Hybrid Unicast-Multicast Routing for Radio Obstruction Resilience

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Solution Overview

Problem

Wireless communication networks face reliability issues due to deteriorated radio characteristics in individual links, leading to poor network performance, especially when temporary obstructions block or attenuate radio signals, necessitating frequent routing updates.

Innovation Solution

Implementing a method where routing nodes receive uplink messages via multicast and forward them via unicast, determining the recipient for downlink messages, and transmitting downlink messages via multicast only if the recipient matches the original sender, while gateways select downlink paths based on radio metrics from multiple hops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If routing updates are performed frequently to adapt to changing radio conditions, then communication reliability is improved, but network overhead and complexity increase

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidrouting update complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic routing by allowing nodes to switch between unicast and multicast transmissions based on real-time radio conditions. When radio characteristics deteriorate, the system dynamically activates alternative multicast paths without requiring complete routing table updates, thus adapting to changing conditions while maintaining stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces multicast transmission as an intermediary mechanism between source and destination nodes. Instead of directly updating unicast routing tables when conditions change, the system uses multicast as a mediator to deliver messages through alternative paths, reducing the need for frequent routing updates while maintaining communication reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If unicast transmission is used for downlink messages, then transmission reliability is improved, but network efficiency and resource utilization deteriorate

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidnetwork efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent makes the downlink transmission mechanism universal by implementing a hybrid approach that can function as either unicast or multicast based on the specific scenario. The system evaluates radio conditions and message characteristics to determine whether to use reliable unicast or efficient multicast, making the transmission system adaptable to different requirements rather than being fixed to one mode.

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

Solution Approach 2:

The patent changes the transmission parameter (unicast vs multicast) based on evaluated conditions. The system monitors radio characteristics and dynamically adjusts the transmission mode parameter, switching from unicast to multicast when conditions permit, thereby optimizing the balance between reliability and network efficiency for different transmission scenarios.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If multicast transmission is used for uplink messages, then network efficiency is improved, but transmission reliability deteriorates due to potential obstructions

Engineering Contradiction:
Improvenetwork efficiencyVSAvoidtransmission reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary evaluation of radio characteristics before finalizing the transmission path. By assessing the quality of multicast reception in advance, the system can identify potential reliability issues with multicast transmission and prepare alternative unicast paths, thus preventing reliability problems before they occur while maintaining the efficiency benefits of multicast when conditions are favorable.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If routing tables are updated constantly to reflect temporary variations in radio conditions, then communication adaptability is improved, but network stability deteriorates due to erratic routing changes

Engineering Contradiction:
Improvecommunication adaptabilityVSAvoidrouting stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent implements dynamic routing by allowing nodes to switch between unicast and multicast transmissions based on real-time radio conditions. When radio characteristics deteriorate, the system dynamically activates alternative multicast paths without requiring complete routing table updates, thus adapting to changing conditions while maintaining stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces multicast transmission as an intermediary mechanism between source and destination nodes. Instead of directly updating unicast routing tables when conditions change, the system uses multicast as a mediator to deliver messages through alternative paths, reducing the need for frequent routing updates while maintaining communication reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4449745B1Routing data in a communication network
Publication Date: 2025.10.01 ASSA ABLOY AB
  • EP4449745B1 patent drawingFigure 1~2
  • EP4449745B1 patent drawingFigure 3~5

AI summary

It is provided a method for routing data in a communication network (8). The method being performed by a routing node (3). The method comprises: receiving (40) an uplink message from an end node (2) over a multicast wireless transmission; forwarding (42) the uplink message towards a destination node over a unicast transmission; receiving (44) a downlink message over a unicast transmission; determining (46) that a recipient of the downlink message is the end node (2); and transmitting (48) the downlink message over multicast to the end node (2). Corresponding routing node, gateway, computer programs and computer program products are also provided.