Switched Network Architecture Research Articles

On-Chip Optical Switching Network Architecture Based on Hybrid Wavelength and Mode Division Multiplexing

On-Chip Optical Switching Network Architecture Based on Hybrid Wavelength and Mode Division Multiplexing

Fault Diagnosis Knowledge Reasoning of Switching Network in Distributed Generation Based on Petri Net

Telephone network based on IMS technology has been widely applied inpower production and dispatching communication, especially in distributedpower stations. Analysis and positioning failure of IMS network is arduous,because it’s dependent on IP data communication network. In this paper,we first introduced IMS switching network architecture and distributed gen-eration communication network architecture, analyzed and summarized allkinds of network malfunction. Combining typical IMS network fault con-nection relations, we introduced an improved Petri net fault handling modeland reasoning method. The diagnosis and positioning results could reflectthe defects of equipment logic functions. This method on fault diagnosisand location of substation network has been proved to be effective throughpractical application.

Optimizing meta-slots for nonblocking elastic optical switching networks

Elastic optical network is a promising technology for building flexible and wideband communication systems. This technology features the frequency slot unit (FSU) concept, which defines the bandwidth unit in the frequency domain. The utilization of a specified number of consecutive FSUs allows the bandwidth to be flexibly assigned to a data stream. For a successful elastic optical network operation, the use of nonblocking optical switching networks is indispensable. This paper focuses on two previously proposed W-S-W switching network architectures, namely, WSW1 and WSW2. With regard to WSW1, a previous study elucidated that the hardware complexity, which is evaluated by the number of FSUs, decreases by employing the meta-slot scheme. A meta-slot is a frequency range containing one or more FSUs. Although its effectiveness depends on the sizes of meta-slot classes, the previous study did not present how to optimize the meta-slot class sizes. Moreover, the employment of meta-slots was not considered for WSW2 in the previous study. This paper investigates the optimization of meta-slot class sizes and demonstrates that such optimization is modeled as the shortest path problem. For WSW1, the meta-slot scheme optimized by the shortest path model is compared with the previously reported nonblocking conditions. The result confirms the superiority of the optimized meta-slot scheme. For WSW2, the assignment of meta-slots among S-switches is also essential. The paper models the assignment of meta-slots as a bin-packing problem. Thus, the near-optimal assignment can be obtained by a known bin-packing heuristic. For WSW2, the number of S-switches is evaluated for the optimized meta-slot scheme and the previously known nonblocking conditions. The result confirms that the meta-slot scheme is advantageous for WSW2 as well as for WSW1.

Construction of Distributed Optoelectronic Switching Network and OpenFlow Anycast Mechanism of Network on Cloud Computing

Traditional electrical switching network faces the problems of limited bandwidth and large energy consumption. The optoelectronic hybrid data network fully combines the advantages of optical switching and electrical switching, and dynamically adjusts the topology and bandwidth in accordance to the demand, thereby effectively improving network performance and reducing power consumption. A high-performance distributed optoelectronic switching network architecture called DOIN_W was proposed in the study, aiming to solve the problems of the scalability of the optoelectronic switching network architecture and the insufficient flexibility of network resource allocation. The architecture was connected topologically according to the method of 2DTorus, thereby effectively improving the network scale of the photoelectric switching network and supporting the dynamic adjustment of the network scale. The optical switching of DOIN_W adopted the "broadcastselect" method to support different forms of broadcasting communication. A multi-dimensional optical signal switch was designed, and the optical signal broadcast of the switch can reach any of the optical switches in DOIN_W, thereby supporting the direct connection between optical switches. Considering the problems that the multi-broadcast service of DOIN_W was unable to access freely, stateful optical signal communication was hard to maintain and the single path weight resulted in lack priority of communication, the OpenFlow network protocol of the cloud computing network was introduced in the DOIN_W architecture. The anycast mechanism of DOIN_W was optimized based on this protocol. Based on the stream-level network simulator for network performance simulation analysis, the DOIN_W architecture can meet the requirements of network scalability and flexibility. Compared with the OVS architecture and Jellyfish architecture, the DOIN_W architecture can effectively reduce the average flow completion time by more than 30% and reduce average energy consumption by over 25%.

Design of SRIO Reconstruction and Switching Network Architecture

The image processing system of the parallel processor array will face the problems of complex system structure, long development period and the inability to flexibly adjust and upgrade the platform hardware. This paper proposes a design concept of dynamic reconfiguration hardware architecture and a compatible design. Dynamic reconstruction and dynamic reconstructed image processing system of image algorithm. At the same time, CPS1848 is used as the SRIO switch chip as the switching core of the high-speed data network and a switching network routing method is designed. Tests have proved that the transmission performance of the system's SRIO high-speed data internetwork meets the requirements. Compared with previous image processing devices, the system can flexibly meet the task requirements of multiple application scenarios; improve the versatility of the device and save hardware resources and equipment costs.

Realization and Application of Large-Scale Fast Optical Circuit Switch for Data Center Networking

Applying optical switching to data center networks can greatly expand network bandwidth and reduce electrical power consumption, both of which are needed to meet the explosive traffic increase. The optical switch offers large bandwidth switching capability, and so eliminates the multistage switch network architecture needed with electrical switching. Furthermore, the single stage architecture of the optical switch greatly simplifies operating costs, which include cabling, while substantially reducing the number of transponders needed. Data center networks place very different demands on optical systems than communication networks. Grasping the right direction to proceed is of paramount importance. To realize the full potential of optical switches, such as scalability and cost effectiveness, we analyze the role of large-scale optical circuit switches and discuss the realization technologies that combine the two dimensions of space and wavelength. Our recent advances in large port-count optical switches are presented.

High-throughput partial-parallel block-layered decoding architecture for nonbinary LDPC codes

This paper presents a novel forward-backward four-way merger min-max algorithm and high-throughput decoder architecture for nonbinary low-density parity-check (NB-LDPC) decoding, which significantly reduces decoding latency. An efficient partial-parallel block-layered decoder architecture suitable for the proposed forward-backward four-way merger algorithm is presented to speed up the decoder convergence. Moreover, a parallel switch network architecture and parallel-serial check node unit are also proposed to facilitate the implementation of the proposed decoder architecture. The proposed algorithm can reduce the number of check node processing steps by half. Consequently, the decoder architecture using the proposed algorithm can achieve a considerably higher throughput, compared to previous works. Two quasi-cyclic NB-LDPC (QC-NB-LDPC) codes over GF(32) as (837, 726) and (744, 653) are synthesized using a 90-nm CMOS technology. The implementation results demonstrate that the proposed decoder architecture can operate at a 370MHz clock frequency, and the throughputs of these two codes are 92.6 Mbps and 118.86 Mbps, respectively.

Performance Analysis of $f$ -Cast Crosstalk-Free Optical Banyan Networks

Banyan networks serve as a class of important switching network architecture, whose multicast capability is critical for future high-performance switches to support multicast-intensive applications. The available literature indicates that, in order to construct optical multicast banyan networks based on the directional coupler (DC) technology, a high-hardware cost is usually involved to ensure the nonblocking property. In this paper, we conduct blocking probability analysis for such networks to explore the inherent tradeoff between blocking probability and hardware cost. In particular, we focus on a class of DC-based optical networks built on the replicated banyan network (RBN) architecture, and develop a theoretical upper bound on blocking probability for such networks under the general $f$ -cast traffic, which covers the unicast and multicast as special cases. This bound captures the overall blocking behavior of $f$ -cast optical RBN networks and agrees with the conditions of strictly nonblocking $f$ -cast optical RBN networks. The proposed bound is significant because it provides a fundamental guideline to achieve the desirable tradeoff between blocking probability and hardware cost. This paper shows that the hardware cost of an $f$ -cast optical RBN network can be dramatically reduced if a small blocking probability is allowed.

Analysis and experimental demonstration of an optical switching enabled scalable data center network architecture

Optical communication technologies are playing more and more important roles in both intra- and inter- data center networks. Particularly, optical switching network architectures for the inter-rack/pod communications in the data centers have drawn remarkable attention in recent years. By exploiting the high-bandwidth nature and flexible resource allocation capability of optical switching technologies, data center networks (DCNs) may be designed to have high scalability and flexibility, as well as lower cost. Under such design principles, OpenScale architecture has been proposed in our previous works. In OpenScale, reconfigurable optical wavelength/timeslot links connecting with server racks form a logical small-world topology with very simple physical wiring. In this paper, we first review the features of OpenScale and then we investigate the outstanding advantages of OpenScale including high scalability, fault tolerance and effective load balancing. Furthermore, taking data center's inter-rack traffic characteristics into consideration, we verify that OpenScale network can suitably match specific traffic patterns and provide better network performance at the cost of introducing a “vicinity-preferred workload allocation” scheme in the control plane. In addition, a prototype testbed is also introduced, and the proof-of-concept demonstrations of OpenScale's key functionalities in both data plane and control plane are conducted.

Performance analysis of a hierarchical switched network architecture

In an effort to solve the problems encountered by the current internet, we have proposed an original hierarchical switched network HSNet architecture with the new address structure and hierarchical switching and controlling protocols including a per-flow load-balancing algorithm for HSNet. To evaluate the effectiveness and accuracy of the proposed architecture and the load-balancing algorithm, this paper conducts extensive NS-2 simulation experiments. Furthermore, we prototype the switching equipment of HSNet based on the Intel IXP2800 Network Processor and test the equipment by virtue of the professional measuring instrument, i.e., Agilent N2X. In addition to the simulation experiments, a test-bed of HSNet is then built based on the developed switching equipments. Both the simulation and real experimental results demonstrate that the per-flow load balancing algorithm can effectively balance the load on network channels for HSNet, and the developed switching equipment can achieve a high throughput.

BIST Methodology, Architecture and Circuits for Pre-Bond TSV Testing in 3D Stacking IC Systems

This paper presents a built-in self test (BIST) methodology, architecture and circuits for testing Through Silicon Vias (TSVs) in 3D-IC systems prior to stacking in order to improve 3D-IC yield and reduce overall test cost. A scan switch network (SSN) architecture is proposed to perform pre-bond TSV scan testing in test mode, and operate as functional circuit in functional mode, respectively. In the SSN, novel test structures and circuits are proposed to address pre-bond TSV test accessibility issue and perform stuck-at-fault tests and TSV tests. By exploiting the inherent RC delay characteristics of TSV, a novel delay-based TSV test method is also proposed to map the variation of TSV-to-substrate resistance due to TSV defects to a test path delay change. Compared with state-of-art methods, the proposed BIST methodology addresses pre-bond TSV testing with a low-overhead integrated test solution which is compatible to existing 2D-IC testing method. The proposed BIST architecture and method can be implemented by standard DFT design flow and integrated into a unified pre-bond TSV test flow. Experiment results and robustness analysis are presented to verify the effectiveness of the proposed self-test methodology, architecture, and circuits.

An optical circuit switching network architecture and reconfiguration schemes for datacenter

The paper presents an optical circuit switching network architecture and its control and traffic scheduling schemes. This optical switch network is built on a 32×32 AWG and fast wavelength tunable transmitters and is able to support up to 128 interface ports. The feasibility of the architecture is verified through an experimental study. The traffic scheduling scheme takes into account the transmitter wavelength tuning time so as to avoid frequent connection reconfiguration. The simulation results show that fast connection reconfiguration speed and efficient traffic scheduling scheme enable optical circuit switching network to deliver high transmission bandwidth and low packet delay performance in datacenter network.

Design and Simulation of Output Queuing with the Middle stage Buffered (OQMB) Close Packet Switching Network

network, a family of multistage networks, are attractive alternative for constructing scalable packet switches because of its distributed and modular design. The clos packet switching networks are the next step in scaling current crossbar switches to large number of ports. This paper presents the design and simulation of buffer less- buffered- buffered - Clos Packet switching network architecture. This paper proposes a novel the output queuing with the middle stage buffered (OQMB) Clos Packet switching architecture that does not need any schedulers. This architecture employs an ID matching with OQMB packet switching and desynchronize static round robin (DSRR) scheme to achieve Maximum throughput under any admissible traffic. Our queuing analysis demonstrates that only small size buffers are needed in the central stage. The only trade off for the proposed (OQMB) architecture is to employ small extra resequencing buffers. Input modules with desynchronize static round robin (DSRR) scheme connection scheme guarantees no cell contention in input stages. As a result, the OQMB architecture can achieve very high performance, and high throughput under any admissible traffic. General words

A time-shift scheduling-enabled optical flow switched network architecture and its performance

Optical flow switching (OFS) has been proposed as a simple and cost-effective transport technology for users with large transactions (>1 second). In previous studies, a fast wavelength reservation method was deployed for flow transmission in OFS-based networks. However, reserving a single wavelength for users with small transactions encounters a very common problem: inefficient wavelength utilization. In this paper, a flow transmission cycle is introduced to each wavelength, and each cycle consists of multiple slots, so that flows of different transactions can be multiplexed onto a single wavelength. It is assumed that inter-metropolitan area network (MAN) traffic is transported over wide area network (WAN). A global time-shift scheduling methodology taking into account propagation delays in MAN is designed to avoid potential contentions occurring among different flows which are carried by the same wavelength in WAN. The contributions of this paper are, first it provides a new OFS network architecture which can achieve better throughput and average wavelength utilization performance without losing the feature of simple transport structure provided by OFS; second, it is the first time that issues of how OFS networks are managed and controlled are addressed from a system point of view.

An efficient Quality of Service (QoS) scheme for all optical networks

This paper addresses the issue of providing Quality of Service (QoS) for optical burst switching (OBS) systems. In this paper, an efficient QoS oriented integrated scheme based on Optical Burst/Circuit Switching network architecture has been proposed. The proposed scheme utilizes the modified Just-Enough-Time (JET) protocol and advanced reservation based on Linear Predictive Filter (LPF), which can provide differentiated services for optical burst switching (OBS) network. Simulation results show that the proposed scheme is reasonably better than a First Come First Served (FCFS) protocol in guaranteeing QoS of real-time traffic. Also, the results yield significant delay reduction for time-critical traffic, while maintaining the bandwidth overhead within limits. As a result, the proposed scheme has achieved QoS differentiation in terms of burst loss rate in comparison to conventional schemes.

Achieving High Performance Burst Transmission for Bursty Traffic using Optical Burst Chain Switching in WDM Networks

In Optical Burst Switching (OBS) network architecture, edge nodes assemble bursts and send them to the core network arbitrarily, which will lead to inevitable collisions and low network utilization in the core network. Our objective is to achieve high performance burst transmission for bursty traffic while avoiding the use of wavelength converters and excessive optical buffers. To achieve this objective, we propose a novel optical burst chain switching (OBCS) mechanism, which combines the merits of optical circuit switching and optical burst switching with affordable signaling overhead. In the proposed mechanism, switching unit is a burst chain which consists of multiple non-periodic and non-consecutive bursts in one wavelength. Theoretical analysis for the throughput and queuing delay of the proposed scheme is carried out and is also verified by simulation results. We present extensive simulation results to demonstrate its superior performance over OBS networks with/without wavelength converters.

Comparison analysis of optical burst switched network architectures

Optical burst switching (OBS) is a promising paradigm for the next-generation Internet infrastructure. In this paper, a novel efficient network architecture for OBS has been presented and compared with conventional OBS architectures. To enhance OBS system performance, the architecture employs a novel proposed burst assembly algorithm, fiber delay lines (FDLs) and dynamic route selection technique. A queuing model is used to predict the system behavior for both classless and prioritized traffic. Simple closed-form expressions are obtained for the burst-loss probability of both classless and prioritized traffic. Numerical results show that the proposed architecture provides an accurate fit for the performance of the highest traffic class and lower bounds for the other traffic classes that are tighter than earlier known results.

MPLS security: an approach for unicast and multicast environments

Multi-Protocol Label Switching (MPLS) network architecture does not protect the confidentiality of data transmitted. This paper proposes a mechanism to enhance the security in MPLS networks by using multi-path routing combined with a modified (k, n) threshold secret sharing scheme. An Internet Protocol (IP) packet entering MPLS ingress router can be partitioned into n shadow (share) packets, which are then assigned to maximally node disjoint paths across the MPLS network. The egress router at the end will be able to reconstruct the original IP packet if it receives any k share packets. The attacker must therefore tap at least k paths to be able to reconstruct the original IP packet that is being transmitted, while receiving k − 1 or less of share packets makes it hard or even impossible to reconstruct the original IP packet. In this paper, we consider the multicast case in addition to the unicast. To our best knowledge, no work has been published for MPLS multicast security. We have implemented our model and measured its time complexity on variable packets size.

Reduced banyan-type multiplane rearrangeable switching networks

The new concept of the multiplane rearrangeable switching network is presented. The new switching network's architecture is based on the well-known baseline network (the log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (N, 0, 1) switching network). This new architecture can easily be obtained from the baseline network by the removal of some switching elements. It is therefore called the reduced baseline switching network and is denoted by log <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sup> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ((N, 0, 1). The new multiplane rearrangeable reduced baseline switching network requires fewer switching elements and crosspoints than the multiplane switching network which is based on the plain baseline network.

Analysis of a dynamically wavelength-routed optical burst switched network architecture

The concept of optical burst switching (OBS) aims to allow access to optical bandwidth in dense wavelength division multiplexed (DWDM) networks at fractions of the optical line rate to improve bandwidth utilization efficiency. This paper studies an alternative network architecture combining OBS with dynamic wavelength allocation under fast circuit switching to provide a scalable optical architecture with a guaranteed QoS in the presence of dynamic and bursty traffic loads. In the proposed architecture, all processing and buffering are concentrated at the network edge and bursts are routed over an optical transport core using dynamic wavelength assignment. It is assumed that there are no buffers or wavelength conversion in core nodes and that fast tuneable laser sources are used in the edge routers. This eliminates the forwarding bottleneck of electronic routers in DWDM networks for terabit-per-second throughput and guarantees forwarding with predefined delay at the edge and latency due only to propagation time in the core. The edge burst aggregation mechanisms are evaluated for a range of traffic statistics to identify their impact on the allowable burst lengths, required buffer size and achievable edge delays. Bandwidth utilization and wavelength reuse are introduced as new parameters characterizing the network performance in the case of dynamic wavelength allocation. Based on an analytical model, upper bounds for these parameters are derived to quantify the advantages of wavelength channel reuse, including the influence of the signaling round-trip time required for lightpath reservation. The results allow to quantify the operational gain achievable with fast wavelength switching compared to quasistatic wavelength-routed optical networks and can be applied to the design of future optical network architectures.