DirecTV HD Receiver User Manual page 54

Parental, Fav's & Setup - System Setup
High
-Definition Receivers
Certain remote control models feature RF (radio frequency) capability.
Refer to the model number printed on the top left corner of your
DIRECTV Remote Control. Look for the letter(s) "R" or "RB" at the
end of the model number which indicates that the remote supports
radio frequency. To change your remote method of transmission
from Infrared (IR) signals to RF, select "Remote Control", "Program
Remote", "Advanced" and then "IR/RF Setup". While IR transmission
requires a clear line of sight to the front of the receiver, RF
transmission lets your put your receiver inside a cabinet or behind solid
doors and still be able to command it from up to 200 feet away.
DIRECTV USER GUIDE - HD & SD STANDARD RECEIVERS
54