose high-level synthesis (HLS) tools and have led to several research efforts to address these demands. In this paper we: Characterise CMISTs from the synthesis viewpoint; Contend that the synthesis demands of CMISTs can be met within the framework of a general purpose High-level synthesis tool, by making parts of it adaptive to the input, rather than develop a complete tool for a particular type of application; Present an allocation strategy that automatically adapts for CMISTs; Present the Operation and Maintenance (OAM) Protocol of the ATM, its modelling in VHDL and synthesis aspects of the VHDL model; Present the results of applying the synthesis methodology to the OAM as a test case. The results are compared with the result from two commercial High-level synthesis tool; Prove the efficacy of the proposed synthesis methodology by applying it to an industrial design and comparing our obtained by designing manually at register-transfer level; The results is also compared with the results from two commercial HLS tools.
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| 310. |
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