Dual-Connectivity Power Headroom Reporting Across Cell Groups
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Solution Overview
Problem
In dual connectivity scenarios, existing technologies fail to efficiently report power headroom (PH) for each activated serving cell with uplink, which could lead to erroneous decisions by the node that does not effectively address the power headroom reporting (PHR) in dual connectivity scenarios, especially when a Medium Access Control (MAC) entity is not configured with the two-PHR mode, leading to incomplete information and erroneous scheduling.
Innovation Solution
A method is proposed where a terminal device obtains a power headroom (PH) corresponding to a serving cell in a first cell group (CG) based on combined transmission power of multiple physical uplink shared channel (PUSCH) transmissions, and transmits a PH report (PHR) to a second CG, even if the second CG is not configured with the two-PHR mode, thereby providing a flexible and efficient PH reporting mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a MAC entity is not configured with the two-PHR mode, then the conventional PHR procedure cannot be applied, but this leads to incomplete power headroom information and erroneous scheduling decisions
Solution Approach 1:
The patent implements dynamic PHR reporting by allowing the terminal to adaptively select between reporting single PH values and combined PH values based on the configuration of the second CG. When the second CG is configured with two-PHR mode, the terminal reports separate PH values for each PUSCH transmission; when not configured, the terminal reports combined PH values. This dynamic adaptation ensures reliable scheduling decisions while maintaining compatibility across different configuration scenarios.
2Loss of information
If the enhanced PHR MAC CE is used for multiple TRP PUSCH transmissions, then two PH values can be reported, but this increases reporting overhead and complexity for legacy network nodes
Solution Approach 1:
The patent applies local quality by making the PHR reporting format adaptive to the specific configuration of the receiving CG. The terminal device determines whether to report combined PH or separate PH1/PH2 values based on whether the second CG is configured with two-PHR mode. This localized adaptation ensures that complete power headroom information is provided where needed (when second CG supports two-PHR mode) while maintaining simplicity for legacy nodes (when second CG does not support two-PHR mode).
Solution Approach 2:
The patent changes the PHR reporting parameters dynamically based on the configuration of the second CG. The key parameter change is between reporting a single combined PH value versus reporting separate PH1 and PH2 values. This parameter adaptation allows the system to optimize information completeness for advanced network nodes while maintaining compatibility and reducing overhead for legacy network nodes.
3Measurement precision
If separate PH values are reported for each PUSCH transmission, then accurate power information is provided, but this increases reporting overhead when dealing with legacy network nodes
Solution Approach 1:
The patent implements partial action by selectively reporting only the necessary PH information based on the capabilities of the second CG. When the second CG is configured with two-PHR mode, the terminal reports separate PH1 and PH2 values for precise power information. When the second CG is not configured with two-PHR mode, the terminal reports a single combined PH value, providing sufficient information for legacy nodes while minimizing reporting overhead. This partial reporting strategy optimizes the balance between measurement precision and overhead reduction.
Data Source
AI summary
Embodiments of the present disclosure relate to power headroom in dual connectivity. A terminal device obtains a power headroom, PH, corresponding to a serving cell in a first cell group, CG, based on combined transmission power of multiple physical uplink shared channel, PUSCH, transmissions in the serving cell. Then, the terminal device transmits a PH report, PHR, comprising information of the obtained PH to a second CG. In this way, the actual power status for serving cells configured with multiple transmissions in a cell group and reception points, TRPs, can be reported to another cell group configured without two-PHR mode.