Adaptive Random Access Response Window for Non-Terrestrial Networks

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current random access techniques in terrestrial networks do not adequately account for the propagation delays in non-terrestrial networks, such as satellite communications, leading to inefficiencies and power consumption issues.

Innovation Solution

The implementation of an adaptive random access response window length in non-terrestrial networks, which takes into account the varying propagation delays based on satellite orbit altitudes, beam footprint sizes, and elevation angles, allowing UEs to determine their own monitoring window length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed random access response window length is used in non-terrestrial networks, then the system maintains simplicity in configuration, but UEs located at different positions within the satellite beam experience unreliable random access response reception due to varying propagation delays

Engineering Contradiction:
Improverandom access response reception reliabilityVSAvoidrandom access window configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the random access response window length adaptive rather than fixed. The window length is dynamically adjusted based on the UE's location within the satellite beam and the corresponding propagation delay, ensuring that each UE has an appropriate monitoring window duration for reliable random access response reception.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of window length based on propagation delay characteristics. By calculating the appropriate window length according to the UE's distance from the satellite and the beam geometry, the system optimizes the random access response monitoring period for each UE's specific conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the random access response window length is extended to accommodate maximum propagation delay, then all UEs can reliably receive responses, but UEs with smaller delays experience unnecessary power consumption during extended monitoring periods

Engineering Contradiction:
Improverandom access response reception reliabilityVSAvoidUE power consumption during monitoring
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by assigning different window lengths to UEs based on their specific locations within the satellite beam. Instead of using a uniform window length for all UEs, the system tailors the monitoring window duration to each UE's propagation delay characteristics, ensuring reliable reception while minimizing unnecessary power consumption.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent optimizes power consumption by adjusting the window length parameter according to each UE's propagation delay. UEs with smaller delays have shorter monitoring windows, reducing their power consumption, while UEs with maximum delays have appropriately extended windows to ensure reliable response reception.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If the random access response window length is shortened to reduce power consumption, then UE battery life is extended, but UEs experiencing maximum propagation delay may miss their random access responses

Engineering Contradiction:
ImproveUE power consumption during monitoringVSAvoidrandom access response reception reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent resolves this contradiction by dynamically changing the window length parameter based on propagation delay. The system calculates the optimal window length for each UE considering its distance from the satellite, ensuring that the window is long enough to receive the response reliably but not excessively long to waste power.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent makes the monitoring window duration dynamic rather than static. The window length adapts to each UE's specific propagation delay conditions, allowing the system to optimize both power consumption and reliability simultaneously by matching the window duration to the actual communication conditions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3912418B1Adaptive random access response window
Publication Date: 2025.04.09 ZTE CORP
  • EP3912418B1 patent drawingFigure 1
  • EP3912418B1 patent drawingFigure 2
  • EP3912418B1 patent drawingFigure 3

AI summary

This disclosure relates generally to wireless communications and, more particularly, to systems and methods for determining an adaptive random access response window length in non-terrestrial networks. In one embodiment, a method performed by a communication device includes: receiving system information from a communication node, wherein the communication node communicates using a satellite in orbit or a high altitude platform station (HAPS); and determining an adaptive random access response window length based on the system information and whether the communication device has access to situation information that: characterizes a location of the communication device, an ephemeris of the satellite or a trajectory of the HAPS, and a payload type of the satellite or the HAPS.