5G NSA Option 7, 7a, 7x

NSA Option 7

Option 7 Series is a step closer to 5G than the Option 3 Series. In this series, the core network has been switched to the 5G core. In order to connect with the 5G core network, the 4G base station has also been upgraded to an enhanced 4G base station.

However, the control plane anchor of Option 7 series is still on 4G, which is suitable for the early and middle stages of 5G deployment. The coverage is not continuous yet. However, since the core network of 5G has been deployed, in addition to the most basic mobile broadband, the other two services, mMTC and uRLLC, can also be supported.

For this option, the 5G service capability is greatly enhanced, but the coverage needs to be supplemented by 4G.

The Option 7 series is also divided into 7, 7a and 7x, which are differentiated by where data split anchor is located.

Option 7

Option 7a

Option 7x

The data split anchor of Option 7 is in the enhanced 4G base station, Option 7a is in the 5G core network, and Option 7x is in the 5G base station.

Similar to Option 3 series, both Option 7a and 7x are acceptable, but Option 7x is more popular.

Advantages and Disadvantages of NSA Option 7 Series

In summary, the advantages, disadvantages and applicable scenarios of Option 7 series are as follows:

Advantages:

1. There is no requirement for 5G coverage, so we can take advantage of 4G coverage.

2. Dual connection is supported to improve network speed and provide good user experience.

3. 5G core network is introduced to support new 5G functions and services.

Disadvantages:

1. Heavy workload is required to upgrade 4G base stations.

2. The industry might be relatively late to become mature.

3. 5G base stations and enhanced 4G base stations must work together, so they need to come from the same manufacturer, which brings low flexibility.

Applicable scenario:

In the early and mid-phase of 5G deployment, continuous coverage is provided by enhanced 4G base stations, and 5G is used for high-value zones to improve capacity. Option 7x 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.