I am using LoRaE5-HF module. I use SenseCAP M2 gateway (US915). This module and gateway combination works well in USA. I use several AT commands to set this module up. In particular I must set the module to operate in the USA.
I use these commands for USA operation with SenseCAP M2 gateway.
AT+DR=“US915”
AT+CH=NUM,8-15
I now want to use my module in Europe. I guess I use command
AT+DR=“EU868”
I will use SenseCAP M2 (EU868) gateway.
Question 1: Why do I use AT+CH=NUM,8-15 for US915 operation in USA? (I blindly copied this from example software somewhere)
Question 2: What CH command (if any) do I use for EU868 operation?
Question 3: Should I use any other AT commands to specify location of operation?
Thanks for any advice you can give!
Mike
Hi there, So I gleaned this:
The primary differences between the US915 and European (EU868) LoRa bands are in their frequency ranges, channel plans, and regulatory restrictions. Here’s a quick breakdown:
- Frequency Range:
- US915: Operates in the 902–928 MHz band.
- EU868: Operates in the 863–870 MHz band.
- Channel Plan:
- US915: Typically has a large number of channels (e.g., 64 uplink channels in LoRaWAN) with different spreading factor groups. Devices usually use 8 default channels for joining, but additional channels are available for data transmission.
- EU868: Has a more limited channel plan—usually starting with 3 default channels (commonly at 868.1, 868.3, and 868.5 MHz) and then additional channels may be defined by the network operator.
- Regulatory and Duty Cycle Restrictions:
- US915: Governed by FCC regulations, which generally allow higher transmit power without duty cycle restrictions.
- EU868: Governed by ETSI regulations, which impose duty cycle limitations (often around 1% on many channels) and typically lower maximum transmit power. This means devices in Europe must limit how much time they transmit.
- Hardware Considerations:
- Gateways (like the SenseCAP M2) and nodes are typically tuned for the specific frequency bands of their target market. A gateway designed for US915 is optimized for 902–928 MHz, while one designed for EU868 is optimized for 863–870 MHz. Using the wrong version in a different region might affect performance or even violate local regulations.
In summary:
For a SenseCAP M2 gateway:
- The US915 version is designed to operate on the 902–928 MHz band with a channel plan and regulatory settings suited for North America.
- The European version would use the EU868 band (863–870 MHz), with fewer channels and stricter duty cycle and power regulations.
Choosing the correct band version is important for both regulatory compliance and optimal network performance.
And with some tools you get this…
1. Why use AT+CH=NUM,8-15 for US915 operation?
- US915 Channel Plan:
In the US915 band, LoRaWAN devices typically have many available channels (often 64 uplink channels in total). However, during join or operation, you usually enable only a specific subset of those channels.
- The Command’s Role:
The command AT+CH=NUM,8-15 is used to enable (or select) channels numbered 8 through 15. This is done because many networks and example applications expect that these channels will be active for communication in the US915 band.
- Why It’s in Examples:
Many example codes for US915 simply copy this setting so that the device “sees” the right channels when joining a network. It’s not magic—it’s just a way to tell the module “use these channels for your uplink transmissions.”
2. What about EU868 operation?
- EU868 Channel Plan:
In the EU868 band the LoRaWAN specification defines three default channels (typically at 868.1, 868.3, and 868.5 MHz).
- No Extra AT+CH Needed:
For EU868, these default channels are almost always pre-configured in the module’s firmware. That means you usually don’t need to issue an AT+CH command like you do for US915—unless you want to modify or add extra channels (which is not common for normal EU868 use).
- In Practice:
So if you’re operating a SenseCAP M2 gateway that is built for EU868, you can just use the default channel configuration that comes with the firmware.
3. Should you use any other AT commands to specify the region?
- Region Is Often Pre-Configured:
Most LoRa modules (and gateways like the SenseCAP M2) are pre-loaded with the proper frequency plan for the intended region. For instance, a module built for EU868 already knows to use 863–870 MHz and the associated duty cycle limits.
- Optional Region Commands:
Some modules offer an AT command (such as AT+REG or similar) to change or query the regional settings. However, if your module is already built for a specific region (EU868 in your case), there’s usually no need to issue any additional command to “set” the region.
- Check the Documentation:
If you’re unsure, it’s a good idea to check the manufacturer’s documentation for your SenseCAP M2. But generally, once you choose the correct version of the hardware (or firmware) for your region, you don’t have to tell it anything extra about where it is.
In Summary
- For US915:
You use AT+CH=NUM,8-15 to enable a specific subset of channels because the US915 band has a large number of channels, and that command tells the module which ones to use.
- For EU868:
You typically don’t need to issue an AT+CH command since the three default channels are already set up in the firmware.
- Specifying the Region:
There is generally no additional AT command needed to “specify” the region if you’re using firmware that’s already configured for EU868. If your module does offer a regional setting command, it would be mentioned in the documentation—but in many cases, the region is fixed by the version of the hardware/firmware you have.
HTH
GL 
PJ 
Hi PJ!
Thanks for info. I’ve done a little research and agree with your info. The USA differs from Europe in the number of channels available. More in USA. So the sub-banding selected by AT+CH=NUM,8-15 is used in USA but not required in Europe.
I’ll be trying out my setup with just AT+DR=“EU868” and the SenseCAP M2 gateway for EU868 in the next few weeks. I’ll post my results here once I have a chance to try.
Mike