Grant-Free Uplink Data Transmission via Partial Identifier Segmentation
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Solution Overview
Problem
In communications systems, especially those supporting a large number of machine-type communication services, the existing scheduling request mechanism leads to increased signaling overheads and transmission latency due to the need for resource allocation and identifier inclusion in data packets, which becomes inefficient with a large number of terminal devices.
Innovation Solution
Implementing a grant-free transmission method where terminal devices directly transmit uplink data without requesting resource allocation, using pre-allocated transmission resources and including only a partial identifier in the data packet, allowing the network to blindly detect and decode the data, thereby reducing signaling overheads and latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If grant-free transmission is implemented to reduce signaling overheads, then transmission efficiency improves, but the network device cannot identify which terminal device sends the detected uplink data
Solution Approach 1:
The terminal device identifier is segmented into two parts: the first part is used to determine the target contention transmission unit, and the second part is carried in the uplink data packet. This segmentation allows the network device to identify the terminal device through the transmitted second part while the first part enables resource allocation, thus resolving the contradiction between reducing signaling overhead and maintaining terminal identification capability.
Solution Approach 2:
The target contention transmission unit acts as an intermediary that carries implicit identification information. By determining the target CTU based on the first part of the identifier and having the terminal transmit data on this specific resource, the system enables indirect terminal identification without requiring the complete identifier to be transmitted in the data packet.
2Loss of information
If a terminal device identifier is added to the uplink data packet for identification, then the network device can identify the terminal, but the signaling overhead increases significantly
Solution Approach 1:
The identifier is divided into two segments where only the necessary second part is included in the uplink data packet, while the first part is used for resource determination. This reduces the amount of identification information that needs to be transmitted in the data packet, thereby reducing signaling overhead while maintaining identification capability.
Solution Approach 2:
Instead of transmitting the complete terminal device identifier in the uplink data packet, only a partial identifier (the second part) is transmitted. This partial action is sufficient for the network device to identify the terminal when combined with the resource information, thus reducing the quantity of transmitted information and signaling overhead.
3Reliability
If the terminal device divides the data packet into smaller packets for multiple transmissions, then transmission reliability improves, but the proportion of resources occupied by the identifier becomes higher
Solution Approach 1:
The identifier segmentation approach ensures that only the essential second part of the identifier is repeated in each transmitted packet, rather than the complete identifier. This reduces the cumulative identifier overhead across multiple transmissions while maintaining transmission reliability through packet segmentation and retransmission.
Data Source
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AI summary
The present invention discloses a data transmission method and apparatus. The method includes: determining a target CTU from multiple candidate CTUs according to a first partial identifier in a terminal device identifier, where the terminal device identifier includes the first partial identifier and a second partial identifier; and sending an uplink data packet to a network device by using the target CTU, where the uplink data packet carries the second partial identifier. According to the data transmission method and apparatus disclosed in the present invention, the first partial identifier in the terminal device identifier can be implicitly indicated, reducing signaling overheads of a system.