Air-to-Ground Network Access Using Subsector RACH Preambles

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Solution Overview

Problem

Air-to-ground networks face challenges in maintaining stability and efficiency due to the reliance on antenna steering techniques and the lack of universal implementation of secondary networks, which creates additional points of failure.

Innovation Solution

A method for vehicles to determine their location relative to a base station by querying a database using a received base station identifier and on-board location sensors, and transmitting a random access channel preamble message with a specific sequence corresponding to a subsector, allowing for synchronization without relying on secondary networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If antenna steering techniques are used to communicate with vehicles, then the base station can serve vehicles within a large footprint, but the system requires additional dependencies on secondary networks for location determination, creating additional points of failure

Engineering Contradiction:
Improvebase station footprintVSAvoidnetwork stability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent introduces random access sequences as an intermediary mechanism that enables the base station to determine vehicle location and activate appropriate narrowbeams without relying on secondary networks. The sequences act as a mediator between the vehicle's access request and the base station's beam steering response, eliminating the need for external location determination systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/external dependency on secondary networks with an integrated signal processing approach. Instead of using separate location determination systems, the base station uses signal processing techniques (narrowbeam activation based on random access sequences) to determine vehicle location and establish communication, substituting external system dependencies with internal signal-based mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Area of stationary object

If antenna steering techniques are implemented, then the base station can cover a large area, but the system complexity increases due to the need for location determination and beam management

Engineering Contradiction:
Improvebase station footprintVSAvoidsystem complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent segments the base station's coverage area into multiple subsectors, each served by a dedicated narrowbeam. This segmentation allows the system to manage complexity by dividing the large footprint into smaller, independently manageable sections. Each random access sequence corresponds to a specific subsector, enabling localized beam management rather than controlling the entire coverage area as a single unit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning specific random access sequences to specific subsectors and activating corresponding narrowbeams only in those subsectors. This localized approach allows the base station to optimize resources by focusing beam energy only where vehicles are present, rather than maintaining uniform coverage across the entire footprint, thereby reducing overall system complexity.

Inventive Principle:
Principle #3Local quality

3Productivity

If random access sequences are used for subsector identification, then the vehicle can determine its location and establish connection efficiently, but the system requires precise correspondence between sequences and subsectors

Engineering Contradiction:
Improveconnection establishment speedVSAvoidsequence-subsector mapping precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements preliminary action by pre-establishing a correspondence between random access sequences and subsectors before vehicles attempt to connect. The base station configures and broadcasts this mapping information in advance, allowing vehicles to quickly determine their subsector and select the appropriate sequence without requiring complex real-time calculations, thus maintaining high connection establishment speed.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4111802B1Systems and methods for accessing an air-to-ground network
Publication Date: 2026.04.15 GOGO BUSINESS AVIATION LLC
  • EP4111802B1 patent drawingFigure 1
  • EP4111802B1 patent drawingFigure 2A
  • EP4111802B1 patent drawingFigure 2B

AI summary

Systems and method for establishing a connection between a vehicle and a base station are provided. The base station sectors are divided into subsector respectively associated with a narrowbeam antenna. To determine the vehicle location without the use of a complementary network, the base station and the vehicle may associate each subsector with a respective set of radio access preamble sequences. Accordingly, the location of the vehicle can be determined based on the particular radio access preamble sequence included in the synchronization messaging. Additionally or alternatively, the base station may be configured to sequentially activate the narrowbeam antennas to detect a which narrowbeam is active when the vehicle responds to a message communicated over the narrowbeams.