Downlink Channel Search Space Switching for RA-SDT Congestion
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Solution Overview
Problem
Existing wireless communication systems face challenges in determining a Search Space (SS) for channel reception during Random Access-Small Data Transmission (RA-SDT), leading to congestion and reduced success probability of the random access process due to the terminal device continuing to use the same SS for subsequent data transmission.
Innovation Solution
The method specifies a target SS for the terminal device to receive channels after resolving a contention conflict in RA-SDT, using configuration information and indication information provided by the network device to determine the appropriate SS for subsequent transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the terminal device continues to use the same Search Space (SS) for subsequent data transmission after RA-SDT, then the procedure is simple, but resource congestion increases and success probability decreases
Solution Approach 1:
The patent applies dynamics by making the SS selection adaptive rather than static. The terminal device dynamically switches from the initial SS (used for random access) to a target SS (configured by network) for subsequent data transmission. This dynamic transition resolves the contradiction by maintaining simplicity in the initial phase while avoiding resource congestion in the subsequent phase through automated SS switching based on network configuration.
2Reliability
If the terminal device uses a separate Search Space for subsequent data transmission, then resource congestion is reduced, but the complexity of determining and switching SS increases
Solution Approach 1:
The patent applies preliminary action by having the network device pre-configure the target SS parameters (including CORESET configuration, search space configuration, and timing information) before the terminal device needs to switch. The terminal device receives this configuration information in advance and stores it, so when switching is required, it can directly use the pre-configured target SS without performing complex real-time determination or calculation.
Solution Approach 2:
The patent implements feedback through the network device providing configuration information about the target SS to the terminal device. This feedback mechanism allows the terminal to automatically switch to the appropriate SS without complex local determination, as the network has already indicated the correct target SS based on the terminal's identity and the current transmission state.
3Adaptability or versatility
If type-1 PDCCH CSS is used for RA-SDT, then existing resources are utilized, but PDCCH blocking rate increases and legacy UE performance is impacted
Solution Approach 1:
The patent applies segmentation by separating the SS usage into distinct phases: the initial SS (type-1 PDCCH CSS) is used for random access procedures, while a separate target SS (configured by network) is used for subsequent data transmission. This segmentation prevents legacy UEs from being blocked by SDT procedures, as each procedure type uses its designated SS, thereby resolving the PDCCH blocking issue while maintaining compatibility with existing resources.
Data Source
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AI summary
The present application discloses a channel transmission method, comprising: a terminal device receives first configuration information, the first configuration information being used for determining a target search space for the terminal device to receive a downlink channel, and the downlink channel being a channel that is transmitted after a contention conflict is successfully resolved in random access-based small data transmission. The present application also discloses another channel transmission method, a terminal device, a network device, and a storage medium.