Design of a self-routing frequency division multiple access(SR-FDMA) network using an optical ring filter with or without gain as arouter

Self-routing frequency division multiple access (SR-FDMA) network with ASK coherent detection and dual ring topology is proposed. The router, which employs the optical ring filter, is used as a means for selecting the desired channel carrier and at the same time as a bypass of the other channel carriers. The channel capacity and the carrier-to-noise ratio are investigated with the consideration of cross talk and power budget penalty. We find that there exists an optimum coupling coefficient of the transceiver coupler and a trade-off in selecting channel number and data rate. The results show that the router with gain can suppress the cross talk, compensate the power budget penalty, and largely increase the channel number. Therefore, with this router, a self-routing, high-density FDMA network is feasible     

Impact of number of angles on the performance of the data vortex optical interconnection network

Reducing communication latency in multiprocessor interconnection networks can increase system performance on a broad range of applications. The data vortex photonic network reduces message latency by utilizing all-optical end-to-end transparent links and deflection routing. Cylinders replace node storage for buffering messages. The cylinder circumference (measured as number of angles) has a significant impact on the message acceptance rate and average message latency. A new symmetric mode of usage for the data vortex is discussed in which a fraction of the angles is used for input/output (I/O), and the remainder is used for "virtual buffering" of messages. For single-angle injection, six total angles provide the best performance. Likewise, the same ratio of 5 : 1 purely routing nodes versus I/O nodes is shown to produce greater than 99% acceptance, under normal loading conditions for all other network sizes studied. It is shown that for a given network I/O size, a shorter height and wider circumference data vortex organization provides acceptable latency with fewer total nodes than a taller but narrower data vortex. The performance versus system cost is discussed and evaluated, and the 5 : 1 noninjection-to-injection angle ratio is shown to be cost effective when constructing a system in current optical technology.     

The Data Vortex Optical Packet Switched Interconnection Network

A complete review of the data vortex optical packet switched (OPS) interconnection network architecture is presented. The distributed multistage network topology is based on a banyan structure and incorporates a deflection routing scheme ideally suited for implementation with optical components. An implemented 12-port system prototype employs broadband semiconductor optical amplifier switching nodes and is capable of successfully routing multichannel wavelength-division multiplexing packets while maintaining practically error-free signal integrity (BER $ ≪ {hbox{ 10}}^{ - 12}$ ) with median latencies of 110 ns. Packet contentions are resolved without the use of optical buffers via a distributed deflection routing control scheme. The entire payload path in the optical domain exhibits a capacity of nearly 1 Tb/s. Further experimental measurements investigate the OPS interconnection network's flexibility and robustness in terms of optical power dynamic range and network timing. Subsequent experimental investigations support the physical layer scalability of the implemented architecture and serve to substantiate the merits of the data vortex OPS network architectural paradigm. Finally, modified design considerations that aim to increase the network throughput and device-level performance are presented.      

Extension of TDM-PON Standards to a Single-Fiber Ring Access Network Featuring Resilience and Service Overlay

A novel single-fiber ring-tree topology overlying multiple time-division-multiplexed (TDM) passive optical networks is presented and demonstrated. Each TDM service is overlaid on a different wavelength-division-multiplexing channel. A concatenation of advanced coupler-based remote nodes (RNs) distributes the channels in an optimal geographical distribution to secondary trees, which connect to the end users. With the proposed configuration, the network features flexible deployment and provides resilience capabilities in case of a fiber cut. To compensate power losses and fulfill ITU-T G.984/IEEE 802.3ah recommendations in terms of power budget (PB) and sensitivity, remote amplification is implemented at the RNs. This technique amplifies the dropped wavelengths at each RN while keeping a totally passive outside plant. A PB study, together with optical transmission experiments and network dimensioning simulations, demonstrates the feasibility of the network design.     

一种Ad Hoc网络的拓扑功率控制算法

Ad hoc网络是一种无线自组织网络，拓扑功率控制是其网络优化的核心问题之一。它能够有效降低节点间的传输功率，以提高整个网络的稳定性。文章旨在介绍一种基于节点间距离的分布式拓扑功率控制算法，通过改变网络拓扑结构，以达到节省网络能量的效果，并实现了网络中任意两节点间的K连通。     

3-D Topologies for Networks-on-Chip

Several interesting topologies emerge by incorporating the third dimension in networks-on-chip (NoC). The speed and power consumption of 3D NoC are compared to that of 2D NoC. Physical constraints, such as the maximum number of planes that can be vertically stacked and the asymmetry between the horizontal and vertical communication channels of the network, are included in speed and power consumption models of these novel 3D structures. An analytic model for the zero-load latency of each network that considers the effects of the topology on the performance of a 3D NoC is developed. Tradeoffs between the number of nodes utilized in the third dimension, which reduces the average number of hops traversed by a packet, and the number of physical planes used to integrate the functional blocks of the network, which decreases the length of the communication channel, is evaluated for both the latency and power consumption of a network. A performance improvement of 40% and 36% and a decrease of 62% and 58% in power consumption is demonstrated for 3D NoC as compared to a traditional 2D NoC topology for a network size of N = 128 and N = 256 nodes, respectively.     

Light-mesh — A pragmatic optical access network architecture for IP-centric service oriented communication

Contemporary deployments of optical access networks are based on the principles of Passive Optical Networks (PONs). PONs deploy a star topology and dual wavelength for communication between the center and ends of a star. The star topology requires that each end-user be connected to the star splitter (usually a passive coupler). We argue in this paper that while adhering to the requirements of access networks, we are able to provide a better topological solution in terms of the cost-factor and the ability to upgrade to a greater bandwidth. This solution, called a light-mesh, is based on the concept of pragmatic optical packet transport or light-frames results in a unique node architecture, interconnection matrix, and communication protocols. We begin by investigating into the node architecture that is required for a mesh network in the access area. The proposed node architecture has unique benefits in terms of being able to support the intermittent communication in the access area — nodes are not always powered ON, despite which, it is important to maintain mesh connectivity. Hence we propose the use of largely passive components in node architecture design. Passive components in a mesh lead to collisions of packets in the access area, for which we propose a unique collision detection and recovery scheme based on a logical time-overlap method. Collisions make the end-to-end delay uncertain. Analysis of the associated delay is performed. We then propose algorithms to build such a light-mesh network. These algorithms are investigated in terms of network built-out costs and these costs are compared to a PON topology. Cost differences and a performance comparison with PON are presented as part of the numerical analysis.     

Fiber-optic bus-oriented single-hop interconnections amongmulti-transceiver stations

The merits of the single-path selective-broadcast interconnection (SBI) implemented in fiber-optic technology are explored. This is a static, passive, fiber-optic interconnection among a set of stations, each equipped with multiple transmitters, and receivers. It uses c ² buses, each interconnecting a subset of the stations, and provides a single optical path between any two stations. Thus, it succeeds in decoupling transmission rate from aggregate network throughput. It offers substantial advantages in power budget and the maximum number of stations that can be connected without repeaters and amplifiers. When compared with c buses, each interconnecting all stations, this SBI is attractive in terms of the required passive fiber-optic components such as fiber segments and star couplers. For a fixed power budget, the capacity of this SBI is optimal among bus-oriented single-hop interconnections for both a uniform traffic pattern and worst-case unknown skew     

CMOS／SEED光电子集成Crossbar互连网络的实现及控制

本文报道了光电子集成 Crossbar互连网络的光学实现及电控制方法。采用带光窗口的 CMOS/SEED灵巧像元列阵作为逻辑控制交换开关节点 ,输出光强的高低态对比度约为 1.4。由波长为 85 0 nm的半导体激光器发出的光束经过位相计算全息光栅分束器分束 ,形成 8× 2的光束阵列 ,为 CMOS/SEED光调制器窗口列阵提供泵浦光源 ,采用精密加工的高精度二维光纤阵列作为信号输入、输出接口器件。采用计算机并口产生电控制信号实现网络的交叉连接功能 ,编制了相应的控制软件。实验上完成了 16× 16 Crossbar光互连网络的交换功能     

用于机群系统的高速光互连网络接口卡设计

本文在已设计完成的用于计算机点到虚拟并行互连的光互连链路基础上,用现场可编程门阵列（ＦＰＧＡ）器件实现了数据的寻址和转发,设计完成了具有硬件器由功能的光互连环网的网络接口卡。该网络接口卡的旁路数据转发延迟为２１０ｎｓ,目的结点的数据接收处理延迟为３５０ｎｓ。     

Embedded unidirectional incomplete hypercubes for optical networks

Many proposals of virtual regular topologies embedded in physical topologies for high-speed wavelength division multiplexing (WDM) optical networks do not consider the issue of allowing a variable number of nodes in the network. A solution for embedding a virtual unidirectional incomplete hypercube into a physical topology that does is presented. The proposed solution is a multichannel multihop network which has several elegant features: (a) it allows any number of nodes to be connected to the network, (b) it only requires a minor effort to reconfigure the new interconnection whenever a node is added or deleted for the network, (c) it supports a self-routing strategy, (d) the aggregate throughput of the network increases as more nodes are added, and (e) alternate paths are available which have a comparable distance to the destination as the primary path. The performance of the scheme is comparable to the performance of both the unidirectional hypercube and the bidirectional hypercube     

自适应光电混合互连分流结构建模与性能分析

针对片上光电混合互连网络(hybrid optoelect ronic network-on-chip,HONoC)拥 塞控制与自适应能力差、无法实现光电联合仿真等问题,提出一种适用于可重构阵列处理器 的自适应光电混合互连分流结构,在此结构上设计了自适应分流路由算法与一种低损耗无阻 塞的5端口光路由器,并搭建了基于System verilog与Verilog的光电混合互连功能仿真与 性能统计模型。实验结果表明,在边缘节点阻塞的情况下所设计的路由算法避免拥塞能力平 均提升了17.5%,光路由器所需交叉波导与微环谐振器数量大幅减少,平均光路由器级插入 损耗仅为0.522 dB,所设计的光电混合互连性能统计模型具有支持 设计拓扑、结构和路由策 略等功能,并且可以对资源使用、功耗开销、插入损耗等性能进行统计分析。     

Multiconfiguration multihop protocols: a new class of protocols forpacket-switched WDM optical networks

Wavelength-division multiplexing (WDM) local-area networks based on the optical passive-star coupler have traditionally been classified as being either single-hop or multihop. A single-hop network provides a direct connection between the source and the destination of a packet during the packet transfer duration, but may require some amount of coordination between the nodes which may involve tuning of the transmitters or receivers at each node. Since the time required to tune a tunable optical transmitter or receiver may be high, a single-hop network may incur significant overhead. On the other hand, a typical multihop network requires little or no tuning, but a packet may traverse a number of intermediate nodes between the source and destination nodes. Each hop incurs additional queueing delays at each node and also increases the overall load on each link and on the network. In this paper, we propose a new class of multiconfiguration multihop protocols (MMPs) which use tunable transmitters and receivers to cycle through a number of configurations which together make up a multihop logical topology. This class of protocols offers a trade-off between the tuning required in a single-hop network and the number of hops required in a multihop network. We present a generalized framework for comparing the proposed protocols with existing single-hop and multihop protocols, and we show that these protocols may offer significant performance gains for systems with high tuning delays and a limited number of transmitters and receivers at each node     

Low Latency Wireless Ad Hoc Networking: Power and Bandwidth Challenges and a Solution

This paper is concerned with the scaling of the number of relay nodes (i.e., hops) individual messages have to transit through in a large-scale wireless ad hoc network (WANET); we call this hop-count as network latency (NL). A large network latency affects all aspects of data communication in a WANET, including an increase in delay, packet loss, and the power needed to process and store messages in nodes lying on the relay path. We consider network management and data routing challenges in WANETs with scalable network latency, e.g., when NL increases only polylogarithmically in the network size. On the physical side, reducing network latency imposes a significantly higher power and bandwidth demand on nodes, and are captured in a set of new bounds derived in this paper. On the protocol front, designing distributed routing protocols that can guarantee the delivery of data packets within a scalable number of hops is a challenging task. To solve this, we introduce multi-resolution randomized hierarchy (MRRH), a novel power and bandwidth efficient WANET protocol with scalable network latency. MRRH uses a randomized algorithm for building and maintaining a random hierarchical network topology, which together with the proposed routing algorithm, can guarantee efficient delivery of data packets in the wireless network. For a network of size N, MRRH can provide an average latency of only O(log³ N). The power consumption and bandwidth requirements of MRRH are shown to be nearly optimal for the latency it provides. Therefore, MRRH is a provably efficient candidate for truly large-scale wireless ad hoc networking.     

Resource requirements and layouts for field programmableinterconnection chips

Field-programmable interconnection chips (FPIC's) provide the capability of realizing user programmable interconnection for any desired permutation. Such an interconnection is very much desired for supporting rapid prototyping of hardware systems and for providing programmable communication networks for parallel and distributed computing. An FPIC should realize any possible permutation of input to output pins via a set of programmable switches. In this paper, we show that any such architecture requires a minimum of Ω(n log n) switches, where Ω is the number of I/O pins. The result stems from an analysis of the underlying permutation network. In addition, for networks of bounded degree d, we prove an Ω(log_d-1 n) bound on the routing delay (maximum length of routing paths for specific I/O permutations) and an Ω(n log_d-1 n) bound on the average utilization of programmable switches used by the FPIC to implement a specific permutation. For the same type of networks, we prove an Ω(n log_d-1 n) bound on the number of nodes of the network. Furthermore, we design efficient architectures for FPIC's offering a wide variety of routing delays, high average programmable resource utilization, and O(n²)-area two-layer layouts. The proposed structures are called hybrid Benes-Crossbar (HBC) architectures and clearly exhibit a tradeoff between performance (routing delay utilization) and area of the layout     

Quantitative analysis on the computing performance improvement by parallel optical interconnection

This paper compares the optical and electrical interconnect systems by analyzing the efficiency and evaluating the total processing time, and design an experiment to demonstrate this performance promotion. With the increasing demand on large-scale parallel computing tasks, data transmission instead of data computing has become more and more important, so the rapid development of optical chip-to-chip interconnects techniques has gotten more attention. In this paper, we take fast Fourier transform (FFT) computation as an example to study whether and how the optical interconnection has influence on the computing performance, and three topology models are used to judging the transmission latency, and the relationship between the total processing time and the FFT points is also under investigation. Both results show parallel optical interconnection can bring large advantages in promoting computing performance. It is also found that the larger the transmission scale is, the more saving optical interconnection makes.     

Routing protocol over lossy links for ISA100.11a industrial wireless networks

This paper proposes novel routing and topology control algorithms for industrial wireless sensor networks (IWSNs) based on the ISA100.11a standard. The proposed algorithms not only reduces energy consumption at the node level but also reduces packet latency at the network level. Using the residual energy and packet reception rate of neighbor nodes, the source node can estimate the highest election weight. Hence, packets are conveyed by a multi-hop forwarding scheme from source nodes to the sink by the optimal path. Furthermore, energy consumption and network latency are minimized using integer linear programming. Simulation results show that the proposed algorithms are fully effective in terms of energy conservation and network latency for IWSNs.     

A fully implemented 12 /spl times/ 12 data vortex optical packet switching interconnection network

A fully functional optical packet switching (OPS) interconnection network based on the data vortex architecture is presented. The photonic switching fabric uniquely capitalizes on the enormous bandwidth advantage of wavelength division multiplexing (WDM) wavelength parallelism while delivering minimal packet transit latency. Utilizing semiconductor optical amplifier (SOA)-based switching nodes and conventional fiber-optic technology, the 12-port system exhibits a capacity of nearly 1 Tb/s. Optical packets containing an eight-wavelength WDM payload with 10 Gb/s per wavelength are routed successfully to all 12 ports while maintaining a bit error rate (BER) of 10/sup -12/ or better. Median port-to-port latencies of 110 ns are achieved with a distributed deflection routing network that resolves packet contention on-the-fly without the use of optical buffers and maintains the entire payload path in the optical domain.     

A Unified Approach to Local Area Network Interconnection

An approach to local area network interconnection is presented Which combines the advances in static interconnection topologies, demand assignment multiple access protocols, and the availability of high-bandwidth fiber optic channels to create a cost-effective structure capable of interconnecting a large number of LAN's with heavy traffic. This approach is independent of the protocol implemented at each LAN. The structure is based on a hypercube topology where each vertex of the graph represents a LAN. Multiple access channels spanning all dimensional axes are used in this scheme. This approach is compared to a topology with direct point-to-point connections between all nodes sharing a common axis. Through the development of the degree, diameter, average distance, cost, and average packet delay, we show that using fewer high-capacity channels, a LAN interconnection network with excellent performance characteristics can be constructed, able to support a large number of LAN's with heavy traffic at a significant reduction in cost over the point-to-point case. The resulting structure has many of the desirable characteristics for static interconnection networks such as high fault tolerance, totally distributed packet routing in the interconnection network, low average distance for good performance, and low degree, resulting in low cost. For the total number of required LAN nodes and the expected amount of internode traffic, the structure is optimized for minimum cost.     

Algebra-Based Scalable Overlay Network Monitoring: Algorithms, Evaluation, and Applications

Overlay network monitoring enables distributed Internet applications to detect and recover from path outages and periods of degraded performance within seconds. For an overlay network with end hosts, existing systems either require measurements, and thus lack scalability, or can only estimate the latency but not congestion or failures. Our earlier extended abstract [Y. Chen, D. Bindel, and R. H. Katz, ldquoTomography-based overlay network monitoring,rdquo Proceedings of the ACM SIGCOMM Internet Measurement Conference (IMC), 2003] briefly proposes an algebraic approach that selectively monitors linearly independent paths that can fully describe all the paths. The loss rates and latency of these paths can be used to estimate the loss rates and latency of all other paths. Our scheme only assumes knowledge of the underlying IP topology, with links dynamically varying between lossy and normal. In this paper, we improve, implement, and extensively evaluate such a monitoring system. We further make the following contributions: i) scalability analysis indicating that for reasonably large n (e.g., 100), the growth of k is bounded as O(n log n), ii) efficient adaptation algorithms for topology changes, such as the addition or removal of end hosts and routing changes, iii) measurement load balancing schemes, iv) topology measurement error handling, and v) design and implementation of an adaptive streaming media system as a representative application. Both simulation and Internet experiments demonstrate we obtain highly accurate path loss rate estimation while adapting to topology changes within seconds and handling topology errors.