SDN Mobility Management for 5G Handover Latency Reduction

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Solution Overview

Problem

Current wireless networks face challenges in optimizing handover processes due to increased heterogeneity and densification, leading to higher latency and signaling costs, particularly in inter-RAT handovers, and require a transitional architecture to efficiently migrate from 3GPP to 5G networks while minimizing CAPEX and OPEX.

Innovation Solution

The introduction of an SDN-enabled Mobility Management unit (SeMMu) that optimizes handover signaling by reducing the number of messages required during handover preparation and rejection phases, utilizing intelligent mapping of information elements and parallel execution of control plane messages, and integrating SDN capabilities with existing MME and SMF functions to manage handovers across different radio access technologies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of access points is increased to support densification and multi-connectivity, then network capacity and QoS are improved, but handover latency and signaling overhead increase

Engineering Contradiction:
Improvenetwork capacityVSAvoidhandover latency
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent performs handover preparation actions in advance by establishing resource reservations and tunnel setups before the actual handover occurs. The mobility management entity initiates resource allocation requests to target access points and establishes data forwarding tunnels ahead of time, so that when handover is triggered, the mobile terminal can switch immediately without waiting for resource setup, thus reducing handover latency while supporting increased network density

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the handover process into distinct phases: preparation phase (resource reservation, tunnel setup) and execution phase (actual handover). By separating these phases and allowing parallel execution of preparation tasks, the system can handle multiple handovers concurrently without sequential delays, thereby reducing overall handover latency in dense networks with frequent handovers

Inventive Principle:
Principle #1Segmentation

2Productivity

If the number of access points is increased to support densification and multi-connectivity, then network capacity and QoS are improved, but signaling overhead increases

Engineering Contradiction:
Improvenetwork capacityVSAvoidsignaling overhead
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent merges multiple signaling operations into a single handover preparation message. The mobility management entity combines resource reservation requests, tunnel setup instructions, and data forwarding configuration into one consolidated message sent to the target access point. This reduces the number of separate signaling exchanges required during handover, thereby reducing signaling overhead while supporting dense network deployments

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal handover preparation message format that can handle multiple functions simultaneously: resource allocation, tunnel establishment, and data forwarding configuration. This multi-functional message reduces the need for multiple specialized signaling messages, thereby reducing overall signaling overhead in heterogeneous networks with multiple access technologies

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If a complete migration to softwarized core network and Cloud-RAN is implemented, then network flexibility and scalability are improved, but CAPEX and migration time increase

Engineering Contradiction:
Improvenetwork flexibilityVSAvoidmigration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces an SDN controller as an intermediary layer between the legacy EPC and the future 5G softwarized core. The SDN controller manages handover signaling and resource coordination, allowing the system to leverage both legacy infrastructure and new softwarized components. This intermediary approach enables gradual migration while maintaining network flexibility, as operators can transition at their own pace without requiring complete simultaneous migration

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a dynamic architecture where the mobility management entity can operate in hybrid mode, supporting both traditional EPC handovers and future 5G softwarized core handovers. The system can dynamically adapt its handover procedures based on the target network type, allowing operators to migrate incrementally while maintaining full functionality throughout the transition period, thereby reducing migration complexity

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3804405B1Handover method and system for 5g networks
Publication Date: 2023.09.27 UNIV POLITECNICA DE CATALUNYA
  • EP3804405B1 patent drawingFigure 1A
  • EP3804405B1 patent drawingFigure 1B
  • EP3804405B1 patent drawingFigure 2A

AI summary

System for carrying out handover methods, which comprises, a mobile terminal (UE), a current access point (S-NG-RAN, Source eNodeB, Source RNC), a current gateway (PGW-U + UPF, Source serving GW), a mobility management entity (SeMMu), a target access point (Target eNodeB, Target RNC, T-NG-RAN), a target gateway (Target Serving GW, T-UPF, Target PGW-U + UPF), a target support node (Target SeMMu, Target SGSN, T-AMF), where the mobility management entity (SeMMu) is connected to the current access point (S-NG-RAN, Source eNodeB, Source RNC), the target support node (Target SeMMu, Target SGSN, T-AMF), the current gateway (PGW-U + UPF, Source serving GW) and the target gateway (Target Serving GW, T-UPF, Target PGW- U + UPF), the mobility management entity (SeMMu) being configured to allocate identifiers (TEID) and adresses to itself and to the current access point (S-NG-RAN, Source eNodeB, Source RNC), the target support node (Target SeMMu, Target SGSN, T-AMF), the current gateway (PGW-U + UPF, Source serving GW) and the target gateway (Target Serving GW, T-UPF, Target PGW-U + UPF). The invention also relates to handover methods to be carried out in the inventive system.