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Multi-Byte Repeaters

Every packet in a MeshCore mesh carries a record of the repeaters it passed through (its path). Each repeater adds the first 1, 2 or 3 bytes of its Public ID to the path. Each of those entries is a hop.

MeshMapper supports 1-, 2- and 3-byte hops across the wardriving app and the map.

The 1-Byte Problem

In 1-byte mode, a repeater is identified by just the first two hex characters of its Public ID (e.g. A1, 4F, 09). That's only 254 usable IDs (00 and FF are reserved), so growing regions end up with two repeaters sharing an ID.

When that happens, MeshMapper can't tell which repeater a packet went through. The affected repeater is marked Ambiguous (red on the map). Pings still count for coverage, but they aren't linked to it.

With 2 or 3 bytes there are tens of thousands or millions of IDs, so collisions become rare.

How MeshMapper decides

A repeater is judged at its own width, and a hop is only credited when exactly one repeater matches it. See The Rules on the Duplicate Repeater IDs page.

Upgrading to Multi-Byte

You don't need to upgrade every device at once. Multi-byte repeaters still relay packets from repeaters and companions on 1-byte firmware.

Step 1: Update the Repeater

Flash the repeater with MeshCore firmware v1.14.1 or newer, then set its hop width from the repeater's command line.

For 2-byte:

set path.hash.mode 1

For 3-byte:

set path.hash.mode 2

Reboot the repeater, then send a flood advert. MeshMapper reads the width from the repeater's flood advert and updates it automatically.

Step 2: Set the Width for Wardrivers

Once most of your repeaters are upgraded, set App Path Bytes in the region admin panel under Settings → Wardriving → Radio Channels (the Path B column, one per radio preset). Options are Device (leave it to the wardriver's radio), 2 or 3.

This tells the wardriving app what hop width to set on wardrivers' companion radios. It doesn't change repeaters; they get their width from their own adverts. For grouped regions, the group admin sets it.

How MeshMapper Tracks Each Repeater

MeshMapper tracks every repeater separately, so a region can run a mix of 1-, 2- and 3-byte repeaters.

  • Advertised width: taken from the repeater's latest flood advert. If it later adverts at 1 byte again, this goes back down.
  • Multibyte capable: set the first time MeshMapper sees the repeater with a 2- or 3-byte hop, in its own advert, a wardriving ping, or any flood packet an observer hears. Once set, it stays set.

For example, repeater A1B2C3D4E5F6 was known as A1. The first time it's heard as A1B2, it's marked multibyte capable and judged at 2 bytes from then on.

Collisions Clear Up Automatically

As repeaters upgrade, old collisions resolve on their own:

  • AB (1-byte) and AB (1-byte) collide: they can't be told apart.
  • AB12 (2-byte) and AB9F (2-byte) don't: the longer IDs tell them apart.

When a repeater in a collision next adverts, MeshMapper re-checks it and returns it to normal if it can now be told apart.

Tracking Your Region's Upgrade

  • Repeater List (Region menu): the Non-Multibyte Capable and Multibyte Capable tabs show which repeaters still need upgrading.
  • ID width filter (Filter Map Data): show only repeaters and pings using 1-, 2- or 3-byte IDs. See Filters.
  • Multibyte Upgrade Board on the global leaderboard: ranks regions by how far their upgrade has got.

Repeater ID Grid

Open Region → Repeater IDs to see Repeater ID Usage: a grid of every first-byte prefix (00 to FF).

Colour Status Meaning
Green Available No repeater uses this first byte.
Blue Deployed In use, and every repeater here can be told apart.
Red Conflict At least one repeater here can't be told apart from another: two 1-byte repeaters sharing it, or multi-byte repeaters sharing their full 2 or 3 bytes.
Dark grey Reserved 00 and FF, reserved by MeshCore.

Click a cell to see the repeaters using that prefix, with their Public ID, width, hardware and any conflict. Use the search box or the tag filters (MB, Ambiguous, 2-Byte, 3-Byte, No Location, Out of Region, Ghost, Observer, CARpeater) to narrow it down.

Private (🚫) repeaters are listed as Hidden and still count towards usage and conflicts.

In the Wardriving App

  • If the region sets App Path Bytes, the app sets that width on your companion radio and tells you when it changes.
  • If the region leaves it to the device, you can choose the width yourself in the app's wardriving settings.
  • Companion firmware older than 1.14 can only use 1 byte; the app will recommend a firmware update.