as the largest number of mobile communication devices
Base stations are almost everywhere
But
There are many types of base stations
The antenna of the base station is also divided into many kinds
People who can really distinguish
Actually not much
▼Please imagine this scene▼
When you and female (male) votes walk hand in hand on the road
(provided you have)
A base station appears in the distance
you tell her (he)
"Look!
That's a China X-Motion 4G TD-LTE
Directionally polarized smart antennas for three-sector base stations”
What the hell!
What a high profile!
Hidden, ah, there is wood! ! !
Imagine the adoring eyes of female (male) votes!
And the astonishment and praise of passers-by!
You are like a god!
Without further ado, start now!
What is a "base station"
The base station is the Base Station
Generally refers to "public mobile communication base station"
everybody knows
The base station is to provide the signal to the mobile phone
▼For example something like this▼
But in fact
The stuff above is just a tower and an antenna.
Just one component of the base station
In addition to these visible parts of the base station
Also includes a lot of invisible parts
In the era of 2G and 3G
The base station is divided into two layers
As shown below
In the era of 4G LTE
Two layers reduced to one
becomes a separate eNodeB
Take eNodeB as an example
Generally includes the following components
The name is easy to say and easy to remember
BBU = 哔 哔 哟
RRU = ah ah yo
Antenna = Antenna + Feeder
BBU
The following picture is the front view of BBU
It looks like it can't be rained
Therefore, BBUs are usually placed indoors
(that is, in the engine room)
About the engine room, to explain
Base stations usually have a computer room
Some are in an obscure corner of the building
Some are also outdoors, like the following
Field base station room (pheasant)▼
You usually see such a small house under the tower.
I found a special station
I took a real photo ▼
(It's a bit like a thousand-year-old tomb...)
The previous base stations were built brick by brick by operators
Isn't it very troublesome?
So, now it has been changed to an integrated station
That's it ▼
Comes with its own base, find a place to put it, and you're done
(Some even have their own wheels, you can pull them around)
You ask me what's in the computer room?
No key, can't get in. . .
I can only find a photo online
probably like this ▼
(Most of the computer rooms are not so clean, spacious and bright...)
back to topic
BBU, just stuffed in the cabinet of the computer room
There may also be rack power and transmission equipment in the rack
It's easy to identify:
There are many red black blue wires (power wires)
with many switches
Usually a power supply
There are many optical fiber ports and network ports
Plug in a lot of yellow fiber optic cables or something
Usually a transmission device
After talking for a long time, what is the use of BBU?
BBU
Building Baseband Unit, baseband processing unit
Mainly complete the channel encoding and decoding, baseband signal modulation and demodulation, protocol processing and other functions
It doesn't matter if you don't understand, PASS!
RRU
Next, let's talk about RRU
▼This is RRU▼
Is it a bit like a radiator and a suitcase?
Don't underestimate it
This thing is very heavy
I tried to move it by myself
As a result, the old waist was flashed
But I heard that the RRU is much lighter now
RRU
Radio Remote Unit
It mainly completes RF signal modulation and demodulation, RF analog signal power amplification, and transmits it to the antenna feeder
RRU is mainly pole or wall mounted
▼Pole installation▼
▼Wall Mounting▼
Forgot to mention, BBU occasionally hangs on the wall to save space
Different from BBU, RRU is more installed outdoors
Antenna system
Next is the sky
Antenna and feeder including antenna and feeder
People often refer to "antennas"
However, the base station antenna may not be what you think
The most used antenna now is like this ▼
It is just a board, so it is also called "plate antenna"
Pole installation, very convenient
It also saves money and space
One pillar will do it
A "board" is a sector
It is a directional antenna
Usually installed at a high place with the board facing the covering direction
slanted downward at a certain angle
The figure below is a standard three-sector base station
(Have you found the RRU installed on the pole under the antenna?)
There are many types of antennas. . .
According to wavelength: medium wave antenna, short wave antenna, ultrashort wave antenna, microwave antenna...
According to performance: high gain antenna, medium gain antenna...
According to the direction: omnidirectional antenna, directional antenna, sector antenna...
By use: base station antenna, TV antenna, radar antenna, radio antenna...
According to the structure: line antenna, surface antenna...
According to system type: unit antenna, antenna array...
……
Mobile communication base stations are mainly plate directional antennas
There are also omnidirectional antennas
Everyone pay attention to this stuff in the red box in the picture below
we often see it on the tower
But it is not the antenna of the base station!
it is a microwave antenna
This antenna is called a parabolic antenna
Also called dish antenna
Sometimes, the base station is relatively remote,
It will send the signal to the telecommunications equipment elsewhere by means of microwave.
Emergency communication vehicles generally also have microwaves
(because it doesn't have a fixed line)
(look at the top of the antenna)
Except for microwave antennas
There are many other antennas
▼Yagi Antenna▼
▼Whip Antenna▼
Connect the antenna and the RRU's
is the feeder
Usually black, thicker
And more roots
The connector is also huge
In addition, you will often see a small white hat on the side of the antenna
This is a GPS mushroom head
For positioning and clock synchronization
tower
The antenna is mounted on the tower
There are also many types of towers
There are large base stations and small base stations.
Large base stations are called macro base stations (macro base stations)
Small base station is called micro base station (micro base station)
In addition to macro base stations and micro base stations
In order to solve the signal coverage problem at a lower cost
There is also a common equipment - repeater
Repeater
The following is a repeater
It looks similar to RRU
and this
The repeater is actually a signal repeater (Repeater)
Amplify the uplink and downlink RF signals
It is used to solve the coverage problem of the weak area of the signal blind area
The repeater is mainly cheap, and the cost is much lower than that of a base station
Indoor distribution system
Indoor signal coverage
has always been a big problem
Base stations are generally built on high places like the roof of a building.
Once people enter the building
Mobile phone is easy to have no signal
Especially the basement and parking lot
There is also an elevator
(Standard iron box, with proper shielding effect)
so
For indoor environments
Indoor distribution system will be specially laid out,
Also known in the industry as "room division"
"Room division" is actually the secondary relay and enhanced coverage of the signal
Feeder from source (e.g. microcell base station or repeater)
then to each room or passage
Reuse the antenna to send out the signal
It is very similar to the WiFi that everyone often uses
This is the one that everyone often sees overhead in the office
stuff like a pacifier
It is the ceiling antenna of "room division"
▼There are many styles▼
Miniaturized base station
nowadays
Base stations are developing towards miniaturization
On the one hand, because it does not take up space (saving rent = saving money)
On the other hand, it is also energy-saving and environmentally friendly (saving electricity = saving money)
The final deployment is more convenient and quick (saving labor = saving money)
If miniaturized
It is the combination of BBU and RRU
Or RRU and antenna-feeder combination
Simply, BBU, RRU, and antenna feed together
▼Nokia's "Backpack Base Station"▼
In the past, we fought back the radio station, and in the future we fought back the "base station"
tsk tsk~
In short, as small as it can be
and this
Does it look like a WiFi router at home?
it's called Femto
English meaning "one in a trillion, femto"
It is a low-power and small-area coverage home base station
base station identification
Okay! All that needs to be introduced!
As the so-called "experts watch the doorway, laymen watch the fun"
For all kinds of base stations
It is difficult for most people to tell which operator belongs to
but
The real "senior" communication wang
It can be judged by some details
long long ago
Each operator has its own base station
The style and characteristics of each base station are relatively easy to distinguish
E.g
China Mobile generally GSM900 and DSC1800 two G network frequency bands
So generally if you see a base station tower with two floors up and down
or just one layer
(In areas with few people, only G900, no D1800)
Then this base station is likely to be China Mobile.
In addition, the antenna of the DSC1800 is twice as short as that of the GSM900
Do you know why?
And China Unicom also has a CDMA network
So there will be more
If you see a base station with three layers of antennas
It is very likely that the base station of China Unicom
in addition
China Mobile compares local tyrants
The base stations are all beautifully built and tiled. . .
And if the base station house is more dilapidated
Usually connected. . .
You ask me about the base station of telecommunications?
Hold the grass. .
China Telecom had no mobile business before. . .
Telecom used to have PHS
"Half a mobile business"
(You should still remember?)
PHS antenna is very easy to recognize
That's it
No need to count, there are eight in total
Corresponding to the eight channels of PHS
But now PHS has withdrawn from the network
Some of these base stations were transformed into LTE base stations by Telecom
because
If major operators build their own base stations
It is easy to cause high cost and waste of resources
Therefore, my country established the "China Iron Tower"
Specially responsible for the infrastructure construction of the base station site
The three major operators lease sites to it
Avoid duplication of construction and malicious competition
Saved a lot of money and things
Base stations are co-located (that is, many base stations are stacked together)
It's more common now
