Base-Station SPS Release Signaling With Same-Slot PDSCH
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Solution Overview
Problem
In Release 16 of 5G, UEs configured for DL-SPS with one-slot periodicity face challenges as there is no slot without PDSCH where the gNB can send an SPS release command, violating existing UE expectations regarding SPS and unicast PDSCH reception in the same slot.
Innovation Solution
The method allows for transmitting an SPS release command in the same slot as a PDSCH transmission by determining UE capability to receive both, and adjusting the HARQ-ACK procedures to prioritize or separate SPS release and unicast PDSCH acknowledgments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If SPS is configured with one-slot periodicity, then transmission frequency is increased, but there is no slot without PDSCH where gNB can send SPS release command
Solution Approach 1:
The patent combines SPS release command transmission with PDSCH transmission by allowing both to occur in the same slot. The gNB transmits the SPS release command in the PDCCH of the slot where PDSCH is also transmitted, merging two previously separate operations into one time slot. This resolves the contradiction by enabling SPS release capability while maintaining one-slot periodicity transmission frequency.
2Productivity
If UE receives both SPS release command and unicast PDSCH in the same slot, then network efficiency is improved, but UE processing complexity increases
Solution Approach 1:
The patent segments the UE's reception processing into distinct handling paths for SPS release command and unicast PDSCH. The UE identifies which PDCCH carries the SPS release command (using CS-RNTI) and processes it separately from the PDSCH reception processing. This segmentation allows the UE to manage both transmissions in the same slot without overwhelming processing complexity, as each transmission type follows its own established processing procedures.
3Loss of time
If SPS release command is transmitted in slot with PDSCH, then latency is reduced, but existing UE expectations are violated
Solution Approach 1:
The patent applies preliminary action by having the UE prepare for both PDSCH reception and SPS release command processing in advance. The UE is configured to expect and handle the SPS release command in the PDCCH of the slot where PDSCH is transmitted. This preliminary preparation ensures that when both transmissions occur in the same slot, the UE can process them correctly without violating its expectations, as the release command handling is pre-established through configuration.
Data Source
AI summary
A method (700) performed by abase station. The method includes transmitting (s702) configuration information to a user equipment, UE, the configuration information for configuring the UE for semi-persistent scheduling, SPS. The method also includes transmitting (s704) an SPS activation command for activating the configured SPS. The method also includes determining (s706) whether the UE is capable to receive a) an SPS release command for releasing the configured SPS and b) a physical downlink shared channel, PDSCH, transmission for the configured SPS in the same slot. The method also includes, after determining that the UE is capable to receive a) the SPS release command for releasing the configured SPS and b) the PDSCH transmission for the configured SPS in the same slot, transmitting (s708) the SPS release command in a slot in which the UE expects to receive the PDSCH transmission for the configured SPS.