手机报系统的设计与实现

本文简要介绍了手机报系统的结构和功能划分,提出了基于Java技术的手机报系统的实现方案,设计了承载多种通信协议的消息容器,业务功能灵活加载的机制,满足了手机报系统的高性能和灵活扩展的要求.     

Local and remote management integration for flexible service provisioning to the home

Giving the operator the ability to manage in- home devices greatly increases the potential of the cost-efficient provision of new profitable services. In this spirit, standardization undertaken by the DSL forum not only addresses remote management of the residential gateway but recently, also extends to in-house devices. We propose a solution that bridges remote management specified by CWMP with UPnP, already established inside the home environment. This approach will enable providers to remotely configure and manage in-house UPnP-enabled equipment, thus accelerating the deployment of new services. We investigate the nature of the two protocols and specify the bridging functionality, taking into consideration scalability and transparency. Experimental results support the applicability of the proposed approach, highlight the importance of message filtering, and provide general insight into the interplay intricacies of the particular protocol functions.     

A Domain-Based Routing Protocol for SSM Source Mobility in Mobile IPv6 Networks

In Mobile IP, the signaling traffic overhead will be too high since the new Care-of-Address (CoA) of the mobile node (MN) is registered all the way with the home agent (HA) whenever the MN has moved into a new foreign network. To complement Mobile IP in better handling local movement, several IP micro protocols have been proposed. These protocols introduce a hierarchical mobility management scheme, which divides the mobility into micro mobility and macro mobility according to whether the host's movement is intra-domain or inter-domain. Thus, the requirements on performance and flexibility are achieved, especially for frequently moving hosts. This paper introduces a routing protocol for multicast source mobility on the basis of the hierarchical mobile management scheme, which provides a unified global architecture for both uni- and multicast routing in mobile networks. The implementation of multicast services adopts an improved SSM (Source Specific Multicast) model, which combines the advantages of the existing protocols in scalability and mobility transparency. Simulation results show that the proposed protocol has better performance than the existing routing protocols for SSM source mobility.     

Internet网络环境中认证与密钥分配的研究

本文根据ＩＳＯ制定的ＯＳＩ安全结构，提出了一种解决ｉｎｔｒａｎｅｔ安全性问题的全面安全模式，并设计了一个适用于Ｉｎｔｅｒｎｅｔ环境的认证与密钥分配协议；新协议采用分层机制，在低层利用ｉｎｔｒａｎｅｔ本地网的已有认证与密钥分配协议，在高层则采用双钥密码体制来设计跨ｉｎｔｒａｎｅｔ的认证与密钥分配协议。新协议与已有密码协议有很好的兼容性，且不降低原协议的安全性，并为ｉｎ－ｔｒａｎｅｔ的各种远程访问提供安全保护，有利于网络的安全管理     

一种基于移动IPv6协议的软切换实现方案

移动IPv6协议解决了IPv6网络中移动节点的位置更新和路由可达问题,使移动节点能够在不同IPv6子网间进行切换而不中断当前连接。但是这种切换的时延较长,影响移动IPv6网络的性能。为了减少切换时延,文章在移动IPv6协议中引入软切换技术,提出一种采用绑定更新计时器和路由优先级变换机制的软切换工程实现方案,实验结果表明,该软切换方案可以有效提高移动IPv6网络的性能。     

基于ECC的TES网络链路层安全协议的研究

研究了TES网络物理配置和协议配置,分析了当前TES网络可能存在的安全隐患,结合民航TES网络安全的需求,提出了保障TES网络安全的措施;根据TES网络工作的特点,提出了一种基于椭圆曲线加密(ECC)的TES网络链路层安全协议.该协议给出了TES网络安全所需的软件认证、信息加密、密钥分配以及攻击检测等安全方案,并对该协议进行了安全性分析.TES网络链路层安全协议的实施将为TES网络提供鉴别非法用户、防止信息窃取和应对恶意攻击的保障能力.     

Content-based network resource allocation for real time remote laboratory applications

This paper presents a practical solution to make remote laboratories a realizable dream. A remote laboratory is an online laboratory where students can get first-hand experience of engineering labs via Internet. Video transmission can provide hands on experience to the user but the transmission channel or networks typically have variable and low bandwidth that poses a tough constraint for such implementation. This work presents a practical solution to such problems by adaptively transmitting the best available quality of laboratory videos to the user depending on network bandwidth. The concept behind our work is that not all objects or frames of the video have equal importance, and thus bandwidth reduction can be accomplished by intelligently transmitting important parts at relatively higher resolution. A localized Time adaptive mean of Gaussian (L-TAMOG) approach is used to search for moving objects which are then allocated network resources dynamically according to the varying network bandwidth variations. Adaptive motion compensated wavelet-based encoding is used to achieve scalability and high compression. The proposed system tracks the network bandwidth and delivers optimally the most important contents of video to the student. Experimental results over several remote laboratory sequences show the efficiency of the proposed framework.     

Wireless ATM LAN with and without infrastructure

We consider wireless ATM concepts for small LANs, especially for SOHO and future consumer applications. We describe a wireless ATM LAN framework architecture that supports wireless ATM communications in environments with and without fixed ATM infrastructure. For the configuration with an ATM infrastructure, a distributed ATM switched backbone is proposed, which enables a smart ATM switching element to be embedded in every wireless and fixed access point. For bandwidth efficiency and ease of operation (place-and-play), we also propose an ad hoc wireless ATM LAN concept based on the same 5 GHz wireless ATM air interface as is currently under standardization in the ETSI/BRAN and ATM Forum. Unlike CSMA-based ad hoc systems such as HIPERLAN and IEEE802.11, our ad hoc wireless ATM system makes QoS management feasible in an infrastructureless environment by using resource reservation and scheduled medium access protocol. Since cost scalability is essential throughout our system design, we consider forwarding between ad hoc subnets and interworking with the fixed network as important but optional features     

浅析CSCF集群的实现方法

呼叫会话控制功能（CSCF, Call Session Control Function）是IP多媒体子系统（IMS,IPMultimedia Subsystem）中最重要的呼叫控制网元,主要负责对IMS网络中的各种会话进行控制管理,所以对其可靠性、可伸缩性、运行高效性等有很高的要求,利用集群技术将一个个独立的CSCF服务器组成CSCF集群则可以满足这些要求。根据CSCF和集群技术的原理提出了两种CSCF集群的实现方法,并对CSCF集群中的负载均衡策略、会话初始协议（sIP,SesSion Initiation Protocol）流程和互备原理进行了介绍,可供在进行CSCF集群舌白期．划设计爿;口实施建设时泰者．     

The modified star-ring architecture for high-capacity subcarriermultiplexed passive optical networks

A modified star-ring architecture (MSRA) consisting of a star network on the upper level and many concatenated ring subnets on the lower level is proposed for subcarrier multiplexed passive optical network (SCM-PON). The upper level star network ensures high network capacity and its weakness in reliability is overcome by the concatenated ring subnets with self-healing capabilities. The self-healing function can be performed at remote nodes (RNs) by using optical switches (OS) to reconfigure the ring subnets if any link fails. Moreover, we design the cascade add/drop transceiver (CAT) structure in the lower level ring subnets to completely eliminate the optical beat interference (OBI) problem and achieve an OBI-free optical network. Finally, we set up an experimental network to demonstrate the feasibility of this cost-effective survivable structure     

Efficient Synchronization for Embedded On-Chip Multiprocessors

This paper investigates optimized synchronization techniques for shared memory on-chip multiprocessors (CMPs) based on network-on-chip (NoC) and targeted at future mobile systems. The proposed solution is based on the idea of locally performing synchronization operations requiring continuous polling of a shared variable, thus, featuring large contentions (e.g., spin locks and barriers). A hardware (HW) module, the synchronization-operation buffer (SB), has been introduced to queue and to manage the requests issued by the processors. By using this mechanism, we propose a spin lock implementation requiring a constant number of network transactions and memory accesses per lock acquisition. The SB also supports an efficient implementation of barriers. Experimental validation has been carried out by using GRAPES, a cycle-accurate performance/power simulation platform for multiprocessor systems-on-chip (MPSoCs). Two different architectures have been explored to prove that the proposed approach is effective independently from caches and coherence schemes adopted. For an eight-processor target architecture, we show that the SB-based solution achieves up to 50% performance improvement and 30% energy saving with respect to synchronization based on the caching of the synchronization variables and directory-based coherence protocol. Furthermore, we prove the scalability of the proposed approach when the number of processors increases     

网关设备H.248协议的实现

通过对H.248协议、软交换技术和数字程控交换机技术的分析,对H.248协议内容进行了详细描述,对网关的软件、硬件体系结构提出了具体的设计思路及方案,针对软件的可扩展性,提出了分层结构的设计思想,并对软硬件各种组成模块的功能进行了详细介绍。提出了H.248协议在网关设备的设计思路及实现方案,基于标准要求,对注册及呼叫流程提出了具体的实现方法,并针对网关在实际应用中的部署环境,提出了网关双归属实现方案,提高了设备的稳定性及可靠性。     

A wearable point-of-care system for home use that incorporates plug-and-play and wireless standards.

A point-of-care system for continuous health monitoring should be wearable, easy to use, and affordable to promote patient independence and facilitate acceptance of new home healthcare technology. Reconfigurability, interoperability, and scalability are important. Standardization supports these requirements, and encourages an open market where lower product prices result from vendor competition. This paper first discusses candidate standards for wireless communication, plug-and-play device interoperability, and medical information exchange in point-of-care systems. It then addresses the design and implementation of a wearable, plug-and-play system for home care which adopts the IEEE 1073 Medical Information Bus (MIB) standards, and uses Bluetooth as the wireless communication protocol. This standards-based system maximizes user mobility by incorporating a three-level architecture populated by base stations, wearable data loggers, and wearable sensors. Design issues include the implementation of the MIB standards on microcontroller-driven embedded devices, low power consumption, wireless data exchange, and data storage and transmission in a reconfigurable body-area network.     

适用于Intranet的分层鉴别与密钥分配协议

根据ISO制定的网络安全结构,结合Internet的具体特点,提出了一种解决Internet安全性的安全模式,并设计了一个适用于Internet环境的鉴别与密钥分配协议。新协议采用分层机制,在低层利用Intranet的已有鉴别与密钥分配协议,在高层则采用双钥密码体制设计了一个跨Intranet的鉴别与密钥分配协议。该协议不必更换客户机原有的应用软件,只需增加一个网际鉴别服务器,在原鉴别服务器的数据库中增添网际鉴别服务器的密钥即可实现跨Intranet保密通信。新协议与已有协议有很好的兼容性,安全性高,有利于网络的安全管理,并可以在各种远程访问中建立Intranet间的端—端保密通信。     

A DWDM/SCM self-healing architecture for broad-band subscriber networks

A high-capacity dense wavelength-division multiplexing/subcarrier multiplexing (DWDM/SCM) network based on a self-healing star-bus-ring architecture (SBRA) is proposed and demonstrated. This architecture has a star subnet on the upper level to be a high-capacity infrastructure for the network, several bus subnets on the middle level to offer broad-band channels for multiwavelength signals, and many ring subnets on the lower level to serve a number of nodes. We design remote nodes and bidirectional wavelength add-drop multiplexers (WADMs) by using simple optical switches to reconfigure the network under link failure. We further employ M-quadrature amplitude modulation (M-QAM) and frequency shift-keyed (FSK) signals for downstream and upstream channels, respectively. The SBRA ensures an optical-beat-interference-free (OBI-free) and high-reliability optical network. Finally, we set up an experimental network to demonstrate the feasibility of the proposed architecture.     

一种安全网络管理协议的设计与实现

文章以SNMP简单网络管理协议为参照对象,针对SNMP协议现有的一些安全隐患及管理效率的不足,从安全性增强和新型管理库(TLV)设计的角度介绍了一种增强型安全网络管理协议的设计思路及实现方案,并且通过介绍该协议在工程中的应用情况,体现了使用该协议可增加网络传输安全性、可扩展性强和可提高管理效率等优势。     

Broadband multicarrier communication receiver based on analog to digital conversion in the frequency domain

This paper introduces a multicarrier communication receiver for broadband applications based on analog to digital conversion (ADC) of the received signal in the frequency domain. The samples of the spectrum of the received signal are used in the digital receiver to estimate the transmitted symbols through a matched filter operation in the discrete frequency domain. The proposed receiver is aimed at the reception of high information rates in a multicarrier signal with very large bandwidth. Thus, the receiver architecture provides a solution to some of the challenging problems found in the implementation of conventional wideband multicarrier receivers based on time-domain ADC, since It efficiently parallelizes the A/D conversion reducing the sampling speed requirements. We show that the sampling rate requirements are relaxed as the number of frequency samples is increased, which introduces a trade-off between complexity and sampling rate. The new receiver possesses additional advantages, including scalability with increasing frequency samples, the possibility of optimally allocating the available number of bits for the ATD conversion across the frequency domain samples which potentially reduces the distortion introduced by the high-speed ADC, narrowband interference suppression that can be directly carried out in the frequency domain, and inherent robustness to frequency offset which makes it an attractive solution when compared with traditional multicarrier receivers. We also investigate how the proposed receiver responds to common multicarrier communication receiver problems such as phase noise and channel frequency selectivity.     

基于MSTP/CWDM的远程容灾解决方案

文章分析了远程异地容灾的特点以及面临的问题,讨论了容灾中光纤通道储存区域网(FC SAN)技术以及服务器集群的使用,并且详细分析了如何利用多业务传送平台(MSTP)和粗波分复用(CWDM)技术来解决异地FC SAN存储子网之间的传输问题,最后提出了一套完整的、应用级别的远程容灾解决方案.     

A Cooperative QoS Management Scheme Based on DiffServ Network for Real-Time Service

In this paper,an improved scheme based on DiffServ network is proposed to provide a decentralized coopera-tive QoS management for real-time services'admission control and resources'monitoring.The proposed scheme consists of aQoS Control Server(QoSCS),a Service Management Server(SMS),a Network Management Server(NMS)and routersin the concerned management domain.When an application asks for a service with specific QoS requirements,a series ofcooperation are initiated among these components by means of a suit of signaling protocol.Once a service is admitted,itcan provide required QoS services more effectively than original DiffServ network.Monitoring per-flow states are movedfrom edge routers to the QoSCS server.The prototype implementation and experimental results show that this scheme canprovide enhanced manageability and scalability for providing per-flow management in such a distributed way.     

Real-time implementation of a reconfigurable IMT-2000 base stationchannel modem

Research suggests that joint methods combining smart antennas, RAKE reception, multi-user detection or other adaptive methods may be practically implemented for IMT-2000 channel modems using computationally simplified algorithms. Using software-defined radio methods, these modems can be employed in a new generation of adaptive multimode base stations which permit software reconfiguration from second- to third-generation air interfaces. Practical implementation is made possible by corresponding advances in hardware technology, including new processors and high-bandwidth I/O fabrics which replace traditional computer buses with their inherent limitations in bandwidth and scalability. In this article adaptive processing research is reviewed, implementation requirements for second- and third-generation base stations are considered, and the capabilities of selected new monolithic silicon devices are examined. A possible implementation approach for a reconfigurable multimode base station channel modem using software defined radio (SDR) design methods is proposed