Before you throw away your device due to inoperability or start experiencing poor Meshtastic network reliability, I recommend taking the following steps to find out what’s really going on in your network and most likely identify the cause of the problem.
Device settings – always check for errors in your settings. If in doubt, perform the settings as recommended here .
Correct antenna and placement
A quality antenna tuned to 868MHz is an absolute must . The text MESHTASTIC – How to choose an antenna will help you with your choice. It is also important to choose a suitable place for placing the device, for example:
window sill ,
balcony,
roof,
or elevated terrain, such as a hill.
Basic network diagnostics
TEST FOR ACTIVE NODES IN THE NEARBY – Clear NodeDB: After clearing the node database, wait at least 15 minutes and check the number of active nodes in the vicinity . If there are none in your vicinity, or their activity was recorded a few hours ago, there is nothing to complain about – your network logically cannot function without available and active nodes in the vicinity.
NETWORK TRANSMISSION CAPACITY UTILIZATION TEST – Check device activity: Connect the device via USB/SERIAL and monitor what the device sends and receives. Identify whether any messages are being sent at all, network activity, etc. If you do not have the opportunity to monitor the log via cable, at least monitor the “Debug Panel” (Android) in the mobile application for a while. More than 30 packets per minute require a more detailed analysis of what is specifically “going through the air”. On the contrary – if you do not see any traffic even after 15 minutes, you are not within range of other nodes.
NETWORK FREQUENCY BAND UTILIZATION TEST – Use SDR: Software-defined radio (SDR) can help you detect potential nearby sources of interference or the operation of other non-Meshtastic devices. Meshtastic runs in the ISM band, which is also used by other devices, so it is important to determine whether they are negatively affecting your network operation.
This simple diagnostic will help you explain the cause of your network’s unreliability. Don’t jump to conclusions, let alone make serious decisions, without knowing the results of these three tests!
Summary of causes of network unreliability
The main network reliability issues can usually be attributed to just three factors:
Antenna, antenna and antenna again. Choose a better one , or check how it is tuned
Inappropriate device placement.
Insufficient number of active nodes in the vicinity
Setup problem – set up the device exactly as recommended here .
Only then can other factors, such as interference, be addressed. Unfortunately, with absolutely reckless operation, some users are able to cause similar “mess” in the air. Situation Brno-Komín on 2025-02-03, a little before 19:00. None of us want this in our surroundings 🙁
How to function when the network is down?
We already know that the expectation that the Meshtastic network could be a reliable network is misleading. Meshtastic is not and cannot be a reliable network (the current firmware version is 2.5). This follows directly from the nature of its operation and the way packets are distributed in the network. If you get 80% of replies to messages from other users (max. over 3 HOPs), this is probably what can be expected in normal operation today. However, it can still work – for example, number the messages sent to each other in ascending order and request that missing messages (according to the missing number) be sent again. In a crisis situation, exactly what Meshtastic is made for, such communication will be invaluable.
A little about antennas and signals
I have written in more detail about the antennas used in a separate text here . In any case, it can be stated simply: the standard “stick”, which is the antenna below, is a makeshift one. Although it has perfect parameters for its dimensions, it is insufficient for everyday use.
Although I do not have any professional device for measuring the gain and directional characteristics of antennas, according to the measurements and tests I have (and I will describe next time), the antennas can be ranked as follows:
Original supplied antenna (stick) – paper gain +2 dBi. Suitable for home experiments only!
Angled antenna – estimated at >6 dBi**
Gizont – unfortunately the piece I have and measured now gave poor results. However, in relative comparison it takes this place – the gold standard, reliably 4 dBi** and when measuring another piece 8 dBi** (+10 dBi in the catalog).
Magnet – +10 dBi** , if it can be placed on the window sill or roof of the car ( MUST-MUST-MUST have a metal base). Catalog +6 dBi.
Yagi – improvement >9 dBi** , does not need a counterweight (metal base), is installed on a mast or console. However, it is horizontally directional compared to previous antennas . You have to direct it to the area where there are other nodes that you prefer (the signal will be stronger), nodes in other directions will be suppressed (weaker signal). There is also an almost meter-long 20 dBi version ( >16 dBi** ).
By selecting a suitable antenna, please ensure at least:
RSSI greater than -115 dBi (absolute minimum)
SNR higher than -7 dB (absolute minimum)
The values given represent minimum requirements. Under these conditions, it will probably only be possible to establish a direct connection with remote nodes, while the reliability of message delivery will be poor and may also show instability. However, meeting the conditions will allow you to perform basic DX-Meshing – hunting for nearby nodes that will appear in the NodeDB over time. If you are interested in the prerequisites for communication over a mesh network, you can read about it in the text Differences between MediumFast (MF) and LongFast (LF) modes . where it is described under what conditions the network only begins to fulfill its function.
Leave a Reply