Make-Before-Break Handover Latency Reduction via Concurrent PDCP

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Solution Overview

Problem

Current wireless communication systems face challenges in minimizing handover latency and ensuring seamless connectivity during make-before-break (MBB) handovers, which can lead to service disruptions and degraded user experiences.

Innovation Solution

The method involves a user equipment (UE) concurrently communicating with a source base station (BS) and a target BS during the MBB handover procedure, while performing a common packet data convergence protocol (PDCP) function for both connections before releasing the source BS connection. This allows for a simultaneous transition between the two BSs, reducing latency and maintaining service continuity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If traditional break-before-make handover is used, then connection establishment is simple, but handover latency increases and service continuity is disrupted

Engineering Contradiction:

Improvehandover latencyVSAvoidconnection management complexity

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The target base station is selected and connection established before the source base station connection is released. The UE is configured with both source and target connections simultaneously, allowing the target connection to be ready before handover execution, thereby reducing handover latency and avoiding service disruption.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The handover procedure transitions from static sequential connection management to dynamic parallel connection management. The UE maintains active connections with both source and target base stations during the handover process, dynamically switching between connections based on real-time conditions, enabling near-zero latency handover.

Inventive Principle:

Principle #15Dynamics

2Reliability

If concurrent connection with source and target BS is maintained, then handover latency is reduced, but connection management complexity increases

Engineering Contradiction:

Improveservice continuityVSAvoiddual connection management

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The network side (source base station and target base station) acts as an intermediary to manage the dual connections. The source base station provides measurement information and handover instructions, while the target base station provides connection status and readiness confirmation, coordinating the UE's connection management to reduce complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The UE receives feedback from both source and target base stations regarding connection status, signal quality, and handover readiness. Based on this feedback, the UE dynamically adjusts connection management, maintaining optimal service continuity while managing the complexity of dual connections through real-time information exchange.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12295061B2Enhanced make-before-break handover

Publication Date: 2025.05.06 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment concurrently communicates with a source base station (BS) and a target BS on a connection with the source BS and a connection with the target BS as part of a make-before-break (MBB) handover procedure; and performs a common packet data convergence protocol (PDCP) function for the connection with the source BS and the connection with the target BS before the connection with the source BS is released as part of the MBB handover procedure. Numerous other aspects are provided.