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The detailed difference between 4G industrial router...   4G industrial router and 4G DTU both realize the wireless network data transmission function, and the differences between them are mainly from the use method, appearance interface and application environment, etc. Today, we will introduce some differences between 4G router and 4G DTU.   Different methods...

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Application analysis of iot sensing technology   The Internet of things (iot) is widely used in the integration of networks through intelligent perception, recognition technology, pervasive computing and other communication perception technologies. The iot is understood as "Internet connected by things". The Internet of things (iot) connects all objects with...

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What is a single/dual frequency wireless 4G router 1. Introduction to "single frequency" router The single-frequency router only works in the 2.4ghz band, which is generally supported by wireless terminals. However, the 2.4ghz band has large interference, which may affect the wireless rate and stability.   2. Introduction to "dual-frequency" router Dual-frequency...

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Wireless communication DTU features Data Transfer unit (DTU) is a wireless terminal device specially used to convert serial Data into IP Data or convert IP Data into serial Data for transmission through wireless communication network.   DTU advantages: Rapid and flexible network, short construction cycle, low cost; Wide network coverage; Good...

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The advantage of using wireless data transmission module... Data transmission can be simply divided into two major types: wired (including the installation of optical cables, cables or leased telecommunication lines) and wireless (including the establishment of dedicated wireless data transmission system or the borrowing of CDPD, GSM, CDMA and other public network information platforms).     In...

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4G网络的语音解决方案

Category : 技术相关

4G商用已经有一段时间了。国内三家运营商各自使用的4G有些区别。 比如中国联通主要使用TDD LTE技术,而电信与联通主要使用FDD LTE技术。

目前4G主要有三种语音通话的解决方案:双待机、CSFB(Circuit Switched Fallback(电路域回落)和VoLTE(也及Voice over LTE)
1—-双待机:就是4G和3G/2G同时待机,4G用来上网,3G/2G则用来打电话,这种技术手机内部有两套射频发射系统,可想而知,这种技术,手机电池最多撑不到一天的,充电宝赚钱的机会是这样来的:)

2—-CSFB:就是通话时回落到2G模式(无法上网),通话结束后再恢复到4G/3G情况下,这种技术只使用一套射频芯片,现在我们4G测试主要是测试这种方案,毕竟4G网络还在建设中,有一些区域还没有完成覆盖到,这时切换很重要的。苹果用于电信的A1533的回落技术则另外取了一个名字叫做SRLTE,是一种特殊形式的CSFB。
—在国内,可以用DINGLI连三星和索爱的手机可以进行测试,有一些项目直接用IPHONE5S进行体验测试,在国外,主要用NEMO连三星,很少看到有用TEMS来测试!

3—-VoLTE:这种技术牛B呢,它是架构在4G网络上全IP条件下的端到端语音方案,接入时延大大提升,基本上没有掉话,以后肯定主要用这种技术了,毕竟2G时代快结束了,目前这种技术主要用于4G全覆盖的区域。
—测试软件方面,据说要用CHARIOT!

所以,严格的说,LTE网络只是数据网,在未实现VOLTE的情况下,LTE只能称之为3.5G,或是缺陷4G,只有包含了完美语音方案,不依赖2、3G网络的才能叫做4G网络。毕竟对于数据,语音还是很重要的。