Random Access Preamble Signaling for Dynamic TDD Configuration
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Solution Overview
Problem
In dynamic Time Division Duplex (TDD) scenarios, communication devices and network nodes face challenges in determining the correct TDD configuration, leading to random access failures due to inconsistencies in TDD configurations between user equipment (UE) and eNodeB, especially in out-of-sync or link-failure situations.
Innovation Solution
The method involves sending a random access preamble according to a TDD configuration in a system information block (SIB) and receiving a random access response, with the option to switch into a dynamic TDD capable mode to support multiple dynamic TDD configurations, ensuring consistent TDD configuration usage during random access procedures by monitoring downlink channels or receiving a contention resolution message.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple TDD configurations are assigned to support dynamic TDD scenarios, then adaptability is improved, but configuration consistency deteriorates
Solution Approach 1:
The patent applies preliminary action by having the UE select and indicate a specific TDD configuration before initiating the random access procedure. The UE determines which TDD configuration to use from multiple assigned configurations and explicitly indicates this selection to the eNodeB through the random access preamble or subsequent messages. This preliminary indication ensures that both UE and eNodeB operate with the same TDD configuration understanding before random access begins, preventing configuration mismatches that would cause access failures.
2Measurement precision
If TDD configuration is determined through monitoring downlink channels, then configuration accuracy is improved, but access time increases
Solution Approach 1:
The patent applies preliminary action by having the UE determine the appropriate TDD configuration before initiating the random access procedure. The UE uses its knowledge of assigned TDD configurations and current system state to proactively select the correct configuration and indicate it to the eNodeB in advance (through preamble selection or explicit indication). This eliminates the need for time-consuming configuration monitoring and determination during the random access procedure itself, reducing access latency while maintaining accuracy.
3Reliability
If random access preamble is sent according to TDD configuration in SIB, then configuration consistency is improved, but flexibility deteriorates
Solution Approach 1:
The patent applies dynamics by enabling the UE to dynamically select which TDD configuration to use from multiple assigned configurations based on current system conditions and traffic requirements. The UE can adaptively choose the most appropriate TDD configuration (e.g., configuration 0 for downlink-heavy traffic, configuration 1 for uplink-heavy traffic) and indicate this dynamic selection to the eNodeB. This dynamic selection mechanism maintains configuration consistency between UE and eNodeB while providing flexibility to adapt to changing network conditions.
Data Source
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AI summary
One embodiment of the present disclosure relates to a method for random access in a UE in an out-of sync status. The method comprises： sending to a base station a first message including a random access preamble according to a TDD configuration in a SIB； receiving from the base station a second message including a random access response using the random access preamble according to the TDD configuration in the SIB. Another embodiment of the present invention also relates to corresponding method for random access in a base station. According to an aspect of the present disclosure， there are provided corresponding devices.