I am conducting a deep study whether the WIO-E5 in P2P aka test mode can be used under a U.S. Amateur Radio license. The U.S. Amateur Radio Service has a secondary allocation at 902-928 MHz, with a 10 W spread spectrum transmit power limit and no EIRP limit (meaning no limitation on antenna gain).
I need to confirm some assumptions or suspicions about P2P mode. I have determined experimentally that I can send and receive packets with 253 bytes of payload, with any combination of spreading factor and bandwidth. From this I suspect that P2P mode transmits “implicit header” frames, with up to 253 bytes of payload and 2 bytes of CRC = 255 byte maximum RF frame size.
So, can somebody confirm that a WIO-E5 in P2P mode transmits implicit header frames with up to 253 bytes of payload plus 2 bytes of CRC, without any encryption or error correction coding?
And Welcome Here…
So you shouldn’t have to A. hold your breath that long or B. go very Deep… to find those basic answers.
No encryption, implicit header, FEC is built-in, CRC optional/configurable.
LoRa’s explicit header mode includes metadata (payload length, CRC flag, coding rate), and limits payload to 255 total bytes (including header).
To maximize raw payload, the explicit header is omitted, using implicit header mode. In this mode:
Payload length is preconfigured (receiver must know it)
Only payload + CRC (optional) is transmitted
Result: you get up to 253 bytes payload + 2 bytes CRC
3. Encryption?
The LoRa PHY has no built-in encryption in P2P mode.
LoRaWAN (the network layer) adds AES-128 encryption
In raw P2P mode (used by Wio-E5 in test mode), packets are unencrypted
If required, user must implement encryption in the application layer
4. Yes — LoRa always uses FEC, controlled by the Coding Rate:
Typical values: CR = 4/5, 4/6, 4/7, or 4/8
This is not optional; it’s essential to LoRa modulation robustness
So while it’s not “error correction coding” in the typical Reed-Solomon sense, LoRa’s FEC is always there.
5. U.S. Amateur Radio Rules
Under FCC Part 97, especially:
902–928 MHz is available under a secondary allocation
No encryption allowed on Amateur bands -P2P is plaintext
10 W output limit for spread spectrum (Part 97.311)
No restriction on antenna gain, so EIRP can exceed 10 W
Modulation must be non-obscured and open (LoRa qualifies)
One catch: LoRa’s proprietary status sometimes raises eyebrows, but Semtech’s PHY spec is open, and LoRa is not considered encryption or obscuration by FCC (though debate exists).
Summary :
Yes, the Wio-E5 in P2P mode:
Uses implicit header mode when sending 253-byte payloads
Supports raw payload with no encryption
Uses built-in LoRa FEC (Coding Rate selectable)
Includes an optional 2-byte CRC
Appears to meet FCC Part 97 technical criteria when configured properly
Should be permissible on 902–928 MHz under a U.S. Amateur Radio license, assuming proper call sign ID and no encryption
HTH
GL PJ
Get a set of these and try some testing, with ext antennas’
Thank you for the quick reply. I started this project by buying two each of the Grove LoRa-E5, LoRa-E5 mini, and the Mikroelektronika LR 10 Click. I will spend the month of June in southern Utah, a very sparsely populated high desert area, and will do some range testing with the LR 10 Click’s and Yagi antennas. I have working device drivers for Linux (namely the Raspberry Pi), for both plain P2P broadcast mode and another mode that adds call sign and node number fields.
I’m still trying to understand how WIO-E5 FEC works. I am assuming FEC is added to the bit stream after the (up to) 255 byte RF frame has been serialized. I didn’t find any test mode command to change the FEC code rate, though. Is the test mode FEC code rate inferred from SF and bandwidth, like the RF symbol rate is?
So ,I would say “YES” What is to Question? The Spec’s call out the req’s very clear.
You need to have a look at @msfujino Thread on P2P he’s getting great distance. Of course it’s a broadcast medium. Anyone with a “receiver, language…” Both transmitter and receiver need to know of the others presence so to speak.
no encryption, the FEC is added and removed. If your asking about LoRa PHY internals, packet structures, or spectral compliance, just holler at Semtech tech support email. as I said their PHY spec is open They will fill your inbox with info and hard spec’s
to find those basic answers.
5. U.S. Amateur Radio Rules
P2P is plaintext 
One catch: LoRa’s proprietary status sometimes raises eyebrows, but Semtech’s PHY spec is open, and LoRa is not considered encryption or obscuration by FCC (though debate exists).
PJ 
