PDCP Synchronization for Dual-Connectivity Wireless Links

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Solution Overview

Problem

Wireless communication networks face synchronization issues due to the longer delivery time of indirect data portions compared to direct data portions, leading to unsynchronized data receipt by user devices in dual-connectivity scenarios, necessitating re-sequence or re-transmission requests.

Innovation Solution

The Protocol Data Convergence Protocol (PDCP) estimates the transmission time difference between direct and indirect data and applies corresponding delays to synchronize data delivery, ensuring that both data portions are received in a synchronized manner by user equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If indirect data portion is transferred through wireless support node, then data delivery diversity is improved, but delivery time increases

Engineering Contradiction:

Improvedata delivery diversityVSAvoiddelivery time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The PDCP layer performs preliminary estimation of transmission time differences between direct and indirect data paths. Based on this estimation, the system pre-delays the direct data portion before transmission, so that both direct and indirect data portions arrive at the UE simultaneously, eliminating the need for re-sequencing at the receiver

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the timing parameter of data transmission by applying a time delay to the direct data portion. This parameter adjustment equalizes the arrival times of direct and indirect data portions at the UE, resolving the synchronization issue caused by different path lengths

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If direct and indirect data portions are delivered simultaneously, then synchronization is improved, but transmission complexity increases

Engineering Contradiction:

Improvedata synchronizationVSAvoidtransmission complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The PDCP layer acts as an intermediary that coordinates between the direct and indirect data paths. It estimates transmission time differences and applies appropriate delays to the direct data portion, serving as a mediator that balances the timing of data from two different transmission paths without requiring complex coordination at the UE

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11395245B1Synchronized data communications over multiple wireless links and access nodes

Publication Date: 2022.07.19 T MOBILE INNOVATIONS LLC

AI summary

In a wireless access node, a Protocol Data Convergence Protocol (PDCP) separates data into direct data and indirect data. The wireless access node wirelessly transfers the direct data to User Equipment (UE) and transfers the indirect data to a wireless support node. The wireless support node wirelessly transfers the indirect data to the UE. The PDCP estimates a transmission time difference between the direct data and the indirect data. The PDCP separates additional data into direct data and indirect data. The PDCP delays the additional direct and/or indirect data based on the time difference to synchronize delivery. The wireless access node wirelessly transfers the direct data to the UE and transfers the indirect data to the wireless support node. The wireless support node wirelessly transfers the indirect data to the UE.