SPS Release Signaling During Same-Slot PDSCH Transmission

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Solution Overview

Problem

In Release 15, a UE does not expect to receive SPS PDSCH release and unicast PDSCH in the same slot, but with the introduction of one-slot periodicity in Release 16, there is no slot without a PDSCH allocation, making it impossible to send an SPS release command.

Innovation Solution

The method allows for transmitting an SPS release command in the same slot as a PDSCH transmission by determining the UE's capability to receive both, and adjusting the timing of the SPS release command to ensure proper HARQ-ACK handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If one-slot periodicity is introduced for SPS in Release 16, then scheduling efficiency and resource allocation flexibility are improved, but the ability to transmit SPS release commands is lost because there is no slot without PDSCH allocation

Engineering Contradiction:

Improvescheduling efficiencyVSAvoidSPS release command transmission

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The slot is segmented into different time periods: first period for SPS release command transmission and second period for PDSCH transmission. This allows both functions to coexist in the same slot without interference, resolving the contradiction between maintaining one-slot periodicity for efficiency and enabling SPS release command transmission.

Inventive Principle:

Principle #1Segmentation

2Productivity

If SPS release command is transmitted in the same slot as PDSCH transmission, then network efficiency is improved, but HARQ-ACK handling becomes complex and error-prone

Engineering Contradiction:

Improvenetwork efficiencyVSAvoidHARQ-ACK handling

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The slot is divided into two distinct time periods: the first period is dedicated to transmitting the SPS release command, and the second period is dedicated to PDSCH transmission and its corresponding HARQ-ACK. This temporal segmentation ensures that HARQ-ACK for SPS release and PDSCH do not collide, maintaining reliability while achieving network efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The SPS release command is transmitted in advance during the first period of the slot, before the PDSCH transmission in the second period. This preliminary action allows the UE to properly prepare for and handle the HARQ-ACK process without confusion, ensuring reliable operation when both transmissions occur in the same slot.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20260067884A1Systems and methods for transmitting a semi-persistent scheduling (SPS) release command to a user equipment (UE)

Publication Date: 2026.03.05 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method performed by a UE. The method includes the UE decoding an SPS release command transmitted by a base station. The SPS release command is for releasing an active configured SPS in a slot in which the UE expects to receive a Physical Downlink Shared Channel (PDSCH) transmission for the configured SPS and the UE receives the SPS release command before the end of the resource in which the UE expects to receive the PDSCH transmission and the end of the SPS release downlink control information (DCI) comes before or at the end of PDSCH.