共查询到20条相似文献,搜索用时 62 毫秒
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CSFB是一种LTE语音解决方案,其基本思想是LTE用户通过从LTE网络回落到2G¥3G电路域以进行语音业务接续。本文首先介绍CSFB语音解决方案的关键技术,重点分析用户被叫流程时回落的重点和难点。其次介绍MTRF关键技术及其应用场景。最后提出通过MTRF技术可解决CSFB方案的被叫回落异常问题,并分析部署MTRF技术对GSM-TD-SCDAM-TD-LTE融合网络影响。 相似文献
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在LTE网络中用CSFB实现语音功能时,系统消息的读取时间在CSFB时延中占比较大.盲重定向通过在RRCConnection Release消息中加上邻区的系统消息内容,使UE重定向后接入的小区即为已经被下发系统消息的邻区,节省系统消息的读取时间.Flash CSFB通常用这种盲重定向的方式实现,缩短语音回落时延,提升用户感知. 相似文献
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电路域回落技术是解决LTE/EPC网络过渡期间语音呼叫连续性的解决方案之一,通过重用2G/3G网络资源降低业务部署成本。本文探讨了CSFB架构以及技术要求,讨论了用户回落至非注册MSC方案和CSFB组网方案,并对上述技术方案进行比较,最后针对现网部署给出CSFB组网策略建议。 相似文献
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摘要:TD-LTE系统是纯IP网络,只提供PS业务,目前TD-LTE系统语音解决方案有单卡双待和语音回落两种,语音回落方案对终端电池的续航能力有较大提升。本文中重点介绍TD-LTE系统语音回落方式、附着流程、与主被叫流程,对实际工作中CSFB遇到的典型问题如未开启CSFB功能、回落到2G失败、挂机后不能正常返回4G网络等问题进行细致的信令分析,并给出了优化解决建议。 相似文献
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CSFB方案作为目前中国移动TD-LTE网络主流的语音解决方案,涉及2/3/4G网络多个网元,流程复杂、影响因素众多,本文首先对终端开机驻留、呼叫建立、挂机返回及时延异常等常见问题进行了梳理分析;然后详细阐述了CSFB呼叫时延、被叫成功率两大关键指标的优化措施,对于指导CSFB优化工作开展具有较好的参考价值。 相似文献
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LTE建网初期,语音业务目前使用CSFB方式,存在的主要问题为时延较长。2014年,石家庄LTE网络CSFB时延为11.08秒,通过详细分析CSFB信令流程,找出非重要信令开关、TCH立即指配、UE不活动定时器、被叫选择性鉴权等四类可优化参数,分别进行对比验证,时延缩短效果明显,并通过总结优化成果,综合调整网络参数。通过优化调整,在2015年,石家庄CSFB时延已缩短至10秒以内,优化效果显著,有效提升网络运行质量与客户感知。 相似文献
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Michael Reilly 《半导体技术》2004,29(12)
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system. 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test. 相似文献
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The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high. 相似文献
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The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation. 相似文献
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Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible. 相似文献
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Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's. 相似文献
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Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it. 相似文献
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It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory. 相似文献
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A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working. 相似文献
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《中国通信》2014,(7)
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks 相似文献