共查询到18条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
根据HFC网络的结构特点,分析了Cable Modem系统存在的安全性问题,在分析DOCSIS的安全规范BPI和BPI+的基础上,提出了一种保护网络通信安全的策略及其在HFC网络中的实现方案,并对其安全性能进行了分析和评价。 相似文献
5.
HFC宽带接入网络技术得以成熟应用,第二代有线电视网络传输数据的技术规范DOCSIS2.0已正式获得批准成为国际标准。将DOCSIS2.0与DOCSIS1.0/1.1技术标准进行对比分析,着重分析DOCSIS2.0的性能特点,并对两标准实际应用的效果进行对比介绍。 相似文献
6.
7.
利用Cable Modem方案建造CATV宽带综合信息网络的技术早已为大家所熟悉,其原理如图1所示.这一技术走过了DOCSIS1.0、DOCSIS1.1、DOCSIS2.0等几个技术标准的发展阶段,尤其是DOCSIS2.0标准不但兼容DOCSIS1.0与DOCSIS1.1,而且增加了S-CDMA的内容,正因为如此,各商家采用的技术标准不同,生产的设备也不一样,因而导致市场上CMTS的种类很多,而究其实,CMTS从总体上分就只有TDMA和S-CDMA两大类,为方便CATV网络建设合理选择CMTS,现将TDMA和S-CDMA两个系统进行比较如下. 相似文献
8.
HFC网络一直被认为是广电在宽带网上挑战电信的有力武器.但从技术实践来看,HFC表现出来的并不完全是宽带的特性.所谓的HFC宽带更多意义上是从电缆的频带特性本身去考虑,而未从网络的整体和业务的实现去考虑.从HFC网络的拓扑结构、网络环境、业务传递、网络分配等方面分析了限制HFC网络在发展宽带业务时存在的技术问题,并给出了发挥HFC网络优势的建议. 相似文献
9.
HFC网络一直被认为是广电在宽带网上挑战电信的有力武器。但从技术实践来看 ,HFC表现出来的并不完全是宽带的特性。所谓的HFC宽带更多意义上是从电缆的频带特性本身去考虑 ,而未从网络的整体和业务的实现去考虑。从HFC网络的拓扑结构、网络环境、业务传递、网络分配等方面分析了限制HFC网络在发展宽带业务时存在的技术问题 ,并给出了发挥HFC网络优势的建议。 相似文献
10.
HFC网络一直被认为是广电在宽带网上挑战电信的有力武器.但从技术实践来看,HFC表现出来的并不完全是宽带的特性.所谓的HFC宽带更多意义上是从电缆的频带特性本身去考虑,而未从网络的整体和业务的实现去考虑.从HFC网络的拓扑结构、网络环境、业务传递、网络分配等方面分析了限制HFC网络在发展宽带业务时存在的技术问题,并给出了发挥HFC网络优势的建议. 相似文献
11.
阐述了对DOCSIS2.0的上行物理层技术规范及其新特点.它是在DOCSIS1.1的基础上增强协议物理层性能的新规范,增加了光纤同轴电缆混合(HFC)网系统的信道容量,提高了抗干扰能力;采用S-CDMA模式的上行物理层技术规范是DOCSIS2.0的新特点,也是理解和应用该协议的关键. 相似文献
12.
Over the past two decades, cable television has largely supplanted over-the-air broadcast as a TV distribution medium. Several years ago, enterprising companies concluded that they could leverage the extremely wide bandwidth of cable TV systems required to deliver broadcast-quality television as a high-speed conduit for broadband data communications. This led to the birth of the cable modem. Early cable-modem equipment was vendor proprietary, so interoperability between different vendors' products was largely nonexistent. To promote interoperability, Cable Labs (the cable TV industry research arm) developed the Data Over Cable Service Interface Specification (DOCSIS 1.0), an IP-centric, point-to-multipoint standard that quickly replaced the proprietary solutions that preceded it. DOCSIS has now become the accepted cable standard. The newly released DOCSIS 1.1 is destined to play an important role in the delivery of high-quality multimedia across fixed wireless communications networks. With this approach, we can take advantage of all the DOCSIS technology modules that exist in the market today, allowing the wireless platform to migrate toward emerging services such as Internet protocol multicasting and voice over IP (VoIP). We describe the state of current technologies that have made fixed-wireless access a viable and compelling choice. We also discuss some emerging technologies that will bring exciting new fixed-wireless services and capabilities into homes and small businesses in the near future 相似文献
13.
在简要介绍DOCSIS发展历史的基础上,重点叙述了DOCSIS2.0上行物理层新增加的S-CDMA调制技术,并且对DOCSIS2.0与DOCSIS1.x在上行物理层所采用调制技术以及不同调制方式和带宽下的频谱效率、最大数据带宽、载噪比门限等方面作了详细分析和比较,最后对基于DOCSIS ATP2.0 Cable Modem的测试作了归纳和总结. 相似文献
14.
In upstream transmission of the DOCSIS (data over cable service interface specification) 1.0/1.1 and the TDMA mode of DOCSIS 2.0 standard, a packet begins with a preamble, the length and value of which are programmable by the headend. The acquisition process includes packet detection, symbol timing estimation, carrier frequency offset estimation and carrier phase estimation by means of the preamble so that the following information packet can be correctly demodulated. Methods to solve these tasks are not subject to standardization and are left to the system designer. However, they have a great impact on the system performance and thus are key elements for implementation. We present dedicated algorithms. A specific preamble is created and the corresponding scheme for packet acquisition is described in some detail. The packet detecting algorithm is independent of the carrier and symbol timing. The symbol timing estimate is obtained by using the minimum mean square algorithm regardless of the carrier frequency deviation and carrier phase. Algorithms for estimating the carrier frequency offset and carrier phase are proposed. Computer simulation results are given for all algorithms presented. 相似文献
15.
PacketCable是CableLabs开发的一套在HFC网络上传输语音、数据以及视频的技术规范。从PacketCable 2.0中E-UE的Provisioning出发,研究了PacketCable 2.0中E-UE的DHCP流程,结合DOCSIS中CM的DHCP过程和常规DHCP的核心内容,指出了在PacketCable 2.0和DOCSIS下的DHCP应在常规的DHCP架构上所做出的改动。 相似文献
16.
随着有线电视数据业务的发展,DOCSIS2.0标准在部署及运行中已经逐渐不能满足运营商业务发展的需要,DOCSIS3.0标准解决了这些问题。这一新标准能够在降低建设成本的前提下,提供更高的带宽、更优的质量和多业务提供能力,其主要特点在于去耦合设计、通道绑定和模块式构架等。 相似文献
17.
DOCSISV3.0是DOCSISV1.1/V2.0的扩展,它使有线电视HFC网络在扩展频谱、加大流量、增强功能方面有了重大突破,是CableModem接入技术的又一次重大进步。简单介绍DOCSIS研制背景,重点介绍DOCSISV3.0的主要特点,并对DOCSISV3.0的应用前景进行分析,认为EPON/GPON可能是电信网络改造的最佳方案,而双向HFC网络改造不宜采用EPON+EOC方案,CableModem接入才是有线电视双向HFC网络改造的主流技术,能真正实现三重服务的同网传输。 相似文献
18.
基于DOCSIS 2.0扩展HFC上行信道容量的实现方法 总被引:1,自引:0,他引:1
介绍了有线电视数据业务接口规范(DOCSIS)的技术特点和优势,演进过程及各版本,阐述了用DOCSIS2.0实现扩展HFC网络上行信道容量的方法,在保证兼容现有DOCSIS设备的情况下,使上行信道容量扩展到原来的3倍。 相似文献