Multicast Fast Handover via Tunnel Buffering

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Solution Overview

Problem

Existing access routers (ARs) experience significant delays during the handover of a Mobile Node (MN) from one AR to another, particularly when moving out of overlapping coverage areas, leading to potential loss of multicast data streams like IP television.

Innovation Solution

The system anticipates handover by acquiring and forwarding the MN's multicast state data from the previous AR (PAR) to the new AR (NAR), establishing a tunnel to buffer multicast data streams until the MN connects to the NAR, thereby reducing handover delays without specialized mobility signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the MN performs handover from one AR to another AR, then the MN can maintain wireless access coverage mobility, but significant time delay occurs during the handover process causing multicast data stream loss

Engineering Contradiction:
Improvewireless access coverage mobilityVSAvoidhandover delay
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by having the previous AR (PAR) forward multicast state data to the new AR (NAR) before the MN actually connects to the NAR. The NAR pre-establishes multicast delivery trees and buffers packets in advance, so when the MN connects, the handover is seamless and no data is lost.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism where the network component acts as a mediator between the PAR and NAR. This mediator forwards multicast state data, establishes tunnels, and coordinates the handover process, enabling smooth transition without requiring the MN to explicitly signal mobility events.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the MN uses explicit protocols like FMIPv6 with tunneling to forward multicast packets, then multicast data stream continuity is improved, but the system complexity and signaling overhead increase

Engineering Contradiction:
Improvemulticast data stream continuityVSAvoidmobility signaling complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system implements self-service by having the network component automatically detect handover conditions and initiate the data forwarding process without requiring explicit mobility signaling from the MN. The MN simply sends MLS reports, and the network autonomously manages the entire handover process including tunnel establishment and data forwarding.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts the complex mobility signaling and handover management functions from the MN and relocates them to the network component. This extraction reduces the complexity at the MN level while maintaining reliable multicast data stream continuity through automated network-coordinated forwarding.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2067372B1Multicast fast handover
Publication Date: 2020.09.16 HUAWEI TECH CO LTD
  • EP2067372B1 patent drawingFigure 1
  • EP2067372B1 patent drawingFigure 2
  • EP2067372B1 patent drawingFigure 3

AI summary

A network component comprising a processor configured to implement a method comprising receiving a multicast listening state (MLS) report comprising a multicast state data from a mobile node (MN), sending the multicast state data to an access router (AR), establishing a tunnel with the AR, and forwarding at least one multicast data stream associated with the multicast state data to the AR via the tunnel. Also disclosed is an AR configured to implement a method comprising receiving a multicast state data for an MN, evaluating the multicast state data, indicating whether the multicast state data is supported by the AR, establishing a tunnel with a second AR, and receiving at least one multicast data stream associated with the multicast state data from the second AR via the tunnel.