goTenna Mesh community

Aboard a cruise ship

I recently returned from a 6-day Caribbean cruise (Celebrity Eclipse). I was traveling with friends, and we occupied four separate staterooms on the ship, so I brought along four goTenna Mesh units, and loaned them to one person from each stateroom.

Overall, they were extremely valuable for communicating almost anywhere on the ship, with two notable “dead zone” exceptions: the staterooms and the theater. Fortunately, we were spending most of our time elsewhere on the ship, so this was usually not a significant problem. While out and about on the various decks, and even on the verandas of the outside staterooms, coverage was quite reliable. And while in port, we were able to communicate ship-to-shore, across distances of at least 1 km (we didn’t really try much further out).

My traveling companions were quite pleased with the convenience. One of them, who goes on cruises regularly, is already recommending goTenna Mesh to her usual cruising friends.

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Thanks for the update John! Believe it or not I’ve gotten more than a few questions about how goTennas work on large cruise ships. I never knew how to answer, having never been on a cruise ship myself. Happy that you gave us a first-hand account that I can point to now :slightly_smiling_face:

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One speculative possibility why they didn’t seem to work in the theater may be that they were using a cell jammer… Not sure how current cell service freqs match up with the bandwidth used by goTenna mesh, but jammers can be a bit sloppy and cause issue outside the expected freqs, too… They’re illegal to use in the US itself, but once outside the territorial limits then they could run them. This is a common use, avoiding disturbing rings during performances, overseas where jammers are legal.

The staterooms may simply have been densely walled and packed together enough that it prevented the signals from penetrating as needed,

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I took two on a large ship (Voyager of the Seas) and from an inside cabin to an outside on the same side of the ship, it did not work. But mobile phone coverage was cut off when closing the cabin door as well (unless there was a strong signal already). Out and about New Zealand there didn’t seem to be any others in use. I would do a broadcast in each port saying “Hello XXXXX” and didn’t get anything. This was before AUS/NZ certification, so the units wouldn’t have shipped yet through normal means. I don’t know how the power and frequency would change now that AUS/NZ is a thing. Maybe cruising will be better with the different localised settings. Using the default US ones made using the ship pabx phones the easiest (provided one party was stationary and we knew the number).

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Awesome! I’m taking a cruise with my family next month and will need to utilize this. Thanks!

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I can find no reputable mention of jammers on cruise ships or in international waters. Do you have any reference of cruise ship doing this? I would be genuinely interested. There are international treaties that must be obeyed. I don’t know if any specifically cover jamming of RF. It seems to me there would be lost revenue streams and potential litigation.

Sorry to derail the topic.

A cruise ship is a really good example of where a mesh network would be useful. All the metal in the ship hinders the operation but if one or two more groups would have been using the Gotenna Mesh devices you might have had ship wide seamless coverage. You may have even hopped across strangers units and not even known it.

If you don’t have cell service you can put your phone in airplane mode and then turn Bluetooth on. That will keep your phone from killing your battery looking for a tower. It also reduces RF exposure.

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Nothing specific to that potential use I can cite, given we were talking about what was possible, not necessarily what happened given the lack of hard evidence in any specific direction; there have been reports of jamming under other circumstances aboard or near cruise ships or their ports. There have been reports of widespread use, whatever their legality, in theaters overseas after the idea being shot down in the US despite requests from the industry to allow it. And they are widely available. I would post a link, but don’t want to help their business. If curious, Google “jammer store” and if you want to jam it, they probably have it.

From a gov’t briefing on the issue in the US, with several instances of maritime use that certainly raises the possibility of jammer use, not necessarily by the ship itself: https://www.gps.gov/multimedia/presentations/2017/02/COPUOS/hamilton.txt

As that report noted, jammers tend to be dirty and indiscriminate, reason they are also illegal, so they don’t need to be oriented toward a specific band or service to cause problems for services like the goTenna supplies.

Another possibility is jammer use against drones: https://forum.dji.com/thread-35974-1-1.html

Speculative, too, but the comments about radar in that thread raise another possibility for the source. Lots of things like that on a ship. But they also run wifi and given the number of complaints about overcharging for such services, seem to wanna run their own game in providing cell connectivity at a price that they wouldn’t want to interfere with.

Yes, illegal many places, but also used where illegal for many reasons, including documented incidents of use by individuals who simply think people spend too much time yakking on their phones. But it could be any one among a lot of things, as my 3 decades of radio monitoring experience suggests to me. The one place where such use would be reliably legal actually would be in international waters, which could account for the lack of formal complaints there along with no relevant reporting or enforcement agency unlike in domestic waters.

I’ll take a better look at what you posted. Perhaps we can discuss this somewhere else like DM or in a separate thread later if you are interested.

I don’t want to completely hijack the topic.

Yeah, I don’t want to focus on this, but it’s worthwhile that people have a means to evaluate potential interference on something like a cruise ship, which spew RF all across the band plan. A more general thread about interference could be useful.

My experience with goTenna is pretty limited yet, so I’m not really in a position to assess how susceptible this mode is to potential interference. I suspect the mode chose and it’s efficient use of it tends to minimize ta itMaybe a thread on that could be useful, as there’s almost always a solution or time will fix it, so don’t get discouraged.

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@bbwr10coqsm goTenna Mesh does incorporate techniques such as listen before talk, to work around interference. These features work well with common interference sources such as 900 MHz walkie talkies, cordless phones etc.
I feel what you experienced in the theater is probably because of the ships construction. Cruise ships these days are made up pre-assembled metal boxes (think containers).

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Good hint about airplane mode and tower seeking sucking battery. It sure does.

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Sharing some other cruise ship related reports from elsewhere on Mesh Community:

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Yes that’s true and it’s a pretty amazing process.

Good diagram and thanks for the post to remind us that interference does happen, but it’s relatively rare and can usually be mitigated. These ships are all truly different, so does their potential to affect reception by the users of electronic devices.

Interference can also result from a maintenance problem or equipment failure. If there is a problem on one cruise, the next could be fine once something gets fixed.

This does bring up something not yet mentioned, but which may bring results better than any official complaint would. Mention your problem to the crew. They may know a solution. They’d usually welcome a tip about something that causes passenger dissatisfaction, even more so if it leads them to discover a problem with their equipment. And if jammers were actually in use, hearing complaints about the effects might lead to reconsideration of such a policy.

Particularly with UHF, small changes in location or radio orientation can make a big difference with both ordinary reception and interference and those are easy to adjust.

Another things that may work is to use an extra goTenna as a relay, placing it in the window if you have one will work even if you don’t have a balcony or other outside space. This unit will be much more likely to catch signals in a difficult environment, then can relay the signal to users within the cabin. Relays don’t have to cover large distances to be useful.

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Yep, as a professional sailor on large Navy and commercial ships I can attest to the sturdy construction of the ships hull. It blocks rf very well. I don’t think the theater was using a blocker?

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Odds are they weren’t, but it’s a possibility. It’s the fact that these are jammers are used overseas in theaters and that they had no problems other than there and within the staterooms (dense construction). But without knowing the construction of the theater, hard to say. They do tend to be all enclosed without windows, which certainly attenuates a radio signal within a ship’s hull.

What would tell the tale would be to have the appropriate scanners to search for any jamming signals, which should be present and obvious if it is present. The same thing applies whenever interference is actually the problem, rather than simply poor or nonexistent signal reception. This is triceier now that so much is digital, but a jammer tends to have a continuous signal in the case of all but the most sophisticated jammers.

I used them on a cruise ship in Alaska in the fall with my grandparents (ha!) and they worked great. Wasn’t a big ship so worked pretty much anywhere, any deck to any other deck, with the exception of inner cabins.

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Heading out on NCL Dawn in March. I have 8 units I will bring with me. Three will be dedicated stateroom relay units. (NCL likes to unplug your devices when they clean the rooms, so I will have to see what I can do about that). The other 5 will be on people out and about on the ship, and at the ports. I’ll do up a detailed post of the trip and my experiences when I return.

The three staterooms are spread out pretty good, but only one is a balcony. The other two are outside rooms, but with windows only. The balcony room is towards the front of the ship upper decks, and the other two are midway, and towards the back.

Any thoughts?

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The GTM will run for around 24 hours on its internal battery. the relay units can just be plugged back in when you return. They should stay on in the meantime so long as you leave them on when you leave.

I’d McGuyver a way to attach a relay to the balcony. Try to get it as far out as possible. For the rooms with only a window view, try to have them in the window or as close to it as possible. You could even tape them to the window. Try to place them upright as much as possible to keep the transmission wave polarity alike.

Happy cruising!

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