| 1. |
- 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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| 2. |
- 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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| 3. |
- 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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| 4. |
- Wang, Peng, et al.
(författare)
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Low Noise Amplifier Architecture Analysis for OFDM-UWB System in 0.18 um CMOS
- 2008
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Ingår i: 26th Norchip Conference, Norchip. - 9781424424931 ; , s. 184-189
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Konferensbidrag (refereegranskat)abstract
- This paper analyzes architectures of the low noise amplifier (LNA) for orthogonal-frequency-division-multiplexing ultra-wideband (OFDM-UWB) application. Until now, most UWB LNA implementations are focusing how to realize a single LNA covering the whole frequency band. In this work three popular wide-band LNA architectures are compared to a proposed parallel LNA architecture in which different amplifiers cover different frequency bands. Our study reveals that by reusing the source degenerated inductor between the different frequency bands, the parallel LNA architecture can achieve better performance than the single wide-band LNA (S11<-10 dB, voltage gain >15 dB, NF >4.5 dB, power consumption <10 mW) at the expense of a slightly increased circuit area.
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