Relay Station Low Latency Frame Forwarding

Solution Overview

Problem

Existing IEEE 802.11 relay technologies experience delays and inefficiencies when transmitting low latency data frames due to the use of TXOP protection mechanisms, which can result in late and unnecessary frame transmissions, leading to energy wastage and unreliable communication.

Innovation Solution

Implementing a mechanism where a source STA indicates low latency traffic to a relay with a specified transmission completion time, allowing the relay to determine whether to forward the frame based on the availability of the destination STA and the estimated transmission completion time, thereby discarding frames if they cannot be delivered within the specified time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If TXOP protection mechanisms are used for relay transmission, then communication reliability is improved, but transmission latency increases and energy efficiency deteriorates

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidtransmission latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The relay station dynamically adjusts its transmission behavior based on the latency sensitivity of incoming frames. For low-latency frames, the relay transmits immediately without waiting for TXOP protection mechanisms, while for non-low-latency frames, it uses standard TXOP protection. This dynamic adaptation resolves the contradiction by making the system flexible enough to prioritize speed when needed while maintaining reliability when possible.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent introduces a new parameter (low latency indicator) that changes the transmission parameters of the relayed frame. When this indicator is set, the relay station changes its transmission behavior to bypass normal latency-inducing protocols. This parameter-based control allows the system to switch between reliable but slow transmission and fast but less protected transmission based on traffic requirements.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If TXOP protection mechanisms are used for relay transmission, then communication reliability is improved, but energy efficiency deteriorates

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidenergy efficiency

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The relay station dynamically adjusts its transmission behavior based on the latency sensitivity of incoming frames. For low-latency frames, the relay transmits immediately without waiting for TXOP protection mechanisms, while for non-low-latency frames, it uses standard TXOP protection. This dynamic adaptation resolves the contradiction by making the system flexible enough to prioritize speed when needed while maintaining reliability when possible.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent introduces a new parameter (low latency indicator) that changes the transmission parameters of the relayed frame. When this indicator is set, the relay station changes its transmission behavior to bypass normal latency-inducing protocols. This parameter-based control allows the system to switch between reliable but slow transmission and fast but less protected transmission based on traffic requirements.

Inventive Principle:

Principle #35Parameter changes

3Speed

If frames are transmitted without checking transmission completion time, then transmission speed is improved, but reliability deteriorates due to late and unnecessary transmissions

Engineering Contradiction:

Improvetransmission speedVSAvoiddelivery reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The source station performs a preliminary action by setting the transmission completion time indicator in the frame before transmission. This allows the relay station to pre-calculate whether transmission is feasible within the required time window, avoiding both premature transmissions (wasting energy) and delayed transmissions (missing deadlines). The preliminary time assessment enables the relay to make informed decisions about whether to transmit.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The transmission completion time indicator acts as a feedback mechanism from the source to the relay, providing information about the maximum acceptable transmission time. The relay uses this feedback to adjust its transmission timing, ensuring that frames are transmitted neither too early (wasting energy) nor too late (missing deadlines), but at the optimal moment that satisfies both speed and reliability requirements.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20240292458A1Low Latency Relaying

Publication Date: 2024.08.29 OFINNO LLC

AI summary

A first station receives from a second station a first frame indicating a transmission completion time of a second frame destined to a third station. The first station transmits a request-to-send (RTS) frame to the third station and receives a clear-to-send (CTS) frame from the third STA. After receiving the CTS frame, the first STA transmits the second frame to third STA, based on determining that an estimated transmission completion of the second frame is no later than the transmission completion of the second frame indicated in the first frame.