Multi-Band Transmit Power Control for Make-Before-Break Roaming

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional transmit power control algorithms are insufficient for multi-band make-before-break roaming deployments, where a client device maintains connectivity with multiple access points using different radios on different bands, leading to potential communication interruptions.

Innovation Solution

A transmit power control design that adjusts cell sizes and creates a target overlap between different bands of neighboring access points to facilitate seamless multi-band make-before-break roaming by dynamically managing transmission powers of multiple radios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional transmit power control algorithms are used, then single-band roaming is supported, but multi-band make-before-break roaming cannot be achieved

Engineering Contradiction:

Improveroaming capabilityVSAvoidcommunication continuity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the roaming process into multiple independent band operations. The transmit power control is applied separately to each band (first band and second band) with independent power adjustments, allowing the client device to establish connections on different bands independently while maintaining overall communication continuity during transitions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extends the traditional single-band transmit power control to multi-band operations by adding a frequency dimension. Instead of controlling power in one band, the system now manages transmit power across multiple frequency bands simultaneously, enabling make-before-break roaming by creating overlapping coverage areas in the frequency domain.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If transmit power is increased to extend coverage, then cell size increases, but interference with neighboring cells increases

Engineering Contradiction:

Improvecell sizeVSAvoidinterference

Core Design Contradiction:

Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies different transmit power levels to different bands locally. Instead of uniformly increasing power across all bands, the system adjusts power specifically on the first band to extend coverage while maintaining appropriate power levels on the second band, thereby extending cell size in targeted areas without creating widespread interference.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically changes transmit power parameters independently for each band based on roaming conditions. The system monitors connection quality and signal strength on both bands, adjusting the transmit power on the first band to achieve target overlap with the second band, thereby optimizing cell size while controlling interference through parameter adaptation.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12550080B2Transmit power control design for make-before-break roaming deployments

Publication Date: 2026.02.10 CISCO TECHNOLOGY INC

AI summary

Systems and techniques for performing transmit power control for facilitating multi-band make-before-break (MBB) roaming are described. An example technique includes identifying a first access point communicating on a first band within a first cell. A second access point communicating on a second band within a second cell neighboring the first cell is identified. A target overlap between the first band and the second band is created.