Prev

Next

Industrial-grade 4G router TCP/IP network architecture 1. Layering of TCP/IP network system   TCP/IP (TransmissionControlProtocol/InternetProtocol), transmission control protocol/Internet protocol. It was developed by the defense advanced research projects agency in the 1970s, and was later integrated into UNIX and popularized. It emerged in the 1980s as the Internet's...

更多文章

The structure of 4G DTU The main function of DTU is to transmit data from remote devices back to the background center via wired/wireless. Different data transmission modes of DTU include all-network-connected DTU, GPRS DTU, WIFI DTU, CAN DTU and 4G DTU. Today, we will have a look at the structure and work flow of DTU.   To complete...

更多文章

What are the wireless connection technologies of the... Internet of things (iot) applications have been deeply rooted in our lives. The E-Lins H685 industrial-grade router is a small industrial-grade wireless router with single or double LAN ports. TDD/ fdd-lte, 4G, 3G, GPRS network optional. Besides, what are the wireless connectivity technologies for the Internet of things?   1....

更多文章

The use of industrial wireless routers Industrial-grade wireless router adopts high performance 32-bit industrial-grade ARM9 communication processor, which is widely used in finance, electric power, postal, water conservancy, environmental protection, meteorology and other industries.   Industrial router is mainly used in intelligent transportation,...

更多文章

Cascade and stack of industrial-grade 4G routers The most basic star Ethernet architecture, the actual star enterprise network may be much more complex than this. This renaturation is not only reflected in how high-end network equipment, how complex configuration, more importantly, the performance of network switching level is more complex. Industrial routers and firewalls...

更多文章

twitter

4G网络的语音解决方案

文章目录 : 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。

发表评论

You must be logged in to post a comment.