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移动网络如何变成今天的模样

How Cell Service Actually Works

This is electromagnetic radiation.
这是电磁辐射
You can’t see it, but it’s there.
你虽看不到它 但它就在那儿
In fact it’s everywhere.
事实上 它无处不在
But here’s a more relatable form.
不过以一个更贴近生活的方式来说
This is the color cyan.
这是青这个颜色
But more accurately, this is waves
但更确切地说 这其实是
of electromagnetic radiation oscillating at about
以每秒约616856909465021次的频率
616,856,909,465,021 times per second.
震荡的电磁辐射波
As they reach your eyes, light receptive cells
当它到达我们的眼睛 光感受细胞
translate the radiation into electric signals which travel to your brain,
会把辐射波转化为传入大脑的电信号
and are generally perceived as the color that we collectively refer to as cyan.
大脑一般将这些电信号上认定为“青色”——这是共识
If we strip away our interpretation though,
然而 若抛开我们的解释不谈
the radiation scaled up about 100,000 times, looks like this.
那放大十万倍的辐射波 是长这个样子的
The color cyan is waves of energy roughly 486 nanometers wide,
青色是约486纳米宽的辐射波
but what happens if that width tightens?
那么如果这个波长变窄 会怎样呢?
At 380 nanometers, a perception changes to this dark purple.
在宽约380纳米时 大脑对其的感知会变为这种暗紫色
Meanwhile, if it expands to a roomy 780 nanometers,
与此同时 若增加波长至780纳米
our brains interpret the radiation as the shade of dark red.
我们的大脑会将其解读为 暗红这个色度
Essentially, as the wavelength changes,
本质上来说 波长发生变化时
so too do the properties.
波的属性也会变化
So what happens if we change the wavelength more dramatically,
如果我们更夸张地改变一下波长 会怎样呢
like tightening it by 100 times?
比如把它变窄100倍?
Well, now the waves have much higher energy,
那么 此时的波会具有更高更高的能量
they are much more powerful,
变得强劲许多
so much so that they can actually pass through some less dense materials
强到能真正穿透一些密度较低的材质
like fabric or human tissue.
比如织物 或人体组织
But they aren’t quite strong enough to pass through denser materials
但却没有强到足以穿透像金属或骨骼
like metal or bone.
这些密度较高的材质
You can see where this is going.
你应该已经知道了
We refer to these wavelength as X-RAYs,
我们把这样波长的辐射波 称为X射线
and use their special properties to look inside bags at airport security,
它们的特性使其能在机场安检处检查包内物品
and inside humans at the hospital.
还有医院检查人体内脏时发挥作用
So what happens at the other end of spectrum?
如果在光谱另一个极端 会发生什么呢?
What if, instead the width of human DNA, the waves were the width of humans?
假如波长不是像人类DNA这么宽 而是人类本身的宽度呢?
Well, this is what we’d refer to, as an Ultra High Frequency Radio Wave.
那它就是我们所说的 超高频无线电波
Its comparatively enormous wavelength allows it to travel over huge distances,
相对较长的波长 使得它能够传播极远的距离
pass through obstructions and even bend around obstacles,
穿越甚至绕过障碍物
all useful properties if you wanted to use electromagnetic radiation
如果想将电磁辐射用于 比如通信
to, say, communicate.
那么它所有的属性都有用处
Of course, in order to convey information using a radio wave,
当然 为了用无线电波来传递信息
we’d need a way to manipulate the radio wave
我们需要一种能够操纵 与所需信息
that corresponds to the desired information.
相对应的无线电波的方法
For this, there are options.
为此 有几个可选方案
To start with, there’s the strength of the wave.
首先 从辐射波的强度开始
We know that a blue light, for example, can be weak or strong,
我们知道 比如一个蓝色的灯 可明可暗
but no matter if it’s weak or strong, it’s still blue,
但无论是明是暗 它始终是蓝色的
and the fact that it’s blue means that
这个事实就意味着
it’s still fundamentally the same wavelengths of electromagnetic radiation.
电磁辐射波的波长 在根本上始终是相同的
The same principle applies up to spectrum with radio waves.
这个原理也适用于无线电波的波谱
They can be powerful, weak or anywhere in between
它也是可强可弱 或介于强弱之间
and still be the same wavelength.
并始终保持相同波长的
In this context, we call that strength, the Amplitude.
这种情况下 我们把其强度称为 振幅
Therefore, we can transmit an audio signal for example,
因此我们可以通过 以成比例的数值修改振幅
by modifying that amplitude by a proportional amount.
来传输 例如一个音频信号
The receiver just needs to know how to interpret those amplitude modulations
收音机只需要能够解读这些调幅
and translate them back to an audio signal.
并将其转化回音频信号就可以了
In the case of an AM radio station
就调幅无线电台来说
the radio receiver only focuses on the radiation
无线电接收器只聚焦于比如说
with a wavelength for 1119 feet or 341 meters long for example,
波长为1119英尺 或说是341米的辐射波
and it tracks the amplitude modulations
然后它会追踪调幅
to output the audio signal that we end up hearing.
来输出我们最终听到的音频信号
Amplitude modulation radio communication has a number of useful features.
振幅调制无线电通信技术的确有很多优点
It’s exceptionally simple, and can work over huge distances,
它极其简单可行 且能跨越极远的距离
but it does tend to be highly susceptible to outside interference.
但又极易受外部因素干扰
That’s a big reason why AM radio tends to be lower quality,
这就是为什么调幅收音机往往信号质量较差
and a big reason why it’s not as useful a technique
也是它不适合作为更大组数据的传输技术
for transmitting bigger trunks of data.
很重要的一个原因
Of course, the wavelength can also be manipulated.
当然 波长也是可以操控的
That means that we can essentially do the same thing,
这意味着 我们基本上可以利用同样的方法
but this time by ever so slightly modifying the distance between waves.
但这次是通过稍稍修改波之间的距离来实现
In this context we’d refer to this as the frequency,
在这个背景下 我们用频率来描述这个量
which is proportional to wavelength,
它与波长成比例关系
but rather than being a physical measure, it’s a temporal one.
但它是一个时间上 而不是实物计量上的单位
How many times the wave oscillates within a second?
是指波在一秒内震荡的次数
So by slightly modulating frequency, we can transmit the same audio signal,
所以说 我们可以通过略微调频来传输相同的音频信号
but since this method is less susceptible to interference,
而由于这种方法不那么容易受干扰
we can generally get higher quality.
我们通常能得到更高的信号质量
Now traditional radio works by encoding the audio signal itself
现今 传统无线电设备是通过调幅或调频
into radio waves using amplitude or frequency modulation,
将音频信号本身译成无线电波 来发挥作用的
but computers, phones, essentially everything digital nowadays, encodes its data
但电脑 手机 基本上所有当今社会的数码产品
into binary code, sequences of ones and zeros.
都会将数据转化为二进制代码 也就是1和0的序列
This only makes communication using electromagnetic radiation better.
这样只会让利用电磁辐射的通信 变得更好
We can set it up so that
我们可以
when the amplitude is high that corresponds to a one,
将其设置成 当振幅高时对应1
while when it’s low it corresponds to a zero.
而当振幅低时对应0 这样的机制
Or rather when frequency is high that’s a one,
确切地说是 频率高时是1
and when low that’s a zero.
低时是0
This is simple and already more efficient
这样很简便 且已经比
than encoding the analog audio signal,
编码模拟音频信号更高效了
but it could be even more efficient.
但其实还有可能更加高效
That’s because there’s yet another wave property that we can manipulate.
那是因为 还有另一种我们可操控的 波的属性
For these purposes, we can consider one full cycle of a wave,
为此 我们可以想一下波的一个完整循环
going up, down and up again, one phase.
上升 下降 再上升 为一个波段
But we can also consider this,
也可以这样想
the wave going down, then up, then down again, one phase as well.
波先下降 再上升 又下降 也是一个波段
Therefore, we could assign this upward phase to the binary digit one,
因此可以将这个向上的波段确定为二进制数字1
and this one, the downward phase to the binary digit zero.
而这个向下的波段 为二进制数字0
Then we can transmit data using a sequence of these different phases.
然后我们就能利用 这些不同波段排成的序列 来传输数据了
The transmitter doesn’t need one phase to seamlessly go into the next,
发射器不需要一个波段无缝衔接到下个波段
so it’s an even faster, even more efficient way
所以说 这是一个更快 更高效的
of encoding binary sequences into electromagnetic radiation.
将二进制序列编码为电磁辐射的方法
But here’s where things get really cool.
真正精彩的部分要来了
There can be more than two phases.
波段可以有不止两个
We could divide the cycle into one phase starting at the midpoint going upward,
我们可以将此循环分成 一个从中间点向上的波段
one starting at the crest, one starting at the midpoint going downward,
一个以顶峰为起点的 一个从中间点向下的
and one starting at the trough.
和一个以波谷为起点的波段
So with four distinct phases,
那么这四个不同的波段
one can correspond to the binary sequence zero one,
一个可以对应为二进制序列01
one to one one, one to one zero and one to zero zero.
一个为11 一个为10 还有一个为00
Therefore we can cram twice as much data into the same signal.
因此 我们能将双倍之多的数据 塞进同一个信号中
But it doesn’t stop there.
这还没完
We can even take this a step further and have eight distinct phases,
我们还能更进一步 用到八个不同的波段
so that we can transmit every possible three-digit sequence of ones and zeros,
这样 就能传输每个能得到的 0和1组成的三位数序列
thereby tripling efficiency.
从而使效率提高三倍
Eight distinct phases is typically the practical limit for wireless data transmission.
八个不同波段 通常就是无线数据传输实际可行的极限了
It becomes too tough to distinguish between phases with anymore,
如果波段再多 区分它们就会变得过于困难
so the error rate is too high.
导致错误率过高
However this is just manipulating one property of the wave,
然而 这仅仅是操控波的其中一个属性
and there are, of course, two others.
当然了 还有其他两个
This phase, initially upward from the midpoint,
这个从中间点起向上的波段
could be broadcast at a high amplitude or a low amplitude.
可以以一个或高 或低的振幅传播出去
So we can say that
因此我们可以说
the low amplitude version of this correlates to the binary sequence of 0000,
这个低振幅型 关联的是二进制序列0000
or the high amplitude version 0001.
或这个高振幅型 关联的是0001
By adding two amplitude options to each of the eight phases,
通过给这八个波段 各加上两个可选振幅型
we get 16 total transmission options,
一共能得到十六个传输可选项
meaning we have enough to correlate to
这意味着 有足够多的可选项
each of the 16 possible four-digit combinations of zeros and ones.
与每一个可得的0和1组成的四位数序列相关联
If we have an accurate enough method of transmission,
如果有一个足够精准的传输方法
we can further increase the number of phase
就可以进一步增加波段的数量
and amplitude combinations to a total of 64,
和振幅的组合 至一共64个之多
each corresponding to a six-digit binary sequence.
每个都对应一个六位二进制数
In fact, the newest WIFI standards have 1024 phase and amplitude combinations,
事实上 最新的WIFI技术标准有1024种波段和振幅组合
while extremely accurate copper twisted cables can deal with 32,768 combinations,
而极其精确的铜质双绞线 能够处理32768种组合
each corresponding to a 15-digit sequence.
每一种组合都对应一个15位数的序列
Constrained by the accuracy of wireless communication,
受制于无线通信的准确性
your cell phone meanwhile,
我们的手机
uses as few as 16 combinations in the case of some 3G networks,
在3G网络下 仅会用到少至16种组合
and as many as 1024 in the most advanced 5G networks.
而最先进的5G网络下 则多至1024种
Fundamentally though, this is how your cell phone gets a lot of data
本质上 这就是我们的手机从一小段
out of a little slice of the radio spectrum.
无线电频谱中 获取大量数据的方法
Of course, transmitting data is only half the battle,
当然了 传输数据只是成功的一半
something also needs to receive it.
还得有东西接收数据
That something is, of course, a cell site.
这个东西当然就是 基站
Now keep in mind that a cell phone is essentially just a fancy walkie-talkie.
要记住 手机本质上只是一个高级对讲机
It uses the exact same process, just more advanced.
它与对讲机的工作原理完全相同 只不过更先进些
In fact the earliest portable phones, car phones,
事实上 最早的便携式电话——车载电话
which is one step removed from walkie-talkies.
与对讲机的距离只有一步之遥
A telephone company would set up a radio transmitter in a city,
电话公司会在城市里建一个无线电发射器
users would install a bulky system in their car,
而用户需要在车内安装一套笨重的系统
the system would communicate with the transmitter just as a walkie-talkie would,
系统就像对讲机一样 与发射器取得联络
and the tower would then plug the signal into the landline network.
然后信号塔会把信号接入固网
Put it another way, it was just a citywide version of cordless landlines.
换句话说 它其实就是个全市范围版的无线座机
The only difference from walkie-talkies
与对讲机唯一的区别在于
was that these car phones would have a dedicated channel for outbound transmission,
车载电话有专门的传出频道
and a dedicated channel for inbound transmission,
和专门的传入频道
so that both sides could talk simultaneously,
这样两边能同步对话
unlike with a walkie-talkie where one needs to wait and push to talk,
不同于只使用单一频道的对讲机 需要
since only one channel is used.
等待和按着说话
These car phones were fairly similar to today’s cell phones
从用户体验角度来看 这种车载电话
from a user experience perspective,
与当今的手机相当类似
but they were horribly inefficient.
只不过其效率奇低无比
In their early days, there were only 32 available channels,
在它问世的初期 只有32个可用频道
meaning only 32 people in the city could use their car phone simultaneously.
这意味着 全市能同时使用车载电话的 只有32个人
In addition, if one left the service area of that one tower in their home city,
此外 如果用户离开了自己故乡城市信号塔的服务区
their car phones wouldn’t work.
那车载电话就不能用了
Of course, the solution was cells.
当然 解决方案就在于基站
The idea was this,
这个主意是这样的
a given area would be split up into a pattern of hexagons,
将一个指定区域划分为一个个六边形
at the center of each of those hexagons was a cell site.
在每个六边形的中心 是一个基站
These are generally thought of as cell towers,
人们通常认为这些就是手机信号塔
but that’s a misnomer since cell sites can be located on buildings,
其实这是错误的说法 因为基站可以设置在楼房上
inside church steeples, at the tops of mountains,
教堂尖塔内 山顶上 或是
or really anywhere that’s elevated relative to the typical user.
任何相对于普通用户来说较高的地方
Fundamentally, these cell sites just send
本质上说 这些基站只是
and receive radio signals to and from cell phones,
向手机发送 或从手机接收无线电信号
which is a fairly simple process.
这是相当简单的流程
Then they need a way to plug into the wire communication network
随后它们需要通过某种方法接入有线通信网络
to convey data over longer distances.
以实现更远距离数据传输
Often this is accomplished through physical fiber optic cables,
这一过程通常需要使用物理光缆来完成
but especially in more rural areas, that’s not always practical.
但这并不总是可行的 尤其是在许多农村地区
If one put a cell site on the top of a mountain for example,
比如要在山顶上建一个基站
it would likely have to operate completely offer grid
它很有可能必须靠太阳能或发电机
power by solar or a generator.
来为电网供能
And it also couldn’t physically plug into the wire communication network
而且由于它是隔离的 无法在物理上
due to its isolation.
接入有线通信网络
Therefore these more remote cell sites use microwave transmitters.
因此 这些较偏远的基站 会使用微波发射器
Now tiny microwaves, thanks to their extremely rapid frequency,
得益于极高的波频 现如今的微型微波
are incredibly efficient at moving huge amounts of data fast,
在快速传送大量数据方面的效率十分惊人
the most advanced system have reached over 100 gigabits per second,
最先进的系统已经能够达到100GB/s
but they’re not very resilient.
但灵活性不是很强
One needs a direct line of site
要想准确地传输数据
between the transmitter and receiver to accurately transmit,
发射器与接收器之间 必需有一条直通线路
which prevents microwaves used for portable cell phones.
这就阻碍了微波在便携式手机上的应用
However, for fixed cell sites, this is possible.
然而 这对于固定基站来说是可行的
So many are set up with microwave transmission systems
许多基站设有微波传输系统
that relay signal to the closest site
它会将信号转发至最近的
with a physical link to the wire communication network.
且物理上连接着有线通信网络的站点
With both a wired and wireless option,
有了有线和无线两种可选方案
cell sites can be located nearly anywhere,
基站就可以设置在几乎任何地方了
which is important because their location absolutely matters.
这很重要 因为它的所在位置关系重大
Centering their hexagon,
每个基站的信号
the signal from each of these sites must reach far enough
以六边形的中心为起点 必须能到达足够远的距离
that there is some overlap between the cells.
让它们的覆盖范围 有一些重叠部分
That way, if a cell phone is being used on the move,
这样一来 如果手机在移动中使用
the call can be seamlessly passed from one cell site to the next
呼叫就可以在信号不衰减的状态下
with no drop off in signal,
从一个基站无缝连接至下一个
and the network can be expanded far beyond the reach of one transmitter.
且网络覆盖 会扩大到远超单个发射器的范围
However, the system starts to seem less ingenious once you do the math.
然而我们一计算就会发现 它并没那么巧妙
Originally, only 832 different frequencies were allocated for use by cell phones.
最初 仅有832个不同波频分配给手机使用
There are a lot of different uses for the radio spectrum,
无线电频谱有许多不同用处
so regulatory bodies like the American FCC, British Ofcom or German Bundesnetzagentur,
所以像美国联邦通信委员会 英国通信管理局 或德国联邦网络机构这样的管理单位
can only allocate so many frequencies for different industries.
能分配给不同的行业的波频 只有那么多
And spectrum allocation is crucial
而频谱的合理分配很关键
so that two users don’t try to use the same frequency,
这样才不会让两个用户抢用同一个波频
or to render both of their uses useless.
要不然两边都无法使用
So of those 832 frequencies,
所以说这832个波频
42 were used by the cell network for its own back-end internal communication.
其中42个 用于蜂窝网络自己后台的内部通信
That left 790, but a call required both an outbound
还剩790个 而呼叫同时需要一个呼出波频
and an inbound frequency,
和一个呼入波频
effectively meaning that there are only 395 call channels.
实际上意味着 只有395个呼叫频道
However, in order to prevent interference,
然而 为避免干扰
no two bordering cells could use the same frequency.
两个毗邻的基站不能使用相同的波频
As each hexagon has six neighbors,
由于每个六边形都毗邻其它六个
that meant each cell could only use one seventh of the available channels.
每个基站能用的 仅为可用频道的1/7
So each cell had 56 channels,
就是每个基站有56个频道
meaning 56 users within each cell could make a call at a given time.
意味着在指定的时间 每个基站内有56位用户可以打电话
This initially works fine,
最开始还好
but then cell phones got popular.
但随后手机变得普遍
To keep up with demend,
为了跟上人们的需求
cell carriers needed to find a way to do more with a single frequency.
手机运营商需要找到一种能用单个波频做更多事的方法
When the second generation of mobile network came along,
当第二代移动网络出现后
calls were no longer transmitted as analog audio waves,
呼叫便不再以模拟音频波形式来传送了
rather, they started to use those digital signals encoded using phase and amplitude.
反而开始采用利用波段和振幅译成的 数字信号
The thing was, this method was more efficient,
事实是 这个方法更高效
meaning using a whole channel to transmit a single voice conversation was overkill,
明明只需要用到一部分 却利用整个频道来传输
when only needed part of it.
仅一个语音通话 太大材小用了
Of course, the difficulty was that voice conversations happen in a real time,
当然 难点在于语音通话是实时的
it’s not like you could compress an entire two-minute call and send it at the end.
它不像可以压缩 然后再发送的 一整段两分钟的语音
Therefore, cell companies divided a given channel into eight time slots.
为此 手机运营商将指定频道划分为八个时段
These time slots would rotate one after another in a rapid succession,
这些时段会一个接一个地 快速轮换
and a given phone would be told to use, say, the third time slot.
然后规定某个指定的手机使用 比如说时段3
So, each time that time slot came up,
那么每次轮到这个时段出现
it would fire off its ones and zeros quickly
它就会迅速发射出多个10序列
and wait for it to come around again.
然后等待再次轮到它出现
But because the data was compressed into an efficient digital signal,
但由于数据被压缩成了高效的数字信号
the amount received during a time slot
在一个时段内接收到的数据量
would be enough to decode into enough of the conversation,
足以解码一段足够长的对话
to play until the next time slot came up.
来持续播放至轮到该时段再次出现
This system meant that one channel
这个方法意味着
could now be used by eight phones simultaneously.
现在一个频道可同时为八部电话所用了
What was 56 channels, now became 448.
本来的56个频道 现在变成了448个
But eventually, as phones became ever more commonplace,
不过随着手机越来越普遍
the system of Time Division Multiple Access became
这个时分多址的方法
once again, not good enough.
又一次变得不够好用了
The next evolution was where things got complicated,
接下来的这次演变复杂了起来
but also fascinating.
但也颇引人入胜
It’s called Code Division Multiple Access.
它叫作码分多址
It’s an ingenious way
这是一种
where multiple phones can send and receive data
能实现多部手机真正同时
on the same channel, truly simultaneously.
发送和接收数据的巧妙方法
To explain the incredibly simple version,
讲个高度简化的版本吧
let’s say a first user wants to transmit the binary sequence 11,
我们假设第一位用户要传送的是二进制序列11
a second user 01, and a third 10.
第二位用户是01 第三位是10
Now each of these users would be allocated what’s called a spreading code,
现在每个用户 分别分配到一个传播代码
0101, 0011, and 0000 respectively.
0101 0011 和0000
For the first user their first binary digit, 1,
将第一位用户的第一个二进制数字 1
would be compared to each of the four digits of their spreading code.
与其传播代码中的四个数字 一一对比
If the spread code digit and the binary digit is the same,
如果其传播代码中的数字 与二进制数字相同
it would output a zero.
则输出一个0
If it’s different, it would output a one.
如果不相同 则输出一个1
So for user one, the output sequence would be 1010, 1010.
因此 第一位用户输出的序列 将会是1010 1010
The process would repeat for user two, which output 0011, 1100.
第二位用户也会重复这个流程 输出0011 1100
And user three, which output 1111, 0000.
第三位输出1111 0000
Next, the sequences are translated
接下来序列会被翻译
so that zeros become positive ones, and ones become negative ones.
使0变成正1 而1变成负1
Then each digit of the three sequences of numbers are added together.
然后将这三个数列中的每一个数字相加在一起
That outputs the composite sequence -1, 1, -3, -1, -1 ,1 ,1, 3.
会输出复合序列 -1 1 -3 -1 -1 1 1 3
This composite sequence is what is then transmitted using a single channel.
这个复合序列 就是接下来要通过单个频道传输的内容
Now the exact details of this process are not tremendously important,
这个流程的具体细节不是十分重要
but what is, is what happens next.
重要的是 接下来会怎样
What happens next, is that this process is reversed.
接下来 这个流程会倒转过来
So, the receiver of that composite sequence
该复合序列的接收器 会得知
would know each user’s unique spreading code.
每位用户独一无二的传播代码
The spreading code is also translated
该传播代码也会被翻译
so that zeros become positive ones and ones become negative ones.
使0变为正1 而1变为负1
And then the receiver multiply the composite sequence with this translated spreading code.
然后 接收器将复合序列与翻译得来的传播代码相乘
For user one,
则第一位用户
that outputs -1, -1, -3, 1, -1, -1, 1, -3
输出的是-1 -1 -3 1 -1 -1 1 -3
Now the first four digits of the sequence
现在我们知道 序列的前四个数字
which we know correlate with the first digit of the data,
是与数据的首个数字相关联的
are added together to get negative four,
把它们相加 会得出负4
which is then divided by four to get negative one.
用负4除以4 会得出负1
The process repeat for the second set of four to get negative one.
第二组四个数字 通过相同流程得出负1
Now if we translate this back so that negative ones become ones,
现在 如果把它们翻译回去 负1变成1
and positive ones become zeros,
而正1变成0
then we get the data sequence, 11.
那我们就会得到数据序列11
With just the composite sequence and unique spreading code,
仅利用复合序列和独一无二的传播代码
this process figured out what user one’s unique data sequence was.
这个流程就可以计算出用户独一无二的数据序列
If we repeat this entire decoding process with user two spreading code,
如果对第二位用户的传播代码 重复整个解码流程
We’ll get 01, it’s data sequence.
我们会得到数据序列01
And unsurprisingly, it also works for user three.
毫无悬念 这也适用于第三位用户
So, with one composite signal and three unique spreading codes,
因此 通过一个复合信号和三个独一无二的传播代码
we’re able to triple up the use of one channel.
我们就可以让一个频道的功能翻上三倍
In practice, this process works in a much larger, much more complex scale,
实际应用中 这个流程会在更大 更复杂的规模下运作
but it uses the same mathematical principles.
但其数学原理是相同的
This fundamentally, is how Cell Service works.
本质上说 这就是手机服务的工作原理
Making a two-wave radio work for one person is simple,
让一个双波无线电为一个人服务很简单
making a two-wave radio work for everyone in the same area,
让它同时为身在同一个区域的每一个人服务
at the same time, is difficult.
并不简单
It’s all about packing as much data as possible into a single transmission,
都是为了将尽可能多的数据 塞入单次传输
and then packing as many transmissions as possible into a single radio wave.
再将尽可能多次传输 塞入单个辐射波
The aforementioned techniques to accomplish these two goals
前文提到的那些 为了实现这两个目标的技术
are only the tip of the iceberg.
只是冰山一角
Many of the most advanced networks has moved on to a system
许多先进的网络 已经将目光转向
called Orthogonal Frequency Division Multiple Access,
一个名为 正交频分多址的新系统了
to pack even more transmissions into a single wavelength for example.
以求 在比如说单段波长内 塞入更多次传输
But they are indicative of the process that got us to today.
而这些技术 却展现了我们时至今日的发展进程
When we move from 3G to 4G, and 4G to 5,
从3G网络到4G 再从4G到5G
what’s happening in the background is
其背后是一群智者
incredibly smart people finding more and more ingenious methods of transmitting more data,
不停探寻着 能利用同样的资源传输更多数据的
using the same resources, also that we, the end users
巧妙绝伦的方法 此时的我们 这些终端用户
can browse Twitter, and watch Youtube, just ever, so slightly, faster.
浏览Twitter 观看Youtube的速度才会快那么一点

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译制信息
视频概述

从无线电,3G,4G,到现如今的5G网络,其飞速发展的背后,是以操控电磁辐射波不同属性为本质的各种技术。本视频化繁为简,从根本上让我们了解“信号”,“波频”,“波段”,到底都是什么,我们的手机,网络是如何发挥作用的。

听录译者

乱步

翻译译者

Tylosin

审核员

审核员IBRT

视频来源

https://www.youtube.com/watch?v=0faCad2kKeg

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