The provision of acceptable Quality-of-Service (QoS) for multimedia traffic over a geosynchronous earth orbit (GEO) satellite network demands the existence of a well-designed Medium Access Control (MAC) protocol. In t...
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The emerging IEEE 802.15.4 (Zigbee) standard is designed for low data rate, low power consumption and low cost wireless personal area networks (WPANs). Video transmission over such networks is considered an issue sinc...
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The provision of acceptable Quality-of-Service (QoS) for integrated multimedia traffic over a geosynchronous earth orbit (GEO) satellite network demands the existence of a well-designed Medium Access Control (MAC) pro...
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Localization plays an important role in many applications of wireless sensor networks. Recently,mobile anchor assisted localization methods become promising, and the moving trajectory planning of anchor is an interest...
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Localization plays an important role in many applications of wireless sensor networks. Recently,mobile anchor assisted localization methods become promising, and the moving trajectory planning of anchor is an interesting and basic issue in these methods. In this paper, an obstacle-avoidance trajectory planning method for three-dimensional wireless sensor networks is proposed. After dividing the network into grids, a depth-firstsearch algorithm with greedy strategy is proposed to get the approximately shortest path, and a trigonal function based localization method is presented to estimate the positions of the sensor nodes. Simulations show that this method can obtain almost the optimal path and localize almost all the sensor nodes.
The IEEE P802.17 workgroup has standardized a ring network architecture and associated protocol called Resilient Packet Ring (RPR). RPR tries to overcome previous MAN technologies shortcomings in high-speed networks. ...
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In this work a channel access protocol for multihop ad-hoc networks based on topology-dependent transmission scheduling named Collision-Avoidance Time Allocation (Tang and Garcia-Luna-Aceves, 1999), is extended and ev...
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This paper revisits the fundamental trade-off between end-to-end and hop-by-hop transport control. The end-to-end principle has been one of the building blocks of the Internet;but in real-world wireless scenarios, end...
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Video Sensor networks (VSNs) have different characteristics than traditional Wireless Sensor networks (WSNs). The traffic going through a VSN is heavily loaded compared to traditional WSNs with scalar data readings. I...
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The increasing prevalence of integrated on-chip optoelectronic devices has identified serious issues regarding inter-device transmission and coupling losses, highlighting an urgent need for on-chip waveguide amplifier...
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The increasing prevalence of integrated on-chip optoelectronic devices has identified serious issues regarding inter-device transmission and coupling losses, highlighting an urgent need for on-chip waveguide amplifiers to compensate for these losses. Compared with other Er-based optical materials, erbium silicate is ideally suited to high-efficiency on-chip amplifiers and lasers because of its extremely high Er3+concentration(1022cm-3). Nevertheless, erbium silicate must be annealed above 1000℃ to crystallize and activate the Er3+, which damages other on-chip optoelectronic components and is not conducive to device ***, we report a low-fabrication-temperature, high-luminescence-efficiency gain material by adding Bi2O3to an erbium-ytterbium silicate mixed film. Our experiments demonstrate that the proposed film crystallizes at 600℃ while the activation of Er3+is also achieved, which is the lowest activation temperature of on-chip waveguide amplifier to our knowledge. This material forms the basis for a new chip-scale waveguide amplifier design, with a theoretical multi-energy-level model of Bi-Er-Yb in the mixed thin films used to analyze its signal enhancement properties. We achieve a peak on-chip gain of 23 dB in a 3.3-mm-long waveguide under the pump and signal powers of 300 mW and 1 μW, respectively. These results highlight the potential of the proposed material for realizing on-chip amplifiers and lasers for large-scale nanophotonic integrated circuits.
The nine papers in this special section cover energy, power and thermal management approaches in various system architectures, such as computing clusters, battery power systems, hand-hold devices as well as distribute...
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The nine papers in this special section cover energy, power and thermal management approaches in various system architectures, such as computing clusters, battery power systems, hand-hold devices as well as distributed real-time systems.
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