协议互转化智能EPON光模块的研究

针对目前光纤到户、宽带普及以及家庭智能终端网络接入的需求,各式各样的家庭终端如何接入宽带网络是需要解决的关键问题,采用以太无源光网络EPON(Ethernet Passive Optical Network)智能芯片和C语言,设计和实现了一款ONU(Op-tical Network Unit,光网络单元)光模块实现家庭终端的智能接入。以电网通信协议Q/GDW376.1、DL/T645为例,采用QCA8829芯片,实现DL/T645和Q/GDW376.1互转换功能。通过该模块的应用,可以实现终端的高速信息采集和接入。     

Voice service interworking for PSTN and IP networks

This article presents an overview of the main technical problems to be addressed for the provision of interoperable services between IP telephony and the PSTN. The pivotal element of the solution resides in an interworking function. This function is typically implemented in a gateway whose requirements and behavior are here analyzed in terms of signaling and control protocols (control plane) as well as user data transfer (user plane). The presentation is structured around these two planes. The control plane defines the set of signaling protocols to be used in each networking context and the translation between them. Detailed scenarios illustrate the signal translation in the gateway allowing for the establishment of a hybrid phone call. The user plane is responsible for adapting the user data to the properties of each network channel and determines the quality of service of the voice call in terms of delay and speech quality     

A route stability-based multipath QoS routing protocol in cognitive radio ad hoc networks

Wireless Networks - Secondary user (SU) mobility, primary user activity, and spectrum sensing inaccuracy are the main challenges to the stability of a quality of service (QoS) route in cognitive...     

Narrowband ISDN and broadband ISDN service and network interworking

For a significant period of time, B-ISDN will coexist with the 64-kb/s-based (narrowband) ISDN. The specification of a concept and the mapping functions employed for interworking between the two networks, in particular for voice services, is a major factor for the success of B-ISDN     

软交换IP信令互通研究与实现

目前,如何实现下一代网络(NGN)软交换技术中4种关键的协议,即H.323、会话初始协议(SIP)、媒体网关控制协议(MGCP)和H.248的互通有着十分重要的意义.文章在对这些协议进行简要阐述的基础上,提出了软交换信令互通的解决方案,并根据呼叫状态的变迁给出了部分主要的信令映射关系,最后,通过具体实例说明了互通的实现方法.     

Generic signaling protocol: switching, networking, and interworking

The authors show how to design communication networks that are based upon the generic signaling protocol (GSP see ibid., vol.40, no.5, p.957-66, 1992), a simple but powerful connection management protocol. They define the output of a switching system that has multiple GSP interfaces, both its switching output and its event notification output. The behavior of an entity that provides transparent GSP networking is specified and the messages exchanged during an example interswitch call are listed. Also discussed is a scheme that allows a network to evolve its interswitch signaling gradually toward GSP, and to continue to support older network access protocols (e.g. DTMF and Q.931). The advantageous capabilities of GSP are enumerated by comparing GSP to the initial set of ISDN call setup protocols and X.25     

卫星通信IP业务中RIP动态路由协议的应用

在卫星通信IP业务中,传统的静态路由在网络结构或者链路流量发生变化时,无法自动地进行调整而需要人工干预。动态路由则可以适时交互路由信息,从而智能地调整路由路径,因此动态路由技术能够提供更佳的解决方案。     

一种采用资源预约的QoS分级协商方法

先定义了一个适于视频点播业务的分布式系统框架,利用它不但可实现QoS管理,而且可实现QoS分级协商,然后介绍其QoS管理器和QoS代理组成部件,并详细说明了支持QoS协商的这些部件之间的相互作用。     

Incremental service deployment using the hop-by-hop multicast routing protocol

IP multicast is facing a slow take-off although it has been a hotly debated topic for more than a decade. Many reasons are responsible for this status. Hence, the Internet is likely to be organized with both unicast and multicast enabled networks. Thus, it is of utmost importance to design protocols that allow the progressive deployment of the multicast service by supporting unicast clouds. This paper presents HBH (hop-by-hop multicast routing protocol). HBH adopts the source-specific channel abstraction to simplify address allocation and implements data distribution using recursive unicast trees, which allow the transparent support of unicast-only routers. An important original feature of HBH is its tree construction algorithm that takes into account the unicast routing asymmetries. Since most multicast routing protocols rely on the unicast infrastructure, the unicast asymmetries impact the structure of the multicast trees. We show through simulation that HBH outperforms other multicast routing protocols in terms of the delay experienced by the receivers and the bandwidth consumption of the multicast trees. Additionally, we show that HBH can be incrementally deployed and that with a small fraction of HBH-enabled routers in the network HBH outperforms application-layer multicast.     

Quality of service based protection in optical networks using diversity constraint

In this paper, we present a simple approach towards providing quality of service based partial protection in optical networks. We use a diversity based protection mechanism to ensure that in the event of link/node failures, a fraction of demand is always survived. To determine routing of optical paths while honoring restrictions such as wavelength continuity and exclusivity restriction, switching capability of OXCs, etc., we present a mixed-integer linear program formulation. Due to large size of the formulation, we develop an accompanied solution approach based on Lagrangian relaxation and sub-gradient optimization. We then present numerical results towards impact of diversity constraint upon the survivability, switch size, and number of carried wavelengths. Using them, we also show that optical networks based on sparse graphs might require higher number of wavelengths per fiber and the switching capacity of the OXCs to ensure higher values of fraction of accepted demands.     

竞争型脉冲耦合神经网络及用于多约束QoS路由求解

在脉冲耦合神经网络的基础上提出了竞争型脉冲耦合神经网络模型,分析了该模型用于求解网络最短路由时的脉冲波传播特性,并提出了脉冲波任务的产生、分解和状态转换理论,在模型中实现了脉冲波的多约束传播,成功地应用于网络多约束QoS路由问题的求解,并可得到全局最优解.仿真实验表明,与其他算法相比,该方法的计算迭代次数最少,且减少较多;而且迭代次数只与网络路由图中源点与目的点之间的最优QoS路由长度有关,而与节点数、链路数和网络的分布构成复杂性无关,体现出较好的计算性能和优势.     

User-perceived e-mail service QoS parameters and measurement

A group of quality of service(QoS)parameters of electronic mail(e-mail)traffic are proposed from users' perspective.These parameters cover three fields: delay,throughput and usability.Concept and algorithm of each parameter are presented and its effect on user perceptions is described.In order to evaluate the effectiveness of these parameters,an active measurement system is implemented.Measured results show that the group of QoS parameters we proposed can be used to get a comprehensive view of user-perceived e-mail service QoS.     

Label‐QoS switching protocol for quality of service assurance in dynamic swarm robot local network

This paper presents the modeling and analysis of a proposed label–quality of service (QoS) switching protocol for heterogeneous robot in a swarm. Establishing the data communication and network in multirobot task allocation is an important aspect in robot collaboration. Instead of passing the data through the cloud network, each robot can be configured as a node in its swarm for intercommunication. This research was conducted to model and propose aggregation and classification methods in a swarm robot network inspired from multiprotocol label switching, namely, label‐QoS switching protocol. Each packet of data is forwarded with a proposed 2‐side label values that are concerned with addressing and QoS. This proposed protocol was applied in each of the node's routing, and it was set up with forwarding information table. The simulation and analysis were conducted in 2 situations: (1) with a constant n–label switch mobile robot and a number of packet data increasing with time and (2) with a constant number of packet and varying n–label switch mobile robot by time. With reference to the network parameter performances, it shows that the anomaly treatment by the proposed protocol is able to prioritize the data forwarding between the robots at the edge of the swarm with class of service although the robot community at the center is increasing or getting crowded.     

Multiconstrained and multipath QoS aware routing protocol for MANETs

The multimedia applications such as audio, video transmission in Mobile Ad Hoc Network (MANET) requires that the path in which such data transmits must be delay sensitive, reliable and energy efficient. An existing MANET routing protocol Ad Hoc On demand Multipath Distance Vector (AOMDV) fails to perform well in terms of QoS metrics such as delay, jitter, packet delivery ratio (PDR) etc., where there is high mobility and heavy traffic. The paths which are stored in the Routing table are not reliable and energy efficient. It is possible to modify the route discovery of AODV so that more than one node disjoint, link reliable and energy efficient paths are stored in the routing table. The proposed protocol Multiconstrained and Multipath QoS Aware Routing Protocol (MMQARP) is novel, which takes care of QoS parameters dynamically and simultaneously along with path finding, so that only link reliable, energy efficient paths are available for data transmission. The extensive simulation study shows that the proposed protocol performs better in terms of PDR, delay and jitter compared to AOMDV protocol.     

A reservation-based multicast (RBM) routing protocol for mobile networks: initial route construction phase

We propose a combined multicast routing, resource reservation and admission control protocol, termed Reservation-Based Multicast (RBM), that borrows the Rendezvous Point or Core concept from multicast routing algorithms proposed for the Internet, but which is intended for operation in mobile networks and routes hierarchically-encoded data streams based on user-specified fidelity requirements, real-time delivery thresholds and prevailing network bandwidth constraints. The protocol exhibits the fully distributed operation and receiver-initiated orientation of these proposed algorithms; but, unlike them, the protocol is tightly coupled to a class of underlying, distributed, unicast routing protocols thereby facilitating operation in a dynamic topology. This paper focuses on the initial route construction phase, assumed to occur during a static snapshot of the dynamic topology, and is therefore applicable to fixed networks as well, e.g. the Internet.This work was sponsored by the U.S. Navy and the American Society for Engineering Education under the U.S. Navy's Summer Faculty Research Program.Each application must specify a mechanism for ensuring that a processor is always aware of its associated entities. For example, in the current Internet architecture, a group membership protocol [2] serves a similar function of keeping routers informed of the membership their directly attached subnetworks.A processor can be viewed as either an IP router or an ATM switch.     

Adaptive mobile access protocol (AMAP) for the message service of a land mobile satellite experiment (MSAT-X)

This paper describes a feasibility study of the adaptive mobile access protocol (AMAP) for MSAT-X, a proposed experimental mobile satellite communication network. The mobiles are dispersed over a wide geographical area and the channel data rate is limited due to the size and cost limitations of mobile antennas. AMAP is a reservation based multiple-access scheme. The available bandwidth is divided into subchannels, which are divided into reservation and message channels. The ALOHA multiple-access scheme is employed in the reservation channels, while the message channels are demand assigned. AMAP adaptively reallocates the reservation and message channels to optimize system performance. It has been shown that if messages are generated at a rate of one message per hour, AMAP can support approximately 2000 active users per 2400 bit/s channel with an average delay of 1.4 s.     

基于AODV且考虑延时能量节省的路由协议

重点研究基于节能要求兼低延时效应的AODV路由协议的改进。节能以延长无线传感器网络的工作时间,降低延时效应来保证数据传输的实时性,这是评价一个无线传感器网络的两个重要指标。在总结国内外研究成果的基础上,提出了更适用于低速运动的Ad Hoc网络的低延时节能的路由改进策略,包括在低于能量阈值时的动态功率调整、能量意识的路由选择、广播控制、被动路由更新和CMMBCR的引入。节能策略更是引入了位置信息和网络平均能量的概念,而且更适用于项目的实际情况（低速运动网络）。在用NS-2工具对该低延时节能策略进行仿真测试后,得出在最佳情况下网络传输延时和网路寿命两项指标都能得到大幅度的改进。     

QoS for wireless sensor networks: Enabling service differentiation at the MAC sub-layer using CoSenS

Providing service differentiation in wireless sensor networks while proposing simple and highly scalable solution is a challenging problem. We retain the use of CSMA/CA as access protocol because of its simplicity, versatility and good scalability properties. We developed CoSenS, a Collect then Send burst Scheme, on top of it to address its weaknesses while facilitating the implementation of scheduling policies. In this article, we propose a simple and scalable service differentiation solution; we implement fixed priority and earliest deadline first on top of CoSenS. The simulation analysis shows that our solution self-adapts to the traffic variation and greatly enhances end-to-end delay, reliability and deadline meet ratio for urgent traffic while not degrading best effort traffic compared to IEEE 802.15.4 original protocol and IEEE 802.15.4 implementing these scheduling policies. Additionally, CoSenS is implemented and tested on motes. The real experimentation results validated our simulation analysis.     

In‐service QoS monitoring of real‐time applications using SM MIB

Current network management needs an end‐to‐end overview of various flows rather than the information that is purely local to the individual devices. The typical manager‐centric polling approach, however, is not suitable to understand network‐wide behavior of a large‐scale Internet. In this paper, we propose a new management information base (MIB) approach called Service Monitoring MIB (SM MIB). The MIB provides a network manager with dynamic end‐to‐end management information by utilizing special packets. The special packet is an Internet control message protocol (ICMP) application that is sent to a remote network element to monitor Internet services. The SM MIB makes an end‐to‐end management feasible while it reduces management‐related traffic and manager‐to‐manager interactions. Real examples show that the proposed SM MIB is useful for end‐to‐end QoS monitoring. We discuss the accuracy of the obtained data as well as the monitoring overhead. Copyright © 2004 John Wiley & Sons, Ltd.     

A novel QoS routing protocol for LEO and MEO satellite networks

The rapid advance of communication and satellite technology pushes broadband satellite networks to carry on multimedia traffic. However, the function of onboard routing cannot be provided in existing satellite networks with inter‐satellite links, and quality of service (QoS) of satellite networks cannot be reliably guaranteed because of great difficulties in processing of long distance‐dependent traffic. In this paper, a two‐layered low‐Earth orbit and medium‐Earth orbit satellite network (LMSN) is presented. A novel hierarchical and distributed QoS routing protocol (HDRP) is investigated, and an adaptive bandwidth‐constrained minimum‐delay path algorithm is developed to calculate routing tables efficiently using the QoS metric information composed of delays and bandwidth. The performance of LMSN and HDRP is also evaluated through simulations and theoretical analysis. Copyright © 2007 John Wiley & Sons, Ltd.