Inactive-State Small Data Routing for Disaggregated Base Stations

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Solution Overview

Problem

In wireless communications systems, devices in an inactive state, such as RRC inactive state, face inefficiencies and high overhead when performing small data transmissions due to the need for frequent random access procedures, leading to signaling overhead, timing delays, and computational resource expenditure.

Innovation Solution

User equipment (UE) can transmit small data directly to a disaggregated base station without performing a random access procedure by using routing identifiers and DRB identifiers provided in a connection release message, allowing for unsuspended data bearers, and monitoring for downlink data during a specified window.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a UE in RRC inactive state performs small data transmission using service request procedure, then the transmission can be initiated without full connection establishment, but it causes unnecessary wake-up and signaling overhead when there is no data to transmit

Engineering Contradiction:
Improvesmall data transmission efficiencyVSAvoidUE power consumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The network pre-configures uplink resources and transmission parameters for the UE while it is in RRC inactive state. This preliminary configuration allows the UE to perform small data transmission immediately upon having data to send, without needing to establish a full RRC connection first, thereby reducing latency and power consumption while maintaining transmission capability

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the network maintains RRC connected state for small data transmission, then transmission reliability is improved, but signaling overhead and network resource consumption increase

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the RRC connection establishment process by separating the essential uplink resource allocation from the full connection setup. The network provides segmented configuration information (uplink resources, transmission parameters) that enables partial transmission capability without complete connection establishment, reducing signaling overhead while maintaining necessary reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The network provides more configuration information than strictly minimal (including uplink resources, transmission parameters, and configuration indices) to enable reliable small data transmission without requiring full RRC connection establishment. This partial action achieves sufficient reliability for small data while avoiding the excessive signaling of complete connection setup

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If the network provides detailed configuration information for small data transmission, then transmission performance is improved, but the size of configuration messages increases

Engineering Contradiction:
Improvesmall data transmission performanceVSAvoidconfiguration message size
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent uses configuration indices that reference pre-defined configuration templates stored in the UE. Instead of transmitting complete configuration details, the network sends compact index values that point to stored configurations, significantly reducing message size while maintaining full transmission performance. The UE copies the actual configuration parameters from its stored templates using these indices

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4118913B1Small data transmissions in an inactive state to disaggregated base stations
Publication Date: 2026.04.29 QUALCOMM INC
  • EP4118913B1 patent drawingFigure 1
  • EP4118913B1 patent drawingFigure 2
  • EP4118913B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described.. Generally, a user equipment (UE) may directly send small data to a disaggregated base station without performing a random access procedure. The CU-CP may provide a list of routing identifiers and corresponding data resource bearers (DRBs) to a distributed unit (DU) and the DU may transmit a connection release message to the UE. The connection release message may include the list of routing identifiers and the list of DRB identifiers. The connection release message may also include a downlink monitoring timer. The UE may identify data for an uplink transmission and a DRB associated with that data. The UE may transmit a packet with the data and the routing identifiers to a DU, which may derive downlink address information from the routing identifiers and forward the data to a CU-UP of the aggregated base station.