RF transmitter/receiver selection

[noobian]

Hi there, First of all I applogize if I've posted this in the wrong index.

I'm brand new to the world of RF and I'm attempting a design project I've had in my head for a while now. I'm getting overwhelmed while trying to source/specify the correct receiver/transmitter combo for the job.

This is a household application (not just a garage door opener, need range in the entire house/multi levels). Ridiculously low data rate needed.

What frequency range should I be looking at? What type of modulation scheme is recommended? Are there household frequency ranges?

I'm looking for an "off the shelf", ie. digikey, product that's cheap, SMALL, and user friendly. Something that would work with a small antenna or PCB antenna would be good too. Any suggestions? Or any features I should be considering and have not listed here?

A friend suggested ZigBee but that can be costly.

Basically I have no idea where to begin designing this RF link and would love any bits of info you have to share.

 

[Resqueline]

Frequency allotments vary from country to country.
Have you considered modifying a babysitter? They can had with either RF transmission or over-the-mains (HF) transmission and are usually cheap.
Modulation depends on what frequencies you intend to put through it (DC, AC, digital) and on the criticality of noise immunity.
Higher frequencies requires smaller antennas. Garage door openers often use a ferrite cored coil for an antenna.