5G NSA Option 3, 3a, 3x
NSA Option 3
The Option 3 series is divided into 3, 3a and 3x. The difference lies in data split anchor.
The base station of Option 3 series is connected to 4G core network, and the anchor points of the control plane are all in 4G core. It is suitable for the initial phase of 5G deployment, when the coverage is not continuous, and there is not much 5G service. It exists purely as a supplement to 4G wireless broadband.
Option 3
As shown in the figure above, the data split anchor of Option 3 is on the 4G base station. That is to say, 4G is not only responsible for the control and management, but also responsible for splitting the data from the core network into two paths: one is sent to mobile phones by itself, and the other is distributed to 5G base stations to send to mobile phones.
In order for the 4G base station to handle the heavy tasks, software upgrade is required but still it might be too big a challenge to handle all the 5G traffic.
As a result, Option 3 has been rather unpopular and has not received much attention since it was proposed.
NSA Option 3a
Option 3a
Option 3a makes some improvements by placing the data split anchor on the 4G core network, which distributes user data to the 4G and 5G base stations. While this is much better than option 3, it would require a major upgrade to the 4G core network.
NSA Option 3x
Option 3x
Option 3x cleverly places the data split anchor on the 5G base station. In this way, Option 3x avoids making too many changes to the 4G base stations and 4G core network already in operation, and takes advantage of the fast speed and strong capability of 5G base stations. Therefore, it has been widely adopted by the industry and has become the first choice for 5G NSA networking deployment.
Advantages and Disadvantages of NSA Option 3 Series
In summary, the advantages, disadvantages and applicable scenarios of Option 3 series are as follows:
Advantages:
1. It has the earliest completion time of standardization.
2. There is no requirement for 5G coverage, and dual connection is supported for streaming, providing good user experience.
3. Small network changes, fast network construction, relatively smaller investment.
Disadvantages:
1, 5G base stations and the existing 4G base stations must work together, so they need to come from the same manufacturer, which brings low flexibility.
2. Unable to support new functions and services introduced by the 5G core network.
Applicable scenario:
To rapidly provide commercial 5G service for high-value zones. Option 3x is recommended.
Terms Explanation
Control plane: the channel to send the signaling required to manage and schedule resources.
User plane: the channel to send the user data. The user plane and the control plane are completely separate.
Dual connection: As the name suggests, the mobile phone can communicate with both 4G and 5G networks and download data at the same time. Typically, there will be a master connection and a slave connection.
Control plane anchor: the base station responsible for the control plane in the dual connection is called control plane anchor.
Data split anchor: the user's data needs to be split for transmission in the two paths of dual connection, but where should it be split? This location is called data split anchor.
