RRC Inactive Small Data Transfer With gNB Buffering Decisions

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in handling small data transmissions, particularly in RRC inactive and idle states, due to the lack of optimized mechanisms for anchor relocation and signaling procedures, leading to increased latency and resource utilization.

Innovation Solution

Implementing enhanced procedures for mobile originated and terminated data transmissions in RRC inactive and idle states, including optimized anchor relocation and signaling optimizations, to improve efficiency and reduce latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the network uses a conventional approach where the core network determines whether to buffer downlink data for an RRC inactive wireless device, then the network can maintain centralized control, but the data transmission latency increases and network resources are wasted due to unnecessary buffering decisions

Engineering Contradiction:
Improvedata transmission latencyVSAvoidnetwork control complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent extracts the buffering decision-making authority from the core network and relocates it to the gNB (base station). This allows the gNB to autonomously determine whether to buffer downlink data for RRC inactive devices based on local context information, eliminating the need for devices to transition to connected state for small data transmissions and thereby reducing latency while maintaining efficient resource utilization

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If the network buffers downlink data for RRC inactive devices, then data can be delivered without device state transition, but network resources are wasted when no further data is expected

Engineering Contradiction:
Improvedata delivery efficiencyVSAvoidnetwork resource waste
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by having the gNB proactively determine buffering decisions based on predicted data arrival patterns before actual data arrives. The gNB uses context information to predict whether downlink data will arrive within a threshold time, and pre-decides whether to buffer data, thereby avoiding wasted resource allocation while ensuring data can be delivered efficiently when needed

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where the gNB monitors actual data arrival patterns and uses this information to refine future buffering decisions. The network entity receives information about whether predicted data arrivals occurred, and adjusts buffering strategies accordingly, creating a closed-loop system that optimizes resource utilization while maintaining high data delivery efficiency

Inventive Principle:
Principle #23Feedback

3Reliability

If the network transitions inactive devices to connected state for data reception, then all downlink data can be delivered reliably, but signaling overhead increases and network resources are consumed

Engineering Contradiction:
Improvedata delivery reliabilityVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments data transmission handling into two paths: small data transmissions are handled while devices remain in RRC inactive state using buffered data at the gNB, while larger data transmissions trigger state transitions to connected. This segmentation allows the network to handle the majority of data transmissions with minimal signaling overhead while maintaining reliability for larger transfers

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4395413B1Small data transmission
Publication Date: 2026.05.06 CANON KK
  • EP4395413B1 patent drawingFigure 1A~1B
  • EP4395413B1 patent drawingFigure 2A~2B
  • EP4395413B1 patent drawingFigure 3

AI summary

Methods and apparatus are disclosed. A method comprises: sending, from a second base station (104) to a first base station, a request for a context of a wireless device (106), wherein the request comprises assistance information for a small data transmission, SDT, procedure of the wireless device in a radio resource control, RRC, inactive state, the assistance information indicating whether: no further data associated with the SDT procedure is expected; or further data associated with the SDT procedure is expected; and sending, by the second base station to the wireless device in the RRC inactive state, downlink data associated with the SDT procedure received from the first base station.