Macro base stations, distributed base stations, small base stations

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Macro base stations, distributed base stations, small base stations [Copy link]

Base stations are public mobile communication base stations, which are a form of radio stations. They refer to radio transceiver stations that transmit information to mobile phone terminals through mobile communication exchange centers in a certain radio coverage area.

At present, in the 5G era, the networking mode of "macro base stations as the main and small base stations as the auxiliary" is the main way to improve network coverage in the future. The main reason is that the 5G era uses 3.5G and above frequency bands, and the coverage range is reduced in outdoor scenarios. In addition, due to the high cost of macro base station deployment, small base stations are required to cooperate with networking. According to the rules formulated by 3GPP, wireless base stations can be divided into four categories according to their functions, namely macro base stations, micro base stations, pico base stations and flying base stations.

From the equipment division

In terms of equipment classification, mobile communication base stations are mainly divided into integrated base stations and distributed base stations. Integrated base stations are divided into three parts: baseband processing unit (BBU), radio frequency processing unit (RRU) and antenna feed system, while distributed base stations refer to small RRUs that need to be connected to BBU for normal use.

Macro base station
Macro base station refers to the wireless signal transmission base station of the communication operator. The coverage distance of macro base station is large, generally 35Km, suitable for suburban areas with relatively scattered traffic, omnidirectional coverage, and high power;
micro base station is mostly used in cities, with a small coverage distance, generally 1-2km, and directional coverage;
micro-micro base station is mostly used for blind coverage of urban hot spots, generally with very low transmission power and a coverage distance of 500m or less.
The equipment power of macro station is generally 4-10W, which is converted into a wireless signal ratio of 36-40dBm, plus the gain of the base station coverage antenna of 20dBi, which is 56-60dBm. If such power is irradiated on a person, no one can bear it, and it will definitely be barbecued. However, in the range of our lives, there is a lot of air, dust, various sounds and various objects, which can block a lot of electromagnetic radiation, so when high-power electromagnetic waves are emitted from the base station antenna, they have become very weak when they reach us.

Distributed base station
Distributed base station is a new generation of modern products used to complete network coverage. Its main feature is that the radio frequency processing unit and the traditional macro base station baseband processing unit are separated and connected through optical fiber. The core concept of the distributed base station structure is to separate the traditional macro base station baseband processing unit (BBU) and the radio frequency processing unit (RRU), and the two are connected through optical fiber. When the network is deployed, the baseband processing unit is concentrated in the machine room with the core network and wireless network control equipment, and connected to the radio frequency remote unit deployed on the planned site through optical fiber to complete network coverage, thereby reducing construction and maintenance costs and improving efficiency.
Distributed base stations divide traditional macro base station equipment into two functional modules according to their functions. The baseband, main control, transmission, clock and other functions of the base station are integrated into a module called the baseband unit (BBU Base Band Unit). The baseband unit is small in size and has a very flexible installation position; the transceiver, power amplifier and other intermediate radio frequency are integrated in another module called the remote radio frequency module, and the radio frequency unit (RRU Remote Radio Unit) is installed at the antenna end. The radio frequency unit and the baseband unit are connected by optical fiber to form a new distributed base station solution.

From the perspective of volume division
From the perspective of volume division, the difference between macro base stations and small base stations is that the small and micro base station equipment can be deployed in a unified cabinet plus an antenna, and the volume is relatively small. Macro base stations require separate machine rooms and towers, and the equipment, power cabinets, transmission cabinets, and air conditioners are deployed separately, which is relatively large. Advantages of small base stations: At present, small base stations have become an effective supplement to macro base stations, mainly because the signal transmission coverage radius of small base stations is small, suitable for precise coverage in a small range, and easier to deploy (high mobility and high-speed wireless access), flexible (not easily blocked by obstacles, improving signal coverage efficiency, and improving the effective extension of macro base station signals), and can be based on different application scenarios (shopping malls, subways, airports, tunnels, etc.), Make corresponding small base station equipment and network construction modes to improve signal requirements.
Base stations and small base stations work better together through UDN: Because 5G needs to select more spectrum resources and meet greater traffic growth, and needs to target business network scenarios such as wide coverage, high capacity hotspots, low latency, high reliability, and large-scale MTC. Ultra-dense networking (UDN, Ultra-Dense Network) is a technical path based on micro base stations. UDN is used to build new macro base stations and increase the density of micro base stations per unit area, which is an important option to solve the rapid growth of mobile data traffic in hot spots. Under ultra-dense networking, macro base stations and small base stations work more closely together.

Honghuzaitian

If so many base stations have a wide bandwidth, will they be universal? Because it seems a bit of a waste of resources that many networks are not universal.

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