Configure Radio Transmission Speed?

I need a very good range but I do not need a very speedy Radio Transmission. I see that for most Radio Modems, lower is the speed, better is the transmission range (Page 11 of this PDF: Graph by TI ). I do not find any configuration parameter for XBee Radio Transmission Speed: what could be recommended at this level? Thanks! Christophe

Which XBee product are you referring to? The longest range XBee product a the moment is our XBee PRO 868 or XBee PRO 900 HP modules.

I am using XBee PRO 868 and get a “line of sight” range, not too cluttered with trees, of 450 meters. I do not find in XCTU any parameter dealing with radio transmission speed (I am not speaking of the baud rate to communicate with the XBee itself)