Random Access Preamble Indication for Sidelink Resource Allocation
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Solution Overview
Problem
In V2X communication systems, when a terminal equipment in mode 1 lacks available sidelink resources, it triggers a scheduling request (SR), but if no valid PUCCH resources are configured, the network device may not allocate resources correctly, leading to inefficient resource usage and potential transmission of outdated channel state information.
Innovation Solution
A method where the terminal equipment indicates the presence of sidelink data through a random access preamble, allowing the network device to allocate resources appropriately and avoiding unnecessary random access procedures, and the SR is canceled if it exceeds a latency limit to prevent transmission of outdated data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a random access procedure is initiated when PUCCH resources are invalid or timeout occurs, then the terminal equipment can request resources, but the network device cannot determine whether to allocate uplink resources or sidelink resources
Solution Approach 1:
The patent segments the random access procedure into two distinct paths: one for uplink data transmission and another for sidelink data transmission. By introducing separate indication mechanisms (different PUCCH resource configurations or different random access preamble sequences), the system can determine the specific data type the terminal equipment needs to transmit, thereby resolving the ambiguity in resource allocation.
2Reliability
If the terminal equipment transmits SR multiple times until maximum transmission times are reached, then the terminal can ensure data transmission, but the channel state information may have expired due to long elapsed time
Solution Approach 1:
The patent introduces a preliminary check mechanism before initiating the SR transmission process. The terminal equipment checks whether the channel state information is still valid (not expired) before triggering the SR. This preliminary action prevents the system from entering a lengthy SR retransmission process when the channel state information has already expired, thereby avoiding time loss while maintaining transmission reliability when the information is still valid.
Data Source
AI summary
A random access method and apparatus and resource configuration method and apparatus. The random access apparatus includes: a third receiving unit configured to, on a physical random access channel resource, receive a random access preamble transmitted by a terminal equipment; wherein the random access preamble is used to indicate that the terminal equipment has sidelink data to be transmitted, and/or the physical random access channel resource is used to indicate that the terminal equipment has sidelink data to be transmitted; and a second transmitting unit configured to transmit a random access response to the terminal equipment. By indicating in the random access procedure to the network device that the terminal equipment has a sidelink MAC CE to be transmitted, it may be avoided that the network device does not learn that the terminal equipment has a sidelink MAC CE to be transmitted, so that the network device allocates resources for the sidelink, and resource consumption may be lowered.