Relay Node Buffer Management for Multi-Hop Wireless Networks

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Solution Overview

Problem

Multi-hop and multi-path wireless communication networks face issues with data packet losses and corruptions due to signal fading and buffer overload, leading to inefficient use of resources and reduced cell throughput.

Innovation Solution

A method where relay nodes store data packets for a determined duration, transmit them to succeeding nodes, and determine whether to flush them based on received ACK messages, allowing for dynamic buffer management and retransmissions from closer nodes, thereby reducing unnecessary buffering and optimizing resource use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If relay nodes store data packets in buffers for extended periods to enable retransmissions, then data packet loss is reduced, but buffer overload occurs leading to packet drops

Engineering Contradiction:

Improvedata packet delivery reliabilityVSAvoidbuffer occupancy

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by having relay nodes pre-store data packets in buffers before transmission attempts. This allows the relay node to have packets ready for immediate retransmission when acknowledgments are not received, reducing the need for lengthy retransmission chains and improving delivery reliability while controlling buffer usage through selective pre-storing of packets.

Inventive Principle:

Principle #10Preliminary action

2Area of stationary object

If data packets are transmitted through multiple relay nodes, then network coverage is extended, but data packet losses and corruptions increase due to signal fading and interferences

Engineering Contradiction:

Improvenetwork coverage areaVSAvoiddata packet integrity

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by implementing error correction codes and redundancy mechanisms in advance of transmission through multiple relay nodes. This prepares the system to withstand signal fading and interference effects that occur during multi-hop transmission, cushioning against the degradation of packet integrity while extending coverage area.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent implements feedback mechanisms where relay nodes send acknowledgments back to previous nodes in the transmission chain. This feedback allows the system to detect packet losses or corruptions and trigger retransmissions, maintaining data packet integrity even as network coverage is extended through multiple relay nodes.

Inventive Principle:

Principle #23Feedback

3Area of stationary object

If relay nodes forward packets through long chains of multiple relays, then coverage is extended, but retransmission overhead and resource consumption increase

Engineering Contradiction:

Improvenetwork coverage areaVSAvoidretransmission overhead

Core Design Contradiction:

Area of stationary objectVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by having intermediate relay nodes pre-store data packets in their buffers during the forward transmission phase. This preparation allows any node in the chain to perform retransmissions locally without requiring the packet to travel back through the entire chain, significantly reducing retransmission overhead and energy consumption while maintaining extended coverage.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If relay nodes maintain buffers for extended periods, then retransmission capability is improved, but buffer management complexity increases

Engineering Contradiction:

Improveretransmission capabilityVSAvoidbuffer management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by implementing time-based buffer management where relay nodes automatically flush buffers after predetermined time periods or after successful transmission. This dynamic approach balances retransmission capability with buffer management simplicity, allowing nodes to maintain packets only as long as needed while automatically clearing buffers to reduce management complexity.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3292712B1Methods and devices for handling data packet transmissions in a multi-path multi-hop adapted wireless communication network

Publication Date: 2019.11.06 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

There is provided a method performed by a relay node in a wireless network adapted for multi-hop routing of data packets. The method comprises to store a data packet received from a preceding relay node, PRN, in the network in a data packet buffer. The method also comprises to transmit the buffered data packet towards a succeeding relay node, SRN, in the network and to receive, from the SRN, a relay ACK message, RACK message and to determining, based on the received RACK, whether to flush the data packet from the data packet buffer. A corresponding relay node and computer program is also provided. There is also provided a method for handling data packet transmission in a wireless communication network configured for multi-path multi-hop routing together with a corresponding relay node and a corresponding computer program.