A novel IP to 3G multimedia gateway and its applications

In this paper, we use simple 3G modem cards to design and deploy a novel gateway bridging IP network and Wideband Code Division Multiple Access (WCDMA) 3G mobile network in Hong Kong. A simplified Session Initial Protocol (SIP) is devised to implement the gateway together with the 3G-324M protocol. Compared with the existent similar gateways, our gateway is much more implementable and less cost. Using the proposed gateway, we devise and develop a Video Instant Message System (VIMS) which achieves direct audio and video communications from terminals of the Internet like desktop to 3G mobile phones. Moreover, we produce and accomplish a Mobile Robotic Car Remote Control System (MRCRCS) based on the gateway and VIMS. In the MRCRCS, individuals can distantly control the moving direction of a robotic car by using a VIMS client or a 3G cell phone. By a series of practical experiments, we testify the efficiency and robustness of the gateway and its application scheme.     

The residential gateway

Burgeoning competition in telecommunications is multiplying the number of communications paths into the home-but a standard multinetwork connection could sort them out. Services going into the residence may enter over copper wires, hybrid fiber coax, RF transmission, fiber to the curb, or, most importantly, by any combination of these sources and structures. To have a successful market, residential customers must be able to move smoothly from one combination of these offerings to another so that the customers consider the move worthwhile. For this multinetwork-to-multiservice interconnection to have value, it must be simple, and that simplicity is the basis for the residential gateway concept. In other words, the substantial complexity of the interconnection must be hidden from the consumer. The concept is essentially the development of a set of interface standards between the broadband residential access networks and the communication services (the internal networks) required for the consumer's home     

铁安联盟网络安全解决方案专题连载--赤霄过滤网关

信息内容安全面临的威胁 随着计算机网络的快速发展,信息内容安全面临着比过去更多的威胁,可以归纳为:信息破坏、信息传输威胁、信息泄露、信息干扰等。 导致信息内容安全威胁的因素有很多,病毒破坏、蠕虫攻击、木马控制、信息非法扩散、垃圾邮件侵害以及其它具有黑客性质的入侵行为,都可能造成信息内容的不安全。信息内容面对的威胁往往不是单纯的或孤立的     

The multimedia drive

Because of its density, optical storage is a natural not only for multimedia, but for backing up networks and distributing tons of software. The author describes how optical and CD-ROM storage systems complement magnetic-tape backup systems and bring new system capabilities     

支持多链路备份的VPN网关

随着电子政务的快速发展,一些政府的重要系统要保证提供不间断的信息服务。然而,单一的网络链路可能会受到各种各样的攻击(包括物理上的直接攻击),导致信息传播的中断。根据用户的需求,上海安达通信息安全技术有限公司设计了支持链路备份的SJW74系列的安全网关系统,为支持连续不间断的网络服务提供了有力武器。通常,链路备份是指除了一条工作链路之外,允许设立多条备份链路,当工作链路出现异常时能够自动切换到备份链路,从而保证系统继续正常处理。我们将支持拥有多条链路的系统称为“多链路系统”;将这种能够检测链路异常并切换到可用链…     

The CSI multimedia architecture

An instruction set extension designed to accelerate multimedia applications is presented and evaluated. In the proposed complex streamed instruction (CSI) set, a single instruction can process vector data streams of arbitrary length and stride and combines complex memory accesses (with implicit prefetching), program control for vector sectioning, and complex computations on multiple data in a single operation. In this way, CSI eliminates overhead instructions (such as instructions for data sectioning, alignment, reorganization, and packing/unpacking) often needed in applications utilizing MMX-like extensions and accelerates key multimedia kernels. Simulation results demonstrate that a superscalar processor extended with CSI outperforms the same processor enhanced with Sun's VIS extension by a factor of up to 7.77 on key multimedia kernels and by up to 35% on full applications.     

安全隔离网闸在公安系统中的应用

随着计算机技术和网络技术应用的日益普及,各地政府部门都将如何构建一个安全、高效的网络系统作为政府信息化发展的目标之一。作为政府行政机构,上世纪90年代公安系统就已经开始了网络系统工程的建设。目前,在全国的公安系统中已经通过租用运营商的网络服务,陆续建立起跨地市、跨省及全国性的广域网,用来承载公安系统运作的各种数据信息。但是,随着     

易尚网关防火墙

由北京网新易尚科技有限公司研制、开发的易尚网关防火墙,是在网络边界提供完整网络安全保护的硬件产品。它采用新一代ASIC硬件设计体系,通过内容处理芯片和内容处理加速单元,与其它专用硬件一起,利用易尚专有操作系统ESOS的实时分析和协调处理能力,通过优化内容搜索、模式识别和数据分析,达到访问控制、病毒扫描、VPN、内容过滤和基于网络入侵检测处理的高性能,创造了业界性能新纪录。1.强大的ASIC技术。易尚网关防火墙的安全机制采用ASIC技术,克服了传统安全类产品在提高性能上的障碍,突破了传统芯片设计、网络通信、安全防御等诸…     

平滑扩展的VPN网关设备

传统的安全网关放在内网与外网之间,很容易成为网络的瓶颈,甚至会因VPN的故障造成网络中断。例如,如果有一些突发的数据到达时,由于网络设备和服务器受到处理能力、内存CPU的容量、服务器性能等客观条件的限制,一些请求可能无法及时处理,从而造成请求丢弃、应答滞后等问题。不仅如此,由于不少业务是基于TCP协议,造成报文的超时重发,增加了网络设备和服务器的负担,进入恶性循环,降低整个网络的效率甚至导致系统的崩溃。     

The challenge of multimedia standardization

Standards for communication systems once were produced by specific industries in a vertically integrated fashion. Multimedia, which merges different forms of communication, requires a new approach-horizontal or layered-to develop standards. This implies a radical change in the way standards are produced. Increasing the bandwidth to end users also forces a change in the role of public authorities in regulating the use of technology to provide services     

网络安全的门户:3Com公司防火墙

由美国3Com公司生产、北京中青联迪科技发展有限公司中国区独家代理的防火墙采用实时操作系统,并经过修剪,专门用于网络安全功能,彻底避免了传统软件防火墙由于依赖UNIX和Windows NT操作系统而带来的潜在漏洞。同时,采用高性能安全防火墙引擎,提供状态包检测保护,属于专用硬件防火墙,能够为大中小企业提供高性能价格比的解决方案。     

QoS-enabled residential gateway architecture

As networking technologies penetrate wide varieties of devices for daily usage, home networks are becoming a reality. The bandwidth and always-on connectivity provided by the rapidly growing broadband technologies, such as cable and digital subscriber line (DSL), render home networking even more attractive. A residential gateway is a device that interconnects various home devices to one another as well as to the Internet. The home networks being deployed today are simple and inexpensive with the residential gateway providing only connectivity. As home networks evolve and become more widespread, emerging applications on home networks will demand additional features that require quality of service. We present an architecture of a next-generation QoS-enabled residential gateway. Such a residential gateway, in conjunction with the developments in QoS-enabled wireless LAN technologies, will usher in a new generation of home networks that are capable of supporting a wide range of applications.     

防御DDoS的VPN网关

Syn flood攻击是DoS攻击中典型的一种,它利用了TCP/IP协议的弱点,具有破坏力大、隐蔽性强、攻击简单的特点,是现有网络服务的一个严重的威胁.其攻击方式根据源IP地址的不同可以有以下几种:     

浅析多媒体美术教学优势

教育信息化技术的要求,促使多媒体技术被广泛应用于教学活动之中。在教学中运用多媒体,也是课程改革的要求。美术,作为一门传统的教育学科,采用新媒体技术,对美术教学具有很大的促进作用。本文分析了多媒体在美术教学中的优势,为多媒体技术在教学中的普及,提供了有力的参考作用。     

MOSIS-a gateway to silicon

The MOSIS Service, a low-cost prototyping service for standard-cell and full-custom VLSI circuit development, is discussed. MOSIS (an acronym for MOS Implementation System) has developed a methodology that allows the merging of many different projects from various organizations onto one wafer. This cost-sharing gives designers opportunities that might be prohibitive at regular commercial prices. Since designs are combined on a single mask set. MOSIS users pay for only the fraction of the silicon that they use. Runs are scheduled on a regular basis for 3.0-, 2.0-, 1.6-, and 1.2-μm double-metal CMOS/bulk technologies. MOSIS quality control and access to MOSIS are described     

The H.324 multimedia communication standard

ITU-T H.324 is the new international standard for multimedia communication on low-bit-rate circuit-switched networks, including ordinary analog telephone lines. It supplies any combination of real-time video, audio, and data. H.324 was designed, above all, to provide the best possible performance (video and audio quality, delay, etc.) on low-bit-rate networks. This article covers the H.324 system and its component standards, including the V.34 modem, H.223 multiplexer, H.245 control protocol, G.723.1 audio coder, and H.263 video coder. Call setup procedures and optional features like encryption and data application protocols are also described. The standard should ensure interoperability among a diverse variety of H.324 terminals, including PC-based multimedia videoconferencing systems, voice/data modems, encrypted telephones, World Wide Web browsers with live video. Remote security cameras. and standalone videophones. Products compliant with H.324 should all interoperate with each other and, through appropriate gateways, with ITU-T H-series terminals on ISDN, LANs, and ATM/B-ISDN networks     

Convergence of residential gateway technology

A new OSI-based model is described that can be used for the classification of residential gateways. It is applied to analyze current gateway solutions and draw evolutionary paths for the medium to long term. From this it is concluded that particularly set-top boxes and broadband modems, as opposed to game consoles and PCs, have a strong potential to evolve toward gateways that deliver network services to the home on all OSI layers, although they probably will not converge. In our model, we have not found any compelling reasons for the residential gateway industry to support concurrent multiple broadband access network connections on a single residential gateway in the near future.     

The multimedia set-top-box based on PC platform

A comprehensive research on key issues of the multimedia set-top-box used in active TV is conducted. Meanwhile a practical architecture for the multimedia set-top-box based on PC platform is designed. The architecture, with its advanced feature set, high integration and PCI interface is well suited to bring the set-top-box experience to consumers at an affordable price, and makes it very attractive for the consumer.     

计算机多媒体教学投影仪的高级维护

随着我国现代化教育的不断发展,高等院校的计算机多媒体教学得到了广泛的应用,作为多媒体教学中的重要设备之一的投影仪,其工作状态将直接影响到计算机多媒体教学的效果,故而做好投影仪的维护与保养工作尤为重要,然而大多数多媒体设备的管理者对多媒体投影仪定时进行维护保养的重要性认识不够,由此引发了许多计算机多媒体教学中的投影仪故障,多媒体投影仪在使用一段时间后必须要进行清尘保养,这样可有效提高投影仪的清晰度,降低投影仪故障率,延长投影仪的使用寿命,因而技术维护人员应掌握投影仪的维护与保养方法,以便更好地服务于学校的计算机多媒体教学。