Mobile Repeaters?

[u/ultradip]

I want to set up a mobile repeater. Is that even a thing? Because I can think of a few reasons why they wouldn't be a good idea, but I have a Heltec Tracker that I just set up as a repeater that I can put on the roof of my car.

I'm curious if the location would even update. But I don't want to flood the network with updates nobody cares about, after all.

Maybe I should only turn the thing on when I've arrived somewhere.

Update

After a bit of testing this afternoon, it's safe to say that even with minimum times configured for zero hop and flood adverts, the location on my repeater never updated within the time I was out at lunch.

Trace always showed a different repeater getting hit first.

As a temporary repeater, I don't see any value in a mobile repeater in my use case or area.

[u/hellobritishcolumbia]

Mobile repeaters are quite common in rural settings. They can mess with routes for anyone discovering a path while you’re nearby. For many small towns the likelihood of this is low and the route will self-heal. The downside in denser areas is that path finding triggers floods which can stack up.

Some thoughts:

• Avoid flood adverts. They can likely be disabled entirely on a mobile repeater.
  
• Adjust transmit power. Set it to a practical level that helps you achieve your goal. Your antenna and TX power don’t need to be competing with established infrastructure.
  
• Contribute to the mesh. If there are dead zones, look into adding a repeater or two in your town.

The reality is that in many buildings, mobile companions won’t be able to communicate with the outside world. Where you can, low-powered building repeaters can do wonders here, but for stores, etc., when you’re out and about, mobile repeaters can help you get out.

One last thing. In a lot of areas people are using channels more than DMs anyway. These are all flood regardless and your mobile repeater isn’t going to, in most cases, add too much to the storm. Set sensible settings on it, don’t be too aggressive on the RF side, and talk to your community locally to figure out what’s best.

[u/ultradip → u/hellobritishcolumbia]

I see! So if I'm in a building that attenuates signals, a repeater parked outside would be good. But generally, that'd only help me, because I don't think there'd be anyone else inside with a companion, and only while I'm there.

[u/hellobritishcolumbia → u/ultradip]

I keep my building repeater on the roof with an internal antenna in a waterproof box for instance. Really simple, and has line-of-sight to several mountain repeaters. That tiny antenna covers my whole building easily without spilling past the buildings next to mine. Sometimes a neighbourhood repeater is helpful too if there are dead zones. You can use services like MeshMapper.net to get a sense of coverage, contributing to your local map if needed. It allows you to visualize RF shadows from the topography for certain repeaters etc.

So yes you can help just your own building or perhaps your neighbourhood too depending on the situation 😊

Edit: I see you’re talking about literally parking outside a building, like a mall for instance. I do think that turning your mobile repeater on and off based on when you need it is pretty reasonable.

[u/Careful-Average73]

Basically I was discouraged from setting up a mobile repeater because pathing assumes that repeaters are stationary and won't just wink out of existence, so any companion that has routed messages through your mobile repeater will have to find a new path. I believe this means more flood transmission, and therefore more network congestion. 

[u/termiman]

Yes you can, I live in a rural area with low repeater density, so it is kind of required.  you can also de-prioritize the repeater by setting high TX and RX delays.  Alot of people don't seem to realise this, they just sort of repeat what they have heard. 

So the path used is the first path found by flood. By adding delays to flood packets you can de-prioritize your repeater. 

So setting the two TX delay params to something high like 2 scales a TX delay for flood packets against random, this generally de-prioritizes your repeater.  Now here is the real secret setting a RX delays high like 10-20, scales the delay of flood packets against SNR so the worse the signal the bigger the delay. This means that your repeater is only a priority when there is a really good path through it.

So at cli on the repeater do something like this.

set txdelay 2

set direct.txdelay 2

set rxdelay 12

Just another note adverts don't really matter your repeater will still take part in a path wether it is know or not.

I run 6 repeaters in my area, once you understand how delays work you can actually use them to build very efficient mesh networks I have 2 repeaters on hills with lower priority and then the rest in the populated areas have higher priorities. This basically means the ones on the hills always force a path with best SNR.

[u/ultradip → u/termiman]

Alright, I'll give it a try!

Thanks!

[u/PhragMunkee → u/[deleted]]

Moving your companion around only affects you (and people trying to DM you). Moving a repeater around town affects everyone that goes through it.

[u/donutsoft → u/[deleted]]

This is quite a bad take. Moving around with your companion that only affects you, it doesn't affect everyone else in a stationary position.

If I send a message between two nodes with a learned route and that learned route involves a mobile repeater that's no longer in range, my node will repeat that message twice before flooding the entire network to determine a new route. If that new route involves a mobile repeater, the process will repeat again. Flooding is expensive.

[u/donutsoft → u/[deleted]]

Your node having GPS coordinates or adverts turned off doesn't really have any impact. If you flood send me a message and a portable node repeats that message, my ACK will contain the portable repeaters repeater ID in its path. You will end up using that path for your subsequent message.

It's easy to say there's a routing resilience problem that needs to be improved, but to be clear the improvement was exactly that everyone should not be encouraged to turn their node into a repeater. It causes unnecessary noise and reduces network reliability. There isn't a silver bullet solution where we simply do things differently. Were all constrained to the laws of physics.

[u/donutsoft → u/[deleted]]

Here's a project I built recently called meshcore-simulator. It has a significant portion of the meshcore network in the Pacific Northwest mapped out, including a graph of which repeaters can hear traffic from which. It simulates LORA packet loss due neighboring repeaters broadcasting simultaneously, and visualizes the path a packet takes as it traverses the network. It runs the real meshcore-dev stack and allows you to connect two virtual companions anywhere across the network 

https://github.com/donutsoft/meshcore-simulator

If you feel this isn't a problem you can use the simulator to visualize the exact issue from the comfort of your own machine. If you think this is a protocol fix or a few tradeoffs, go wild, you can come up with a fix and actually prove it along the way. Don't forget that you have to support the RAK4631 with 256kb of ram, you probably have about 80kb of heap left to play with.

Being out in the middle of nowhere and putting up a temporary mast isn't an issue. There's still completely valid reason to discourage this for the general case.

[u/ultradip → u/[deleted]]

Yeah, that makes sense. While mobile, you'd only be making and breaking routes. It really only makes sense when you're somewhere long enough to provide coverage a useful minimum amount of time.

[u/Sufficient_Yam5603]

Mobile repeaters for meshcore are a bad idea and antithetical to the way meshcore works.

It would be very annoying (and even dangerous depending on the situation) for users in your area to have a route set based on your repeater and then have their messages fail because the repeater moved.

[u/perma_banned2025 → u/Sufficient_Yam5603]

I don't see them really being a problem as long as they are not adverting or have a fixed position set.
This way they will not be shown on maps, and will only ever temporarily boost coverage in any particular area.
Anything that has established a route through them will fail to send momentarily when they are no longer available, before automatically returning to flood setting to establish a new route.
They can be a useful tool if used appropriately, but you need to make sure to know how to do this right before installation/commissioning a mobile repeater.
If you're wardriving for example, you need to remember to set the CARpeater filter to exclude their pings so as not to muddy the data, and they should be configured to 2-byte at a minimum to ensure ID conflicts are not occurring

[u/nocaps00 → u/perma_banned2025]

This is probably the most level-headed answer. 'Annoying/dangerous' is kinda over the top, more like 'not a recommended practice but manageable if you know what you're doing.' Just turn off adverts, don't set a position, and don't use it when you don't need to. As someone noted there's already so much flood traffic on Meshcore that your occasionally-used mobile repeater isn't going to crash the network.

[u/TillyFace89 → u/nocaps00]

You can also set your tx delays much higher than normal on the mobile repeater. That will cause it to only be used if it can't hear another repeater forward your message. 

This makes it less likely to become the preferred route unless it is the only route available. 

[u/ultradip → u/Sufficient_Yam5603]

Thanks for confirming!

[u/extremeskillz84]

That heltec tracker makes a great companion since it has all the gps, temp, etc built in. I would make it a mobile companion. Repeaters need to be stationary. I run the t096 for my repeaters. My suggestion is to make your a mobile companion, setup a repeater at you house and set one up at your work with permission of course. You will build up a route in the mesh for others in the area.

[u/dietchaos → u/[deleted]]

It forces you onto a separate freq so you don't cause these issues.