In this part of the ‘When All Else Fails’ series, I’ll have a look how the Garmin InReach Mini 2 works in urban scenarios. The device is advertised as a satellite communication tool for adventurers in the wilderness, which is quite a different environment compared to my use case in mostly urban canyons. As I couldn’t find any information of how well messages can be sent and received there, I was anxious to find out.
The catch of the Iridium network is that there are relatively few satellites. Despite being in a low earth orbit at an altitude of around 780 km, the satellites are still far from the surface. That makes it tough for a handheld device with only a small antenna and very limited transmit power to send and receive messages. Also, satellites are often very low on the horizon, so just being outside in a deep urban canyon might also be problematic. Fortunately, things turned out much better than I thought.
From Indoors to Rooftop and Back
As the satellites are far away, I assumed the device would probably not work indoors. But perhaps at a window? When I first registered the device for service, I put it next to a window from which a good part of the sky and even the horizon could be seen. That’s one of the advantages of living at the top floor of a six floor building in Cologne. However, even after 30 minutes, the registration procedure would not start. So I went to the rooftop and tried again. Here, the registration process started almost immediately and finished within a minute or two. After that, I sent my first message which also went out within a minute. So rooftop communication with pretty much all of the horizon visible is no problem!
Where It Works At Street Level
I then went back into the apartment and tried the window again. Perhaps it was just the activation procedure? But still, no message could be sent from that window. Next, I tried another window just 2 meters away at which a different part of the sky and the horizon was visible. Even with the window closed, the message was sent almost immediately. Cool, but perhaps I only got lucky!? So I tried some more and to my surprise, all messages were sent within a minute or two. I have no idea why it works at one window but not at the other, as the amount of sky and visible horizon is pretty much the same at both. It’s just different patches of the sky. I tried several times again over the next couple of days and the result was always the same. No messages going out at one window, while there was no problem at the other. So it’s a systematic thing.
So how about outdoors at street level? Unlike on the sixth floor, there is little to no horizon visible most of the time. Most streets in Cologne are lined by houses with five to six floors, so not much of the sky and even less of the horizon is visible from there most of the time. I did a lot of ‘walk testing’ with the Garmin InReach Mini 2 in the breast pocket of my jacket for several days, and to my positive surprise, all my messages were eventually sent. Sometimes it would take 5 to 15 minutes, but out they went. It seems that the broader the street, the sooner the message is sent out. The situation is even better in parks, of which we have plenty in Cologne. Most parks have lots of trees lining them, while there are typically fewer trees in the park itself. Standing in the middle of a parks, I usually had a good view of the sky and also partly of the horizon. Messages were typically sent within a minute or two. So from a street level point of view, a park is the ideal place to go to if sending a message and having a high chance of catching incoming replies quickly is a top priority.
Where It Doesn’t Work At Street Level
Then I got a bit more ‘adventurous’ and tried sending messages at the windows of cafes at street level. That didn’t work at all however, despite some sky and horizon visible. I guess the heat insulation, which also has a very detrimental effect on the signal strength of earthbound mobile networks pretty much kills it. In cases where the messages couldn’t be sent to a satellite, I also wasn’t able to get a GPS lock on my smartphone. Mobile networks, however, still got through the insulated window. Next, I took a train which also had heat insulated windows through which mobile networks would go, but no GPS signal. As expected, my InReach messages would also not be sent. Only by chance, one message went through. The stars (or the satellites) must have aligned for a moment!? To my great puzzlement, I also found places with good visibility of the sky and horizon where messages would just not be sent at all, not even after 20 minutes. This is really strange, and I wonder if interference from a nearby radio source of some kind could be the problem!?
I’m very positively surprised that the Garmin InReach Mini 2 has no problems sending and receiving text messages in Cologne’s urban canyons and parks. From a building density and height point of view, I’d say that the city is a typical European city, so it’s likely that my results are typical rather than exceptional for larger cities.