MME Control Plane NAS Connection Retention for 5G to 4G TAU

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Solution Overview

Problem

The existing 5G-to-4G idle state Tracking Area Update (TAU) process in communication technology leads to a waste of air interface resources due to the unnecessary establishment and release of air interface bearers during the dedicated bearer creation scheme, as the Mobility Management Entity (MME) always sets up a Data Radio Bearer, regardless of whether a dedicated bearer is created.

Innovation Solution

The MME keeps the control plane NAS connection after the TAU procedure and creates a dedicated bearer using this connection only when a dedicated bearer request is received from the PDN gateway, thereby optimizing the air interface bearer creation according to practical needs and preventing unnecessary resource waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the MME always sets up a Data Radio Bearer during the TAU process, then the air interface bearer establishment is ensured, but air interface resources are wasted due to unnecessary bearer creation and subsequent release

Engineering Contradiction:
Improveair interface bearer establishmentVSAvoidair interface resource waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the Data Radio Bearer setup conditional rather than static. The MME dynamically decides whether to establish a Data Radio Bearer based on the actual need for dedicated bearer creation. If no dedicated bearer is to be created, the MME skips the Data Radio Bearer setup, allowing the radio resource to be released immediately, thus avoiding resource waste while ensuring reliability when needed.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the MME establishes a Data Radio Bearer during TAU, then the bearer creation process is completed, but the subsequent bearer release causes signaling overhead and resource inefficiency

Engineering Contradiction:
Improvebearer creation completionVSAvoidsignaling overhead and resource inefficiency
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the MME determine in advance whether a dedicated bearer needs to be created before initiating the Data Radio Bearer setup. This preliminary decision prevents unnecessary bearer establishment and subsequent release, eliminating the associated signaling overhead and time loss while ensuring that bearer creation is completed when actually needed.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3716680B1Dedicated bearer creation method and mobility management entity
Publication Date: 2023.07.26 DATANG MOBILE COMM EQUIP CO LTD
  • EP3716680B1 patent drawingFigure 1
  • EP3716680B1 patent drawingFigure 2
  • EP3716680B1 patent drawingFigure 3~4

AI summary

A dedicated bearer creation method, an MME, and a PDN gateway are provided. The dedicated bearer creation method includes: in a TAU procedure, when it is determined that a UE has moved from a 5G network to a 4G network based on identification information provided by the UE, keeping a control plane NAS connection after the TAU procedure; and when a create dedicated bearer request has been received from a PDN gateway, creating a dedicated bearer for the UE using the NAS connection. According to the present disclosure, it is able to create a radio bearer based on the practical need, and prevent the occurrence of a waste of air interface resources caused when the MME requests an eNB to create a user plane radio bearer in the TAU procedure, thereby to solve the problem in the related art where the waste of the air interface resources is caused by a dedicated bearer creation scheme.