Fake Handover Signaling for Automatic Neighbor Cell Discovery

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Solution Overview

Problem

In mobile communications systems, especially in LTE and 5G-NR networks, it is challenging for mobile network operators to dynamically and precisely discover neighboring cells operating on unlicensed or shared spectrum, such as CBRS, as the frequency allocations can change dynamically and are not always known to the operators, leading to operational inefficiencies and potential misuse of licensed spectrum.

Innovation Solution

The solution involves initiating a fake handover request from a source RAN cell to a target RAN cell using existing handover signaling, which includes pseudo UE identity and source RAN cell information, allowing the target RAN to discover and add the source RAN cell to its neighboring list without actual UE involvement, thus enabling dynamic and precise neighbor cell discovery without requiring hardware or software updates in the target RAN.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional measurement configuration methods are used to discover neighboring cells, then the network can identify neighboring cells, but the process is inefficient and cannot dynamically adapt to changing frequency allocations in unlicensed or shared spectrum

Engineering Contradiction:

Improveneighbor cell discovery efficiencyVSAvoidadaptability to dynamic frequency allocations

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The source RAN cell performs preliminary action by proactively initiating handover requests to the target RAN cell before actual UE handover occurs. This preliminary handover initiation allows the target RAN to discover and add the source RAN to its neighboring list in advance, enabling dynamic adaptation to changing frequency allocations without waiting for actual UE mobility events.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The source RAN cell performs self-service by autonomously initiating handover requests to discover neighboring cells. This self-service mechanism eliminates the need for the target RAN to actively search for or be configured with neighboring cell information, allowing the network to automatically discover and adapt to dynamic frequency allocations through the handover discovery process.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If the target RAN actively searches for neighboring cells, then comprehensive neighbor cell discovery is achieved, but the complexity of the discovery process increases

Engineering Contradiction:

Improveneighbor cell discovery accuracyVSAvoiddiscovery process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent inverts the traditional discovery approach by having the source RAN cell initiate handover requests to the target RAN cell, rather than having the target RAN actively search for or be configured with neighboring cell information. This inversion simplifies the discovery process for the target RAN while maintaining accurate neighbor cell identification through the handover signaling mechanism.

Inventive Principle:

Principle #13The other way round (Inversion)

3Reliability

If actual UE handover is used for neighbor cell discovery, then reliable cell information is obtained, but the process requires actual UE connections and cannot occur independently

Engineering Contradiction:

Improvecell information reliabilityVSAvoidautomation of discovery process

Core Design Contradiction:

ReliabilityVSExtent of automation

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The handover request signaling message acts as an intermediary mechanism that carries cell identification information from the source RAN cell to the target RAN cell. This intermediary approach allows reliable cell information exchange without requiring actual UE connections, as the handover request serves as a mediator to transmit the necessary identification data for neighbor cell discovery.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11665602B2Automatic cell discovery of a source radio access network (RAN) cell by a neighboring, target RAN by initiating a fake handover of a user equipment (UE) from the source RAN cell to the target RAN

Publication Date: 2023.05.30 ANI ACQUISITION SUB LLC

AI summary

Automatic cell discovery of a source radio access network (RAN) cell by a neighboring, target RAN by initiating a fake handover of a user equipment (UE) from a source RAN cell to a target RAN. A source RAN cell initiates a handover request using handover signaling to the target RAN(s). The handover request is a fake handover request without actual intention of handing over UE to the target RAN. The source RAN cell includes information in initiated handover request that can be used by target RAN to discover source RAN cell. The handover request will fail, because the handover request is not for any actual UE moving from the source RAN cell to the target RAN. However, the target RAN becomes aware of the source RAN cell as a result of this process and can add the source RAN cell (e.g., its EARFCN) to a list of its neighboring cells.