RedCap PDSCH Scheduling for Over-5 MHz Broadcast Reception

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Solution Overview

Problem

Reduced capability (RedCap) user equipment (UE) faces challenges in handling broadcast PDSCH that is larger than 5 MHz, such as random access response (RAR) and paging channels, due to bandwidth limitations, leading to unclear network and UE handling procedures.

Innovation Solution

RedCap UEs implement specific procedures to handle broadcast PDSCH larger than 5 MHz by adjusting processing timelines and transmission rules, including retransmitting PRACH if time duration exceeds a threshold, and applying modified processing times based on bandwidth and subcarrier spacing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If RedCap UEs are equipped with reduced bandwidth capability (5 MHz for data channels) to reduce device complexity and cost, then device complexity and cost are reduced, but the ability to handle broadcast PDSCH larger than 5 MHz becomes limited

Engineering Contradiction:

ImproveUE bandwidth capabilityVSAvoidability to handle broadcast PDSCH

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The network performs preliminary actions by scheduling broadcast PDSCH within 5 MHz bandwidth for RedCap UEs, ensuring compatibility before transmission. The gNB identifies RedCap UEs and restricts broadcast PDSCH scheduling to the reduced bandwidth, preventing the UE from receiving bandwidth allocation it cannot process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system segments UE handling into two groups: RedCap UEs with 5 MHz bandwidth capability and non-RedCap UEs with full bandwidth capability. Different scheduling procedures are applied to each segment, allowing the network to optimize for reduced capability devices while maintaining support for full-capability devices.

Inventive Principle:

Principle #1Segmentation

2Use of energy by moving object

If RedCap UEs process only 5 MHz bandwidth to reduce power consumption, then power efficiency is improved, but network scheduling flexibility is reduced

Engineering Contradiction:

Improvepower consumptionVSAvoidnetwork scheduling flexibility

Core Design Contradiction:

Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The system dynamically adjusts scheduling based on UE capability. The gNB determines whether a UE is a RedCap UE and adapts the broadcast PDSCH scheduling accordingly - using 5 MHz bandwidth for RedCap UEs and full bandwidth for non-RedCap UEs. This dynamic adaptation allows power efficiency for RedCap UEs while maintaining network scheduling flexibility overall.

Inventive Principle:

Principle #15Dynamics

3Productivity

If the network schedules broadcast PDSCH larger than 5 MHz to improve network efficiency, then network efficiency is improved, but RedCap UEs cannot process the transmission

Engineering Contradiction:

Improvenetwork efficiencyVSAvoidsuccessful reception by RedCap UEs

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The network applies local quality by providing different broadcast PDSCH scheduling quality to different UE types. RedCap UEs receive broadcast PDSCH with restricted 5 MHz bandwidth quality, while non-RedCap UEs receive full bandwidth transmissions. This localized quality adjustment ensures each UE type receives appropriate transmission quality for its capability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The network performs preliminary identification of RedCap UEs before scheduling broadcast PDSCH. By determining UE capability in advance, the network can pre-adjust scheduling parameters to ensure RedCap UEs receive only transmissions within their processing capability, guaranteeing reliable reception.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP4569990B1Pdsch for reduced capability user equipment

Publication Date: 2026.01.21 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

According to some embodiments, a method is performed by a reduced capability (RedCap) wireless device. The method comprises: receiving a physical downlink shared channel (PDSCH), the PDSCH including scheduling for an uplink transmission; determining whether a time duration between receiving the PDSCH and a start of the scheduled uplink transmission is greater than a 5 threshold; and upon determining that the time duration between receiving the PDSCH and the start of the scheduled uplink transmission is greater than the threshold, transmitting the scheduled uplink transmission. The threshold depends on whether the PDSCH is received in a bandwidth that is larger than a reduced bandwidth associated with RedCap wireless devices.