Secured Uplink Data in RRC_INACTIVE Without Resume

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wireless communication systems experience high latency in uplink data transmission when a user equipment (UE) operates in the RRC_INACTIVE state due to the need for a full RRC resume procedure for transmitting even small packets, which involves multiple message exchanges with the base station.

Innovation Solution

The UE applies security functions such as encryption and integrity protection to generate secured packets, allowing direct transmission of data in the RRC_INACTIVE state without transitioning to RRC_CONNECTED, using mechanisms like I-RNTI for identification and security verification at the base station.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE transitions to RRC_CONNECTED state to transmit data in uplink, then the data transmission can be performed with full protocol support, but the latency increases due to the RRC resume procedure requiring multiple message exchanges

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidtransmission latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The network configures the UE with uplink data transmission resources and security parameters while the UE is in RRC_INACTIVE state, before any data transmission is needed. This preliminary configuration allows the UE to transmit data immediately upon having data available, without needing to perform the RRC resume procedure first, thus reducing latency while maintaining transmission reliability through pre-established security and resource allocation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent separates the data transmission function from the complete RRC connection establishment process. The UE can transmit uplink data in a simplified manner while remaining in RRC_INACTIVE state for small packets, and only transitions to RRC_CONNECTED state when necessary for larger data volumes or complex communication requirements, thus avoiding unnecessary state transition overhead

Inventive Principle:
Principle #1Segmentation

2Reliability

If the UE performs the complete RRC resume procedure to transmit small packets, then the communication protocol requirements are fully satisfied, but the communication efficiency decreases due to multiple message exchanges

Engineering Contradiction:
Improveprotocol complianceVSAvoidcommunication efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial action by implementing a simplified uplink data transmission mechanism that satisfies the essential protocol requirements for small data packets without requiring the complete RRC resume procedure. The UE can transmit data with basic security protection and network identification while remaining in RRC_INACTIVE state, reserving the option to perform full RRC resume only when necessary, thus improving communication efficiency while maintaining adequate protocol compliance

Inventive Principle:
Principle #16Partial or excessive action

3Loss of time

If the UE remains in RRC_INACTIVE state to reduce latency, then the transmission speed improves, but the device complexity increases due to security function application and secured packet generation

Engineering Contradiction:
Improvestate transition timeVSAvoidsecurity processing complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The network provides pre-configured security parameters and keys to the UE while it is in RRC_INACTIVE state, before any data transmission occurs. This preliminary provision of security materials allows the UE to quickly generate secured packets without needing to perform complex security negotiations or key derivations during the transmission process, thus reducing the perceived complexity and enabling fast transmission

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4128993B1Data communication in an inactive state
Publication Date: 2025.10.08 GOOGLE LLC
  • EP4128993B1 patent drawingFigure 1A
  • EP4128993B1 patent drawingFigure 1B~2
  • EP4128993B1 patent drawingFigure 3~4B

AI summary

To communicate data in an inactive state associated with a protocol for controlling radio resources, a UE determines, when the UE is in the inactive state, that data is available for transmission to a RAN (1602). The UE applies a security function to the data to generate a secured packet (1604) and transmits the secured packet to the RAN while the UE is in the inactive state (1606). In response to determining that the RAN has not received the secured packet, performing at least one of (i) re-transmitting the secured packet in an uplink message associated with a second random access procedure, or (ii) transmitting, to the RAN, a request to resume or set up a radio connection.