1 files changed, 97 insertions, 1 deletions
diff --git a/doc/protocols/ground-rxtx.txt b/doc/protocols/ground-rxtx.txt
index 12e5a0c..96dd7fb 100644
--- a/doc/protocols/ground-rxtx.txt
+++ b/doc/protocols/ground-rxtx.txt
@@ -1,3 +1,32 @@
+Features Needed:
+
+* Download Images
+* Download Piezo Sample Data
+* Broadcast Messages (random or sequential)
+
+
+Features Nice To Have:
+* Download additional Telemetry
+* Store and Forward Messaging
+* Choose Best Image before Download
+
+
+Additional Telemetry Information not included in TTX Beacon:
+* RTC current time
+
+
+Protocol Features Needed:
+* scheduling broadcasts @time | @geolocation
+* start download now
+
+
+
+• VHF, 144-146MHz, Bmax = 18kHz
+• UHF, 434.79-438MHz, Bmax = 30kHz
+Due to the constraints imposed by the payload
+
+
+
 Protokoll:
 
 self made downlink protokoll:
@@ -147,12 +176,79 @@ Msg Store/Forward Feature Wishes:
 
 
 
+= Layers =
+
+=== Physical Layer ===
+GMSK NRZ-I 
+=== Data Link Layer ===
+HDLC / AX.25
+=== Network Layer ===
+(AX.25)
+=== Transport Layer ===
+(AX.25)
+=== Session Layer ===
+BC2P
+=== Presentation Layer ===
+BC2P
+=== Application Layer ===
+BC2P
+
+
+
+
+
+= Optional HDLC + Custom or AX.25 = 
+
+Both options are encapsulated within a synchronous HDLC Frame.
+
+Data-Stream-Start-Flag: 01111110 
+Data-Stream-End-Flag  : 01111110
+Frame-Separator-Flag  : 01111110
+
+If the Start/End-Flag sequence should occur withing the data-stream, bit-stuffing is applied.
+I.e. On the sender side, after 5 consecutive 1s of data one 0 is appended.
+     On the reciever's side, 5 consecutive 1s followed by one 0 is transformed to 5 consecutive 1s aka the 0 is removed.
+
+e.g.
+1010 1010 0100 1111 1111 1100
+might be transformed into the following 2 frames
+01111110 1010 1010 0100 01111110 1111 1011 1110 00 01111110
+
+
+=== Option1: HDLC based custom framing (less overhead) ===
+
+Content Types Bit Field:
+3 orthogonal bit pattern values:
+110  Data encoded with FEC scheme
+011  Data only
+101  separate FEC data
+
+
+
+=== Option2: AX.25 Framing (more compatibility) ===
+
+
+    .------------------------------------------------------------------------.
+    . StartFlag | Address      | ControlInfo |  Data    | CRC     | StopFlag .
+    .------------------------------------------------------------------------.
+    . 01111110  | 112/224 bits | 8/16 bits   | n*8 bits | 16 bits | 01111110 .
+    '------------------------------------------------------------------------'
+
+
+= BC2P =
+
+BC2P is the Bernhard Christian Patrick Protocol
+
+
+
+
 Open Questions:
 * frame bits !!
-* HDLC Frame looks like what ?
+* maximum Frame length ????
 * think it through..
 * describe it properly
 * bandbreite basisbandsignal gmsk
 * bandbreite fertiges signal
+* Layers ?
 * ...