From cbb95c79c89b2fa57b6ecab4d36f21c4f9191936 Mon Sep 17 00:00:00 2001 From: Bernhard Tittelbach Date: Thu, 17 May 2012 06:14:37 +0000 Subject: doc frame types git-svn-id: https://svn.spreadspace.org/mur.sat@423 7de4ea59-55d0-425e-a1af-a3118ea81d4c --- doc/protocols/ground-rxtx.txt | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) (limited to 'doc') diff --git a/doc/protocols/ground-rxtx.txt b/doc/protocols/ground-rxtx.txt index 96dd7fb..49d006b 100644 --- a/doc/protocols/ground-rxtx.txt +++ b/doc/protocols/ground-rxtx.txt @@ -240,9 +240,28 @@ Content Types Bit Field: BC2P is the Bernhard Christian Patrick Protocol +Frame Types: +* [Dn] Data Frame +* [RS] Reed Solomon FEC Frame, carrying FEC Data for previous N (configurable via DFpRS) data frames +variable DFpRS ratio: If too many frame errors are encountered, the ration can be increased up to 1:1, + respectively if no errors are encountered it can be set to 1:inf (i.e. switch of FEC Frames) + Note that in AX.25 Mode, where a TNC may just discard frames with bad CRC without forwarding it to the PC, + this may not a very helpful FEC mode and should thus be switched off. + Thankfully, GENSO operates it's TNCs in FlexNet Mode and thus get's the raw AX.25 frames which it stores as recieved. -Open Questions: +variable FrameLength: should be configured depending on encountered fading. + i.e. should be very small in the beginning and can be increased for more throughput, + once it is clear that satellite rotation (source of rapid fading) is slow enough. + +Possible Frame Sequence with DFpRS 1:3 (meaning 1 in 3 errornous frames can be corrected): + +...[D1][D2][D3][RS][D4][D5][D6][RS]... + + + + +"document this" TODO: * frame bits !! * maximum Frame length ???? * think it through.. @@ -252,3 +271,8 @@ Open Questions: * Layers ? * ... + + + + + -- cgit v1.2.3