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International Conference on Photonics in Switching (PS)

作者： Zuqing Zhu Bo Xiang Loukas Paraschis S.J. Ben Yoo Department of Electrical and Computer Engineering University of California Davis California USA Optical Networking Advanced Technology Group Cisco Systems USA Department of Electrical and Computer Engineering University of California Davis California 95616 USA. Email: yoo@ece.ucdavis.edu

We demonstrate an all-optical clock-and-data recovery technology for 10-Gb/s NRZ-DPSK signals. With a relatively simple configuration, the clock-recovery scheme achieves less than 1.5-ps RMS jitter for signals after f... 详细信息

关键词： Clocks Optical attenuators Optical wavelength conversion Optical filters Optical fiber polarization Optical interferometry Optical modulation High speed optical techniques Differential quadrature phase shift keying Stimulated emission

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Location verification using bidirectional one-way hash function in wireless sensor networks

Location verification using bidirectional one-way hash funct...

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作者： Lee, Yann-Hang Lee, Jin Wook Phadke, Vikram Deshmukh, Amit Department of Computer Science and Engineering Arizona State University Tempe AZ 85287-8809 United States Networking Technology Lab. Samsung Advanced Institute of Technology P.O. Box 111 Suwon 440-600 Korea Republic of Software Group Qualcomm Inc. 5775 Morehouse Drive San Diego CA 92121 United States Software Group Siemens Information and Communication Mobile LLC 16745 West Bernardo Drive San Diego CA 92127 United States

Evolving networks of wireless ad hoc sensing nodes have many attractive applications. Localisation, that is to determine where a given node is physically located, is a key enabler for many applications of sensor *** sensor networks move closer to extensive deployments, security becomes a major concern, resulting in a new demand for secure localisation and location proving systems. We propose a secure localisation system based on a secure hop algorithm. A location verification system that allows the base station to verify the location claims of sensor nodes is also presented. It prevents a node from falsifying reported location information and can be used for location-based access control. In order to support the resource-constrained sensor nodes, the proposed approach makes use of efficient one-way hash functions. Finally, we report the evaluation of the secure localisation system. The proposed scheme performs well under a range of scenarios tested and is resilient against an attacker creating incorrect location information in other nodes. Copyright © 2007 Inderscience Enterprises Ltd.

关键词： Sensor nodes

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Tomlinson-Harashima precoding with adaptive modulation for fixed relay networks

Tomlinson-Harashima precoding with adaptive modulation for f...

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2006 IEEE 7th Workshop on Signal Processing Advances in Wireless Communications, SPAWC

作者： Tang, Taiwen Chae, Chan-Byoung Heath Jr., Robert W. Cho, Sunghyun Department of Electrical and Computer Engineering Wireless Networking and Communications Group University of Texas at Austin Austin TX United States Samsung Advanced Institute of Technology Suwon Korea Republic of

ISBN: (纸本)078039710X

In this paper, a relaying strategy that uses multiple input multiple output (MIMO) fixed relays with linear processing for multiuser transmission in cellular networks is proposed. This approach applies to the two hop relaying scenario for coverage enhancement, where the base station transmits data to multiple users through one fixed relay (multiuser transmission). The fixed relay processes the received signal by applying a linear transformation and forwards the processed signal to multiple users. We propose an implementable multiuser precoding strategy that combines Tomlinson-Harashima precoding at the base station and linear signal processing at the relay with adaptive stream selection and QAM modulation. We propose a reduced complexity algorithm to select a subset of users to avoid an exhaustive search over all user permutations. Simulations illustrate the sum rate using Tomlinson-Harashima precoding without coding.

关键词： Base stations

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NXG01-1: Improving the Accuracy of EEAC-SV with Smart Packet Marking

NXG01-1: Improving the Accuracy of EEAC-SV with Smart Packet...

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IEEE Globecom 2006

作者： Nan Wang Nirwan Ansari Roberto Rojas-Cessa Advanced Networking Laboratory Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA

Explicit endpoint admission control with service vector (EEAC-SV) is a solution that allows a multi-hop connection in a Diffserv network to utilize different service classes in different routers along the path, thus enabling the network to provide QoS with fine granularity and improved network utilization. EEAC-SV relies on the QoS information in the pre-marked probing packet to select the optimal service vector. However, owing to the overhead constraint, the QoS information in the probing packet can only be conveyed in a quantized manner. The mathematical model indicates that with the same amount of overhead, the performance of EEAC-SV can be optimized with the proper packet marking strategy. In this paper, we propose the smart packet marking strategy to improve the EEAC-SV performance in terms of reducing the false routing probability. Smart packet marking is a stochastic solution which, based on the knowledge of the history of network QoS performances and user behaviors, defines the boundaries of each quantization level in such a way to improve the routing accuracy. Through extensive simulations, we demonstrate that smart packet marking outperforms the packet marking strategy that does not take stochastic information into consideration.

关键词： Quality of service Probability distribution Routing Admission control Stochastic processes Data communication Measurement Delay effects Laboratories Spread spectrum communication

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Big blue: A multidisciplinary capstone engineering design project

Big blue: A multidisciplinary capstone engineering design pr...

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113th Annual ASEE Conference and Exposition, 2006

作者： Lumpp, James Jacob, Jamey Smith, Suzanne Smith, William University of Kentucky United States Department of Electrical and Computer Engineering University of Kentucky United States IEEE AIAA United States ACM SWE United States Center for Advanced Networking Advanced Science and Technology Commercialization Center University of Kentucky United States Department of Mechanical Engineering Department of Mechanical Engineering University of Kentucky United States ASME SEM ASEE University of Kentucky Lexington United States ARRL United States

The BIG BLUE project at the University of Kentucky is an attempt to integrating systems engineering concepts and processes into undergraduate engineering education. NASA is addressing the anticipated shortage of aerospace engineers through workforce development projects of the National Space Grant College and Fellowship Program. BIG BLUE is a workforce development project currently in its fourth year at Kentucky funded by NASA. BIG BLUE is a comprehensive systems engineering experience for undergraduate engineers to propose, design, and implement a complex aerospace system while managing the financial and human resources. The system the students develop is a Mars aircraft and a prototype high-altitude test-bed UAV that is launched in high Earth atmosphere. In essence, students involved in BIG BLUE joined the aerospace workforce while participating in the project, which influenced their decision to choose and pursue an aerospace career. Opportunities were also available to visit and work with practicing aerospace engineers in industry and at NASA. Annual support and expenditures, student and faculty involvement in project management and aerospace workforce development results are included. With three successful flight experiments in three years, a review of BIG BLUE reveals the effort, cost and results of experiential systems engineering and aerospace workforce development. © American Society for engineering Education, 2006.

关键词： engineering technology

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Enhancing /spl epsiv/-approximation algorithms with the optimal linear scaling factor

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IEEE Transactions on Communications 2006年第9期54卷 1624-1632页

作者： Gang Cheng N. Ansari Li Zhu VPI Systems Inc. Holmdel NJ USA Advanced Networking Laboratory Electrical and Computer Engineering Department New Jersey Institute of Technology Newark NJ USA

Finding a least-cost path subject to a delay constraint in a network is an NP-complete problem and has been extensively studied. Many works reported in the literature tackle this problem by using epsiv-approximation schemes and scaling techniques, i.e., by mapping link costs into integers or at least discrete numbers, a solution which satisfies the delay constraint and has a cost within a factor of the optimal one, that can be computed with pseudopolynomial computational complexity. In this paper, having observed that the computational complexities of the epsiv-approximation algorithms using the linear scaling technique are linearly proportional to the linear scaling factor, we investigate the issue of finding the optimal (the smallest) linear scaling factor to reduce the computational complexities, and propose two algorithms, the optimal linear scaling algorithm (OLSA) and the transformed OLSA. We analytically show that the computational complexities of our proposed algorithms are very low, as compared with those of epsiv-approximation algorithms. Therefore, incorporating the two algorithms can enhance the epsiv-approximation algorithms by granting them a practically important capability: self-adaptively picking the optimal linear scaling factors in different networks. As such, epsiv-approximation algorithms become more flexible and efficient

关键词： Routing Computational complexity Delay Cost function Laboratories computer networks NP-complete problem Algorithm design and analysis Telecommunication traffic

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Demonstration of 264,000 km, 10 Gb/s Field Fiber Transmission using 1,000 Cascaded All-optical 3R Regeneration Stages

Demonstration of 264,000 km, 10 Gb/s Field Fiber Transmissio...

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32nd European Conference on Optical Communication (ECOC 2006),vol.3

作者： Zuqing Zhu Zhong Pan Masaki Funabashi Bo Xiang S. J. B. Yoo Loukas Paraschis David L. Harris Department of Electrical and Computer Engineering University of California Davis CA USA Optical Networking Advanced Technology Group of Cisco Systems Advanced Technology Laboratories Sprint

We demonstrate 10-Gb/s, error-free transmission over 264,000-km field fiber with 1,000 optical 3R regeneration stages using all-optical clock recovery. Experimental results show only 1.5-dB power penalty at BER 10{sup... 详细信息

关键词： Repeaters Optical interferometry Clocks Optical filters Stimulated emission Optical modulation Optical fiber polarization Erbium-doped fiber amplifier Optical sensors Signal to noise ratio

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Demonstration of Field Trial Experiments to Investigate the Cascadability of a 10 Gb/s Optical 3R Regenerator with All-optical Clock Recovery

Demonstration of Field Trial Experiments to Investigate the ...

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International Conference on Photonics in Switching (PS)

作者： Zuqing Zhu Zhong Pan Masaki Funabashi Bo Xiang Loukas Paraschis David L. Harris S. J. B. Yoo Department of Electrical and Computer Engineering University of California Davis CA USA Optical Networking Advanced Technology Group Cisco Systems USA Advanced Technology Labs Sprint USA

We demonstrate field trial experiments to evaluate a 10-Gb/s optical 3R regenerator using fiber recirculation loops built with 264-km and 462-km SSMF fiber in field. Error-free transmission over 264,000-km with 1,000 optical 3R regeneration stages has been achieved. Experimental results indicate only 1.5-dB power penalty at BER 10 -9 after 264,000-km.

关键词： Repeaters Clocks Optical fiber polarization Optical filters Optical interferometry High speed optical techniques Stimulated emission Optical receivers Optical modulation Optical fiber networks

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WLC04-6: Network Coordination and Interference Mitigation for HSDPA and EV-DO Forward Link

WLC04-6: Network Coordination and Interference Mitigation fo...

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IEEE Globecom 2006

作者： Shupeng Li Fang-Chen Cheng Lei Song Nirwan Ansari Lucent Technologies Inc. Whippany NJ USA Advanced Networking Laboratory Department of Electrical & Computer Engineering New Jersey Institute of Technology Newark NJ USA

To provision the enhanced support for wireless Internet services, high speed downlink packet access (HSDPA) was standardized in 3GPP. It offers peak air interface data rates of up to 14.4 Mbps with 5 Mhz bandwidth, thus dramatically improving the existing packet service capability of UMTS R99. At the same time, Evolution-Data Optimized (EV-DO) has been standardized in 3GPP2 to provide up to 4.9 Mbps throughput with 1.25 Mhz bandwidth. However, because of inter-cell interferences, users in the cell edge area generally cannot enjoy the higher data rate supported by the standard. Moreover, to meet the system fairness criterion, a base station usually needs to allocate un-proportional radio resource to these users. In this paper, we propose a simple interference mitigation scheme to enhance cell edge user data rate through network coordination. It is demonstrated through extensive simulations that the scheme significantly improves cell edge user throughput without lowering the total system capacity and spectral efficiency.

关键词： Interference Multiaccess communication Resource management Throughput Base stations Scheduling Downlink Bandwidth 3G mobile communication Space technology

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On Achievable Sum Rates of A Multiuser MIMO Relay Channel

On Achievable Sum Rates of A Multiuser MIMO Relay Channel

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IEEE International Symposium on Information Theory

作者： Taiwen Tang Chan-byoung Chae Robert W. Heath Sunghyun Cho Department of Electrical & Computer Engineering Wireless Networking & Communications Group University of Texas Austin Austin TX USA Samsung Advanced Institute of Technology Suwon South Korea

ISBN: (纸本)142440505X

In this paper, we investigate a multiple input multiple output (MIMO) multiuser relay channel, where a source with multiple antennas sends data to multiple users via a relay with multiple antennas. The relay applies linear processing to the received signal and forwards the processed signal to multiple users. In our system model, the direct links from the source to the users are neglected. We propose algorithms to compute achievable sum rates of this system based on dirty paper coding. An achievable sum rate defines a sum rate that can be achieved in the MIMO multiuser relay channel with zero error probability for any user, hence it is also a lower bound of the capacity of this channel. These algorithms also produce coefficients of the precoder at the source node and the coefficients of the linear processing unit at the relay. Simulations show that the proposed system architecture and algorithms achieve sum rate performance that is close to the derived performance upper bound

关键词： MIMO Relays Signal processing Power system relaying Base stations Decoding Broadcasting Channel capacity Upper bound Resistance heating

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