NTN Backup Beam Reconfiguration for Fast Beam Failure Recovery
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Solution Overview
Problem
Conventional beam failure recovery mechanisms in non-terrestrial networks (NTN) are inadequate due to high frequency of cell changes and unpredictable beam failures, particularly in low-earth orbit scenarios, leading to increased signaling overhead and latency.
Innovation Solution
Implement a backup beam configuration mechanism in NTN systems, where the infrastructure equipment receives assistance information from the communications device, such as location reports or measurement data, to proactively update backup beam configurations based on satellite ephemeris and beam distribution, reserving unique radio resources for each spot beam to facilitate efficient beam failure recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional beam failure recovery mechanisms are used in NTN, then beam failure can be detected and recovered, but latency and signaling overhead increase due to high frequency of cell changes and unpredictable beam failures
Solution Approach 1:
The patent applies preliminary action by proactively identifying and reserving backup beams before beam failure occurs. The network configures multiple candidate beams in advance based on satellite ephemeris data and predicted beam footprints, so that when beam failure is detected, the UE can immediately switch to a pre-configured backup beam without undergoing lengthy measurement and selection procedures, thereby reducing recovery latency.
Solution Approach 2:
The patent implements beforehand cushioning by maintaining pre-configured backup beam configurations that act as a buffer against beam failure. These backup configurations are prepared in advance based on predicted satellite positions and beam patterns, providing a safety cushion that enables rapid failover when the primary beam fails, thus cushioning the impact of beam failure on service continuity.
2Reliability
If conventional beam failure recovery mechanisms are used in NTN, then beam failure can be detected and recovered, but signaling overhead increases due to frequent cell changes and unpredictable beam failures
Solution Approach 1:
The network performs preliminary configuration of multiple candidate beams and their associated parameters in advance, based on satellite ephemeris data and predicted beam footprints. This preliminary action reduces the need for frequent signaling exchanges during beam failure recovery, as the UE already has pre-configured backup options ready to use, thereby reducing signaling overhead.
Solution Approach 2:
The patent uses copying by creating pre-configured backup beam configurations that are copies or alternatives to the primary beam configuration. These backup configurations contain all necessary parameters and settings, allowing the UE to quickly switch without extensive signaling, thus reducing the information exchange overhead during beam failure recovery events.
3Loss of time
If backup beam configuration is updated proactively based on satellite ephemeris and beam distribution, then beam failure recovery latency is reduced, but device complexity increases due to assistance information processing
Solution Approach 1:
The patent introduces an intermediary approach where the network infrastructure (gNB) performs the complex processing of satellite ephemeris data and beam distribution calculations to generate backup beam configurations. The UE receives these pre-processed configurations as assistance information, thereby offloading the complex computational tasks from the device to the network, reducing device complexity while maintaining low recovery latency.
Solution Approach 2:
The network autonomously performs self-service by automatically generating and updating backup beam configurations based on satellite ephemeris data and predicted beam footprints without requiring complex processing at the UE side. The pre-configured backup beams are prepared in advance by the network, enabling the UE to simply switch to the indicated backup configuration, thereby reducing device complexity while achieving rapid beam failure recovery.
Data Source
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AI summary
A method for operating an infrastructure equipment forming part of a wireless communications network is provided. The wireless communications network comprises a base station and a non-terrestrial network part, the non-terrestrial network part transmitting a plurality of spot beams to provide a wireless access interface for transmitting signals to and receiving signals representing data from a communications device within a coverage region formed by a first of the spot beams. The method comprises receiving assistance information from the communications device, identifying, based on the received assistance information, that a backup configuration should be updated to indicate one or more others of the spot beams, the one or more others of the spot beams being backups to the first spot beam in case of beam failure of the first spot beam, and transmitting a backup beam reconfiguration message to the communications device, the backup beam configuration message comprising an indication of the updated backup configuration.