We can get a general idea from the name itself. The term "new open market" contains two words: "new" and "open market." This raises two questions: What is open market? And what's new about it?
What is the air interface? A mobile communication system mainly consists of three parts: terminals, base stations, and the core network, forming two subsystems. Terminals and base stations together form the base station subsystem, while the core network contains many complex network elements that make up the network subsystem.
What is air communication?
The terminal is generally our most commonly used mobile phone, the base station is the tower that transmits signals, and the core network is located at the very end; essentially, it's a router that connects the various base stations so they can communicate with each other. The interface between the mobile phone and the base station, which uses electromagnetic waves propagating through the air, is called the "air interface." Therefore, the air interface is specifically for the base station subsystem and has no direct connection to the core network. In the 5G era, the independence of the base station and core network subsystems has increased. Therefore, 5G is very flexible; it can be deployed independently or in a non-standalone network with 4G. In standalone deployment, 5G base stations connect to the 5G core network; in non-standalone deployment, 5G and 4G base stations can connect to either the 4G or 5G core network.
5G network deployment methods
The 5G base station subsystem includes both 4G and 5G base stations, and the network subsystem also includes both 4G core network and 5G core network. Furthermore, 5G base stations can connect to the 4G core network, and 4G base stations can also connect to the 5G core network. Therefore, the wireless and core networks are separated and evolve independently.
The composition of a 5G system is actually as follows:
What's new about 5G's "New Radio"? The image below shows the architecture of non-standalone (NSA) network options 3 and 7. In this architecture, both 4G and 5G base stations are connected to the same core network, forming a 5G NSA network system.
New air outlet
In this way, regardless of whether the core network being connected is 4G's EPC or 5G's 5GC, the same mobile phone has two air interface connections: the link with the 4G base station is the "old air interface," and the connection with the 5G base station is the so-called "new air interface." The 5G new air interface is designed based on 4G air interface technology and also uses OFDM modulation. It corrects some of the shortcomings of 4G in its frame structure, increases support for massive connectivity and low latency, and is therefore more flexible and has higher spectrum efficiency. How will operators deploy 5G NR?
There are three main approaches for operators to deploy 5G:
① Non-Standalone (NSA): LTE + 5G NR millimeter wave
This deployment method, exemplified by Verizon and AT&T in the United States, involves deploying 5G NR millimeter wave on existing LTE networks to supplement coverage hotspots or deploy 5G fixed wireless.
② Non-Standalone (NSA): LTE + NR bands less than 6GHz
This deployment method can quickly achieve better 5G NR coverage, but it involves the complexity of technologies such as the interface between 4G LTE and 5G NR and carrier aggregation.
For non-standalone deployments, there are two evolution paths:
Path 1: Option 3 series -> Option 2: Deploy the 5G radio access network first, then deploy the 5G core network, and finally migrate the 5G radio access network to the 5G core network.
Path 2: Option 3 series -> Option 7 series or Option 5: Deploy the 5G radio access network first, then deploy the 5G core network, and finally connect the 4G and 5G radio access networks together to the 5G core network.
③ Independent deployment
It involves directly deploying a complete 5G network, simplifying the migration process from non-standalone deployments to the 5G core network. It is less complex, but requires more complete and mature 5G coverage and ecosystem.
How is spectrum defined and allocated for 5G NR?
3GPP has specified a list of frequency bands supported by 5G NR, with a spectrum range of up to 100GHz, specifying two main frequency ranges:
①Frequency range 1 (FR1): This refers to the frequency band below 6 GHz.
• Frequency range:
• Maximum channel bandwidth 100MHz
②Frequency range 2 (FR2): This refers to the millimeter wave frequency band.
• Frequency range:
• Maximum channel bandwidth 400MHz
5G NR supports 16CC carrier aggregation.
Because 5G NR defines flexible subcarrier spacing, different subcarrier spacings correspond to different frequency ranges, as follows:
5G NR bands are divided into: FDD, TDD, SUL, and SDL. SUL and SDL are supplementary bands, representing uplink and downlink respectively.
Unlike LTE, 5G NR band numbers begin with "n", such as LTE's B20 (Band 20), while 5G NR is called n20.
The specific 5G NR frequency bands currently designated by 3GPP are as follows:
FR1 (450 MHz–6000MHz):
FR2:
As shown in the diagram above, 5G NR includes some LTE frequency bands and also adds some new frequency bands. Currently, the most likely 5G frequency bands to be deployed globally are n77, n78, n79, n257, n258, and n260, which correspond to 3.3GHz-4.2GHz, 4.4GHz-5.0GHz, and the millimeter wave bands 26GHz/28GHz/39GHz.
5G has been officially commercialized, and there are still many more new technologies for everyone to explore and learn. Let's work together to create a perfect 5G path, benefiting all walks of life. 5G is something to look forward to!
