Multicast NACK via HE-LTF Resource Blocks
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Solution Overview
Problem
Existing wireless local area networks (WLANs) face inefficiencies in resource allocation and packet retransmission, particularly when handling both newer high-efficiency wireless (HEW) devices and legacy devices, which can lead to suboptimal bandwidth utilization and response times.
Innovation Solution
Implementing a method that uses a master station to transmit HEW frames with configurable subchannel bandwidth and multiple access techniques like OFDMA and MU-MIMO, allowing HEW stations to communicate during a controlled period while legacy devices are excluded, and employing a 1-bit feedback mechanism using resource block identifications (RBIDs) for simultaneous acknowledgments and negative acknowledgments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a master station transmits multicast packets to multiple HEW stations simultaneously, then bandwidth utilization improves, but reliable delivery confirmation becomes difficult to obtain
Solution Approach 1:
The patent implements a feedback mechanism where HEW stations send acknowledgments back to the master station using the HE-LTF resource blocks. Each station transmits a 1-bit acknowledgment (ACK or NACK) on the resource block corresponding to the packet sequence number, enabling the master station to reliably determine which packets were successfully received despite simultaneous multicast transmission to multiple stations
Solution Approach 2:
The patent utilizes the HE-LTF training field resource blocks, originally intended for channel estimation purposes, as an additional dimension for feedback transmission. By mapping acknowledgment bits to specific resource block identifications (RBIDs) within the HE-LTF structure, the system enables reliable feedback without consuming additional uplink data transmission resources
2Loss of time
If the system uses simultaneous feedback from multiple HEW stations, then response time improves, but feedback reliability may deteriorate due to potential collisions
Solution Approach 1:
The patent segments the feedback resource space by dividing HE-LTF resource blocks into distinct identifications (RBIDs), with each RBID assigned to specific packet sequence numbers. This segmentation allows multiple stations to transmit feedback simultaneously on different resource blocks without collision, as each station sends its acknowledgment on the RBID corresponding to the packet it is acknowledging
Solution Approach 2:
The system enables HEW stations to self-organize their feedback transmissions by autonomously determining which RBID to use based on the packet sequence number in the multicast transmission. Each station independently selects its feedback resource without requiring centralized scheduling, allowing simultaneous feedback while avoiding collisions through the structured RBID mapping
Data Source
AI summary
Apparatuses, computer readable media, and methods for multicast negative acknowledgements using high-energy long-training fields for feedback are disclosed. An apparatus of a wireless device is disclosed. The apparatus includes memory and processing circuitry coupled to the memory where the processing circuitry configured to: encode one or more packets in accordance with multicast or broadcast, cause to be transmitted the one or more packets to one or more stations, and decode feedback from the one or more stations. The feedback may be received simultaneously on a same resource block for each packet of the one or more packets. Each packet may be represented by one resource block of the one or more resource blocks. The resource blocks may be thirty-six resource blocks per 20 MHz subchannel with nine resource blocks in a frequency domain by four spatial streams.