TTIG Noobean Question

Gateways TTIG - The Things Indoor Gateway
1

Hi All,

I’m rather new to LoRa and the likes of it and just re-used my TTIG with an external antenna and got a rather ‘OK, I see some data but what does it mean’ situation.

When using the mapper I got a rather eh, colorful view of green, blue, yellow and red symbols. I reckon there is a meaning of these colors ?

So after clicking on my blue gateway it shows me some data, right. How many channels does the TTIG have, mine only shows 3 is that correct ?

Doing some clicking and viewing in the mapper options etc. I got this message received by my GW from 77 km distance.
image

Can someone explain how I need to read the values displayed.

2

Some answers:

RSSI 0dBm means perfection. No signal loss between your node and gateway. You will never see this :slight_smile:

Red color is bad* because you are very close** to gateway and you can transmit with less SF or with less power. In your case you can’t lower SF, but only power.

Blue color is the opposite. You are on the limit of communication.

* According to my view
** This is also relative :-)
3

Thank you for the answers.

So if I look at my radar view, and looking at the above picture, my TTIG received very few packages from a rather far distance of up to 77 km with a very weak signal, since they all are blue.
image

What surprises me is that compared to yesterday where I had only 3 channels I now have 7 channels and I didn’t change a thing.

Guess I can find somewhere that DR value of SF7BW125.

Thanks again and I’d probably want to add some nodes in a cyclic way to see if my receiving has some weak spots/areas.

4

Does this mean that for the same transmission power, each SF will have a different RSSI?

TTN Mapper simply did not receive on all channels yet, from a mapping node. (TTN Mapper only knows about nodes that are explicitly taken on the road for mapping.)

Aside, see TTN Coverage for more colors.

5

Hoi Dankje Arjan,

looks on the map like someone is spotting for gateway locations using a TTGO T-Beam.
image

Groetjes,

Peter.

6

I think you have right. More SF raises the ‘sensitivity’ (forgot the right word now. It’s better to say that more sf increases the link budget?) of the gw, not RSSI. Just made an experiment (txPower 3dBm, 3 meters from gw)

Freq, SF, RSSI, SNR
868.1, SF7BW125, -59, 10.5
868.1, SF8BW125, -60, 10.8
868.1, SF9BW125, -65, 13
868.1, SF12BW125, -63, 10.5 - ironically my GW missed the SF12, had to resend.