DU-CU SDT Configuration for Low-Latency Inactive-State Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems lack clear methods for providing Small Data Transmission (SDT) configuration parameters to User Equipment (UE) when transitioning between RRC_INACTIVE and RRC_CONNECTED states in wireless communication networks.
Innovation Solution
A Distributed Unit (DU) and Central Unit (CU) communicate to manage SDT configuration by exchanging context modification messages, with the DU receiving an initial configuration and responding with a modified configuration, and the CU transmitting this configuration to the UE via the DU.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a UE transitions to RRC_CONNECTED state to transmit data, then data transmission capability is improved, but network resource utilization deteriorates and latency increases
Solution Approach 1:
The patent segments the data transmission process by enabling small data packets to be transmitted directly in the RRC_INACTIVE state through SDT procedures, separating this functionality from the full RRC_CONNECTED state. This allows the UE to maintain inactive status while still transmitting small data packets efficiently, avoiding the overhead of full connection establishment and improving network resource utilization.
Solution Approach 2:
The network performs preliminary configuration of SDT parameters and resources while the UE is in RRC_INACTIVE state, including configuring uplink grants, downlink assignments, and other transmission parameters in advance. This preliminary action enables the UE to immediately transmit small data packets without transitioning to connected state, reducing latency and resource overhead.
2Reliability
If a UE transitions to RRC_CONNECTED state to transmit data, then data transmission capability is improved, but transmission latency deteriorates
Solution Approach 1:
The network configures SDT parameters, uplink grants, and downlink assignments in advance while the UE remains in RRC_INACTIVE state. This preliminary configuration enables immediate data transmission without the latency of connection establishment, as all necessary transmission resources and parameters are pre-configured and available when the UE has small data to send.
Solution Approach 2:
The SDT procedure uses a simplified copy of the full connection establishment process, where essential transmission parameters and resources are replicated from the RRC_CONNECTED state configuration but adapted for inactive state operation. This allows small data transmission with reduced overhead and faster access compared to full connection establishment.
3Ease of operation
If SDT configuration parameters are provided through clear methods, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The patent extracts only the essential SDT configuration parameters needed for small data transmission from the full RRC configuration set, including uplink grants, downlink assignments, and SDT-specific parameters. This extraction provides clear, focused configuration methods for SDT operation while avoiding the complexity of managing complete connected-state configurations, reducing device processing burden.
Data Source
AI summary
A distributed unit (DU) communicating with a central unit (CU) can implement a method for managing small data transmission (SDT) configuration for a user equipment (UE). The method includes: (i) receiving, at the DU, a first SDT configuration for the UE; (ii) receiving, at the DU and from the CU, a UE context modification message including an SDT configuration request; and (iii) transmitting, from the DU to the CU and responsive to the receiving of the UE context modification message, a UE context modification response including a second SDT configuration based on the first SDT configuration.