Inactive-State PDCCH Scheduling for Subsequent UE Transmission

Solution Overview

Problem

In wireless communication networks, UEs in RRC_INACTIVE state experience unnecessary power consumption and signaling overhead due to frequent transitions to RRC_CONNECTED state for small and infrequent data transmissions, which undermines the latency and efficiency benefits of the INACTIVE state.

Innovation Solution

A base station apparatus and method that allows UEs to monitor network scheduling through a physical downlink control channel (PDCCH) for subsequent data transmissions during an active period without transitioning to RRC_CONNECTED state, using dedicated scheduling configurations and timers to manage this monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If UE transitions to RRC_CONNECTED state for small data transmissions, then data transmission can be performed, but power consumption increases and signaling overhead increases

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent segments the RRC_CONNECTED state into two distinct states: RRC_INACTIVE for small data transmissions and RRC_CONNECTED for large data transmissions. This segmentation allows the system to maintain connectivity for small data without triggering full state transitions, thereby reducing power consumption while preserving data transmission capability when needed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by pre-configuring the UE with a timer and PDCCH monitoring capabilities during RRC_INACTIVE state. When data transmission is needed, the UE can immediately utilize these pre-configured resources to transmit small data without first transitioning to RRC_CONNECTED state, thus avoiding the signaling overhead and power consumption associated with state transitions.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If UE transitions to RRC_CONNECTED state for small data transmissions, then data transmission can be performed, but signaling overhead increases

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidsignaling overhead

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the RRC_CONNECTED state into two distinct states: RRC_INACTIVE for small data transmissions and RRC_CONNECTED for large data transmissions. This segmentation allows the system to maintain connectivity for small data without triggering full state transitions, thereby reducing power consumption while preserving data transmission capability when needed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by pre-configuring the UE with a timer and PDCCH monitoring capabilities during RRC_INACTIVE state. When data transmission is needed, the UE can immediately utilize these pre-configured resources to transmit small data without first transitioning to RRC_CONNECTED state, thus avoiding the signaling overhead and power consumption associated with state transitions.

Inventive Principle:

Principle #10Preliminary action

3Use of energy by moving object

If UE returns to INACTIVE state after first transmission, then power saving is achieved, but network must perform RAN paging to trigger UE return to CONNECTED state for feedback reception

Engineering Contradiction:

Improvepower consumptionVSAvoidfeedback transmission latency

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the UE configure a timer and continue monitoring PDCCH for a predetermined period after the initial data transmission while remaining in RRC_INACTIVE state. This preliminary configuration eliminates the need for RAN paging to trigger feedback reception, as the UE is already prepared to receive and process feedback data within the configured time window, thus reducing feedback transmission latency while maintaining power savings.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent enables continuity of useful action by allowing the UE to continue monitoring the PDCCH for subsequent data transmissions during the active period without transitioning to RRC_CONNECTED state. This continuous monitoring capability ensures that feedback and subsequent data can be received immediately without the interruption and signaling overhead associated with state transitions, thereby reducing latency while maintaining power efficiency.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS20260006675A1Methods and apparatus of a base station for subsequent transmission in inactive state in wireless communication

Publication Date: 2026.01.01 APPLE INC

AI summary

A base station (BS) comprising a processor configured to perform operations is described. In an exemplary embodiment, the operations include receiving an initial data from a UE is in a RRC_INACTIVE while the UE does not transition from the RRC_INACTIVE state to a RRC_CONNECTED state. In addition, the operations include transmitting a physical downlink control channel (PDCCH) for a UE dedicated scheduling for a transmission or reception of a subsequent data during an active period, while the UE is in the RRC INACTIVE state. Furthermore, the operations include receiving or transmitting the subsequent data transmission based on the dedicated scheduling. The operations additionally include transmitting one or more configurations for the transmission or reception of the subsequent data. The one or more configurations is transmitted as part of the RRC release message. The one or more configurations is transmitted as part of a System Information Block (SIB).