Partial State Block Acknowledgment for Multicast Retries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multicast data transmissions are unreliable due to collisions and lack of retry or inter-packet Forward Error Correction mechanisms, especially in large groups and high-bandwidth video flows, where existing schemes like Directed Multicast Service and Group Cast Retries are inefficient or impossible.
Innovation Solution
Implementing a partial state block acknowledgement mechanism that reserves a channel for transmission opportunities, allowing for block acknowledgement requests and responses within a single or multiple transmission opportunities, preventing other stations from gaining control and ensuring reliable packet retransmissions through scheduled and individual block acknowledgments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multicast transmissions are sent without retry or inter-packet Forward Error Correction mechanisms, then transmission speed is maintained, but reliability deteriorates due to collisions
Solution Approach 1:
The patent reserves channel access in advance for transmission opportunities (TXOPs) to send multicast data, block acknowledgement requests, and receive responses. This preliminary reservation prevents collisions by ensuring dedicated time slots for multicast transmissions and their acknowledgments, thereby improving reliability without sacrificing overall transmission efficiency.
Solution Approach 2:
The patent implements a continuous multicast transmission process where data packets are sent followed by block acknowledgement requests within the same reserved TXOP. This continuous action ensures that retransmissions can occur immediately within the reserved time slot, maintaining high reliability while preserving transmission efficiency through uninterrupted communication flow.
2Reliability
If Directed Multicast Service performs multicast to unicast conversion, then reliability improves through unicast retry mechanism, but device complexity and efficiency worsen
Solution Approach 1:
The patent extracts the acknowledgement mechanism from individual unicast conversions and implements a consolidated block acknowledgement system. Instead of converting each multicast packet to individual unicast acknowledgments, the system uses a single block acknowledgement request that collects status from multiple receivers, thereby reducing device complexity while maintaining delivery reliability.
Solution Approach 2:
The patent merges multiple individual acknowledgement requests into a single block acknowledgement mechanism. By combining the acknowledgment phase for multiple multicast packets into one unified process within the reserved TXOP, the system reduces complexity associated with multiple separate unicast conversion operations while ensuring reliable delivery to all group members.
3Reliability
If Group Cast Retries uses Full State Block Acknowledgment, then reliability improves, but transmission flexibility and productivity deteriorate due to restrictions on outstanding flows
Solution Approach 1:
The patent implements a partial state block acknowledgement mechanism that tracks only the necessary packet acknowledgments within the reserved TXOP rather than maintaining full state for all outstanding flows. This partial tracking approach provides sufficient reliability for the current transmission while allowing multiple flows and traffic identifiers to coexist, thereby restoring transmission flexibility and adaptability.
Solution Approach 2:
The patent makes the block acknowledgement mechanism dynamic by allowing multiple traffic identifiers and flows to be handled within the same reserved TXOP structure. The system can adaptively manage different multicast flows with varying requirements, enabling flexible resource allocation while maintaining reliability through the reserved acknowledgment time slots.
4Reliability
If channel is reserved for transmission opportunity including retries, then reliability improves through collision prevention, but loss of time increases due to channel reservation overhead
Solution Approach 1:
The patent segments the channel reservation into precise time slots within the TXOP structure - one slot for multicast data transmission, another for block acknowledgement requests, and designated time for receiving responses. This segmentation allows the system to reserve only the minimum necessary time for each function, reducing overall time loss while ensuring reliable transmission through structured collision-free intervals.
Solution Approach 2:
The patent uses periodic transmission opportunities with structured time allocation for data and acknowledgments. By organizing communications into regular periodic TXOPs with predetermined time slots, the system minimizes channel reservation overhead while ensuring reliable delivery through consistent, collision-free transmission and acknowledgment cycles.
Data Source
AI summary
Described herein are techniques that provide for the transmission of a multicast stream that can resend frames that were not received using the partial state block acknowledgement mechanism. In an example embodiment, an access point reserves a channel for a transmission opportunity of a sufficient length to allow the sending of multicast data, block acknowledgement request, and receipt of a block acknowledgement. Optionally, the transmission opportunity may be of sufficient length to enable packets that re resent to be sent during the transmission opportunity, thereby preventing other stations on the channel from gaining control of the channel. Alternatively the access point may employ an appropriate backoff between TXOPs to AP prevent (T)DLS traffic to the recipients of the multicast stream. The access point does not send any frames from other queues during the transmission opportunity.