BWP Switching Latency Reduction via Pre-Activation

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Solution Overview

Problem

In 5G NR systems, switching between carrier bandwidth parts (BWP) by terminal devices results in high latency due to the need for deactivation and activation operations, which impacts communication efficiency.

Innovation Solution

The solution involves maintaining a second BWP in a to-be-activated state alongside the active BWP, allowing for seamless switching with approximately zero latency, thereby reducing BWP switching latency and enhancing communication quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the base station activates only one carrier bandwidth part at a same moment, then the system operates with simple state management, but the terminal device experiences high latency when switching between carrier bandwidth parts

Engineering Contradiction:
ImproveBWP switching latencyVSAvoidBWP state management complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-activating a target carrier bandwidth part before the terminal device needs to switch to it. The base station activates the target BWP in advance, so when switching is required, the terminal device can immediately use the pre-activated BWP without waiting for activation procedures, thereby reducing switching latency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamics by allowing multiple carrier bandwidth parts to be in an active state simultaneously, rather than maintaining a static single-active-BWP configuration. This dynamic state management enables the terminal device to switch between actively available BWPs without latency, as the system can transition between multiple active states based on communication needs.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the terminal device performs deactivation and activation operations during BWP switching, then the BWP state transitions are controlled, but the switching process takes time resulting in high latency

Engineering Contradiction:
ImproveBWP switching reliabilityVSAvoidSwitching time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The base station performs preliminary activation of the target carrier bandwidth part before the terminal device needs to switch. This pre-activation ensures that when the terminal device initiates a switch, the target BWP is already in an active state, eliminating the activation time from the switching process while maintaining reliable state transitions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent maintains continuity of useful action by keeping multiple carrier bandwidth parts in active states simultaneously. This allows the terminal device to switch between BWPs without interruption or delay, as the target BWP is already prepared and available, ensuring continuous communication functionality during transitions.

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If multiple carrier bandwidth parts are configured for the terminal device, then the system provides greater flexibility, but the terminal device needs to switch working carrier bandwidth parts which increases latency

Engineering Contradiction:
ImproveCarrier bandwidth part configuration flexibilityVSAvoidWorking process latency
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by enabling multiple carrier bandwidth parts to be simultaneously active, creating a dynamic environment where the terminal device can switch between multiple ready-to-use BWPs. This dynamic configuration maintains the flexibility benefits of multiple BWPs while eliminating switching latency through pre-activation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The base station performs preliminary activation of target carrier bandwidth parts based on anticipated communication needs. This pre-activation prepares multiple BWP options in advance, allowing the terminal device to switch between them instantly when needed, thus maintaining configuration flexibility without incurring switching latency.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3817480B1Signal transmission method and apparatus
Publication Date: 2023.07.26 HUAWEI TECH CO LTD
  • EP3817480B1 patent drawingFigure 1~3
  • EP3817480B1 patent drawingFigure 4~5
  • EP3817480B1 patent drawingFigure 6~7

AI summary

A signal transmission method and an apparatus are provided. The signal transmission method includes: receiving a first message in an active first carrier bandwidth part BWP; determining, based on the first message, that a new active BWP of a terminal device is a second BWP, where the second BWP is a BWP in one or more to-be-activated BWPs of the terminal device, and the to-be-activated BWP is a state configured by a network device for the terminal device; and transmitting a signal in the second BWP. In embodiments of this application, the one or more to-be-activated BWPs is configured. At a same moment, in addition to the first BWP in an active state, the second BWP in a to-be-activated state further exists. It may be considered that switching from the active BWP to the to-be-activated BWP by the terminal device can be implemented with an approximately zero latency, so that a latency of switching the carrier bandwidth part by the terminal device is reduced, and communication quality is improved.