5G Terminal AM (Access and Mobility) Application Examples

In 5G (NR) systems, the policy management and execution of network and terminal service capabilities are entirely guaranteed by the PCF (Policy Control Function) and AMF (Mobility Function), which are also known as AM policy management. Application examples are as follows:

Example 1: AM/UE Policy Control Based on Consumption Limits This is a new function introduced by 3GPP in Rel-18, allowing the PCF responsible for the UE to perform AM/UE policy decisions in non-roaming scenarios based on available consumption limit information (such as whether the user's daily/weekly/monthly mobile data consumption limit has been reached or is close to being reached). This example demonstrates how to implement the operator's AM/UE policy management policy in the PCF.

• The PCF interacts with the CHF (Charging Function) to request and/or subscribe to receive consumption limit-related reports for one or more "policy counters" (i.e., consumption limit indicators). Once configured, the CHF will notify the PCF of any changes to the current or pending status of subscribed policy counters, and optionally, the activation time of pending statuses (e.g., due to an upcoming billing cycle expiration). The PCF will then use all these dynamically collected policy counter states and related information as input to its internal policy decisions to apply relevant pre-configured operator-defined actions.

With this functionality, operators can dynamically configure, establish, and execute AM/UE policy decisions (such as downgrading or upgrading the UE-AMBR, changing URSP rules, and updating service area restrictions) based on expenditure limit information.

In 3GPP Rel-19, this functionality is further extended to roaming scenarios to support dynamic changes to UE policies based on expenditure limit information.

Example 2: Network-Assisted Performance Level Enhancement Using Frequency Management Recommendations AM policy management plays a crucial role in improving network performance by enhancing RFSP index management.

• The PCF can implement more dynamic and differentiated mobility control policies. The PCF can provide RFSP index values ​​to the AMF to assist in frequency selection and enable finer-grained radio resource management at the UE end.
• PCF determines the RFSP index values ​​to provide based on multiple factors, such as cumulative usage information (e.g., usage volume, usage duration, or both), network analysis data from NWDAF (including current load levels of relevant network slice instances or UE communication-related information), UE communication behavior information, user data congestion information, and perceived service experience.

This flexible frequency selection and mobility management policy framework enhances user experience, optimizes network efficiency, and supports differentiated service delivery across different user groups and network conditions.

With the introduction of 5G-A (3GPP Rel-18 and later) and artificial intelligence technologies, these capabilities will be further enhanced, enabling more autonomous, dynamic, and intelligent network management. This paves the way for increased control over how the network treats user equipment (UEs), such as: real-time policy management based on AI-native network architecture and intent-driven automation; more granular UE differentiation for personalized experiences; and efficient connection of a large number and diverse range of UEs (e.g., IoT devices, sensors). We look forward to the rollout of these exciting new features and application scenarios in the future.