Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

github.com

Post reply on HN
Print view View original

41–50 of 60 posts

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#41

Post by lxgr »

matrix2003 wrote: post #39
lxgr wrote: post #25

Earlier quoted context omitted.

$50/month, these days, if I'm not mistaken. (You can only use it abroad for two months at a time, but you can update your location as as far as I'm aware, and it's $/€ 50 in most places.) Price wise, it's no comparison, but the two don't directly compete yet – power usage and antenna size of Iridium and Starlink are orders of magnitude apart (largely due to the L-band spectrum available to Iridium globally).

The higher rate gets you oceanic use, which is a big benefit of iridium. You are correct that it can be $50, but AFAIK that’s a different plan that is land or near-land only.

Ah yes, good point.

I believe the $50 plan used to have a pay-per-GB option for offshore use – $2 or so per GB, compared to $5 and more per MB for the competitors. But even at 300 or so, it’s orders of magnitude better for high-bandwidth use cases.

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#42

Post by tbone902 »

thadt wrote: post #30

Ah, that's cool. We built a similar system using Iridium SBD and LTE for controlling drones a few years back. SBD isn't the fastest comms around, and it can get rough if you don't have clear sky view, but it works pretty much everywhere, with a small antenna. If you don't have line of sight or LTE, it's a solid fallback.

[dead]

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#43

Post by thadt »

tbone902 wrote: post #42
thadt wrote: post #30

Ah, that's cool. We built a similar system using Iridium SBD and LTE for controlling drones a few years back. SBD isn't the fastest comms around, and it can get rough if you don't have clear sky view, but it works pretty much everywhere, with a small antenna. If you don't have line of sight or LTE, it's a solid fallback.

[dead]

Their constellation wasn't deployed when we were building it. Also this would have been a non-starter:

> Swarm is easy to use and lower cost, but the latency for message delivery is significantly longer, potentially several hours.

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#44

Post by nirav72 »

cyberax wrote: post #16
matrix2003 wrote: post #14

Earlier quoted context omitted.

Depending on how you look at it, Starlink can be incredibly cheap compared to Iridium. It’s still not cheap from where I’m sitting in my clapped out Honda Civic, though. Edit: I think $250 for 50GB of truly global data. I can’t do the math right now, but it seems like a better deal at face value.

> Depending on how you look at it, Starlink can be incredibly cheap compared to Iridium. They don't have sat-to-sat communications deployed yet, so they can work only near the ground stations.

They have sat-to-sat now. I was on a cruise ship this past summer that used starlink. I was able to get a consistent 3-5 mbps up/down in the middle of the ocean with nearest land at least several hundred miles away.

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#45

Post by keepamovin »

lxgr wrote: post #26
keepamovin wrote: post #4

This is so cool! Thanks for sharing and creating something like this :) BTW do you use Iridium handsets? Do you have recommendations?

OP is using Iridium SBD according to the article, specifically this modem: https://www.groundcontrol.com/product/rockblock-9603-compact...

Oh ok, I mean I got they were using some special build for the project. But based on them saying "I often go all around the world" (to the effect of that), seemed they'd probably be using handsets, outside of the article.

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#46

Post by anthk »

therein wrote: post #35
KMnO4 wrote: post #5

For anyone else wondering, the satellite transceiver is a RockBoard, which charges: - $302 for the hardware - $17/month for a “line fee” - $0.20/message (50 characters) Would be nice if there was an actually affordable, programmable Iridium device.

You can actually achieve this even with Iridium Go. I tried it years ago and it worked. It isn't too documented, or let me say it isn't documented at all but you can write AT commands and start raw TCP connections and read and write to that socket. And it is actually reasonably priced. I tried to open SSH connections and it was barely usable. You get a very small number of bits per second. Edit: Found the private rep…

Mosh will be much faster.

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#47

Post by myself248 »

wkat4242 wrote: post #31
KMnO4 wrote: post #5

For anyone else wondering, the satellite transceiver is a RockBoard, which charges: - $302 for the hardware - $17/month for a “line fee” - $0.20/message (50 characters) Would be nice if there was an actually affordable, programmable Iridium device.

The keyword of the problem there is Iridium. Their SBD (short burst data) and in fact all their services are just extremely expensive. This reseller doesn't really seem to put much margin on it. When I had a sat phone (needed to travel sometimes to questionable places for work) I used Thuraya which is much cheaper for airtime. 40€ gets you a whole year's worth of inbound service (airtime) and about 15 mins of call cr…

It's really a shame. Iridium could sell best-effort hobbyist-grade service in their excess capacity, which would get the hardware into people's hands, but they don't.

Cynically I assume this is because it would be no different than their expensive service in practice, and cannibalize their premium offerings.

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#48

Post by jviotti »

Great stuff! I'm starting to work a lot on the satellite space (https://www.sourcemeta.com), building a binary serialization format around JSON called JSON BinPack (https://jsonbinpack.sourcemeta.com) that is extremely space-efficient to pack more documents in the same Iridium uplink/downlink operation (up to 74% more compact than Protocol Buffers. See reproducible benchmark here: https://arxiv.org/abs/2211.12799).

It is still a heavy work in progress, but if anybody here is suffering from expensive Iridium bills, I would love to connect and discuss to make sure JSON BinPack is built the right way!

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#49

Post by themoonisachees »

LeoPanthera wrote: post #36
0xffff2 wrote: post #24

Earlier quoted context omitted.

I've always assumed that answering a phone call would be free for me (excepting the dawn of cell phones when they had a limited number of minutes per month). If answering a sat-phone call is "cheaper" rather than free, does anything warn me that I'm incurring extra charges?

Paying to receive a call seems to a mostly American phenomenon. In most (all?) of Europe, receiving calls is always free, no matter where or how they originate.

I think now this is correct due to European laws, but not that long ago, if you were not in your home country and someone called you, you could be billed for the international part of the call. Nowadays the agreements telcos were forced to put in place means this is largely solved in the EU, and quite cheap outside of it.

Re: Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

#50

Post by thadt »

jviotti wrote: post #48

Great stuff! I'm starting to work a lot on the satellite space ( https://www.sourcemeta.com ), building a binary serialization format around JSON called JSON BinPack ( https://jsonbinpack.sourcemeta.com ) that is extremely space-efficient to pack more documents in the same Iridium uplink/downlink operation (up to 74% more compact than Protocol Buffers. See reproducible benchmark here: https://arxiv.org/abs/2211.12799…

Hey Juan, this looks promising - using a pre-shared schema would allow you to reduce payload sizes in the same way using pre-shared dictionaries makes compression more efficient (such as with zstd or brotli). Having worked on exactly this space in the past (sending and receiving messages from a microcontroller that eventually go through an Iridium SBD modem), some feedback:

After spending a few minutes poking around your landing page, I'm not sure how JSON BinPack works. I see a JSON Schema, a JSON document and then a payload, but I'd be interested in the low level details of how I get from a schema to a payload. When I'm on a microcontroller, I'm going to care quite a bit about the code that has to run to make that, and also the code that's receiving it. Is this something I could hand-jam on the micro, and then decode with a nice schema on the receiving side? Understanding the path from code and data to serialized payload would be important to me.

One thing that was nice about using ProtocolBuffers for this was that I had libraries at hand to encode/decode messages in several different languages (which were used) - what is the roadmap or current language support?

I can understand how ProtocolBuffers handles schema evolution, but I'm still not sure how JSON Schema evolution would work with JSON BinPack. An example would move mountains.

Finally, if I were digging into this and found it had switched from Apache to AGPL, and required a commercial license, it would be a hard sell vs all the permissively licensed alternatives. At the end of the day, Iridium SBD messages are like 270 bytes and even hand rolling a binary format is pretty manageable. I think I could swing budget for support, consulting, maintenance or some other service. But if I were evaluating this back when I needed a serialization format, and ran into AGPL, I would bounce almost immediately.

Post reply on HN