how to understand the transmission time on air? #1547
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chris-william0829
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Thanks for the question, however your question does not look to be an issue or question specifically related to this project. I would recommend that you ask your question on Semtech LoRa Developers Forum being a more suitable place to ask questions. |
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hey guys,
i am studying LoRa recently.
In sx127x Datasheet, it says the lora phy frame is consist of preamble, header, payload, and payload crc.
especially, the header is within a code rate of 4/8.
But in the calculation of Time on Air,
it says, nPayload = 8 + max(ceil((8PL-4SF+28+16CRC-20IH)/4(SF-2DE))*(CR+4),0)
how to understand the calculation of the payload?
is the 20IH means the length of the header?
but header is within a code rate of 4/8, isn't it?
why we calculate the header and payload together within the same code rate?
I would be grateful if someone could help me.
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