Go homepage(回首页) Upload pictures (上传图片) Write articles (发文字帖)
The author:(作者)delvpublished in(发表于) 2014/1/27 8:21:22 Popular science： how fast does LTE 4G，100Mbps，
Popular science: how fast does LTE 4G,100Mbps -4G kepu, how fast LTE,LTE FDD,LTE TDD,4G,100Mbps-IT information Popular science: how fast does LTE 4G,100Mbps
From the perspective of technical standard, as defined in the International Telecommunication Union, static transmission speeds up to 1Gbps, users can reach 100Mbps in a fast-moving State, as one of the 4G technology. But a variety of literature can bring a lot of doubts to some readers, such as LTE, whether 4G, TD-LTE is "mainstream", why would I use China Mobile's 4G've never seen 100MB/s download speed? The author compiled some key issues:
Judging from the current situation in the world,WiMAX-Advanced and 4G standards are divided into at least two--LTE Advanced. LTE Advanced is divided into LTE FDD(frequency division duplex long-term evolution) and LTE TDD(time division duplex long-term evolution, that is called TD-LTE in Taiwan).
WiMAX-Advanced (updated version of worldwide interoperability for microwave access) standard by the WiMAX (Worldwide Interoperability for Microwave Access) Forum led by, is recognized by the International Telecommunications Union 4G standard, however, with Intel in 2010 exit operator WiMAX technology is gradually being abandoned.
English Long Term Evolution LTE (long term evolution) acronym. Although commonly called 4G LTE in commercial promotion, but are actually HSDPA the transition towards a 4G version of 3.5G is not a true 4G. December 6, 2010 International Telecommunication Union official definition of 4G LTE Advanced.
LTE Advanced fully backward compatible with LTE, usually passed on the LTE software upgrade, the upgrade process is similar to upgrade from WCDMA to HSPA. Was among the first to be recognized by the International Telecommunication Union 4G standard, is in fact the only mainstream 4G.
LTE TDD and LTE FDD, the former is by far the most mature technology, the most widely used around the world, the Terminal offering standard. Local media frequently promotional "domestic standard" TD-LTE is in fact by the ASB, Nokia Siemens Networks, Huawei Technologies, ZTE, Datang Telecom, China Mobile, Qualcomm, ST-Ericsson and other companies develop, technically still belongs to LTE. Of course, the Chinese Government and enterprises are the prime movers of the TD-LTE standard. Terms of acceptance around the world over more than 10 operators have already or plan to use TD-LTE, but that more than more than 100 global LTE network is not needed. TD-LTE standard is not "mainstream".
While the current "bandwidth" is generally used to describe a network data rate, but there must be some readers Mbps on bandwidth (megabits per second) was puzzled. Mbps is an abbreviation for Million bits per second, and 1,000,000 bps=1 Mbps=1,000,000 bit/s=0.95367 Mebi bit/s. 100Mbps equates to 100M bits transmitted every second, because in order to guarantee the correctness of the information transmission in transport need to increase most helpless at the transport between each byte of code and calibration code, so if you convert MB units we use will need to be divided by 8, so 100Mbps is converted into our easy to understand form is 12.5MB/s. Which means China Mobile's propaganda used in the "Internet speeds of up to hundred megabytes per second" real meaning is 12.5MB/s, and if concurrent users more, may also fall short of that figure.
科普：LTE是不是4G，100Mbps究竟有多快 - 4G科普,LTE,LTE FDD,LTE TDD,4G,100Mbps有多快 - IT资讯科普：LTE是不是4G，100Mbps究竟有多快
从技术标准的角度看，按照国际电信联盟的定义，静态传输速率达到1Gbps，用户在高速移动状态下可以达到100Mbps，就可以作为4G的技术之一。但各种宣传资料可能给部分读者带来了不少疑惑，比如LTE到底是不是4G、TD-LTE真的是“国际主流”、为什么我用中国移动的4G从没见过100MB/s的下载速度？笔者整理了一些主要问题：
从目前世界上的情况来看，4G标准至少分为两种——LTE Advanced和WiMAX-Advanced。其中LTE Advanced又分为LTE FDD（频分双工长期演进技术）和LTE TDD（时分双工长期演进技术，即国内所称的TD-LTE）。
WiMAX-Advanced（全球互通微波存取升级版）标准由WiMAX（Worldwide Interoperability for Microwave Access）Forum所主导，是国际电信联盟承认的4G标准，不过随着英特尔于2010年退出，WiMAX技术也逐渐被运营商放弃。
LTE是英文Long Term Evolution（长期演进技术）的缩写。虽然在商业宣传上通常被称作4G LTE，但实际上是3.5G下的HSDPA迈向4G的过渡版本并非真正意义上的4G。2010年12月6日国际电信联盟把LTE Advanced正式定义为4G。
LTE Advanced完全向后兼容LTE，通常通过在LTE上通过软件升级即可，升级过程类似于从WCDMA升级到HSPA。是第一批被国际电信联盟承认的4G标准，也是事实上的唯一主流4G标准。
对于LTE FDD和LTE TDD来说，前者是目前该技术最成熟，全球应用最广泛，终端种类最多的标准。国内媒体经常宣传的“国产标准”TD-LTE事实上是由上海贝尔、诺基亚西门子通信、大唐电信、华为技术、中兴通讯、中国移动、高通、ST-Ericsson等业者共同开发的，其技术上仍然属于LTE。当然，中国政府和企业是TD-LTE标准的主要推动者。从接受程度上来看，世界各地有十多家运营商已经或计划使用TD-LTE，不过这在全球一百余个LTE网络中所占的比例不大。所以TD-LTE标准并不是“国际主流”。
虽然当前“带宽”普遍被用来描述网络的数据传输速率，但肯定有部分读者对带宽的单位Mbps（兆位/秒）感到疑惑。Mbps是Million bits per second的缩写，1,000,000 bps=1 Mbps=1,000,000 bit/s=0.95367 Mebi bit/s。100Mbps也就等于每秒传输100M比特，由于在传输过程中为了保证信息传输的正确性需要在传输的每个字节之间增加仃码和校验码，因此如果换算成我们常用的MB单位就需要除以8，所以100Mbps换算成我们易于理解的形式就是12.5MB/s。也就是说中国移动宣传中所使用的“网速可达每秒百兆”真实含义是12.5MB/s，而且如果同时使用的用户比较多，可能还达不到这个数值。
赞