upd documentation foxmash-protocol and APRS ref.

docs/lora/foxmash-protocol.md

@@ -0,0 +1,37 @@
+# FoxMash - Protocol
+
+English version. In case of doubt, the English text shall be binding.
+*[Deutsche Version anzeigen](foxmash-protocol_de.md)*
+
+## Automatic Stations at the ARDF Transmitting Facilities (Foxes)
+
+A fox regularly broadcasts its identifier and telemetry data.
+This is done, whenever possible, at times when the fox is not transmitting on the 80m or 2m bands.
+The purpose of this is, on the one hand, the time synchronization of adjacent nodes, and on the other hand, the regular official announcement of the call sign.
+Usually, the call sign of the organizer or host of the direction-finding competition is used.
+
+## Beacon
+
+Composed based on the modified AX.25, APRS, and MeshCom protocols as follows:
+
+Pseudo-Byte-Stream:
+`{OE3TKT-03nnnnnn`
+
+
+### Structure:
+
+* **Byte 0: `"{ "` (0x7B)**
+  * **Data Type Identifier (DTI):** Derived from the APRS & MeshCom protocol specification (see [APRS Protocol Reference](https://ui-view.net)).
+  * **Reasoning:** This data type identifier is currently marked as `[Unused]` in the specification, and the character visually resembles a station icon.
+
+* **Bytes 1–6: `"OE3TKT"` (0x4F 0x45 0x33 0x54 0x4B 0x54)**
+  * **International Call Sign:** Formatted as a 1–2 character prefix, followed by one or more digits, and a 1–3 letter suffix.
+  * **Padding:** This field is strictly 6 characters wide. If the call sign is shorter, it must be right-padded with trailing spaces.
+
+* **Bytes 7+: Station Number / SSID Identifier**
+  * **Standard Notation (IDs 0–99):** Uses a hyphen followed by a two-digit SSID (Bytes 7–9), for example, `"-03"` (0x2D 0x30 0x33).
+  * **Extended Notation (IDs ≥ 100):** If the station number exceeds 100, you may take any letters as described in https://aprs11/SSIDs.txt (e.g., `OE3TKT-S6` for any special 6th station).
+  * **Backup / Hot-Standby Nodes:** To designate a station as a replacement node or an immediate hot-standby node, the hyphen is replaced by a tilde symbol (e.g., `OE3TKT~03`).
+
+* **Bytes 10–13: Telemetry Data (`nnnnnn`)**
+  * **Timestamp:** Signed 32-bit integer representing the number of milliseconds since the start of the competition day.