Two-Step Grant Active Time Handling for Uplink

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Solution Overview

Problem

In the current Discontinuous Reception (DRX) framework of LTE, user equipment (UE) may not be in Active Time before receiving a complete uplink transmission grant, leading to missed messages from the eNB due to not monitoring the PDCCH channel effectively.

Innovation Solution

The UE is configured to enter Active Time upon receiving the first trigger of a two-step grant, allowing it to listen on the physical downlink control channel for messages from the network even before the complete grant is provided, enabling the eNB to send messages during this time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the UE enters DRX sleep mode to save battery power, then energy consumption is reduced, but the UE cannot receive messages from the network during sleep periods

Engineering Contradiction:

Improvebattery power consumptionVSAvoidmessage reception reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The UE enters Active Time upon receiving the first trigger of a two-step grant before the complete grant is received. This preliminary action ensures the UE is awake and monitoring PDCCH when the eNB may send messages, preventing missed communications while still allowing DRX sleep for extended periods between grants

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the UE monitors PDCCH continuously to ensure no messages are missed, then message reception reliability is improved, but energy consumption increases

Engineering Contradiction:

Improvemessage reception reliabilityVSAvoidbattery power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The UE uses periodic DRX cycles with Active Time periods strategically aligned with two-step grant reception. Instead of continuous monitoring, the UE wakes up periodically during Active Time to monitor PDCCH, achieving reliable message reception during critical periods while conserving energy during sleep periods

Inventive Principle:

Principle #19Periodic action

3Use of energy by moving object

If the UE waits for the complete two-step grant before entering Active Time, then energy is saved by staying in DRX sleep, but messages from eNB may be missed during the waiting period

Engineering Contradiction:

Improvebattery power consumptionVSAvoidmissed messages

Core Design Contradiction:

Use of energy by moving objectVSLoss of information

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11968737B2Active time handling with 2-step granting

Publication Date: 2024.04.23 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A wireless communications device, operating according to a DRX configuration and configured to receive two-step grants for uplink transmissions, determines whether the device has received a first trigger of a two-step grant. The device enters a state in which the device listens on a physical downlink control channel for messages from the network, in response to determining that the device has received the first trigger, without necessarily receiving the second trigger.