Base Station PDCP SDU Flow ID Extraction for Seamless Handover

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Solution Overview

Problem

Inter-system mobility between LTE and next-generation networks poses challenges for seamless service continuity as existing technologies struggle to handle handovers effectively, leading to potential misdecoding of IP packets due to flow IDs.

Innovation Solution

A base station system that associates PDCP SDUs with sequence numbers, initiates handovers, and forwards only IP packets without flow IDs to ensure smooth transitions between base stations, preventing misdecoding and ensuring seamless service continuity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flow ID is forwarded during handover, then packet identification is maintained, but misdecoding occurs due to network changes

Engineering Contradiction:

Improveservice continuityVSAvoidmisdecoding

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the flow ID from the PDCP SDU before forwarding during handover. The base station removes the flow ID field from the packet while maintaining the IP packet integrity, thereby preventing misdecoding issues that would occur if the flow ID were forwarded across different networks.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the PDCP SDU into two parts: the flow ID portion and the IP packet portion. During handover, only the IP packet portion is forwarded to the target base station, while the flow ID is handled separately or discarded, allowing seamless transition without carrying potentially problematic flow ID information.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If complete PDCP SDU is forwarded, then packet structure is preserved, but handover smoothness is reduced due to flow ID conflicts

Engineering Contradiction:

Improvepacket structureVSAvoidhandover smoothness

Core Design Contradiction:

Stability of the object's compositionVSEase of operation

Solution Approach 1:

The patent extracts and removes the flow ID from the PDCP SDU structure during handover preparation. This maintains the essential IP packet structure and functionality while eliminating the flow ID component that would cause conflicts or misdecoding in the target network.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different handling to different parts of the PDCP SDU: the flow ID portion is modified or removed, while the IP packet portion is preserved and forwarded. This localized differentiation allows the packet to maintain necessary structure while avoiding flow ID-related issues.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10764794B2Base station and communication device can handover between two base stations

Publication Date: 2020.09.01 HTC CORP

AI summary

A first base station (BS) includes: a storage device, configured to store program codes; a first communication interfacing device, configured to transmit signals or receive signals with a second BS; a second communication interfacing device, configured to transmit signals or receive signals with a first communication device; and a processing circuit, configured to execute the program codes. Executing the program codes includes: (a) associating a first Packet Data Convergence Protocol Service Data Unit (PDCP SDU) or an Internet Protocol (IP) packet in the first PDCP SDU with a first PDCP Sequence Number (SN) for the first communication device, the first PDCP SDU including a flow ID and the IP packet; (b) initiating a handover for the first communication device to the second BS; and (c) controlling the first communication interfacing device to only forward the IP packet to the second BS in response to the handover.