Data Forwarding Tunnel Determination for EPS to 5G Handover

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Solution Overview

Problem

Conventional handovers from EPS to 5G systems impact the EPS and increase signaling overhead, complicating data forwarding.

Innovation Solution

A method for determining a data forwarding tunnel involves notifying a target 5G base station of data forwarding information, configuring a 5G base station forwarding tunnel, and obtaining a 5G core network forwarding tunnel, which is then allocated by the MME to the 4G core network, ensuring seamless handover without increasing signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional handover process from EPS to 5G system is used, then data forwarding can be implemented, but signaling overhead increases and EPS is impacted

Engineering Contradiction:
Improvedata forwarding completionVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces an AMF entity as an intermediary between the 5G core network and the EPS network. The AMF obtains forwarding tunnel information from the 5G core network and relays it to the MME, which then allocates the forwarding tunnel. This intermediary approach allows data forwarding to be implemented without directly impacting the EPS signaling flow, thereby reducing signaling overhead while ensuring reliable data forwarding completion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary action by having the AMF entity obtain the forwarding tunnel information from the 5G core network in advance, before the actual handover execution. This advance preparation allows the forwarding tunnel to be ready when needed, eliminating the need for additional signaling during the handover process itself, thus reducing signaling overhead while ensuring data forwarding reliability.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If conventional handover process from EPS to 5G system is used, then data forwarding can be implemented, but EPS operations are impacted

Engineering Contradiction:
Improvedata forwarding completionVSAvoidEPS operation independence
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The AMF entity serves as a mediator that translates between 5G core network forwarding requirements and EPS network operations. By handling the forwarding tunnel allocation through the AMF and MME interface, the EPS network operations remain independent and are not directly impacted by 5G-specific data forwarding requirements, thus maintaining EPS adaptability while ensuring data forwarding completion.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If 5G base station configures forwarding tunnel, then data forwarding is enabled, but signaling overhead increases

Engineering Contradiction:
Improveforwarding tunnel configurationVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the forwarding tunnel configuration process from the direct 5G base station to UE path and relocates it through the AMF entity. The AMF obtains the forwarding tunnel information from the 5G core network and relays it to the MME, which then allocates it. This extraction removes the signaling overhead burden from the 5G base station-UE direct interface, enabling forwarding tunnel configuration while reducing overall signaling overhead.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3687203B1Data forwarding tunnel determination method, access and mobility management device and base station
Publication Date: 2021.12.15 DATANG MOBILE COMM EQUIP CO LTD
  • EP3687203B1 patent drawingFigure 1
  • EP3687203B1 patent drawingFigure 2~3
  • EP3687203B1 patent drawingFigure 4~5

AI summary

A method for determining a data forwarding tunnel, an AMF entity, and a base station (BS) are provided. The method includes: receiving data forwarding information of target UE forwarded by MME, and acquiring a QoS flow configured by a 5G core network for each bearer of the target UE, and mapping relationship between a bearer and a QoS flow, where the data forwarding information includes a list of bearers allocated by EPS to the target UE and an indication of a determination by a 4G BS as to whether each bearer of the target UE has data to forward; transmitting the data forwarding information, the configured QoS flow, and the mapping relationship to a target 5G BS; and receiving forwarding tunnel information of a 5G BS configured for the target UE by the target 5G BS according to the data forwarding information, the configured QoS flow, and the mapping relationship.