More details on hopping sequence and channels for Xtend-PKG

Question

Hi,
the product data sheet of the Xtend-PKG states that the channel capacity is 10 hop sequences sharing 50 frequencies https://www.digi.com/pdf/ds_xtend.pdf

The AT command interface gives the user the ability to select the sequence via the ATHP command.
Is it possible to know the table of actual carrier frequencies per hopping sequence (for the two data rates, ie 9.6 and 115.2 kbps)?
I wasn't able to find any information on this in the documentation. Of course I can play around with the spectrum analyzer but I'd like to understand what is the expected behavior of the the RF modem.
Thanks,
Roberto

Answer 1

Roberto,

The radio in question use 10 pseudorandom patterns that use all 50 frequencies between 902 - 928MHz regardless of what RF data rate you are running at.

Comments

Hi,
thanks for your answer. Yes, I understand that the selection of the frequencies within the hopping list is pseudo-random, but if possible I'd like to get more visibility of the actual carrier frequencies in that frequency list of 50, and if there's any difference among the 10 hopping sets you make available for selection from a host.

For instance, the 50 carrier frequencies could be evenly spread with the same separation across the whole band.

Or alternatively, they could be 'packed up' to utilize the min possible band by simply separating them by min defined by FCC and mind bandwidth.

I am assuming, since you have a 125 kbps FSK PHY, that the carrier separation must be at least between 150-250 kHz.

Hope this clarifies the background behind my question.
Thanks,
Roberto