Semi-Persistent Scheduling for Multicast Data Transmission

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Solution Overview

Problem

In mobile communication systems, dynamic scheduling of multicast transmission over a physical downlink shared channel becomes complex, leading to inefficient radio resource utilization, especially in Single-Cell Point-To-Multipoint (SCPTM) transmissions.

Innovation Solution

Implementing semi-persistent scheduling (SPS) managed by base stations, where user terminals are instructed to activate SPS for receiving multicast data via a physical downlink shared channel, reducing overhead and simplifying radio resource allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If dynamic scheduling is used for multicast transmission on PDSCH, then flexibility in resource allocation is improved, but scheduling complexity increases

Engineering Contradiction:

Improveflexibility in resource allocationVSAvoidscheduling complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the scheduling approach by introducing a semi-persistent scheduling mode that operates separately from dynamic scheduling. This creates distinct scheduling paths: semi-persistent scheduling for periodic multicast traffic and dynamic scheduling for other purposes, thereby reducing the complexity of multicast-specific scheduling while maintaining flexibility through the coexistence of multiple scheduling modes.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If MBSFN subframes are used for MBMS transmission, then multicast transmission capability is improved, but radio resource utilization efficiency deteriorates due to inability to dynamically change subframes

Engineering Contradiction:

Improvemulticast transmission capabilityVSAvoidradio resource utilization efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent applies dynamics by enabling flexible configuration of semi-persistent scheduling parameters including periodicity, resource allocation, and activation/deactivation timing. This allows the system to adapt radio resource allocation dynamically through control signaling while maintaining the efficiency benefits of semi-persistent scheduling, effectively combining the advantages of both static and dynamic approaches.

Inventive Principle:

Principle #15Dynamics

3Device complexity

If semi-persistent scheduling is activated for user terminals, then scheduling complexity is reduced, but control signaling overhead increases

Engineering Contradiction:

Improvescheduling complexityVSAvoidcontrol signaling overhead

Core Design Contradiction:

Device complexityVSQuantity of substance

Solution Approach 1:

The patent implements periodic action through semi-persistent scheduling where resource allocations are established for periodic intervals rather than requiring individual scheduling decisions for each transmission. This periodic structure reduces the frequency of control signaling while maintaining the ability to activate and deactivate schedules as needed, thereby reducing overall signaling overhead compared to purely dynamic scheduling.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS10476694B2Base station and user terminal, for transmitting and receiving multicast data using semi-persistent scheduling

Publication Date: 2019.11.12 KYOCERA CORP

AI summary

A base station according to a first aspect manages a cell in which a group including a plurality of user terminals exists. The base station comprises: a controller configured to instruct, if starting transmission of multicast data to the plurality of user terminals, each of the plurality of user terminals to activate a semi-persistent scheduling; and a transmitter configured to use the semi-persistent scheduling to transmit the multicast data to the plurality of user terminals via a physical downlink shared channel.