Dynamic Preamble Group Reselection for Wireless Random Access
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Solution Overview
Problem
The existing preamble selection mechanism in wireless communication systems, particularly in LTE and NR, leads to mismatched magnitude of Msg3 and preamble group, resulting in increased delays and conflicts during Random Access (RA) procedures, especially in Non-Terrestrial Networks (NTNs), which can cause RA failures due to repeated attempts in the same group.
Innovation Solution
A method that allows for dynamic reselection of preamble groups based on conditions related to packet size and transmission time, enabling adaptive matching of Msg3 magnitude and reducing conflict probabilities by introducing a condition that triggers reselection when specific thresholds are met, thereby improving RA success rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE selects a preamble group based on initial Msg3 magnitude and pathloss, then the RA procedure can be initiated, but the Msg3 magnitude may change during retransmissions causing mismatch between selected preamble group and actual Msg3 magnitude
Solution Approach 1:
The patent makes the preamble group selection dynamic by allowing reselection based on current Msg3 magnitude and pathloss conditions. Instead of fixing the preamble group selection at the beginning of the RA procedure, the UE can reevaluate and switch between Group A and Group B based on updated buffer status and channel conditions during retransmissions, thereby adapting to changing network conditions.
Solution Approach 2:
The patent implements a feedback mechanism where the UE monitors its own Msg3 magnitude and pathloss conditions throughout the RA procedure. Based on this self-feedback, the UE determines whether to maintain the originally selected preamble group or switch to the other group, ensuring that the preamble group always matches the current transmission conditions.
2Productivity
If multiple UEs with similar features select the same preamble group simultaneously, then the RA procedure can proceed efficiently, but conflicts increase leading to RA failures
Solution Approach 1:
The patent changes the selection parameters dynamically by allowing UEs to switch between Group A and Group B based on real-time evaluation of Msg3 magnitude and pathloss. This parameter change capability means that even UEs with initially similar features may select different groups after reevaluation, reducing collisions while maintaining efficient RA procedures.
3Duration of action of stationary object
If the UE continuously retransmits preambles in the same group with large delay, then the transmission attempts continue, but the data amount buffered increases causing group mismatch
Solution Approach 1:
The patent introduces dynamics into the preamble group selection by enabling reselection during the RA procedure. As the RA procedure extends over time with retransmissions, the UE can update its Msg3 magnitude assessment and switch preamble groups accordingly, preventing the mismatch that would occur with static selection in long-delay environments.
Solution Approach 2:
The patent prepares for potential group mismatch by establishing the capability to switch groups before the mismatch becomes critical. The UE can proactively reevaluate conditions and switch preamble groups in advance, rather than waiting for the mismatch to cause failure.
Data Source
AI summary
The present disclosure provides a method and device in a communication node for wireless communications. A communication node receives a first signaling; transmits a first signal; receives a second signal; transmits a third signal; and when a first condition is satisfied, transmits a fourth signal; the first signaling comprises K1 first-type signal(s) and K2 second-type signal(s); the K1 first-type signals(s) is(are) different from the K2 second-type signal(s); a sum of K1 and K2 is of a fixed magnitude; the K1 and the K2 are both positive integers; the first signal is one of the K1 first-type signal(s); the fourth signal is one of the K2 second-type signal(s); the second signal is used for determining time-frequency resources of the third signal; the first condition is related to a parameter of the third signal. The present disclosure allows that a preamble group is reselected to improve probability of random access success.