Base Station Subframe Configuration for Multicast Efficiency
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Solution Overview
Problem
In 3GPP mobile communication systems, there is a wastage of radio resources in MBSFN subframes since the physical downlink shared channel (PDSCH) is not efficiently utilized for multicast data transmission, leading to a need for a technique that can efficiently use these resources for group communication.
Innovation Solution
A communication control method and base station configuration that transmit specific subframe information to user terminals using a bitmap format, indicating which subframes can constitute a PDSCH for multicast, along with group-RNTI and TMGI, to enable efficient multicast data transmission through the PDSCH, suppressing MBMS transmission in specific subframes and reserving others for MBSFN.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MBSFN subframes are reserved for MBMS transmission, then multicast service coverage is improved, but radio resource utilization efficiency deteriorates
Solution Approach 1:
The patent segments MBSFN subframes into two distinct types: type 1 for MBMS transmission and type 2 for unicast transmission. This segmentation allows the system to dedicate specific subframes to multicast services while utilizing other subframes for unicast data transmission, thereby improving overall radio resource utilization without compromising multicast service coverage
Solution Approach 2:
The patent introduces dynamic subframe configuration where the base station can flexibly assign subframes as either type 1 or type 2 based on real-time traffic conditions and service requirements. This dynamic adjustment enables the system to optimize resource allocation between multicast and unicast services, improving radio resource utilization efficiency while maintaining reliable multicast coverage
2Reliability
If PDSCH is not used in MBSFN subframes, then MBMS transmission reliability is improved, but data transmission efficiency deteriorates
Solution Approach 1:
The patent segments the downlink transmission channels by creating distinct subframe types: type 1 MBSFN subframes dedicated to MBMS transmission using PMCH, and type 2 MBSFN subframes that allow PDSCH for unicast data transmission. This segmentation ensures MBMS transmission reliability in type 1 subframes while improving data transmission efficiency by enabling PDSCH usage in type 2 subframes
Solution Approach 2:
The patent makes MBSFN subframes multi-functional by allowing them to serve both MBMS transmission purposes (type 1) and unicast data transmission purposes (type 2). This multi-functionality resolves the contradiction by enabling the same subframe structure to support different transmission modes, thereby improving overall data transmission efficiency without compromising MBMS reliability
Data Source
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AI summary
A base station includes a controller configured to perform a process of transmitting configuration information for a user terminal having a group communication function specified in 3rd Generation Partnership Project (3GPP). The configuration information includes specific subframe information indicating a specific subframe capable of constituting a physical downlink shared channel (PDSCH) for multicast.