NB-IoT SPS Activation and Deactivation via Reduced Search Space Monitoring

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Solution Overview

Problem

Current LTE systems do not support semi-persistent scheduling (SPS) for Narrowband Internet of Things (NB-IoT) devices, leading to increased power consumption due to frequent monitoring of downlink control channels, which is inefficient for low-power devices with predictable traffic patterns.

Innovation Solution

Configuring a reduced search space for NB-IoT devices to monitor downlink control information (DCI) for activating or deactivating SPS, allowing less frequent monitoring and reducing power consumption while maintaining scheduling flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If NB-IoT devices monitor downlink control channels frequently to receive scheduling information, then scheduling flexibility is maintained, but power consumption increases significantly

Engineering Contradiction:

Improvescheduling flexibilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent segments the control channel monitoring function by introducing a dedicated search space for SPS activation/deactivation DCIs, separate from the main search space for dynamic scheduling. This allows devices to monitor only the essential SPS control information less frequently, reducing power consumption while maintaining scheduling flexibility through the segmented monitoring approach.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic monitoring of the dedicated search space for SPS activation/deactivation DCIs at configured intervals rather than continuous monitoring. This periodic action allows the device to maintain scheduling flexibility for SPS while significantly reducing overall power consumption by sleeping between monitoring intervals.

Inventive Principle:

Principle #19Periodic action

2Use of energy by moving object

If a reduced search space is configured for SPS DCI monitoring, then power consumption is reduced, but the complexity of scheduling control increases

Engineering Contradiction:

Improvepower consumptionVSAvoidscheduling control complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent extracts the SPS activation/deactivation DCI monitoring function from the main control channel monitoring process by creating a dedicated search space. This extraction simplifies the device's scheduling control by separating SPS-specific monitoring from general dynamic scheduling monitoring, reducing the complexity burden on the device while enabling lower power consumption.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies local quality by creating a dedicated search space with specific properties (smaller size, specific DCI formats) tailored for SPS activation/deactivation only. This localized approach reduces the device's processing complexity by focusing monitoring resources only on SPS-related information rather than all possible control information.

Inventive Principle:

Principle #3Local quality

3Use of energy by moving object

If SPS is activated for NB-IoT devices, then power consumption is reduced through less frequent monitoring, but the need for precise DCI detection in reduced search space increases

Engineering Contradiction:

Improvepower consumptionVSAvoidDCI detection precision

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-configuring the dedicated search space parameters, DCI formats, and monitoring intervals before the device needs to operate in low-power mode. This pre-configuration ensures that when the device monitors the reduced search space, it can do so with high precision using known parameters, eliminating the need for complex real-time detection while maintaining low power consumption.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12363743B2Activation and de-activation of semi-persistent scheduling

Publication Date: 2025.07.15 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method performed by a wireless device, UE, for configuring a semi-persistent scheduling, SPS is described. In accordance with the method, the UE may be configured to monitor a first search space of a physical downlink control channel for downlink control information, DCI, dedicated to the UE. The method may include receiving from the communication network SPS configuration data to configure a second search space to be monitored by the UE for DCI to activate or de-activate the SPS, the second search space being smaller than the first search space, and monitoring the second search space to detect the DCI to activate or de-activate the SPS. A corresponding method may be performed by a network node.