US915 "sub-bands"?
- This topic has 7 replies, 2 voices, and was last updated 7 years, 4 months ago by
.
Viewing 8 posts - 1 through 8 (of 8 total)
Viewing 8 posts - 1 through 8 (of 8 total)
- You must be logged in to reply to this topic.
Jason Reiss.
andrew@bitfinder.coI see reference to “sub-bands” 1 through 8 for the US915 region.
It is a selectable option in the Network Settings page on the Conduit, and a few wiki and documentation pages refer to it.
The LoraWAN spec v1.0.1 even uses the term “sub-band” in 4 places.
But as far as I can figure out, there is no definition of explanation of “sub-band” for the US015 region, either in the Multitech documentation or in the LoraWAN spec itself.
What am I missing?
Jason ReissThe US915 region has defined 64 channels.
The MTAC-LORA cards with a single Sx1301 concentrator support only 8 125 KHz channels and one 500 kHz channel.
The each US915 sub-band defines a channel mask enabling only 8 of the 125 kHz channels and a single 500 kHz channel to be used with a single gateway card.
andrew@bitfinder.coAh, great, that makes it much clearer.
I had a few follow-up questions, then:
Does the conduit listen on all of those 8+1 channels simultaneously? So if an end node transmits, assuming the channel mask is set correctly and there is no collision and no TxTimeout, then the Conduit should receive it?
And I assume that the Conduit will set the matching 8+1 channel mask for the selected sub-band to the end nodes?
And lastly: If there is only one 500Khz uplink channel available, and my end node is only sending long payloads, does that imply that it will always be on a single 500KHz width uplink channel?
andrew@bitfinder.coandrew@bitfinder.coAh, apparently this forum doesn’t support emoji (cricket emoji, specifically …)
Jason ReissThe channels are monitored simultaneously.
If the end-device transmits on the correct channel the gateway should receive it. It will not receive packets transmitted on the wrong channels.
One one 500 kHz channel is enabled therefore only one 500 kHz channel will be used,
Max payloads are also available to DR3 using 125 kHz channel with SF7.
andrew@bitfinder.coIs there a tabulation of which channels belong to which frequency sub-band? A specific version of the standard or of the regional parameters?
I assume it is something like:
Band 1 = upstream 125Khz channels [0-7] and downstream 500Khz channel 0
Band 2 = upstream 125Khz channels [8-5] and downstream 500Khz channel 1
and so on …
But I am having some difficulty getting things to work properly, using an end-node where “frequency sub-band” is not defined.
Jason ReissSee Channel Mask setting.
http://www.multitech.net/developer/software/aep/lorawan-aep/lorawan-network-settings/