Internet资源预留协议——RSVP

ＲＳＶＰ协议研究的主要目的是将综合业务引入Ｉｎｔｅｒｎｅｔ网络,因而受到国内外普遍关注。本文首先介绍ＲＳＶＰ协议的基本概念,其次叙述了ＲＳＶＰ协议的工作原理和协议框架,最后简要描述了ＲＳＶＰ协议设计原则和技术特点。     

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。     

面向QoS的UWB分布式MAC协议设计

提出了一种在分布式UWB网络结构中提供QoS服务的MAC协议.该MAC协议能够自适应地协调功耗与速率,设计过程分为资源分配和多路接入两方面.仿真结果表明,通过与功率控制机制及速率控制机制的比较.提出的协议在功率消耗,网络吞吐量及延时方面都有较好的改善.     

SPANRACS中Rq接口实现资源预留的研究

下一代网络TISPAN主要研究固网与移动网络融合,它提出的资源接纳控制子系统实现了接入控制、资源预留等功能。Rq接口是RACS中连接SPDF,A—RAC两个功能实体重要的接口。本文对RACS的整体架构、实体功能进行了描述;对Rq接口的功能、信息模型、具体的消息进行了研究;以IPTV具体业务为例,描述了Rq接口实现资源预留过程的具体消息流程。     

基于FMIPv6的资源预留协议扩展研究

提出一种在无线移动环境下保障用户通信服务质量的资源预留扩展方案。该方案有效地利用了FMIPv6（Fast Handovers for Mobile IPv6）的工作过程,通过扩展FBU（Fast Binding Update）和HI（Handoff Initiate）消息,使其能够携带QoS（Quality of Service）对象,从而将移动管理和资源预留两个过程合并为一个过程。该方案引入了提前预留与公共路径利用等一系列新机制。分析结果表明,在无线移动环境下该方案能够有效地降低预留重建延迟,提高了链路资源的使用效率。     

因特网上RSVP（资源预留协议）简介

1 简介 因特网上的多媒体应用日益增多,为了在网上获得实时业务服务质量(QoS)的保证,因特网运用了一些控制协议,它们和其它协议如路由协议、传输层以及较低层协议一起完成所要求的QoS性能。这些控制协议有实时传输协议/实时传输控制协议(RTP/RTCP)、RSVP等。本文对RSVP作一简述。 RSVP是资源预留建立协议的简称,它是为实施综合业务因特网设计的。当一主机在网络上应用数据流的服务质量有特殊要求时。可     

Internet综合业务模型和资源预留协议RSVP

简要介绍了Ｉｎｔｅｒｎｅｔ综合业务模型的基本组成和实现机制，并对Ｉｎｔｅｒｎｅｔ综合业务模型中提出的资源预留协议ＲＳＶＰ进行了简要和分析。     

光突发交换中的单向资源预留协议

介绍了光突发交换网中的单向资源预留协议,对各种协议的特点进行了比较,并以JIT协议为例,详细说明了单向资源预留和资源释放的实现方式。     

光突发交换网络中的资源预留协议概述

本文介绍了光突发交换的网络原理、网络结构和模块功能,结合国内外的研究成果,总结和讨论了光突发交换的资源预约机制,分析了它们的网络性能。     

结合资源预留的分布式QoS组播路由算法

针对网络资源信息的动态变化对QoS组播路由算法的巨大影响,该文提出了一种与资源预留结合的分布式组播路由算法DQMTR。DQMTR通过在路径探索过程中进行资源预留克服网络信息变化对QoS路由算法的影响。DQMTR还通过记录预约资源的数量解决资源的过预约问题,并利用DiffServ体系下QoS路由算法的特点使算法能够适用于DiffServ网络。仿真实验表明,DQMTR提高了组成员加入的成功率,优化了平均路径代价值。     

A Distributed End-to-End Reservation Protocol for IEEE 802.11-Based Wireless Mesh Networks

This paper presents an end-to-end reservation protocol for quality-of-service (QoS) support in the medium access control layer of wireless multihop mesh networks. It reserves periodically repeating time slots for QoS-demanding applications, while retaining the distributed coordination function (DCF) for best effort applications. The key features of the new protocol, called "distributed end-to-end allocation of time slots for real-time traffic (DARE), are distributed setup, interference protection, and scheduling of real-time data packets, as well as the repair of broken reservations and the release of unused reservations. A simulation-based performance study compares the delay and throughput of DARE with those of DCF and the priority-based enhanced distributed channel access (EDCA) used in IEEE 802.11e. In contrast to DCF and EDCA, DARE has a low, nonvarying delay and a constant throughput for each reserved flow     

UWB无线视频传输系统的设计实现

UWB无线视频传输系统具有传输速率高、频谱利用率高等特点,能够很好地满足家庭等对带宽有较高需求的局域无线应用场合,因而倍受业界关注。提出一种UWB无线视频传输系统的设计实现方案,经过测试验证,该设计方案可行。通过该方案能够加速UWB技术的转换实现,特别适用于点对点高速传输的应用场合,可以为超宽带无线通信技术的标准化和产业化提供有力支撑。     

超宽带无线收发机中的正交LC VCO设计

基于SMIC 0.18 μm CMOS工艺设计了一种可应用于MB-OFDM UWB无线收发机的宽带正交压控振荡器(QV-CO,Quadrature VCO).在研究VCO的相位噪声理论的基础上,采用了优化噪声的电路结构.此外,鉴于片上螺旋电感在VCO设计中的重要性,采用了一种快速选取工艺库螺旋电感的方法.仿真结果显示,QVCO的频率调谐范围为3.4～4.5 GHz,在1 MHz频率偏移处,相位噪声小于-119.6 dBc/Hz.在1.8 V电源电压下,电路总功耗为27 mw.     

无线传感器网络UDHR协议的设计与实现

针对无线传感器网络(WSN)数据流的特点,提出一种WSN上下行路由异构的协议(UDHR),上下行路由可采用不同的算法,适合于时间驱动、事件驱动以及查询的数据收集模式.利用OMNeT++平台对UDHR协议进行建模仿真,结果表明该协议开销小、扩展性好、健壮稳定.并且在自主开发的Testbed平台上实现了该路由协议,利用该平台可实时观察整个WSN网络拓扑变化、网络开销、监测每个节点能量消耗以及数据收集等情况.     

Performance Analysis of UWB Channels for Wireless Personal Area Networks

Ultra-wide band (UWB) communication is one of the most promising technology for high data rate networks over short-range communication. The ultra-wide bandwidth offers pulses with very short duration that provides frequency diversity and multipath resolution. Ultra-wide band (UWB) channels raise new effects in the receiver, the amplitude fading statistics being different compared to the conventional narrow band wireless channels. This review paper focuses on modeling of ultra-wide band channels, especially for simulation of personal area networks and also discusses the benefits, application potential and technical challenges in wideband communication. The concept of Orthogonal Frequency Division Multiplexing (OFDM) has recently been applied in wireless communication systems due to its high data rate transmission capability with high bandwidth efficiency and its robustness to multi-path delay. UWB OFDM communication was proposed for physical layer in the IEEE 802.15.3a standard which covers wideband communication in wireless personal area networks. Since the channel model for multicarrier UWB communication is different from that of plain ultra-wide band channel, a novel modification method in UWB channel model is proposed with specific center frequency and multipath resolution. Moreover, dynamic channel estimation is necessary before demodulation of UWB OFDM signals since the radio channel is time varying and frequency selective for wideband systems. The performance of the proposed method is statistically analyzed using LS and MMSE based channel estimation methods.     

A Centralized MAC Protocol for QoS Support in UWB-Based Wireless Networks

In this paper we introduce a novel MAC protocol that provides Quality of Service (QoS) support for multimedia traffic in UWB-based wireless local area networks. The proposed protocol allocates transmission opportunities to QoS and best effort traffic using a set of scheduling and resource control algorithms. The algorithms account for the UWB characteristics such as the co-existence of multiple simultaneous transmissions as well as the possibility of dynamically assigning the nodes' transmission rate and power. The simulation results show that the proposed protocol can provide QoS support while optimizing resource utilization. Yuechun Chu received her B.Sc. degree in electrical engineering from Shanghai University, China, in 1996 and M.Sc. degree in electrical engineering from University of Science and Technology of China in 1999. She is currently pursuing the Ph.D. degree in the department of electrical and computer engineering at the University of Massachusetts Amherst. Her research interests include MAC protocol design for UWB-based networks, wireless multimedia applications, and architectures and protocols for wireless networks with QoS guarantees. Aura Ganz is currently an Associate Professor and Director of the Multimedia Networks Laboratory at the ECE Department, University of Massachusetts at Amherst. She has experience in topics related to multimedia wireless networks, optical networks and ubiquitous computing. The research results are validated by a combination of analytical, simulation and prototyping tools. She has published a book “Multimedia Wireless Networks: Technologies, Standards and QoS” (Prentice Hall) and authored over one hundred and fifty peer reviewed publications. Dr. Ganz received her BSc, MSc and Ph.D degrees in Computer Science from the Technion in Israel.     

A Distributed Query Protocol in Wireless Sensor Networks

In wireless sensor networks, query execution over a specific geographical region is an essential function for collecting sensed data. However, sensor nodes deployed in sensor networks have limited battery power. Hence, the minimum number of connected sensor nodes that covers the queried region in a sensor network must be determined. This paper proposes an efficient distributed protocol to find a subset of connected sensor nodes to cover the queried region. Each node determines whether to be a sensing node to sense the queried region according to its priority. The proposed protocol can efficiently construct a subset of connected sensing nodes and respond the query request to the sink node. In addition, the proposed protocol is extended to solve the k-coverage request. Simulation results show that our protocol is more efficient and has a lower communication overhead than the existing protocol.     

超宽带无线通信系统的调制方式研究

超宽带技术是目前无线通信中非常有发展前途的技术.本文介绍了超宽带通信的基本原理,着重分析了目前使用的几种调制方法,简要说明了各种调制方法的频谱特性,并比较了这些调制方法的性能.     

Multi-factor and Distributed Clustering Routing Protocol in Wireless Sensor Networks

One of important issues in wireless sensor networks is how to effectively use the limited node energy to prolong the lifetime of the networks. Clustering is a promising approach in wireless sensor networks, which can increase the network lifetime and scalability. However, in existing clustering algorithms, too heavy burden of cluster heads may lead to rapid death of the sensor nodes. The location of function nodes and the number of the neighbor nodes are also not carefully considered during clustering. In this paper, a multi-factor and distributed clustering routing protocol MFDCRP based on communication nodes is proposed by combining cluster-based routing protocol and multi-hop transmission. Communication nodes are introduced to relay the multi-hop transmission and elect cluster heads in order to ease the overload of cluster heads. The protocol optimizes the election of cluster nodes by combining various factors such as the residual energy of nodes, the distance between cluster heads and the base station, and the number of the neighbor nodes. The local optimal path construction algorithm for multi-hop transmission is also improved. Simulation results show that MFDCRP can effectively save the energy of sensor nodes, balance the network energy distribution, and greatly prolong the network lifetime, compared with the existing protocols.