In search of energy-efficient mobile networking

With the proliferation of mobile fixed-power devices, energy consumption emerged as a vibrant research and development subject area in networking. Mobile devices are designed with several hard constraints such as low cost and small geometries, as well as, low heat dissipation, and operation using fixed power sources. Manufacturers have been adding an ever increasing set of features to small mobile devices, which are no longer binary-use gadgets, but fully-fledged computers. With respect to power management, several mechanisms have been introduced; but, by and large, gains in power consumption at the hardware level have been essentially traded for extended functionality. All in all, the overall operational time has not increased. For example, early GSM cellular phones could only allow for less than an hour of talk time in a single battery charge. By the late 1990s, top models, introduced through better engineering and an evolutionary development approach, featured talk times increased by a factor of 3-5. This level of performance has remained the same over the last decade, although it is well below user expectations. This article reviews the evolution from simple cell phones toward the feature-rich mobile networked devices we have come to expect from manufacturers, and explains the factors that have led to stagnation in operational time. We then turn our attention to the multiaccess nature of modern mobile devices and the respective implications for power management. We find that the current host-centric mobile networking paradigm, based on end-to-end always on connectivity, leads to energy-inefficient operation. Finally, this article introduces information-centric networking and outlines open research issues in the design of energy-efficient future Internet architectures.     

Connection management for multiwavelength optical networking

This paper describes the connection management research done by the Network Control and Management (NC&M) task force under the multiwavelength optical networking (MONET) program. MONET is sponsored by the Defense Advanced Research Project Agency (DARPA) the US Government Department of Defense, with participation from Bellcore, AT&T, Lucent Technologies, several government agencies, and regional Bell operating companies. MONET's vision is to develop a flexible reliable high-capacity high-performance cost-effective national optical network based on multiwavelength fiber optic technology. As an important component in realizing this vision, the MONET program includes the architecture and design of a prototype network control and management system for MONET's reconfigurable wavelength-division multiplexing (WDM) all-optical network. The primary objectives of the prototype research work are to develop the architecture and framework for managing national-scale transparent reconfigurable WDM optical networks and to demonstrate the feasibility of the NC&M prototype system in a field experiment network in Washington, DC. This prototype system allows the program participants to conduct experiments and gain experience in the management and operations of reconfigurable optical networks. This paper describes the connection management aspects of the prototype system, addressing issues such as the management architecture, information model, and provisioning algorithms of the prototype management system     

用于全光网的光交叉连接技术研究

介绍了用于全光网的光交叉连接的主要特点、构成部件和应用 ,详细讨论了其结构 ,并特别探讨了其用于实现全光交换的核心部件光开关的主要技术     

MEMS technology for optical networking applications

The explosion of the Internet has brought about an acute need for broadband communications, which can only be filled with optical networking. This in turn has resulted in an unprecedented interest in optical micro-electromechanical systems. Since the early days of fiber optics, it has been recognized that micro-optics was a fertile ground for the applications of MEMS. MEMS-based products offer substantial cost and performance advantages for optical networking applications in the area of switching fabrics, variable attenuators, tunable lasers, and other devices. This article provides a review of various types of MEMS technologies for optical networking applications     

Intelligent optical networking for multilayer survivability

In recent years, telecommunication networks have faced explosive (IP) traffic growth. As traffic keeps growing, network reliability gains more and more importance. This article investigates to which extent switched connections and fast connection provisioning, typical for intelligent optical networks (IONs), can be used to provide resilience in an IP-over-optical multilayer network scenario. This solution, based on transport network flexibility, is compared with more traditional static multilayer resilience schemes in terms of cost (capacity) requirements and operational (dis)advantages     

Progress in optical networking

This article summarizes the present state of optical networking, how we got to this point, and what needs to be done to complete the job. The point of departure is an assumed future two-level structure in which the transport is by means of steadily growing interconnected all-optical islands of transparency, while the remainder of the communication layers are based on IP, both levels being managed by an MPLS-based control plane. After reviewing why such networks are becoming inevitable, a review is given of the various optical layer technology and architecture bottlenecks that have had to be solved. Issues that remain center on increasing the number of channels and reducing the technology costs     

Standards: the blueprints for optical networking

The definition of standards for optical networking is a new work item for the International Telecommunication Union (ITU) 1997-2000 Study Period. The authors provide a brief overview of this nascent standards development effort, with a specific focus on key issues currently under discussion that, when resolved, will have far-reaching impact on the ultimate realization of “optical networking”     

安全应用的高速光学传感器基于人脑功能获得立体三维视频图像的摄像机

当今世界，人们对安全的要求与日聚增，无源光学传感器已成为帮助人类获得安全的重要工具。这种传感器一般是装在能在屏幕上产生二维图像的视频摄像机中。对于安全应用，二维成像目前存在的问题是：当自动处理和分析二维图像时，虚警率高。这是因为二维图像所丢失的用于识别物体的三维景物的信息达50％以上。     

A high-throughput energy-efficient passive optical datacenter network

Datacenter applications impose heavy demands on bandwidth and also generate a variety of communication patterns (unicast, multicast, incast, and broadcast). Supporting such traffic demands leads to networks built with exorbitant facility costs and formidable power consumption if conventional design is followed. In this paper, we propose a novel high-throughput datacenter network that leverages passive optical technologies to efficiently support communications with mixed traffic patterns. Our network enables a dynamic traffic allocation that caters to diverse communication patterns at low power consumption. Specifically, our proposed network consists of two optical planes, each optimized for specific traffic patterns. We compare the proposed network with its optical and electronic counterparts and highlight its potential benefits in terms of facility costs and power consumption reductions. To avoid frame collisions, a high-efficiency distributed protocol is designed to dynamically distribute traffic between the two optical planes. Moreover, we formulate the scheduling process as a mixed integer programming problem and design three greedy heuristic algorithms. Finally, simulation results show that our proposed scheme outperforms the previous POXN architecture in terms of throughput and mean packet delay.     

Sustainable green networking: exploiting degrees of freedom towards energy-efficient 5G systems

Wireless Networks - The carbon footprint concern in the development and deployment of 5G new radio systems has drawn the attention to several stakeholders. In this article, we analyze the critical...     

Twisting and annealing optical fiber for current sensors

We demonstrate that twisting a fiber a few turns per meter before it is annealed largely eliminates the residual linear birefringence. This dramatically improves the yield of annealed coils used for current sensing and makes it possible to use fibers that previously had large residual linear birefringence. Twisting the fiber is effective because the residual birefringence, associated with core ellipticity, is reduced to near zero by twisting. A theoretical model of the twisted and annealed fiber current sensor is compared to experimental data. We also show good temperature stability for a sensor made with this new technique     

光缆联网中应注意的一些问题

随着一些地方有线电视光缆联网的成功以及广播电视事业发展的迫切要求,使广播电视光缆联网在全国大地蓬勃发展。对还未接触的人来说好像很难想象,而对于有接触但并不很懂的人而言则觉得很简单,因为不外乎一端是光发射机,另一端是光接收机,中间是光缆。而实际情况并没...     

Pan-European optical networking using wavelength divisionmultiplexing

The development of the information society will require the introduction of high-capacity transport networks with high performance and low cost. There are currently two ACTS (Advanced Communications Technologies and Services program launched by the European Commission) projects addressing specifically the problem of trans-European optical transport networks using WDM (wavelength division multiplexing). Important issues addressed are the high capacity transmission on existing fiber infrastructure and the introduction of flexibility in the network through the use of optical cross-connects. If these networks become a reality, they could drastically change the evolution of both telecommunication and computer networking because of their transparency and the abundance of inexpensive bandwidth     

Microprocessor-based phase determination for high-resolution optical sensors

A microprocessor-controlled phase measuring system for high-resolution optical sensors is described. An automatic calibration procedure provides drift compensation and long-term accuracy. Using a 12 bit A/D convertor, phase interpolation with a resolution of 0.12° (~1/3000 of a period) is demonstrated.     

Dielectric thin films for MEMS-based optical sensors

Nanoindentation and optical measurements have been employed in order to investigate the mechanical properties of low-temperature (50–330 °C) plasma-enhanced chemical vapour deposited (PECVD) SiN_x, as well as thermally evaporated SiO_x and Ge thin films for applications in micro-electro-mechanical systems (MEMS) fabricated on temperature sensitive, non-standard substrates. The temperature of the SiN_x deposition process is found to strongly influence Young’s modulus, hardness, and stress, with a critical deposition temperature in the 100 °C to 150 °C range which depends on the details of other deposition conditions such as chamber pressure and RF-power. The properties of PECVD SiN_x films deposited above this critical temperature are found to be suitable for MEMS applications, whereas films deposited at lower temperatures exhibit low Young’s modulus and hardness, as well as environment-induced stress instabilities. The investigated thin films have been incorporated into a monolithic integrated technology comprising low-temperature (125 °C) MEMS and HgCdTe IR detectors, in order to realize successful prototypes of tuneable IR microspectrometers.     

Analysis and design of backbone architecture alternatives for IP optical networking

The unprecedented growth of IP traffic is leading Internet service providers and network operators worldwide to investigate architectural alternatives for cost effective, reliable, scalable, and flexible multiterabit IP backbones. In this paper, several overlay, service, and transport layer networking architectures, which employ IP, MPLS, SONET/SDH, and DWDM technologies, are proposed and analyzed. Multiple parameters, such as network capacity, cost, restoration strategy, reconfigurability, and accommodation of preemptable traffic, are considered for the architectural comparison. Detailed network design and economic analysis are provided for the different alternatives considering a typical nationwide U.S. backbone with projected IP traffic in approximately three years. Several sensitivity analysis results are also shown, to evaluate the effect of cost changes in some of the critical technological factors in these architectures, such as 10 Gb/s optics cost or IP router cost. The results show the value of transport layer networking architectures for multiterabit IP backbones, and how, when compared to service layer architectures, they provide additional desirable features such as wavelength reconfigurability and restoration scalability.     

JumpStart deployments in ultra-high-performance optical networking testbeds

This article describes deployments of the JumpStart architecture and protocols in several ultra-high-performance optical networking testbeds. JumpStart interoperates with a variety of commercial optical switching gear, and supports operator-, user-, application-, and protocol-initiated ultra-fast lightpath provisioning. We briefly describe JumpStart's data and control plane architectures, and the functionality and performance of its edge and core components. We summarize results from JumpStart testbed demonstrations supporting ultra-fast lightpath provisioning for grids, high-performance file transfers, low-latency zero-jitter interactive visualization, and optical transport using optical burst switching.     

一种新颖的表面等离子谐振效应光波导水质传感技术

光学表面等离子谐振（ＳＰＲ）效应是一种很有效的水质检测技术，经过详细的理论推导，同了ＳＰＲ反射光强的普遍适用公式。在纯水与受污染水两种情况下，根据一些已知参数计算出结果。由计算结果数据一出的曲线比较表明，ＳＰＲ效应在两种情况下有明显差别，这也正是ＳＰＲ效应用于水质检测的理论根据。     

3-D optical and electrical simulation for CMOS image sensors

The optical and electrical characteristics of CMOS image sensors, such as readout, saturation, reset, charge-voltage conversion, and crosstalk characteristics, are analyzed by a three-dimensional (3-D) device simulator SPECTRA and a 3-D optical simulator TOCCATA which were developed for the analysis of CCD image sensors. The model of readout operation for a buried photodiode with potential barrier and dip is discussed with consideration of thermal diffusion. The transient simulation is executed for readout and reset operation. A novel calculation method for photodiode saturation condition is proposed. The optical and electronic crosstalk is analyzed individually by ray-tracing and current calculation. It is found that the above methods successfully analyze the optical and electrical characteristics of CMOS image sensors.