一种适用于星载光交换网络的资源预留协议

根据卫星光交换网络应用需求,结合现有的地面光突发交换资源预留方法,提出了一种基于突发流的资源预留协议。首先通过流量估计把突发数据按照目的地址和QoS区分为单个突发和突发流,然后按照这两种分类对卫星光网络资源进行了成功预留。为了对该预留方法进行考察,建立了平均端-端时延、吞吐量、链路利用率数学分析模型。理论分析与仿真证明了该资源预留方法通过降低光交换矩阵的重置时间和交换时延,有效降低了端-端时延,提高了网络吞吐量,适用于星载光交换网络。     

Providing service differentiation for optical-burst-switched networks

This paper proposes a service differentiation scheme called preemptive wavelength reservation protocol (PWRP) to provide proportional quality of service (QoS) for optical-burst-switched (OBS) networks. In the context of service differentiation, traffic is divided into different service classes based on traffic characteristics. A service differentiation scheme then provides different degrees of resource assurance to different classes of traffic in proportion to their service classes. Unlike existing approaches, which may degrade to classless schemes or which may suffer from low wavelength utilization, the mechanism in this paper is robust and efficient and supports an incremental deployment of QoS support. A usage profile for each class is maintained at the router, and a preemptive wavelength reservation mechanism is implemented to ensure QoS. An analytical model is derived and simulations are conducted to evaluate the performance. The results show that the approach described in this paper performs better than existing mechanisms in terms of lower blocking probability and higher resource utilization, making it an excellent QoS mechanism for OBS networks.     

FRR for latency reduction and QoS provisioning in OBS networks

We propose a forward resource reservation (FRR) scheme to reduce the data burst delay at edge nodes in optical burst switching (OBS) systems. We also explore algorithms to implement the various intrinsic features of the FRR scheme. Linear predictive filter (LPF)-based methods are investigated and demonstrated to be effective for dynamic burst-length prediction. An aggressive resource reservation algorithm is proposed to deliver a significant performance improvement with controllable bandwidth cost. By reserving resources in an aggressive manner, an FRR system can reduce both the signaling retransmission probability and the bandwidth wastage as compared with a system without the aggressive reservation. An FRR-based QoS strategy is also proposed to achieve burst delay differentiation for different classes of traffic. Theoretical analysis and simulation results verify the feasibility of the proposed algorithms and show that our FRR scheme yields a significant delay reduction for time-critical traffic without incurring a deleterious bandwidth overhead.     

IP QoS综合服务模型研究

本文讨论了一种资源预留和QoS控制模型。对该模型中的接纳控制、策略控制和调度算法进行了分析,并且讨论了模型的核心协议－资源预留协议（RSVP）,从讨论中可以看到,该模型能在IP网上提供不同级别的QoS以满足不同的需求。     

基于BD技术的光突发竞争解决方案

将BD法结合波长资源预留算法提出一种新的突发竞争解决方案。该方案通过在突发竞争时牺牲低优先级突发的传输完整性,以保证高优先级的业务的丢失率,同时降低了传输时延。最后对基于BD法的突发竞争解决方案进行了网络仿真,并和传统的传统基于额外偏置时间(JET)的方案比较,结果表明在平均数据丢失率相当的前提下,改进的BD法能有效的降低突发包的端对端时延。     

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.     

E-OBS网络中一种基于窗口的资源预留机制

为了有效地降低突发包的阻塞率和保证网络的服务质量,提出了模拟光突发交换（E-OBS）网络中一种偏置时间连续可变的基于窗口资源预留机制。在E-OBS核心路由器的控制信道（CC）上设置资源预留窗口,以此决定是否允许控制包为相应的突发包预留链路资源,并且给出了该机制下关于阻塞概率的近似方程式。仿真结果表明,适当增加资源预留窗...     

Fast RSVP: Efficient RSVP Mobility Support for Mobile IPv6

In recent years, with the development of mobile communication technologies and the increase of available wireless transmission bandwidth, deploying multimedia services in next generation mobile IPv6 networks has become an inevitable trend. RSVP (resource reservation protocol) proposed by the IETF is designed for hardwired and fixed networks and can not be used in mobile environments. This paper proposes a protocol, called Fast RSVP, to reserve resources for mobile IPv6. The protocol adopts a cross-layer design approach where two modules (RSVP module and Mobile IPv6 module) at different layers cooperate with each other. Fast RSVP divides a handover process with QoS guarantees into two stages: (1) setup of the resource reservation neighbor tunnel and (2) resource reservation on the optimized route. It can help a mobile node realize fast handover with QoS guarantees as well as avoid resource wasting by triangular routes, advanced reservations and duplicate reservations. In addition, fast RSVP reserves “guard channels” for handover sessions, thus greatly reducing the handover session forced termination rate while maintaining high performance of the network. Based on extensive performance analysis and simulations, Fast RSVP, compared with existing methods of resource reservation in mobile environments, performs better in terms of packet delay and throughput during handover, QoS recovery time after handover, resource reservation cost, handover session forced termination rate and overall session completion rate.     

Dynamic reservation TDMA protocol for wireless ATM networks

A dynamic reservation time division multiple access (DR-TDMA) control protocol that extends the capabilities of asynchronous transfer mode (ATM) networks over the wireless channel is proposed in this paper. DR-TDMA combines the advantages of distributed access and centralized control for transporting constant bit rate (CBR), variable bit rate (VBR), and available bit rate (ABR) traffic efficiently over a wireless channel. The contention slots access for reservation requests is governed by the framed pseudo-Bayesian priority (FPBP) Aloha protocol that provides different access priorities to the control packets in order to improve the quality-of-service (QoS) offered to time sensitive connections. DR-TDMA also features a novel integrated resource allocation algorithm that efficiently schedules terminals' reserved access to the wireless ATM channel by considering their requested bandwidth and QoS. Integration of CBR, voice, VBR, data, and control traffic over the wireless ATM channel using the proposed DR-TDMA protocol is considered in this paper. Simulation results are presented to show that the protocol respects the required QoS of each traffic category while providing a highly efficient utilization of approximately 96% for the wireless ATM channel     

A partial-success-rate-based resource reservation scheme for slotted OBS networks

Optical burst switching (OBS) is a promising technology for next-generation optical networks. Slotted OBS is an improved version of OBS to reduce burst loss rate, in which wavelength channels are divided into time slots. Slotted OBS has an implicit and under-used property that resources for two bursts with the same source and the same destination are interchangeable. The property further means that resource for a long-distance burst can be partially used by a short-distance burst. In this paper, we utilize the property to design a resource reservation scheme for slotted OBS networks. The scheme reserves a batch of slots every time; the specific number of slots is calculated according to number of arrived bursts and partial success rate (a newly introduced conception in this paper) at each node. Simulation results show that the proposed scheme can get lower burst loss rate, comparing with the well-performing two-way signaling scheme.     

基于RSVP的QoS参数控制报文设计与实现

本文提出一种高速网络服务质量(QoS)参数的设计与实现方法.该方法在Internet标准RFC2205的基础上,根据不同的多媒体应用类型和服务质量需求,首先对服务质量进行量化和分类,然后设计和定义基于RSVP(Reservation Protocol)的、可供路由器和端系统识别的各类服务质量控制报文,并设计和实现一种利用这些报文进行QoS控制的方法.这些QoS参数控制报文的提出使得RSVP协议在广域网上的实现成为可能,从而提高Internet传送多媒体应用的能力.     

Architecture for mobility and QoS support in all-IP wireless networks

Mobility management and quality-of-service (QoS) provisioning are the important tasks on the future development of wireless networks. The high host mobility makes these tasks more challenging. In this paper, we propose an architecture which supports both mobility and QoS management in Internet protocol (IP)-based wireless networks. In mobility management, the fast handoff, which the packets are forwarded in advance to the neighboring locations where a mobile node (MN) may move to, is provided to reduce the service disruption. Also, the fast location lookup, which the routing information about a MN is replicated to some routers, is provided to avoid the triangular routing problem incurred by the protocol of mobile IP. In QoS provisioning, we enable the end-to-end QoS guarantee by using the resource reservation protocol (RSVP) signaling. In particular, the RSVP aggregation technique is used to avoid the scalability problem. Also, the technique of passive resource reservation is used to reduce the influence of host mobility on the resource reservation delay. We emphasize the integration of mobility and QoS management in the architecture design. A performance analysis is given to justify the benefits of our proposed architecture.     

Composite-two-phase wavelength reservation scheme for dynamic optical networks

An enhanced hybrid scheme of wavelength reservation for dynamic wavelength routed optical networks is proposed. The performance of a newly introduced composite-two-phase reservation protocol (C2P-RP) is evaluated and compared with the existing hybrid reservation protocol. By offering connection requests an enhanced scope of finding an end-to-end available wavelength, the C2P-RP scheme shows improved connection-request blocking performance.     

A scalable model for interbandwidth broker resource reservation and provisioning

As the Internet evolves into global communication and commercial infrastructure, the need for quality-of-services (QoSs) in the Internet becomes more and more important. With a bandwidth broker (BB) support in each administrative domain, differentiated services (Diffserv) is seen as a key technology for achieving QoS guarantees in a scalable, efficient, and deployable manner in the Internet. In this paper, we present a scalable model for inter-BB resource reservation and provisioning. Our BB uses centralized network state maintenance and pipe-based intradomain resource management schemes that significantly reduce admission control time and minimize scalability problems present in prior research. For inter-BB communication, we design and implement a BB resource reservation and provisioning protocol (BBRP). BBRP performs destination-based aggregated resource reservation based on bilateral service level agreements (SLAs) between peer-BBs. BBRP significantly reduces the BB and border routers state scalability problem by maintaining reservation state based only on destination region. It minimizes inter-BB signaling scalability by using aggregated type resource reservation and provisioning. Both analytical and experimental results verify the BBRP achievements.     

Quality-of-service mechanisms in all-IP wireless access networks

In this paper, we focus on resource reservation protocol (RSVP)-based quality-of-service (QoS) provisioning schemes under Internet protocol (IP) micromobility. We consider QoS provisioning mechanisms for on-going RSVP flows during handoff. First, the rerouting of RSVP branch path at a crossover router (CR) at every handoff event can minimize resource reservation delays and signaling overheads, and in turn the handoff service degradation can be minimized. We show that RSVP branch path rerouting scheme could give a good tradeoff between the resource reservation cost and the link usage. Second, the new RSVP reservation can be made along the branch path toward the CR via a new base station in advance, while the existing reservation path is maintained, and in turn the on-going flow can be kept with the guaranteed QoS. We also show that seamless switching of RSVP branch path could provide the QoS guarantee by adaptively adjusting the pilot signal threshold values. Third, during RSVP resource reservation over wireless link, dynamic resource allocation scheme is used to give a statistical guarantee on the handoff success of on-going flows. We finally obtain the forced termination probability of guaranteed service flows, the average system time of best effort flows by using a transition rate matrix approach.     

采用动态波长分插复用器的光突发交换环网中的控制协议研究

提出了一种光突发交换(OBS)环网控制协议——延迟光突发固定周期(DBFP)协议。它采用动态波长分插复用器(WADM)。即采用波长可调发送可调接收(TTTR)机制．通过提前的光突发控制分组(BCP)．为光突发数据分组(BDP)预留资源，并利用固定长度的光纤延迟线(FDL)将突发数据包延迟同定的时间，以便等待所有已经预留的突发数据包发送完毕，从而完全避免突发数据包冲突问题。仿真结果表明。延迟光突发固定周期协议能完全避免突发数据包冲突。同时有效地实现了波长统计复用、按需分配和空间重用，波长重用效率高达160％。从而提高链路利用率．特别适合于突发性的业务；并且延迟光突发固定周期协议所引入的时延为1ms左右．对业务的影响不大。     

Hybrid Control and Reservation Architecture for Multidomain Burst Switched Network

Optical burst switching realizes all-optical communication by dividing data transmission system into control plane and data plane. In order to implement control plane two controlling mechanisms such as distributed and centralized control and reservation models have been presented in literature. Both of the architectures have pros and cons associated such as distributed model lacks efficient resource utilization while centralized model is nonscalable. In order to overcome these, a new hybrid control and reservation mechanism has been presented by the authors. The proposed model is based on clustering technique where each cluster consists of cluster head and member nodes. Cluster head performs major functionalities in the network such as path establishment, routing and resource management, fault management, etc., while member nodes perform data switching functionality. In order to implement the architecture, a signaling protocol is also presented. In this paper, we discuss different scenarios required for the implementation of the proposed hybrid model. These scenarios detail the message dialogs exchange between different network nodes and between different software modules during lightpath establishment, data transmission, and connection teardown operations. The goal of efficient resource utilization is achieved through centralized control of network resources while scalability is achieved through dividing the network into multiple domains. Finally, the simulation section shows the mechanism of designing the multidomain architecture, network bandwidth utilization comparison and reduction in end-to-end data transmission latency.      

Block Reservation Time Division Multiple Access (BRTDMA) Protocol for a High Capacity Wireless Network

Next generation high capacity wireless networks need to support various types of traffic, including voice, video and data, each of which have different Quality of Service (QoS) requirements for successful transmission. This paper presents an advanced reservation packet access protocol BRTDMA (Block Reservation Time Division Multiple Access) that can accommodate voice and data traffic with equal efficiency in a wireless network. The proposed BRTDMA protocol has been designed to operate in a dynamic fashion by allocating resources according to the QoS criteria of voice and data traffic. Most of the existing reservation protocols offers reservation to voice traffic while data packets are transmitted using contention mode. In this paper we propose a block reservation technique to reserve transmission slots for data traffic for a short duration, which minimizes the speech packet loss and reduce the end-to-end delay for wireless data traffic. The optimum block reservation length for data traffic has been studied in a cellular mobile radio environment using a simulation model. Simulation results show that the BRTDMA protocol offers higher traffic capacity than standard PRMA protocol for integrated voice and data traffic and offers flexibility in accommodating multimedia traffic.     

QoS specification languages for distributed multimedia applications: a survey and taxonomy

Following considerable research into quality-of-service-aware application programming interface design and QoS specification language development for multimedia systems, we present a survey and taxonomy of existing QoS specification languages. As computer and communication technology evolves, distributed multimedia applications are becoming ubiquitous, and quality of service (QoS) is becoming ever more integral to those applications. Because they consume so many resources (such as memory and bandwidth), multimedia applications need resource management at different layers of the communications protocol stack to ensure end-to-end service quality, and to regulate resource contention for equitable resource sharing. However, before an application can invoke any QoS-aware resource management mechanisms and policies - such as admission control, resource reservation, enforcement, and adaptation - it must specify its QoS requirements and the corresponding resource allocations. Furthermore, the application must describe how QoS should be scaled and adapted in cases of resource contention or resource scarcity during runtime. Our goal in this article is to systematically classify and compare the existing QoS specification languages that span several QoS layers with diverse properties. The provided taxonomy and the extensive analysis will give us a detailed look at the existing QoS specification languages along with their properties and relations.     

A flow rejection algorithm for QoS maintenance in a variable bandwidth wireless IP environment

A flow rejection algorithm for the dynamic resource reservation protocol (dRSVP) protocol is proposed. dRSVP is an enhanced version of RSVP, aiming at providing dynamic quality-of-service (QoS) support in a variable bandwidth environment (e.g., wireless) through guarantees of ranges of bandwidth instead of specific values. Flow rejection occurs when the channel quality decreases to a level that even the minimum bandwidth requirements per flow cannot be fulfilled. The proposed algorithm aims at improving the flow dropping probability of dRSVP, without affecting the bandwidth utilization. Its operation is based on setting priority classes and rejecting the minimum required number of flows per class, in order to guarantee QoS to the remaining. Both mathematical analysis and simulation results show that the overall flow dropping probability can be significantly reduced.