Single-point wake-up will not continuously wake up non-target devices when waking up. E330-400T13S uses FSK/GFSK modulation, so its packet is different from LoRa. The most important thing is that FSK/GFSK has a synchronization word (SYNCWORD) filtering mechanism. Set the address as the sync word. When the sync word is different, the data will be directly filtered by the hardware, resulting in communication failure.
https://www.ru-ebyte.com/products/E330-400T13S
Single-point wake-up no longer uses LoRa to send a very long preamble, because sending a preamble on the same channel will definitely wake up all devices of the same type, and will remain awake, causing the entire network to receive data, but it has been blocked. Forced wake-up to enter receive mode.
Single-point wake-up has been optimized on this point. It chooses to use short preamble + synchronization word + 0 (DATA) to replace the long preamble. As shown in the figure below, the sending time of the short packet should also be longer than one WOR cycle.
The difference is that single-point wakeup utilizes the hardware sync word filtering function:
When the synchronization word is different, directly discard the subsequent data and enter the sleep mode, waiting for the next cycle to enter the receiving mode;
When the sync word is the same, the receiving time will be extended automatically until the complete packet data is received.
