Network Node Broadcast Reliability via Negative Acknowledgement

Solution Overview

Problem

Broadcast and multicast transmissions in wireless communication systems lack reliability due to the absence of acknowledgment mechanisms, leading to inefficiencies in message delivery and increased latency.

Innovation Solution

Implementing a method where a network node sends a first broadcast message indicating that a second message will follow, and if not received, wireless devices send a negative acknowledgement (NACK) to ensure message delivery, thereby increasing reliability and reducing contention and energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If broadcast messages are transmitted without acknowledgment mechanisms, then network flooding and energy consumption are reduced, but message delivery reliability deteriorates

Engineering Contradiction:

Improveenergy consumptionVSAvoidmessage delivery reliability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent inverts the traditional acknowledgment approach by using negative acknowledgments (NACK) instead of positive acknowledgments (ACK). Only wireless devices that fail to receive the broadcast message transmit a NACK signal, rather than all devices transmitting ACK signals. This inversion reduces network flooding while maintaining reliability, as fewer devices need to transmit feedback signals.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent implements a feedback mechanism where wireless devices provide feedback to the network node about whether they successfully received the broadcast message. The feedback is transmitted as a NACK signal when reception fails, allowing the network node to detect missing messages and initiate retransmission, thereby ensuring reliable message delivery.

Inventive Principle:

Principle #23Feedback

2Reliability

If positive acknowledgments are used for all received broadcast messages, then message delivery reliability is improved, but network contention and latency increase

Engineering Contradiction:

Improvemessage delivery reliabilityVSAvoidacknowledgment transmission time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent inverts the traditional acknowledgment approach by using negative acknowledgments (NACK) instead of positive acknowledgments (ACK). Only wireless devices that fail to receive the broadcast message transmit a NACK signal, rather than all devices transmitting ACK signals. This inversion reduces network flooding while maintaining reliability, as fewer devices need to transmit feedback signals.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies partial action by having only the necessary subset of wireless devices (those that failed to receive the message) transmit acknowledgment signals, rather than all devices transmitting ACK signals. This reduces the total number of feedback transmissions and associated latency.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If broadcast messages are retransmitted upon failure, then message delivery reliability is improved, but network latency and energy consumption increase

Engineering Contradiction:

Improvemessage delivery reliabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements a feedback mechanism where wireless devices provide feedback to the network node about whether they successfully received the broadcast message. The feedback is transmitted as a NACK signal when reception fails, allowing the network node to detect missing messages and initiate retransmission, thereby ensuring reliable message delivery.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent enables wireless devices to self-diagnose reception status by monitoring whether they successfully decoded the broadcast message. Devices that fail to receive the message automatically initiate a NACK transmission without requiring external probing, allowing the system to self-correct delivery failures efficiently.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10623145B2Network node, wireless device and methods performed thereby for the network node to provide information to the wireless device

Publication Date: 2020.04.14 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A network node, a wireless device and respective methods performed thereby for the network node to provide information to one or more wireless devices are provided. The network node and the wireless device are operable in a wireless communication network. The method performed by the network node comprises transmitting (120) a first message by means of broadcast indicating that a second message associated with the first message will be broadcasted after the transmission of the first message, the first message also indicating to the one or more wireless devices that feedback with regard to the second message is required should the second message not be received; and transmitting (130) the second message by means of broadcast.