GC-PDCCH Multicast Signaling for Accurate HARQ Data Identification
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Solution Overview
Problem
Existing communication systems face inefficiencies in identifying and handling multicast broadcast service (MBS) data due to the mixing of Hybrid Automatic Repeat Request (HARQ) process IDs (HPIDs) and New Data Indicators (NDIs) between unicast and multicast services, leading to transmission identification errors.
Innovation Solution
A method and apparatus that allows terminal devices to directly identify multicast data by recognizing a Group-Common PDCCH (GC-PDCCH), independent of NDIs, and manage HARQ processes separately for unicast and multicast, thereby improving communication efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ process IDs and New Data Indicators are mixed between unicast and multicast services, then the existing communication framework can be maintained, but transmission identification errors occur and communication efficiency deteriorates
Solution Approach 1:
The patent divides the HARQ process management into separate domains: unicast HARQ processes and multicast HARQ processes are independently managed with separate process IDs. This segmentation eliminates the mixing of unicast and multicast services in the same HARQ framework, thereby preventing transmission identification errors while maintaining manageable complexity through clear separation of concerns
Solution Approach 2:
The patent extracts the multicast service from the existing unicast HARQ framework and creates a dedicated multicast HARQ management mechanism. By taking out multicast-specific functionality and establishing independent process IDs and New Data Indicators for multicast, the system achieves accurate transmission identification without being constrained by the limitations of the unicast framework
2Reliability
If terminal devices rely on New Data Indicators to identify multicast data, then compatibility with existing unicast protocols is maintained, but transmission identification errors occur due to NDI toggling ambiguity
Solution Approach 1:
The patent extracts the New Data Indicator functionality from the unicast protocol and creates a dedicated multicast NDI mechanism. The multicast NDI operates independently from unicast NDI, allowing terminal devices to accurately identify multicast data without being confused by unicast NDI toggling, thereby eliminating identification errors while maintaining efficient processing
Solution Approach 2:
The patent applies different identification rules for different service types: unicast services use their own NDI toggling mechanism while multicast services use a separate multicast NDI mechanism. This local quality differentiation ensures that multicast data identification is accurate and unambiguous, preventing the confusion that would arise from using a unified NDI approach
Data Source
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AI summary
Provided are a communication method and a communication apparatus. The method comprises: a terminal device determines that a first physical downlink control channel (PDCCH) is a group-common physical downlink control channel (GC-PDCCH); the terminal device determines that data carried in a first PDSCH scheduled by a first PDCCH is initial transmission of new data of multicast. In the method in embodiments of the present application, it may be determined that the current data (i.e., the data transmitted by the first PDSCH) is initial transmission of new data of an MBS service, without using a new data indicator (NDI) carried in the first PDCCH, thereby improving the communication efficiency.