An Optical Network Architecture With Distributed Switching Inside Node Clusters Features Improved Loss, Efficiency, and Cost

The novel core network architecture presented in this paper realizes distributed all-optical switching of payload by partitioning the network into a number of geographically limited domains, where two-way reservations are effective. Thus, inside each domain, loss is eliminated, while traffic from many nodes can be aggregated into single bursts, improving efficiency. Clustered nodes contribute contiguous optical slots, which are marshaled into composite optical frames destined for other clusters, under the guidance of a reservation-based control protocol. The lossless aggregation of traffic from several core nodes allows the use of cost-effective bufferless all-optical transport among the domains with electrical buffers employed at the periphery of the system. The end result is a triple improvement in loss probabilities, efficiency, and cost. This is achieved by exploiting three features of the architecture: the distributed switching functionality (as in early LANs when centralized switching was expensive), localized reservations (avoiding the intolerable delays of end-to-end reservations), and a reduced number of source-destination pairs (by means of node clustering into reservation domains)     

TRACE: time reservation using adaptive control for energy efficiency

Time reservation using adaptive control for energy efficiency (TRACE) is a time frame based media access control (MAC) protocol designed primarily for energy-efficient reliable real-time voice packet broadcasting in a peer-to-peer, single-hop infrastructureless radio network. Such networks have many application areas for various scenarios that obey a strongly connected group mobility model, such as interactive group trips, small military or security units, and mobile groups of hearing impaired people. TRACE is a centralized MAC protocol that separates contention and data transmission, providing high throughput, bounded delay, and stability under a wide range of data traffic. Furthermore, TRACE uses dynamic scheduling of data transmissions and data summarization prior to data transmission to achieve energy efficiency, which is crucial for battery operated lightweight radios. In addition, energy dissipation is evenly distributed among the nodes by switching network controllers when the energy from the current controller is lower than other nodes in the network, and reliability is achieved through automatic controller backup features. TRACE can support multiple levels of quality-of-service, and minimum bandwidth and maximum delay for voice packets are guaranteed to be within certain bounds. In this paper, we describe TRACE in detail and evaluate its performance through computer simulations and theoretical analysis.     

Layer 1 Virtual Private Networks in Multidomain Next-Generation Networks

High-capacity e-science and consumer applications require transport networks that are dynamically provisioned. Rapid advances in next-generation SONET/SPH and optical switching along with GMPLS control have enabled many new services' provisioning capabilities. In particular, a key paradigm is the new layer 1 virtual private network framework, which allows clients to directly provision their own services without deploying expensive infrastructures. This article presents an overview of L1-VPN and describes a resource management scheme that will enable transport network virtualization across a multidomain network infrastructure. The scheme is implemented in both centralized and distributed control frameworks, and allows for dynamic sharing of transport resources. A case study of performance analysis results is presented showing a distributed control plane in a multidomain network architecture achieving higher VPN carrying capacity than a centralized control plane     

Resilient burst ring: extend IEEE 802.17 to WDM networks

In this article, a novel network architecture called resilient burst ring is proposed to implement the next-generation WDM-supported ultrahigh- speed (100 gigabit or higher) carrier Ethernet. This architecture inherits all the best features of resilient packet ring (IEEE 802.17), provides a burst-mode data transmission scheme through a two-sublayer (optical and electronic) hierarchy, and realizes the WDM-supported ultra-high-speed Ethernet with scalability and reliability. RBR adopts a two-layer buffering scheme to resolve the contentions of optical burst packets and provides three different data transmission modes. With the proposed Priority- Only-Destination-Delay resource reservation control protocol, RBR can provide a flexible QoS strategy to implement the transmission of all of the applications and services in existing networks.     

Distributed Reservation Protocol and QoS Method in WR-OBS System

1IntroductionOptical Burst Switching (OBS)[1 ~4]provides a feasi-ble paradigm for Internet Protocol (IP) over Wave-length-Division Multiplexing ( WDM) integration[5 ~10],which has been the focus of intense investigation owingtoits flexibilityin utilizingthe terahertz bandwidth of asingle fiber andits capabilitytosupport transparent datatransmissions. However , with the emergence of allkinds of applications such as data ,voice ,the next-gen-eration network must also be designedto provide …     

Efficient QoS support in a slotted multihop WDM metro ring

A novel distributed access protocol for a slotted wavelength-division-multiplexing (WDM) metro ring employing all-optical packet switching and supporting quality-of-service (QoS) classes is presented and analyzed. Since we assume that there are more nodes than available wavelengths in the network, we obtain a scalable multihop WDM ring as underlying network architecture. By dividing each channel into several time slots and further applying destination release and slot reuse, data packets can be efficiently transmitted and received in a statistically multiplexed manner. In our architecture, each node is equipped with one tunable transmitter and one fixed-tuned receiver. Furthermore, as we generally consider so-called a posteriori access strategies, different packet selection schemes are proposed and compared. An analytical model based on the semi-Markov process methodology is developed to quantify the performance of one of these schemes. As a key element of the protocol, an efficient QoS support access mechanism is proposed and its performance is evaluated. The new QoS control scheme adopts a frame-based slot reservation strategy including connection setup and termination, which only slightly increases the signaling and node processing overhead. Thus, an efficient hybrid protocol combining connectionless and connection-oriented packet transmissions is proposed     

Performance Analysis of Infrastructure Service Provision with GMPLS-Based Traffic Engineering

Dynamic sharing of the common physical network is envisioned as a key enabler for the emerging Internet technologies. This paper addresses challenges related to resource sharing in the physical layer and analyzes the performance of infrastructure service provision with control plane mechanisms based on generalized multi protocol label switching (GMPLS). In our approach, the provisioning of infrastructure services is supported by two novel concepts for GMPLS traffic engineering (TE): resource visibility and inter-domain exchange. Resource visibility is a new network control plane concept, which defines the usage polices for transmission, multiplexing, and switching resources in multiple GMPLS layers. In our architecture, every network resource may exhibit different visibility to different services at different layers. The inter-domain exchange, here referred to as GMPLS exchange point (GXP), is the physical layer equivalent of the Internet exchange point (IXP). Just as how the IXP manages interconnections of autonomous systems (AS) in the Internet, the GXP manages dynamic interconnections of multiple provider domains and enables them to advertise their physical resources to other domains. We model the dynamic provisioning of infrastructure services using graph theory and deploy GMPLS traffic engineering (TE) to optimize the routing and resource yields. The results obtained demonstrate that traffic engineering with resource visibility and GXP brings significant performance benefits in resource utilization and infrastructure extensibility, especially when network providers set up LSPs as a result of collaborative and carrier-neutral traffic engineering where they share information about resource capabilities and utilization     

A resilient star-ring optical broadcast-and-select network with a centralized multi-carrier light source

This article presents a resilient star-ring optical broadcast-and-select network with a centralized multi-carrier light source (C-MCLS). It consists of a star part network and a ring part network. Optical carriers generated by the C-MCLS are broadcast to all network nodes, which select and utilize them for data transmission. Optical carrier distribution as well as data transmission and receiving are performed in the star part network. The ring part network is for fiber failure recovery. The network resilience property enables the design of a fast distributed failure recovery scheme to deal with single and multiple fiber failures. We introduce a fiber connection automatic protection switching (FC-APS) architecture that only consists of optical couplers and 1 × 2 optical switches for each network node. Based on the FC-APS architecture, we design a distributed failure recovery scheme to recover the carriers and data affected by fiber failures. The fiber failure detection and failure recovery operations are performed by each network node independently only using its local information. We evaluate the recovery time of the distributed failure recovery scheme compared with that of the centralized one. Numerical results show that the distributed scheme greatly reduces the recovery time compared to the centralized configuration in the recoveries of both single and multiple fiber failures. Optical power loss analysis and compensation of the recovery routes in the distributed scheme are also presented. We show the required number of optical amplifiers for the longest recovery route in the distributed scheme under different numbers of network nodes and fiber span lengths.     

Research on the access network and MAC technique for beyond 3G systems

Based on the requirements of beyond 3G mobile communication systems, the access network architecture and media access control technique for B3G systems are studied. The proposed novel access network architecture, which can reduce network complexity and improve system performance, is introduced. Centralized mini-slot packet reservation multiple access (CMPRMA), based on OFDMA, is proposed, which not only can inherit the advantages of MPRMA and support real-time traffic well, but can also supply the resource reservation scheme for data traffic and support transmission for data traffic efficiently     

Photonic burst switching (PBS) architecture for hop and span-constrained optical networks

The paper presents a new architecture, called photonic burst switching (PBS), with variable time slot provisioning, supporting high-speed bursty data transmission within hop and span-constrained networks. First, the edge and switching node architecture for in-band and out-of-band signaling is defined with optical switch fabric performance parameters. Second, the edge router regions of operation for burst assembly are studied via simulations. Third, we introduce: (i) a GMPLS-based PBS software architecture in terms of control and data plane operations that is extended to enable the PBS optical interfaces with software building blocks for edge and switching nodes; (ii) an adaptive PBS MAC layer functionality and framing of multiple generic payloads. The integration of the proposed PBS network architecture with low-cost optical switching fabrics and GMPLS-based software architecture should provide the means for robust and efficient optical transport of bandwidth-demanding applications within enterprise networks.     

通用多协议标记交换技术分析与设计

文章分析了通用多协议标记交换(GMPLS)的基本原理和操作机制，针对一种多粒度交换的节点模型一光路由器，设计出了一种基于GMPLS的控制平面软件结构，该控制平面软件可以实现IP over WDM集成流量工程技术和多层联合的保护／恢复技术，同时有助于提高光因特网的整体资源利用率，降低网络呼叫阻塞率、     

QoS in DSL access

Which enrichments are required for the DSL architecture to transform the DSL access network from a vehicle for best effort Internet access to a multiservice platform enabling added value conversational and data services? This article details an architecture for DSL access facilitating IP service guarantees leveraging the available QoS mechanisms in the transport-technology-specific data plane, while extending the control plane. Enhanced resource and information control, policy enforcement, and advanced IP connection establishment mechanisms are key elements for the network access provider to enter the value chain for delivery of IP services.     

A vertical Path Computation Element (PCE) based path provisioning scheme in multilayer optical networks

The explosive growth of Internet traffic has led to a dramatic increase in demand for data transmission capacity, which requires high transmission rates beyond the conventional transmission capability. This demand has spurred tremendous research activities in new high-speed transmission and switching technologies. As optical transmission technology keeps maturing, next generation optical networks are expected to be controlled by Generalized Multiprotocol Label Switching (GMPLS) protocol suite and operating at multiple switching layers. In order to ensure the most efficient utilization of multilayer network resources, and to maximize revenue from existing capacity, effective global provisioning solution that providing the network with the possibility of reacting in advance to traffic changes should be provided. This paper proposes a new path provisioning scheme in multilayer optical networks based on the vertical Path Computation Element (PCE) architecture to efficiently exploit multiple PCE cooperation. This paper also investigated the problem of how network nodes overcome limited visibility of network resources. Unlike most of the previous studies, the topology of the upper switching layer is not always equal to the physical topology of lower switching layer.     

下一代光因特网体系结构的选择与比较

下一代光因特网(NGOI)体系结构的基本特征是两层(业务层和传送层)和三个平面(数据平面、控制平面、管理平面)。分析和归纳了四种主流的面向下一代光因特网体系结构模型。提出了一种基于通用多协议标记交换(GMPLS)技术和光电混合交换技术的集成光因特网模型,该模型与其它模型相比较,结合了光电两个领域的技术优势,具有网络综合性能高,容易实现,扩展性好等优点。     

Cross-stratum resource reservation (CSRR) algorithm for deadline-driven applications in datacenter networks

Nowadays, datacenters interconnected with optical networks have become the fundamental infrastructure to accommodate high-performance datacenter applications. Lacking of layer interaction between datacenters and networks during service provisioning, many end user applications cannot efficiently utilize the network capabilities, nor can they achieve the desired quality of service objectives. In response to these challenges, cross-stratum optimization has been studied to optimize the computing and network resources utilization from a united view. Meanwhile, the type of network applications becomes diverse. Compared to traditional immediate reservation (IR) request, a new type of request called advance reservation (AR) has recently been gaining attention for optical networks. IR’s start time of data transmission is assumed to be immediate, while AR request typically specifies the earliest time or the deadline of data transmission. According to the time features of AR request, AR applications should be scheduled in time dimension. Thus, it is both important and challenging to reserve computing and network resources in efficient manners. In this study, a cross-stratum resource model considering time dimension is set up, and a cross-stratum resource reservation (CSRR) algorithm is proposed to schedule AR applications and to reserve cross-stratum resource. Simulation results show that CSRR can reduce the failure rates of AR applications and improve the resource consumption ratio significantly.     

A non-competing hybrid optical burst switch architecture for QoS differentiation

In this paper, we present a new hybrid optical burst switch architecture (HOBS) that takes advantage of the pre-transmission idle time during lightpath establishment. In dynamic circuit switching (wavelength routing) networks, capacity is immediately hard-reserved upon the arrival of a setup message at a node, but it is used at least a round-trip time delay later. This waste of resources is significant in optical multi-gigabit networks and can be used to transmit traffic of a lower class of service in a non-competing way. The proposed hybrid OBS architecture, takes advantage of this idle time to transmit one-way optical bursts of a lower class of service, while high priority data explicitly requests and establishes end-to-end lightpaths. In the proposed scheme, the two control planes (two-way and one-way OBS reservation) are merged, in the sense that each SETUP message, used for the two-way lightpath establishment, is associated with one-way burst transmission and therefore it is modified to carry routing and overhead information for the one-way traffic as well. In this paper, we present the main architectural features of the proposed hybrid scheme and further we assess its performance by conducting simulation experiments on the NSF net backbone topology. The extensive network study revealed that the proposed hybrid architecture can achieve and sustain an adequate burst transmission rate with a finite worst case delay.     

移动栅格网中跨层资源管理方法研究

移动栅格网是一种全移动多跳无线栅格网络,采用了面向服务的全IP技术体制和全新的分层协议模型。针对这种新型网络结构和协议模型,提出了一种跨层资源管理方法,通过将呼叫接纳控制、路由选择、资源预留、排队机制以及信道接入机制等进行跨层设计,增加层间协作机制和方法以达到资源利用的优化和业务服务质量的提高。对跨层资源管理的总体框架和思路进行了详细描述,对具体实现途径进行了探讨。     

Pervasive, secure access to a hierarchical sensor-based healthcare monitoring architecture in wireless heterogeneous networks

This study presents a healthcare monitoring architecture coupled with wearable sensor systems and an environmental sensor network for monitoring elderly or chronic patients in their residence. The wearable sensor system, built into a fabric belt, consists of various medical sensors that collect a timely set of physiological health indicators transmitted via low energy wireless communication to mobile computing devices. Three application scenarios are implemented using the proposed network architecture. The group-based data collection and data transmission using the ad hoc mode promote outpatient healthcare services for only one medical staff member assigned to a set of patients. Adaptive security issues for data transmission are performed based on different wireless capabilities. This study also presents a monitoring application prototype for capturing sensor data from wireless sensor nodes. The implemented schemes were verified as performing efficiently and rapidly in the proposed network architecture.     

基于光突发交换的下一代光互联网技术

给出了基于光突发交换的下一代光互联网技术的体系结构,然后从光突发数据格式、光突发的装配、光突发交换节点与网络结构、资源预留协议,以及数据信道调度算法等方面讨论了其核心技术问题.最后,简要地指出了下一代光互联网技术的未来研究方向和主要研究内容.     

时隙光突发交换网络调度问题研究

光突发交换（OBS）是构造下一代全光网络的潜在技术之一,但存在网络参数设计困难和阻塞性能有限等问题。文章介绍了一种新型基于时隙的OBS网络体系,简要阐明了其各部分功能,并将其与常规OBS网络进行了对比。提出了网络节点中关键的时隙分配与调度问题,并给出相应的在线调度策略,仿真结果表明BF算法性能较优。