Questions and Comments

Why does meshtastic work well in our area?

Meshtastic works well in our area because of the ideal mountain and valley geography. The valley is surrounded on two sides by a long chain of mountains. Locating Meshtastic radios on these mountains allows for an ideal coverage scenario:

  1. People in the valley can reach a mountain-top radio to send their messages. If they dont have a line-of-site to the mountain-top, perhaps a nearby radio can reach the mountain top and relay the message for you.

  2. Once a message reaches a mountain-top radio, it gets repeated to all the other mountain-top radios, allowing the message to travel from mountain to mountain, covering a long distance in the process.

What is the LORA configuration in our area?

The area uses the default LongFast Lora Configuration

  • Region: US
  • Preset: Long Range - Fast
  • Number of Hops: User's preference, I am using 5
  • Frequency Slot: 20 (906.875)

How many nodes can be seen?

I have seen numbers range from 50-100+ nodes from my location.

Feel free to send me node reports and I will update here.

Mountain top nodes should use the router role

In my experience using meshtastic, mountain top nodes should be set to the router role. The client role does not always relay messages, an algorithm is used to determine if a message is already being relayed by other nodes, and if so, avoids relaying the message again. Since a mountain top node has a very good perspective to receive from many nodes in the valley below, it will easily receive relayed messages already being sent from neighbors within the valley.

Our area has many nodes high up on mountain tops. This is great, when setup properly, it allows messages to be sent hundreds of miles. Messages hop from mountain top to mountain top traveling long distances with every hop. Since mountain top nodes are much further apart and generally more rare, the client role does not detect long-distance messages being relayed, so it gladly relays the message into the valley.

Here is the problem... when someone in the valley tries to reply, neighboring nodes in the valley will begin relaying the message, and the mountain top node notices this and avoids sending the message back to the sender. The reply message never leaves the valley.

The router role avoids this problem completely. All messages are forwarded early and unconditionally. Yes more battery power is required. Yes more airtime is required for the mountaintop router, but in theory less airtime is required for nodes down in the valley because they are set to one of other roles, and the algorithm is detecting the mountain top relaying the message.

Unfortunately, when a mountain top node is set to the client role, some messages still leave the valley. It is not immediately obvious that many messages are not leaving the valley. Its only after careful consideration and testing when the issue can be observed.

NOTE: In my testing, the router_late role also does not reliably relay all messages, it avoids using the early 'router' transmit window in order to be more polite to neighboring nodes, which means when the mesh is busy and messages get queued up, some messages can get dropped due to contention. 'router' really is the only reliable role for mountain top nodes.

Comments or Questions about mountain top nodes? Visit the Discord Server

Why do I sometimes have trouble sending messages?

Occasionally meshtastic does not confirm messages have been sent. Technically, the meshtastic radio transmits your message, then listens for another radio to re-transmit the message. If your radio hears another radio re-transmit, then the delivery confirmation icon appears.

It is possible that interference or contention may be preventing your message from being received properly by nearby radios. Your radio will retry a few times, but if a nearby radio still doesn't receive your message, you will not receive a delivery confirmation.

Having a better signal to a mountain-top radio may help with sending messages to the entire area. Mountain-top radios are usually configured to 'router' mode because they have such a good transmit position, so if they receive your message they will reliably retransmit it.

Finally, Meshtastic uses a managed-flood algorithm, which works well but may fail in some specific cases.

The Managed Flood Algorithm

Why do I get no responses to my test messages?

Two reasons I can see...

  1. Nobody is currently paying attention to their meshtastic radios. People usually try to respond to test messages, but there are times when many/most are busy.

  2. Your message did not make it very far into the network. Meshtastic messages have a hop limit, every time they jump to another node, the hop count is reduced. When the hop limit reaches 0, it does not get re-transmitted any further. Try bumping up your hop limit, or move your radio to a position where it can reach a mount-top router.

More questions or comments?

Send them and will update this page.

Or visit the Discord Server.