Uplink Data Transmission Using Multiple CTUs
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Solution Overview
Problem
In next-generation communications networks, the traditional scheduling/grant mechanism for uplink data transmission in radio communications networks leads to excessive signaling overhead and transmission latency, especially during massive user access, and the grant-free transmission scheme faces reliability issues due to contention conflicts among user equipment (UEs) sharing the same time-frequency-code resources.
Innovation Solution
A method where a network device receives a message from a terminal device indicating its capability to transmit uplink data using multiple contention transmission units (CTUs) within the same time interval, and sends a second message with indication information to allow the terminal device to determine a suitable CTU for transmission, thereby improving reliability and reducing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If grant-free transmission scheme is used to support massive user access, then user access capacity is improved, but transmission reliability deteriorates due to contention conflicts
Solution Approach 1:
The patent segments the uplink transmission resources by dividing them into multiple contention transmission units (CTUs) within the same time interval. This segmentation allows terminal devices to select multiple CTUs for transmission, thereby reducing contention conflicts and improving transmission reliability while maintaining support for massive user access.
Solution Approach 2:
The patent introduces a new dimension for resource allocation by allowing terminal devices to transmit on multiple CTUs within the same time interval. This multi-dimensional approach (multiple CTUs in one time interval) provides additional transmission opportunities and reduces the impact of contention conflicts, thereby improving reliability without sacrificing user access capacity.
2Reliability
If traditional scheduling/grant mechanism is used for uplink data transmission, then transmission reliability is improved through centralized control, but signaling overhead and transmission latency increase
Solution Approach 1:
The patent extracts the essential function of centralized control (BS defining CTUs and mapping rules) while removing the time-consuming scheduling/grant signaling process. Terminal devices autonomously select CTUs based on pre-configured mapping rules, eliminating the need for real-time uplink grants and significantly reducing transmission latency while maintaining reliable transmission through structured resource allocation.
Solution Approach 2:
The patent implements preliminary action by pre-configuring CTU mapping rules and terminal-CTU mappings before actual data transmission. This advance preparation allows terminal devices to immediately transmit data on selected CTUs without waiting for scheduling grants, thereby reducing transmission latency while the BS maintains overall control through the pre-defined structure.
3Productivity
If multiple UEs use the same signature for contention-based access, then resource utilization is improved, but contention conflicts increase and detection difficulty worsens
Solution Approach 1:
The patent segments the code resource space by associating multiple signatures with each CTU. This segmentation allows the BS to detect conflicts at the CTU level and identify which specific signatures are involved, making conflict detection more manageable while still allowing multiple UEs to share the same time-frequency resources through different signature combinations.
Solution Approach 2:
The patent implements feedback mechanisms where the BS detects contention conflicts on CTUs and can trigger remapping operations. This feedback loop allows the system to identify and resolve conflicts dynamically, maintaining high resource utilization while managing detection difficulty through structured conflict identification and resolution protocols.
Data Source
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AI summary
Embodiments of the present invention provide an uplink data transmission method and apparatus. The method includes: receiving a first message including transmission mode information, where the transmission mode information is used to indicate that a terminal device is capable of transmitting uplink data by using at least two contention transmission units CTUs that are in a same time interval TTI, the CTU refers to a transmission resource combining a time, a frequency, and a code domain, or a transmission resource combining a time, a frequency, and a pilot, or a transmission resource combining a time, a frequency, a code domain, and a pilot, and the uplink data transmitted by using the at least two CTUs is partially same or totally same; and sending a second message including indication information, where the indication information is used to enable the terminal device to determine, according to the indication information, a CTU for uplink data transmission. The terminal device is capable of transmitting uplink data by using at least two CTUs that are in a same TTI. Therefore, reliability of data transmission can be improved, and a transmission latency can be reduced.