共查询到19条相似文献,搜索用时 125 毫秒
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王金旺 《数字社区&智能家居》2007,(13)
以CDMA为多址复用方式是现代移动通讯的主要特征.移动通讯经历了从模拟制式到数字制式,从单纯提供语言业务到全面提供高质量跟传输业务的快速发展历程.随着Internet和多媒体技术的迅速发展,使高速和更先进的移动通讯崛起,已经成为世界电信业的焦点. 相似文献
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信息产业的繁荣使得无线通讯得到迅速发展,同时也导致了通讯厂商间的激烈竞争,为了保证移动通讯系统的可靠运行,提高客户满意程度,通讯厂商必须为用户提供高效的服务支持。如何保证移动通讯系统的稳定性和可靠性,成为各地通讯主管部门和企业面临的巨大挑战。浙江移动通讯有限责任公司(ZMCC)与HP公司的合作成为在提高移动通讯系统运行稳定性和可靠性方面的一个成功案例。 ZMCC是中国电信(香港)有限公司的内地子公司,负责浙江省邮电移动网络的规划、建设和维护管理,主要经营移动电话业务、移动数据业务和传真业务,移动通讯终端以零配件销售、设计、维护、技术咨询和售后服务等。其 相似文献
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随着3G时代的到来和移动通讯网络的迅速发展,手机终端也将实现由通讯终端向信息终端的转变,移动业务的发展对终端的依赖将进一步加强,业务的不断发展有赖于终端能力的不断提升。而CDMA的业务特点、产业价值链的竞争能力和目标市场的定位都与GSM业务存在较大的差异,因此CDMA业务的发展必然离不开CDMA终端的支持。本文将对CDMA终端和CDMA业务发展的相关性作进一步的阐述。 相似文献
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张杨 《数字社区&智能家居》2010,(12)
移动通信是世界电信领域中发展最迅速,前景最广阔的技术,是通讯技术向信息时代全面发展的一个重要标志。建立在全球移动综合业务基础上的第三代通信系统(3rd Generation,简称为3G),为移动多媒体带来高速的数据传输带宽、完善的移动终端,同时提供多种优质的语音和非语音业务,是未来电信领域的发展方向,该文将对第三代通信系统的发展概况、结构、定位等做粗浅探索。 相似文献
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移动通信技术的成熟和广泛商业化为移动商务提供了通信技术基础,而功能强大、价格便宜的移动通信终端的普及为移动商务提供了有利的发展条件。本文对移动商务的优点、典型解决方案及其发展前景等方面进行了探讨。 相似文献
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Steve Lord 《Network Security》2003,2003(1):10-12
GSM is a series of standards defining various aspects of mobile voice and data communications. These standards provide a framework that looks set to underlie modern mobile business communications well into the 21st century. 相似文献
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近些年来,我国的移动通信业务的规模不断的扩大,移动通信的形式也不断的发展,3G技术已经实现了推广和运行,这种情况下优化无线网络运营环境,实现3G移动通信网络的系统技术升级,就是未来通信行业发展所要面临的最主要的问题. 相似文献
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近年来,随着3G时代的到来,移动通信业务发生了巨大的变化。对于一直居于产业链龙头地位的运营商来说,这是一个历史机遇也是个挑战。本文在总结影响3G业务发展的主要因素的基础上,对3G业务发展的趋势进行了分析。 相似文献
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Voice over Internet Protocol (VoIP) has become increasingly popular among individuals and business organisations, with millions of users communicating using VoIP applications (apps) on their smart mobile devices. Since Android is one of the most popular mobile platforms, this research focuses on Android devices. In this paper we survey the research that examines the security and privacy of mVoIP published in English from January 2009 to January 2014. We also examine the ten most popular free mVoIP apps for Android devices, and analyse the communications to determine whether the voice and text communications using these mVoIP apps are encrypted. The results indicate that most of the apps encrypt text communications, but voice communications may not have been encrypted in Fring, ICQ, Tango, Viber, Vonage, WeChat and Yahoo. The findings described in this paper contribute to an in-depth understanding of the potential privacy risks inherent in the communications using these apps, a previously understudied app category. Six potential research topics are also outlined. 相似文献
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为了适应应用发展的需求,人们提出了下一代移动系统的概念,下一代移动系统对服务提供的灵活性等方面提出了较高的要求;由TINA-C组织提出并标准化的电信信息联网体系结构(TINA),作为下一代网络的体系结构,具有开放的结构,服务的焦点以及服务提供与连接提供相分离等特色;文章从商业模型和服务体系结构的角度,对TINA在下一代移动系统中的应用进行了研究和探讨。 相似文献
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运营商通过分析各时段、各区域的历史移动通信业务数据,能够预测未来一段时间的业务量,从而提供面向管理层的决策支持。为准确把握国内移动通信用户数的波动规律,提高预测精度,通过对2012年1月到2014年2月的26个月忙时移动通信用户总数和3G用户数进行分析,采用差分自回归移动平均模型(ARIMA)对业务量时间序列数据进行线性建模,并采用支持向量机(SVM)对ARIMA模型残差进行非线性建模,将ARIMA模型与SVM模型组合对忙时移动通信用户数进行预测,结果表明,ARIMA-SVM组合模型预测精度明显优于单一模型,发挥了两种模型各自的优势。该组合模型是一种切实可行的移动通信业务预测方法。 相似文献
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Communications channels—from mobile phones to value-added networks to corporate-owned communications lines—are vital to business. Organizations must redesign their corporate structures to readily and effectively handle internal information flows and link with external customers and suppliers. A survey reveals how leading US corporations define responsibilities and specializations in this area and examines some management approaches to adopting communications technologies. 相似文献
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Ad hoc networks are self-configurable networks with dynamic topologies. All involved nodes in the network share the responsibility for routing, access, and communications. The mobile ad hoc network can be considered as a short-lived collection of mobile nodes communicating with each other. Such networks are more vulnerable to security threats than traditional wireless networks because of the absence of the fixed infrastructure. For providing secure communications in such networks, lots of mechanisms have been proposed since the early 1990s, which also have to deal with the limitations of the mobile ad hoc networks, including high power saving and low bandwidth. Besides, public key infrastructure (PKI) is a well-known method for providing confidential communications in mobile ad hoc networks. In 2004, Varadharajan et al. proposed a secure communication scheme for cluster-based ad hoc networks based on PKI. Since the computation overheads of the PKI cryptosystem are heavy for each involved communicating node in the cluster, we propose an ID-based version for providing secure communications in ad hoc networks. Without adopting PKI cryptosystems, computation overheads of involved nodes in our scheme can be reduced by 25% at least. 相似文献