Change preambleLength to 8 symbols to reduce airtime #1902
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
🤖 Pull request artifacts
|
thebentern
added a commit
to meshtastic/artifacts
that referenced
this pull request
Nov 5, 2022
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This changes the preamble length from 32 to 8 symbols, which is the same as is used in LoRaWAN. I saw in the source that it was set to 32 in order to let the device sleep longer, but since the LoRa chip itself doesn’t sleep, this does not make sense to me.
It does reduce the time on air quite significantly, namely more than 20% when sending 10 bytes (from 854ms to 657ms on Long Fast). It think we should test it a bit, because it may have an influence on the performance of Channel Activity Detection, but I don’t think it is significant. RadioLib sets the CAD duration for SX126x to 8 symbols and for SX127x, it is only around 2 symbols.
I did some initial testing and messaging works for me. It seems even not to be a breaking change as I also received messages from my solar node on 1.3.x.