Beast Mode and Bandwidth Setting

[Jim Campi]

The application notes suggest setting the bandwidth at 25 kHz. Is there a performance difference between 12.5 and 25 kHz?

 

[Jim Frame]

The application notes suggest setting the bandwidth at 25 kHz. Is there a performance difference between 12.5 and 25 kHz?

I thought the FCC now requires 12.5 kHz.

 

[Javad]

From technical point of view, 25 Hz makes data transmission faster and make Beast RTK more feasible, but makes the range a bit shorter. Others will comment about FCC regulations.

 

[Jim Campi]

Hi Jim,

I believe that the FCC licenses no more than 12.5 kHz channel spacing unless you meet the "equivalent efficiency" standard.

This is not my area of expertise. My basic understanding is that as channel width increases, so does max data rate. With a base transmission rate of 1 Hz we aren't filling the 25 kHz channel spacing (or even the 12.5 kHz spacing). If we can prove that we are transmitting at least 4.8 kbps per 6.25 kHz channel (19.2 kbps per 25 kHz channel) then our efficiency (filling the channel) is equivalent to using lower data rates with smaller channel widths.

Essentially the regulators don't want us to occupy a large pipe with a tiny flow rate. If we can prove the pipe is full, then they might allow the increase.

 

[Jim Campi]

So the technical questions is:

What is the data rate with a 5 Hz base transmission rate and max satellites in view?