IR overview

IR signals are digital pulses of invisible intrared light at a specific frequency. Obviously, the sender must be line-of-site to the receiver, and the closer the better.
Computer IR signals (IRDA, et al) are typically at a different frequency than consumer A/V devices (receivers, CD players, DVD, televisions).
Some IR tranceivers have hardware that works at a fixed frequency (like most laptops). Others can control the frequency with software, but usually have limited range (like handheld computers and PDA's).