RoCE Wireless Transmission via Placeholder Frames

Solution Overview

Problem

The RoCE protocol faces challenges in adapting to wireless links due to its requirement for quasi-deterministic transport and low loss, making it difficult to maintain reliable data transfer over wireless networks like Wi-Fi, which are prone to interference and congestion.

Innovation Solution

The implementation of a wireless device with a transmission queue that preemptsively inserts placeholder frames and uses multiple subcarrier resource units to ensure deterministic and reliable data transfer by reducing latency and improving redundancy through coding schemes and dynamic priority queue management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If RoCE protocol is used over wireless link, then data transfer can be enabled, but reliability deteriorates due to interference and congestion

Engineering Contradiction:

ImproveRoCE over wirelessVSAvoiddata transfer reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary actions by preemptively allocating transmission resources and inserting placeholder frames into priority queues before actual data arrives. This advance preparation ensures that when RoCE packets need to be transmitted, the channel access is already reserved, eliminating waiting delays and ensuring deterministic transmission timing even over unreliable wireless links.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements beforehand cushioning through redundancy mechanisms including duplicate packet transmission and forward error correction codes. By preparing backup transmission paths and error correction capabilities in advance, the system can withstand wireless interference and packet loss without compromising reliability, cushioning against the inherent unreliability of wireless media.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Device complexity

If traditional transmission queuing is used, then simplicity is maintained, but latency increases due to waiting for channel access

Engineering Contradiction:

Improvetransmission managementVSAvoidtransmission latency

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by preemptively allocating transmission resources and inserting placeholder frames into priority queues before actual data arrives. This advance preparation ensures that when RoCE packets need to be transmitted, the channel access is already reserved, eliminating waiting delays and ensuring deterministic transmission timing even over unreliable wireless links.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the transmission process into distinct phases: resource allocation phase (where placeholder frames are inserted), data arrival phase (where actual packets are mapped to reserved resources), and transmission phase. This segmentation allows complex resource management to be decoupled from data transmission, reducing overall system complexity while enabling low-latency performance.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If wireless medium is used for RoCE, then network flexibility improves, but data loss increases due to interference

Engineering Contradiction:

Improvenetwork flexibilityVSAvoiddata loss

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent implements beforehand cushioning through redundancy mechanisms including duplicate packet transmission and forward error correction codes. By preparing backup transmission paths and error correction capabilities in advance, the system can withstand wireless interference and packet loss without compromising reliability, cushioning against the inherent unreliability of wireless media.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The system creates copies of critical RoCE data packets and transmits them through multiple channels or with redundant encoding. This copying mechanism ensures that even if the original packet is lost due to wireless interference, identical or corrected copies can be received, preventing data loss while maintaining network flexibility.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS11513985B2RoCE over wireless

Publication Date: 2022.11.29 CISCO TECHNOLOGY INC

AI summary

A wireless device can achieve higher predictability for its transmissions by inserting a placeholder frame in a transmission queue before time sensitive data has been received. In addition, a contention countdown associated with the placeholder frame can start before the time sensitive data is ready for transmission. Once the data is available, the device can insert the data into the payload of the placeholder frame, thereby reducing the wait time before the data can be transmitted wirelessly. Additionally, the device can improve reliability by transmitting data using multiple subcarrier RUs in a channel. The data blocks and the duplicative data can be transmitted in parallel using the subcarrier RUs. If a subset of the subcarrier RUs are blocked because of narrowband interference, the receiving device can nonetheless recover the data blocks and reconstruct the packet from the data transported on the RUs that did not have interference.