WirelessMoves – Page 21 – My Thoughts on the Evolution of Wireless, FOSS and the Past, Present and Future of Computing

When All Else Fails – The Garmin InReach Mini 2 – Part 9 – More Iridium Tech Stuff

In part 8 on this series on the Garmin InReach Mini 2 and the Iridium network behind it, I’ve assembled a summary of the few pieces of technical background information that is available on the Internet. Iridium offers a number of different services such as voice telephony and SMS, and quite a bit of the higher layer protocols seem to be adapted from GSM. Looking at the messaging service provided by Garmin’s InReach Service, I came to the conclusion that it is most likely NOT based on Iridium SMS. Instead, it looks like the service might be based on the Short Burst Data (SBD) service. I can’t be sure because there is no documentation, but here’s how SBD works:

When All Else Fails – The Garmin InReach Mini 2 – Part 8 – Iridium Tech Stuff

Ok, it’s nice to know that in case all terrestrial networks fail in my area, I will probably still be able to send and receive messages between Garmin InReach devices that use the Iridium satellite network. There are only four Iridium ground stations in the network, so it’s likely that a local or even country wide power outage would leave that infrastructure untouched. Being an engineer, I of course would like to know more how the Iridium and the Garmin InReach service actually work, what kind of protocols are used, etc. etc. Unfortunately, there is very little official information out there that goes into the technical details. Everything about the system is proprietary. I can’t even be certain if the messages that are exchanged between InReach devices remain in the network, or if they first go to some Garmin server and then back into the network. Should they be routed via some extra Garmin infrastructure, how is this part connected to Iridium and how redundant is it? Questions over questions. Fortunately, I’m not the only one who’s interested in the details and when digging a bit, one can find very interesting technical details on the Internet.

When All Else Fails – Part 7 – Satellite Distribution

In the previous parts on this topic I have mentioned a few times how amazed I am that despite a transmit power of only 1.5 watts, the small Garmin InReach Mini 2 can send text messages to Iridium satellites that are thousands of kilometers away. This becomes even more impressive when one sees where the satellites are actually located during the message transfer.

The screenshot on the left was taken from the Irdiumwhere website at a time when my Mini 2 reported that a message had been sent successfully. According to this map, which is updated in real time, the message I sent from Cologne was either exchanged with a satellite that was just over the Mediterranean island of Sardinia or with a satellite that was over Iceland at the time.

I continue to be amazed, so in the next part of this series, I’ll have a look of what kind of technical information is available on the Iridium constellation.

When All Else Fails – The Garmin InReach Mini 2 – Part 6: Power Consumption

The Garmin InReach Mini 2 charging at 2.5 watts

When all else fails, my Garmin InReach Mini 2 would be the last device standing. The question then is how long I could use it before its battery runs out. On their web page, Garmin says the device has a standby time of up to 30 days (720 hours). But that’s the best case with full view of the sky and the complete horizon. In my urban valley scenario, that’s unlikely to happen. So what kind of endurance can I expect in such an environment?

When All Else Fails – The Garmin InReach Mini 2 – Part 5: Composing Messages

Composing a text message on the Garmin InReach Mini 2

This might seem like a benign topic, but how does one compose text messages on the Garmin InReach Mini 2? As you can see above, the device has no keyboard, not even digit keys at the front. This is quite intentional, as I wanted to have a device that is as small and as light as possible for emergency communication with members of the household, should local terrestrial networks fail. What the device has, however, are five keys at the side. One of them is the firmly protected EMERGENCY button to contact an emergency center. On the right, there’s an OK and a BACK button. And finally, there’s an UP and DOWN button on the left. Not much to work with.

Running Ubuntu Linux on Bleeding Edge Hardware: Lenovo E14 Gen 4

In the past, I liked buying used notebooks and use them as my day to day workhorses. It felt good from an environmental point of view and they were significantly cheaper compared to new notebooks, particularly when it came to business notebooks like the Lenovo Thinkpad series. But in recent years, prices for used notebooks have significantly increased, while the performance gap between 3-4 year old computers and current models has significantly widened. So when I recently had some trouble with my AMD based Lenovo X13 Gen 1 (I’ll have a separate post on that), I had to get a new spare notebook and was wondering which one to buy.

After some deliberation, I decided to go for a Lenovo E14 Gen 4, which came with an AMD Ryzen 5 5625U. This processor is from early 2022, and this particular notebook started shipping about half a year ago (March 2022). So how would my production operating system based on a 2 year old Ubuntu 20.04 work on this device? Also, the E-series is the low cost line of the Thinkpad series, so I was wondering how it would do from a performance and connectivity point of view.

When All Else Fails – The Garmin InReach Mini 2 – Part 4: Will It Work In Urban Environments?

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.

When All Else Fails – The Garmin InReach Mini 2 – Part 3: Pricing and Message Handling

In this part, I’d like to muse a bit on Garmin’s pricing of the InReach service for my use-case and the general procedure of sending and receiving messages. While Garmin’s main application for InReach is outdoor communication and tracking in the wilderness, my use-case is to be able to communicate with far away family members when terrestrial networks fail, e.g. during a larger scale power outage. In practice, that means I want to be able to communicate between two InReach devices, or, if terrestrial networks still work at one side, I’d like to communicate between one InReach device and a mobile phone via SMS or email on the other side. In other words, I’m not interested in 2 minute periodic location information being sent or emergency center communication. However, getting the GPS coordinates from which a message is sent is a nice bonus.

When All Else Fails – The Garmin InReach Mini 2 – Part 2: Activation

Let’s get back to the Garmin InReach Mini 2. In part 1, I’ve given a general overview of how satellite messaging services works with the device in general. In this part, I’ll have a closer look at how to get started and how long it takes to activate a device.

Once you have the device in your hand and Internet connectivity is available, it can be activated in just a few minutes and the device can then be used immediately. To work, the device needs to be tied to a subscription. Garmin has several types of subscriptions. The cheapest yearly subscription includes unlimited preset messages and 10 outgoing or incoming self composed messages with up to 160 characters and costs around 15 euros per month. In addition there’s a 30 to 40 euro initial activation charge. More about that in a follow-up post.

When All Else Fails: The Garmin InReach Mini 2 – Part 1

The times are getting stranger and stranger. Only a few years ago, I didn’t worry too much about scenarios which would prevent me from communicating with members of the household while any of us were traveling. But the world has changed massively in the past few years, and at least from a European point of view, I can no longer ignore scenarios of prolonged power and network outages. Whether that’s likely or not is hard to say but I can’t just shrug it off anymore. So I was looking for a way how I could keep in touch ‘when all else fails’.