NTN PRACH Configuration Adaptation for Low-Power UEs

The patent applies local quality by providing different PRACH configurations tailored to specific UE transmit power levels. Low power UEs receive configurations with additional RACH occasion repetitions to ensure reliable link closure, while high power UEs use standard configurations. This differentiated approach ensures each UE type receives optimized parameters for its specific transmission capabilities, resolving the contradiction between maintaining standard complexity and improving reliability for vulnerable devices.

The patent changes key RACH parameters including the number of RACH occasion repetitions, PRACH format selections, and resource allocation patterns based on UE transmit power categories. By dynamically adjusting these parameters rather than using fixed standard configurations, the system achieves improved reliability for low power UEs without unnecessarily complicating the overall RACH framework, as high power UEs continue to use efficient standard parameters.

The patent segments the RACH procedure into distinct configurations based on UE power levels. Low power UEs are assigned specific RACH occasions with repetitions scheduled in dedicated time slots, while high power UEs use standard single-shot procedures. This segmentation allows the system to pay the time penalty only for the subset of UEs that actually need the repetitions, rather than extending RACH time for all devices, thus improving link closure reliability for vulnerable UEs while minimizing overall time loss.

The patent implements periodic RACH occasion repetitions for low power UEs, where the same PRACH preamble is transmitted multiple times at scheduled intervals. This periodic transmission increases the probability of successful reception by the satellite despite low transmit power, while the periodic structure allows the network to predict and plan resource allocation efficiently, preventing unbounded time extension.

The patent enables UEs to self-identify their transmit power category and autonomously select the appropriate PRACH configuration from predefined sets. The network broadcasts multiple configuration options with clear identification markers, and each UE independently chooses the configuration matching its power capabilities. This self-service mechanism eliminates the need for complex network-side UE classification and manual configuration assignment, achieving high adaptability to different power levels while keeping configuration management simple through UE autonomy.

The patent creates a universal RACH configuration framework that serves multiple UE power levels through a single standardized interface. The network broadcasts a set of configurations that collectively support both low and high power UEs using the same signaling mechanisms and resource structures. Each configuration is designed to be self-descriptive, allowing any UE to determine its appropriate configuration without network intervention, thus achieving multi-functionality across different device types while maintaining configuration management simplicity.