5G System Learning --- User Equipment (UE) Radio Capability Information Indication

1. User equipment (UE) radio capabilities refer to the set of radio interface features supported by the UE. The UE reports these capabilities to the network so that the network can optimize service and resource allocation. These capabilities include supported radio access technologies (2G, 3G, 4G, 5G), supported frequency bands (low, mid, and high), and advanced features such as carrier aggregation, MIMO, and beamforming. The network uses this information during registration to customize the configuration for improved performance and compatibility.

2. 5G UE radio capabilities include:

• RAT and frequency band support: Information about the radio access technologies (such as 5G) and frequency bands (low, mid, and high bands) on which the UE can operate.
• Carrier aggregation: The ability to combine multiple frequency bands to increase data rates and capacity.
• Modulation and coding schemes: Supported methods for encoding and transmitting data.
• Advanced features: Support for features such as MIMO (multiple-input, multiple-output) and beamforming, which enhance signal quality and efficiency.
• Protocol stack parameters: Functionality related to the PDCP, RLC, and MAC layers. Radio Frequency Parameters: Specific characteristics of radio frequency components.
• FGI (Function Group Indicator) and Function ID: Identifiers used to indicate a function set and optimize signaling between the UE and the network.

3. The UE Radio Capability Information Indication procedure is intended to enable the NG-RAN node to provide information related to the UE's radio capabilities to the AMF. The UE Radio Capability Information Indication procedure uses UE-related signaling; successful operation is indicated as shown in Figure 8.14.1.2-1 below, where:

The NG-RAN node controlling the UE-associated logical NG connection initiates the procedure by sending a UE Radio Capability Information Indication message containing UE radio capability information to the AMF.

• The UE Radio Capability Information Indication message may also include paging-specific UE radio capability information in the UE Radio Paging Capability IE. If the UE Radio Paging Capability IE includes the UE NR Radio Paging Capability IE and the UE Radio Paging Capability E-UTRA IE, the AMF shall (if supported) use it as specified in TS 23.501.
• The UE radio capability information received by the AMF shall replace the UE radio capability information previously stored in the AMF, as specified in TS 23.501.
• If the UE Radio Capability Information Indication message contains the UE Radio Capability - E-UTRA Format IE, the AMF shall (if supported) use it as specified in TS 23.501.
• If the UE Radio Capability Information Indication message contains the XR Device (with 2Rx) IE, the AMF shall (if supported) store this information and use it accordingly.