RRC_INACTIVE BWP Switching for Timely Uplink Transmission

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in managing resource allocation and power consumption in the RRC_INACTIVE state, leading to potential overloading of bandwidth parts and suboptimal support for uplink timing adjustments.

Innovation Solution

Introduction of an INACTIVE DL BWP for downlink communication in the RRC_INACTIVE state, allowing for flexible resource management and improved support for uplink timing adjustments through optimized air interface configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the UE uses the initial BWP for uplink transmission in RRC_INACTIVE state, then the network resource allocation is simplified, but the bandwidth may be insufficient for timely uplink communications

Engineering Contradiction:

Improveuplink transmission timelinessVSAvoidBWP configuration complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the BWP configuration into two distinct types: initial BWP for basic uplink access and dedicated BWP for optimized uplink transmission. This segmentation allows the system to use the simple initial BWP for initial access while switching to the dedicated BWP for timely uplink communications, resolving the contradiction between simplicity and performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic BWP switching capability that allows the UE to transition between initial BWP and dedicated BWP based on transmission requirements. This dynamic adaptation enables the system to maintain simplicity when possible while achieving high performance when needed, resolving the timeliness vs. complexity contradiction.

Inventive Principle:

Principle #15Dynamics

2Reliability

If the network allocates dedicated resources for each UE in RRC_INACTIVE state, then uplink timing adjustment is improved, but network resource overhead increases

Engineering Contradiction:

Improveuplink timing accuracyVSAvoidnetwork resource overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent creates a dedicated BWP configuration that can serve multiple UEs in RRC_INACTIVE state with similar requirements. This dedicated BWP is not exclusively assigned to one UE but can be shared among multiple UEs, providing improved timing accuracy while avoiding the resource overhead of individual dedicated allocations for each UE.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent modifies BWP parameters (bandwidth, frequency location, subcarrier spacing) to create optimized configurations for uplink transmission. By adjusting these parameters, the system achieves better timing accuracy without requiring full dedicated resource allocation, thus reducing overall network overhead while maintaining reliability.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the UE monitors paging in RRC_INACTIVE state, then network reachability is maintained, but power consumption increases

Engineering Contradiction:

Improvenetwork reachabilityVSAvoidUE power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements discontinuous reception (DRX) with periodic monitoring cycles for paging in RRC_INACTIVE state. Instead of continuous monitoring, the UE wakes up at predetermined intervals to check for paging messages and then returns to sleep mode. This periodic action maintains network reachability while dramatically reducing power consumption compared to continuous monitoring.

Inventive Principle:

Principle #19Periodic action

4Adaptability or versatility

If the UE switches BWP frequently in RRC_INACTIVE state, then transmission adaptability is improved, but processing overhead increases

Engineering Contradiction:

Improvetransmission adaptabilityVSAvoidBWP switching delay

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent pre-configures multiple BWPs with different characteristics (bandwidths, subcarrier spacings, frequency locations) before the UE enters RRC_INACTIVE state. These pre-configured BWPs are stored in the UE's context, allowing rapid switching without real-time configuration processing. This preliminary action enables transmission adaptability while minimizing switching delays.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP4042828B1Methods for resource configuration for transmission in inactive state

Publication Date: 2026.01.28 HUAWEI TECH CO LTD

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AI summary

Some aspects of the present disclosure introduce a new downlink (DL) bandwidth part (BWP) and a new uplink (UL) BWP for communication in the RRC_INACTIVE state. In addition, aspects of the disclosure also provide for configuring generic parameters of the BWP, which include, but not limited to, frequency location, bandwidth, subcarrier spacing (SCS), and cyclic prefix (CP). Some aspects of the present disclosure may support a reinterpretation of generic parameters of a BWP, for example which may be configured for the RRC_CONNECTED state, to be used in the RRC_INACTIVE state. Some aspects of the present disclosure are directed to implicit DL BWP switching in the RRC_INACTIVE state where no BWP identifier (ID) indication is needed as part of the switching mechanism.