Virtual Associated State for UE D2D Control

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Solution Overview

Problem

Current device-to-device (D2D) communication systems face challenges in efficiently managing state transitions between RRC_CONNECTED and RRC_IDLE states, leading to increased communication delay and burden on eNBs, especially in densely crowded cellular networks, due to the need for infrastructure relay even among users in the same cell coverage.

Innovation Solution

Introducing a 'virtual associated' state that allows UEs to transition back to an idle state efficiently using a trusted local access point or inter-operating network as a ProSe discovery agent, enabling quick and cost-effective network control, where UEs can maintain context with associated agents for reduced overhead and improved offloading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UEs maintain RRC_CONNECTED state for D2D communication, then network control and mobility management are ensured, but communication delay increases and eNB burden increases

Engineering Contradiction:
Improvenetwork controlVSAvoidcommunication delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the network control function by introducing intermediate network elements (ProSe discovery agents, MME) that can handle D2D control plane traffic independently from eNB. This allows UEs to transition to RRC_IDLE state for D2D communication while network control functions are distributed to other network elements, reducing eNB burden and communication delay.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces ProSe discovery agents and MME as intermediary elements between UEs and the core network. These intermediaries handle control plane functions for D2D communications, allowing UEs to be in RRC_IDLE state while maintaining network control through the intermediary elements, thus reducing both delay and eNB burden.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If UEs use infrastructure communication path, then network control is maintained, but traffic load on eNB increases and power consumption increases

Engineering Contradiction:
Improvenetwork controlVSAvoidtraffic load
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts the control plane traffic for D2D communications from the eNB by routing it through ProSe discovery agents and MME. This separation allows user plane traffic to be offloaded to direct D2D links while control plane functions are handled by other network elements, reducing eNB traffic load while maintaining network control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent enables UEs to perform autonomous D2D discovery and communication using pre-configured parameters and local decision-making capabilities. UEs can autonomously select communication paths and manage their own state transitions, reducing the need for continuous eNB involvement and thereby reducing traffic load on eNB.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If UEs perform autonomous D2D discovery, then device flexibility increases, but state management complexity increases

Engineering Contradiction:
Improvedevice flexibilityVSAvoidstate management
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic state management where UEs can flexibly transition between RRC_CONNECTED and RRC_IDLE states based on D2D communication requirements. The system adapts to different scenarios by allowing autonomous operation in RRC_IDLE state for simple D2D communications while maintaining the option to transition to RRC_CONNECTED state when network control is needed, providing both flexibility and simplified management.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2936915B1Methods and network elements for controlling UE's state transition in proximity wireless communication
Publication Date: 2020.03.04 NOKIA TECHNOLOGIES OY
  • EP2936915B1 patent drawingFigure 1
  • EP2936915B1 patent drawingFigure 2
  • EP2936915B1 patent drawingFigure 3

AI summary

Disclosed are methods and apparatus for controlling state transition of a user equipment UE in proximity wireless communication. A method can comprise: learning about an associated agent's context of a connected UE and said UE's capability; deciding to put the connected UE into virtual associated state; sending to said UE a message with indication of putting said UE into said virtual associated state as well as the UE's context; and maintaining said associated agent's context of the UE.