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.     

Reliable RSVP path reservation for multimedia communications under an IP micromobility scenario

We focus on how quality of service (QoS) guarantees can be provided for RSVP flows during handoff events in an IP micromobility network. For this purpose, RSVP message delays and signaling overheads should be minimized, and handoff service disruption should also be minimized. By rerouting the RSVP branch path at a crossover router at every handoff event, and establishing the new RSVP path between the CR and new BS in advance while the existing reservation path is maintained, ongoing RSVP flows can be kept with the guaranteed QoS. We propose the seamless switching of an RSVP branch path for soft handoff, and also show that this scheme could provide QoS guarantee with simulation and examples.     

移动IPv6环境中集成RSVP信令机制

本文针对在移动无线IP网络中运行RSVP信令协议存在的问题，提出了一种把RSVP信令集成于Ipv6数据包头扩展字段的方案，以减少切换过程中资源预留路径建立的时间，为移动节点提供了服务质量保障。并将此方案和原始RSVP方案在资源预留时间和信令负荷方面进行了性能比较。     

一种改进的支持无线IP网络的资源预留协议

移动IP技术能够支持基于IP的无线网络,资源预留协议(RSVP)用来保证多媒体传输的服务质量。然而把现有的RSVP应用于移动IP网络就会存在许多问题。提出了一种改进的RSVP支持方案(ERSVP)来实现无线IP网络的服务质量保证。ERSVP在分层网络中结合了MRSVP和RSVP隧道技术。根据性能分析,ERSVP方案能够获得比MRSVP较少的信令延迟、信令负载和资源耗费。     

一种改进的HMRSVP方案

介绍了RSVP与MRSVP,以及在Mobile IP中采用MRSVP实现QoS保障的机制。分析和比较了3种HMRSVP方案,特别是指针转发的HMRSVP方案,并提出一种改进的方案。在此方案中,若移动主机在同一个分层区域内移动,则利用它在移动时所具有的本地性,采用指针转发的HMRSVP方案;若移动主机进入新的分层区域,则要求它建立新的RSVP通路,开始新的指针转发过程。同时对本地化特性进行了讨论。对改进的方案在两种情况下分别进行了建模、分析、结果表明,改进的方案性能更加优越。     

Efficient resource reservation based on communication paradigms for multicast multimedia applications

In modern multimedia applications, heterogeneous hosts may get involved in a complicated multicast communication paradigm. For facilitating the analysis on resource reservation in such an environment, a useful model for describing the multicast communication paradigm, termed the CP graph, is presented in this paper. Based on this model, we develop a set of reservation modeling frameworks, respectively employing the RSVP reservation scheme and a proposed scheme. We prove the proposed scheme is able to achieve more efficient reservation than the RSVP scheme, while incurs very limited information and processing overheads. We simulate two applications: one with a distant learning scenario and the other B2B bargain scenario. The simulation results confirm the effectiveness of our scheme.     

基于非线性服务曲线的RSVP资源分配方式

本文主要针对基于RSVP的保证服务，讨论了如何利用非线性服务曲线进行资源分配，以实现带宽和时延要求的解耦。提出了一种简单有效的非线性服务曲线，数值分析结果表明就资源利用率而言，其性能远远优于传统的线性服务曲线。最后论文讨论了未来的发展趋势并给出了有待研究的一些课题。     

RSVP extensions for real-time services in wireless mobile networks

Currently, the RSVP model, which is efficient resource reservation in the fixed endpoints, becomes invalid under host mobility. We investigate the problems of standard RSVP in providing real-time services in wireless mobile networks. We also observe carefully how to interoperate IntServ services over DiffServ networks, and how to map IntServ QoS parameters into a wireless link. We then identify the advantages and drawbacks of the existing RSVP proposals to support QoS under both micromobility and macromobility. We finally propose a dynamic resource allocation scheme for reducing service disruption of real-time applications due to frequent mobility of a host     

RSVP Extensions for Real-Time Services in Hierarchical Mobile IPv6

The Mobile IPv6 (MIPv6) provides many great features, such as sufficient addressing space, mobility, and security; MIPv6 is one of the most important protocols for next generation mobile Internet. Simultaneously, with the rapid improvement of wireless technologies, the real-time multi-media IP services such as video on demand, videoconference, interactive games, IP telephony and video IP phone will be delivered in the near future. Thus, to furnish accurate QoS for real-time services is one of the most important thing in the next generation mobile Internet. Although RSVP, which is a resource reservation protocol, processes signaling messages to establish QoS paths between senders and receivers, RSVP was originally designed for stationary networks and not aware of the mobility of MNs. Therefore, this paper proposes a novel RSVP extension to support real-time services in Hierarchical Mobile IPv6 (HMIPv6) environments. For intra-site mobility, the concept of QoS Agent (QA) is proposed to handle the RSVP QoS update messages and provide the advanced reservation models for real-time services. For inter-site mobility, IP multicast can help to invite inter-site QAs to make pre-reservation and minimize the service disruption caused by re-routing the data path during handover. Simulation results show that the proposed scheme over HMIPv6 is more suitable for real-time services than the famous RSVP tunnel-based solution.     

用于QoS的两种服务模型的集成

分析了用于QoS的两个服务模型IntServ/RSVP和DiffServ,然后针对一个具体的网络结构详细介绍了AggregationofRSVP如何解决两个服务模型之间的交互问题,描述了其工作过程并给出了时序图。     

基于3GPP2框架的无线移动网络的RSVP扩展研究

本文讨论了面向固定网络设计的RSVP协议应用于无线移动网络需要解决的问题,并针对3GPP2框架下的无线移动网络提出了一种RSVP扩展方案.该方案采用隧道预留技术建立端-端主动预留,为数据连接提供服务质量保证;采用移动预测和被动预留技术在移动节点可能进入的蜂窝内提前预留无线资源,提高切换成功的概率;通过采用主动切换技术减小预留路径调整的时间,进一步提高通信的连续性.     

RSVP在数字视频网络传输中的应用研究

数字视频网络的广泛应用,要求实时性传输中IP能够提供足够的带宽、较高的优先级以及较低的包丢失率,为此,Internet工程任务组(IETF)开发了一套用于因特网的综合服务协议和标准,通过RSVP来管理网络资源分配以提供不同级别的服务,讨论怎样将该协议与典型的数字视频网络传输方案相结合,使现有支持QoS的网络可以达到更为稳定流畅的传输效果.     

An efficient primary-segmented backup scheme for dependable real-time communication in multihop networks

Several distributed real-time applications (e.g., medical imaging, air traffic control, video conferencing) demand hard guarantees on the message delivery latency and the recovery delay from component failures. As these demands cannot be met in traditional datagram services, special schemes have been proposed to provide timely recovery for real-time communications in multihop networks. These schemes reserve additional network resources (spare resources) a priori along a backup channel that is disjoint with the primary. Upon a failure in the primary channel, its backup is activated, making the real-time connection dependable. We propose a new backup method, called segmented backups, in which backup paths are provided for partial segments of the primary path rather than for its entire length, as is done in the existing schemes. We show that our method offers: 1) improved network resource utilization; 2) higher average call acceptance rate; 3) better quality-of-service guarantees on propagation delays and failure-recovery times; 4) increased flexibility to control the level of fault tolerance of each connection separately. We provide an algorithm for routing the segmented backups and prove its optimality with respect to spare resource reservation. We detail necessary extensions to resource reservation protocol (RSVP) to support our scheme and argue that they increase the implementation complexity of RSVP minimally. Our simulation studies on various network topologies demonstrate that spare resource aggregation methods, such as backup multiplexing, are more effective when applied to our scheme than to earlier schemes.     

Architecture and experimental results for quality of service in mobile networks using RSVP and CBQ

Efforts are underway to enhance the Internet with Quality of Service (QoS) capabilities for transporting real‐time data. The issue of wireless networks and mobile hosts being able to support applications that require QoS has become very significant. The ReSerVation Protocol (RSVP) provides a signaling mechanism for end‐to‐end QoS negotiation. RSVP has been designed to work with wired networks. To make RSVP suitable for wireless networks, changes need to be made by: (i) changing the way control messages are sent, and (ii) introducing wireless/mobile specific QoS parameters that take into account the major features of wireless networks, namely, high losses, low bandwidth, power constraints and mobility. In this paper, an architecture with a modified RSVP protocol that helps to provide QoS support for mobile hosts is presented. The modified RSVP protocol has been implemented in an experimental wireless and mobile testbed to study the feasibility and performance of our approach. Class Based Queueing (CBQ) which is used as the underlying bandwidth enforcing mechanism is also modified to fit our approach. The experimental results show that the modified RSVP and CBQ help in satisfying resource requests for mobile hosts, after handoff occurs. The experiments also show how different power and loss profile mechanisms can be used with our framework. The system performance using the modified RSVP control mechanism is also studied. This revised version was published online in July 2006 with corrections to the Cover Date.     

IP 网络QoS 机制研究

本文首先对资源预约协议RSVP的原理与性质进行了论述,然后简要讨论了对网络的QoS仿真的原理与配置模块,最后运用给出的模块,给出了应用RSVP技术传送IP语音的仿真结果。结果表明,如果业务对明延敏感,考虑使用RSVP是相当必要的。     

浅谈IP QoS机制

本文阐述了几种IP QoS解决机制.从最早的IntServ/RSVP机制到DiffServ机制,以及现今比较流行的MPLS机制.对其产生背景、主要思想、基本原理和优缺点等做了分析,对IP QoS技术的发展前景做了展望.     

Mobility protocols and RSVP performance in wireless IPv6 networks: shortcomings and solutions

Resource reservation protocol (RSVP) is a network‐control protocol used to guarantee Quality‐of‐Service (QoS) requirements for real‐time applications such as Voice‐over‐IP (VoIP) or Video‐over‐IP (VIP). However, RSVP was designed for end‐systems whose IP addresses do not change. Once mobility of an end‐system is allowed, the dynamically changing mobile IP address inevitably impacts on RSVP performance. Our study aims to first quantify the significance of this impact, and then propose a modified RSVP mechanism that provides improved performance during handoffs. Our simulations reveal that the deployment of standard RSVP over Mobile IPv6 (MIPv6) does not yield a satisfactory result, particularly in the case of VIP traffic. Fast Handovers for Mobile IPv6 (FMIPv6) was found to be providing the best performance in all tested scenarios, followed by Hierarchical Mobile IPv6 (HMIPv6) with a single exception: during low handoff rates with VoIP traffic, MIPv6 outperformed HMIPv6. We then designed a new RSVP mechanism, and tested it against standard RSVP. We found that the proposed approach provides a significant improvement of 54.1% in the Total Interruption in QoS (TI_QoS) when deployed over a MIPv6 wireless network. For HMIPv6, performance depended primarily on the number of hierarchical levels in the network, with no improvement in TI_QoS for single‐level hierarchy and up to 37% for a 5‐level hierarchy. FMIPv6 on the other hand, provided no room for improvement due to pre‐handoff signaling and the tunneling mechanism used to ensure a mobile node (MN)'s connectivity during a handoff, regardless of the RSVP mechanism used. Copyright © 2007 John Wiley & Sons, Ltd.     

Analyses of soft‐state signaling protocols in GMPLS‐Based WDM networks

Wavelength‐routed Generalized Multi‐Protocol Label Switching (GMPLS) networks use Resource reSerVation Protocol—Traffic Engineering (RSVP‐TE) as signaling protocol to set up and tear down lightpaths. RSVP‐TE uses a soft‐state control mechanism to manage lightpaths. In the soft‐state control mechanism, each node sets a timer for each control state and resets the timer with refresh messages to maintain the state. When the timer expires due to losses of refresh messages, the control state is initialized and a reserved resource managed with the state is released. It has been considered that resource utilization of soft‐state protocols is inferior to that of hard‐state protocols, since soft‐state protocols may reserve resources until control states are deleted due to timeout. Therefore, some extensions to promote the performance of soft‐state protocols, such as message retransmission, have been considered. In this paper, we analyze the behavior of GMPLS RSVP‐TE and its variants with a Markov model and analyze the performance of RSVP‐TE. From the results, we demonstrate that resource utilization of RSVP‐TE can be equivalent to that of a hard‐state protocol when the loss probability of signaling messages is low. We also investigate the effectiveness of message retransmission and show that using message retransmission leads to poor resource utilization in some cases. Copyright © 2012 John Wiley & Sons, Ltd.     

RSVP: a new resource ReSerVation Protocol

A resource reservation protocol (RSVP), a flexible and scalable receiver-oriented simplex protocol, is described. RSVP provides receiver-initiated reservations to accommodate heterogeneity among receivers as well as dynamic membership changes; separates the filters from the reservation, thus allowing channel changing behavior; supports a dynamic and robust multipoint-to-multipoint communication model by taking a soft-state approach in maintaining resource reservations; and decouples the reservation and routing functions. A simple network configuration with five hosts connected by seven point-to-point links and three switches is presented to illustrate how RSVP works. Related work and unresolved issues are discussed