Legacy LongRange Mode information (mode 1 in the my attached link)


Joined Feb 24, 2006
OMG! Im stunned :)
Im a junior engineer in my first steps, so I need much to learn and there's much to learn about networking and engineering.

PS. if you have any link for a good book for improving my thinking as an engineer would be really appreciated ! thanks alot.
I mean by improving my thinking is to think differently and grasp new perspective/approaches in order to solve problems more quickly !

thanks alot
This kind of stuff does not come from a book. It comes from struggling, endless struggling with problems that other people find intractable. You need to find someone fast to keep from sticking your neck out too far. Maybe she will show you the ropes.

Thread Starter


Joined Aug 1, 2020
You missed the part about the sync word going on the wire Least Significant Bit (LSB) first. Start with the F on the right hand end of the sync word and write the bits in reverse order. Reversing the bits like this will yield a sync word that doesn't look anything like the one which is written MSB (Most Significant Bit) first. If you're going to do anything in communications you gotta get used to doing things like this by paying close attention to details. Just take the bit string you wrote in post #4 and write it again reading from right to left but writing the bits from left to right. Now what you have written is what the bits will look like "on the wire". Actually this is RF so there is no wire, so maybe I should say on the scope looking at the receiver.

For the Payload and the Termination I'm guessing that the N*8*2*2 is going to be the total number of symbols for the payload, and 6*2*2 is the total number of symbols for the termination. N is the number of bytes and DSSS = 2, so that each bit is replaced by 4 symbols. So the symbol rate is 4 times the bitrate. That is just a guess.
Im still confused about N , is it the number of Bytes of my PayLoad or all my Packet data(includes number of preamble bytes and syncword bytes and ...etc ) what I guess it's just the Payload Bytes but Im not sure.
thanks for your help.


Joined Feb 24, 2006
It looks like N is the number of "bytes" theat come out of the FEC Encoder, but to tell you the truth I'm having trouble keeping track of all the "balls in the air".
Get a copy of Sklar without delay.