Dedicated Uplink Resource Assignment for Synchronization

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in uplink temporal synchronization, particularly when the timing advance (TA) is invalid, leading to unpredictable delays and increased power consumption due to the need for constant DL/UL transmissions to maintain synchronization, especially in situations where not all connection types require continuous synchronization.

Innovation Solution

A method where the network assigns a dedicated uplink resource to user equipment (UE) for transmitting a special synchronization burst, allowing the network to calculate and update the TA without using the contention-based RACH channel, thereby avoiding collisions and reducing resource load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the network uses contention-based RACH channel for uplink synchronization, then the UE can establish initial connection and adjust TA, but the channel experiences collisions and unpredictable delays

Engineering Contradiction:
Improveuplink synchronization reliabilityVSAvoidsynchronization setup delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the synchronization function from the contention-based RACH channel by dedicating specific uplink resources (time-frequency resources) exclusively for synchronization purposes. This separation removes the collision risk inherent in contention-based access while maintaining the synchronization capability, thereby improving reliability and reducing delays.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The network pre-allocates dedicated uplink resources for synchronization before the UE needs to synchronize. This preliminary allocation eliminates the need for contention-based access during synchronization, allowing UEs to immediately use the pre-assigned resources without waiting for RACH opportunities, thus reducing setup delays.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the network requires constant DL/UL transmissions to maintain TA validity, then uplink synchronization is maintained, but power consumption increases

Engineering Contradiction:
Improveuplink synchronization maintenanceVSAvoidUE power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of requiring constant transmissions, the patent implements periodic synchronization opportunities using dedicated uplink resources. UEs can maintain synchronization by utilizing these pre-allocated resources at intervals rather than continuously, significantly reducing power consumption while ensuring synchronization is maintained when needed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The dedicated uplink resources enable UEs to autonomously perform synchronization maintenance without requiring continuous network scheduling or coordination. The UE can independently use the dedicated resources to refresh its TA when necessary, reducing the overhead and power consumption associated with continuous network-managed synchronization.

Inventive Principle:
Principle #25Self-service

3Productivity

If the network allocates dedicated uplink resources for synchronization, then collision risks are eliminated and resource efficiency improves, but device complexity increases

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidsynchronization management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The dedicated uplink resources serve multiple functions: initial synchronization, TA maintenance, and potential data transmission. This multi-functionality reduces the need for separate mechanisms for each purpose, simplifying overall system management despite the dedicated resource allocation. The same resources can be reused for different synchronization scenarios.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2016689B1Apparatus, method and computer program product providing uplink synchronization through use of dedicated uplink resource assignment
Publication Date: 2017.06.21 NOKIA TECHNOLOGIES OY
  • EP2016689B1 patent drawingFigure 1
  • EP2016689B1 patent drawingFigure 2
  • EP2016689B1 patent drawingFigure 3A~3B

AI summary

An assignment of an uplink resource on which to send an uplink synchronization signal is transmitted to a user equipment. The user equipment sends on the uplink resource an uplink synchronization signal. From the uplink synchronization signal is determined a timing advance for the user equipment. Various indications are used to indicate to the user equipment that the assignment of uplink resources is for the purpose of sending its synchronization signal, such as expiration of its timing advance timer, a field in the allocation table that assigns the uplink resources, or explicit signaling from the network. Methods, devices, and computer program products are detailed for both network and user equipment embodiments.