Wireless Device Transmit Opportunity Segmentation Avoiding EIFS
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Solution Overview
Problem
In wireless local area networks (WLANs), the extended interframe space (EIFS) leads to a biased access procedure due to varying reception capabilities of stations, causing some stations to wait unnecessarily, while others that receive a faulty frame check sequence (FCS) wait for EIFS, disrupting impartial access.
Innovation Solution
A wireless device transmits a message during a transmit opportunity (TXOP) with a first portion at a first data rate and a second portion at a higher data rate, followed by a terminating message at the first data rate, allowing stations to receive and decode the terminating message even if they couldn't receive the higher data rate portion, thus avoiding EIFS and ensuring a more impartial access procedure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a frame is transmitted at a high data rate, then transmission efficiency is improved, but stations with limited reception capability cannot correctly receive the frame and must wait for EIFS
Solution Approach 1:
The transmission is segmented into two distinct portions: a first portion transmitted at a lower data rate that all stations can receive, and a second portion transmitted at a higher data rate for improved efficiency. This segmentation allows stations with different reception capabilities to successfully receive at least the first portion, preventing them from entering EIFS state.
Solution Approach 2:
Different portions of the same transmission have different data rates tailored to different station capabilities. The first portion uses a lower data rate suitable for all stations, while the second portion uses a higher data rate for stations with better reception capability, creating local quality variations within the transmission structure.
2Reliability
If stations wait for EIFS after receiving a faulty frame, then they allow time for ACK transmission, but this creates biased access procedure and unnecessary delays
Solution Approach 1:
The first portion of the transmission is sent at a lower data rate in advance to ensure all stations can correctly receive it. This preliminary action provides stations with the information needed to determine whether to wait for EIFS or continue with backoff, eliminating unnecessary delays while still allowing ACK transmission when needed.
Solution Approach 2:
Stations use the successfully received first portion as feedback to make informed decisions about whether to enter EIFS state. By correctly receiving the first portion, stations can determine that the transmission was intended for them and proceed with appropriate backoff behavior rather than unnecessarily waiting for EIFS.
3Stability of the object's composition
If all stations receive the same data rate, then reception consistency is improved, but transmission efficiency is reduced due to using only the lowest common denominator rate
Solution Approach 1:
The transmission is divided into segments with different data rates. The first segment uses a lower data rate to ensure consistency for all stations, while the second segment uses a higher data rate to improve overall transmission efficiency, combining both benefits in a segmented structure.
Solution Approach 2:
Different segments of the transmission have different data rates appropriate for different reception capabilities. This local quality approach allows the system to maintain reception consistency for all stations while achieving higher transmission efficiency for the overall message.
Data Source
AI summary
Methods, systems, and devices are described for avoiding extended interframe space (EIFS) in a wireless local area network (WLAN). A wireless device may transmit a message during a transmit opportunity (TXOP) that includes a first portion transmitted at a first data rate and a second portion transmitted at a second rate that is higher than the first. The wireless device may then transmit a terminating message at the first data rate. The wireless device may also receive a second message prior to transmitting the terminating message. The terminating message may be a clear-to-send message (CTS) or an acknowledgement (ACK) message. The first message may be an aggregate media access control packet data unit (A-MPDU) in which the first portion is a preamble and the second portion is an MPDU.