Small Data Transmission Mobility Enhancement in Wireless Systems
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Solution Overview
Problem
Existing wireless communication systems, particularly in 5G NR, face challenges in mobility enhancement and small data transmission when transitioning between terrestrial and non-terrestrial networks, leading to inefficiencies and potential service disruptions.
Innovation Solution
A method for a User Equipment (UE) to enhance mobility by performing specific procedures when transitioning between terrestrial and non-terrestrial networks, including capability enquiries, assistance information delivery, and appropriate radio resource control states, to ensure seamless small data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If UE performs full RRC connection resume procedure for small data transmission, then transmission reliability is improved, but procedure complexity and time consumption increase
Solution Approach 1:
The patent extracts the essential functionality of RRC connection resume procedure and separates it into two independent paths: a lightweight SDT path for small data transmission and a full RRC resume path for reliable communication. This extraction allows the UE to choose the appropriate path based on data size requirements, avoiding the complexity of full resume procedure for small data while maintaining reliability when needed.
Solution Approach 2:
The patent segments the RRC connection resume procedure into distinct components: SDT-specific procedures for small data transmission and full RRC resume procedures for comprehensive connection establishment. This segmentation enables the system to perform only the necessary procedures based on transmission requirements, reducing overall complexity while maintaining reliability for critical transmissions.
2Loss of time
If UE uses SDT procedure for small data transmission, then procedure time is reduced, but transmission reliability may deteriorate
Solution Approach 1:
The patent applies partial action by implementing SDT procedure that performs only the essential steps required for small data transmission, omitting unnecessary full RRC resume steps. This partial action reduces procedure time significantly while maintaining adequate reliability for small data packets through alternative mechanisms such as pre-established contexts and streamlined handover procedures.
Solution Approach 2:
The patent changes key parameters of the connection procedure, such as reducing the completeness requirement of RRC resume, modifying handover timing, and adjusting reliability thresholds based on data size. These parameter changes enable the system to achieve faster transmission for small data while maintaining acceptable reliability levels through optimized protocol parameters.
3Adaptability or versatility
If UE transitions between terrestrial and non-terrestrial networks, then network coverage is improved, but mobility management complexity increases
Solution Approach 1:
The patent implements a universal mobility management framework that handles both terrestrial and non-terrestrial network transitions through a single unified procedure set. The core mobility management functions are designed to be multi-functional, automatically adapting to different network types based on configuration parameters, thereby improving network coverage without proportionally increasing complexity.
Solution Approach 2:
The patent introduces an intermediary mobility management entity that mediates between terrestrial and non-terrestrial network elements. This intermediary layer simplifies the complexity by centralizing the decision-making logic for network type detection, handover triggering, and parameter translation, allowing the UE to interact with a standardized interface regardless of the underlying network type.
4Reliability
If UE performs capability enquiry and assistance information delivery, then mobility transition reliability is improved, but signaling overhead increases
Solution Approach 1:
The patent applies preliminary action by performing capability enquiry and assistance information delivery during RRC setup or reconfiguration phases before actual mobility transitions occur. This advance preparation ensures that all necessary information is already exchanged and configured, improving transition reliability while minimizing the signaling overhead during the actual transition event itself.
Solution Approach 2:
The patent maintains continuity of useful action by establishing and maintaining capability information and assistance data in a persistent state during RRC connected mode. This continuous availability of pre-exchanged information eliminates the need for repeated capability enquiries during each mobility transition, thereby improving reliability while reducing redundant signaling overhead.
Data Source
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AI summary
A method for mobility enhancement in wireless communication systems is provided. The method is performed by a User Equipment (UE) configured with a first Small Data Transmission (SDT) configuration by a first cell. The method includes receiving a Radio Resource Control (RRC) release message including a suspend configuration from the first cell; transitioning to an RRC INACTIVE state in response to receiving the RRC release message; receiving, in the RRC INACTIVE state, a System Information Block Type 1 (SIB1) including a second SDT configuration from a second cell; camping on the second cell in response to receiving the SIB1 from the second cell; and while the UE is camping on the second cell, refraining from using the first SDT configuration to initiate an SDT procedure associated with the second cell in a case that the UE does not support performing the SDT procedure associated with the second cell.