IP Address Allocation in 5G Control and User Plane Separation

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Solution Overview

Problem

In the context of 4.5G and 5G mobile communications, the separation of control plane and user plane network functions leads to an IP address conflict when both devices attempt to allocate an IP address for a user equipment (UE) simultaneously, with current solutions lacking a viable method to address this issue.

Innovation Solution

A method where a control plane network device assesses the capability of a user plane network device to allocate an IP address based on service information and service capability information, and sends an address allocation indication to determine which device should allocate the IP address, thereby preventing simultaneous allocation and conflicts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the control plane device and user plane device both allocate IP addresses simultaneously, then the network function separation is achieved, but IP address conflicts occur

Engineering Contradiction:

Improvenetwork function separationVSAvoidIP address allocation

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The control plane device determines in advance whether the user plane device has IP address allocation capability before initiating IP address allocation. This preliminary assessment prevents simultaneous allocation by establishing allocation responsibility beforehand, thereby avoiding IP address conflicts while maintaining network function separation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control plane device acts as an intermediary that coordinates IP address allocation between the control plane and user plane devices. By introducing this coordination mechanism, the system resolves the conflict that arises from both devices attempting to allocate IP addresses independently, ensuring reliable IP address assignment while preserving the benefits of network function separation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the control plane device determines user plane device capability, then IP address conflict is avoided, but additional signaling overhead is introduced

Engineering Contradiction:

ImproveIP address allocationVSAvoidsignaling overhead

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The capability determination is performed in advance during session establishment or device initialization, rather than during each IP address allocation event. This preliminary action ensures reliable IP address allocation while minimizing signaling overhead by establishing allocation rules once, rather than repeatedly during each allocation process.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11212252B2IP address allocation method, and device

Publication Date: 2021.12.28 HUAWEI TECH CO LTD

AI summary

An Internet Protocol (IP) address allocation method and a device to resolve a technical problem that an IP address conflict occurs when a control plane device and a user plane device allocate an IP address for one user equipment (UE) at the same time. When receiving a session establishment request message, a control plane network device may determine whether a first user plane network device is capable of allocating an IP address for a terminal device. If the first user plane network device is capable of allocating the IP address for the terminal device, the control plane network device may send an address allocation indication to the first user plane network device.