Multi-ACKed Multicast Protocol for Isochronous Networks

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Solution Overview

Problem

Multicast transmissions in multimedia isochronous systems face challenges in reducing packet latency and jitter, especially in congested networks, as existing protocols lack efficient mechanisms for individual acknowledgments from multiple receivers, leading to suboptimal quality of service (QoS) in multimedia applications.

Innovation Solution

The Multi-ACKed Multicast protocol allows a group of receiving devices to receive the same data and return individual acknowledgments within predetermined windows, enabling continuous transmission and medium access without re-contending, using modified SOF and RSOF delimiters to facilitate multi-acknowledgment periods, compatible with existing CSMA-based protocols.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multicast transmissions are used in congested networks, then network bandwidth utilization is improved, but packet latency and jitter increase

Engineering Contradiction:

Improvenetwork bandwidth utilizationVSAvoidpacket latency

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The acknowledgment process is segmented by assigning predetermined time windows to different receiving devices. Each device transmits its ACK only in its assigned window, preventing collisions and reducing latency while maintaining multicast efficiency

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Time windows for ACK transmission are predetermined and assigned to receiving devices before the actual data transmission occurs. This preliminary arrangement eliminates contention delays during the acknowledgment phase, reducing overall packet latency

Inventive Principle:

Principle #10Preliminary action

2Reliability

If individual acknowledgments are collected from multiple receivers, then transmission reliability is improved, but communication time increases

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidcommunication time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

ACK transmissions are organized into periodic time windows assigned to different receivers. This structured periodic approach allows multiple individual acknowledgments to be collected systematically without extending total communication time, as each device knows exactly when to transmit its ACK

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The time window assignments are predetermined, eliminating the need for dynamic negotiation or contention during ACK collection. This preliminary structuring ensures that reliability is maintained through individual ACKs while communication time is minimized through pre-planned transmission slots

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If re-contending for medium access is required, then network fairness is improved, but transmission efficiency decreases

Engineering Contradiction:

Improvenetwork fairnessVSAvoidtransmission efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The transmitter maintains continuous control of the medium during the multicast transmission and predetermined ACK collection period without relinquishing it for re-contending. This continuous action eliminates contention delays and improves transmission efficiency while fairness is maintained through the structured ACK window assignments

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentEP3035632B1Multi- acked multicast protocol

Publication Date: 2019.01.09 STMICROELECTRONICS INC

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AI summary

Multicast transmissions do not allow for individual receivers to acknowledge that data was received by each receiver in the network. This is not acceptable for isochronous systems that require specific levels of QoS for each device. A multimedia communications protocol supports using multicast transmissions (one-to-many) in multimedia isochronous systems. A transmitter establishes a Multi-ACKed Multicast protocol within which a group of receiving devices can acknowledge the multicast transmission during a multi-acknowledgment period.