Slot Format Information for 5G URLLC Latency
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Solution Overview
Problem
Current uplink-downlink configurations in 5G mobile communication systems, particularly for the URLLC scenario, fail to meet the stringent requirements of low latency and high reliability, as they lack a granular control over symbol-level switching, leading to inefficiencies in data transmission.
Innovation Solution
The proposed method involves determining and transmitting slot format information that specifies the positions of uplink, downlink, and unknown symbols within a slot, allowing for finer granularity in uplink-downlink configuration, enabling faster switching and meeting the latency requirements of URLLC scenarios by using a network device to determine and send slot format information to terminal devices, which then adjust their transmission accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If existing uplink-downlink configuration is used in 5G NR, then system compatibility is maintained, but latency requirement for URLLC scenario cannot be met
Solution Approach 1:
The patent segments the uplink-downlink configuration from subframe level to symbol level. Instead of configuring entire subframes as uplink or downlink, the system now configures each symbol individually, allowing granular control over switching points and enabling latency optimization for URLLC while maintaining overall system compatibility through the same TDD framework
Solution Approach 2:
The patent introduces dynamic slot format indication (SFI) mechanisms that allow the network to adaptively adjust uplink-downlink configurations in real-time based on traffic requirements. The slot format can be dynamically changed through DCI signaling, enabling the system to optimize for low latency URLLC traffic when needed while maintaining flexibility for other service types
2Loss of time
If symbol-level switching control is implemented, then latency is reduced, but system complexity increases
Solution Approach 1:
The patent employs semi-static configuration of slot formats through RRC signaling before actual data transmission. This preliminary configuration establishes a framework of possible uplink-downlink patterns, and then dynamic SFI signaling simply selects from these pre-defined options, reducing the complexity of real-time decision-making while still enabling fast switching when needed
3Reliability
If existing TDD configuration is used, then implementation simplicity is maintained, but transmission reliability for URLLC cannot be ensured
Solution Approach 1:
The patent applies different configuration granularities to different parts of the TDD structure. Symbol-level configuration is applied specifically to slots requiring low latency (such as those carrying URLLC traffic), while other slots can maintain coarser configuration. This localized application of fine-grained control ensures reliability for critical traffic without unnecessarily complicating the entire system
Data Source
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AI summary
Embodiments of this application provide an information transmission method and device. The method includes: determining, by a network device, slot format information, where the slot format information is used to indicate position of uplink symbols, position of downlink symbols, and position of unknown symbols in a slot; sending, by the network device, the slot format information; receiving, by a terminal device, the slot format information from the network device, where the slot format information is used to indicate position of the uplink symbols, position of the downlink symbols, and position of the unknown symbols in the slot; and determining, by the terminal device, a slot format based on the slot format information. An uplink-downlink configuration provided in the embodiments of this application may be applicable to requirements of low-latency and high-reliability scenarios.