Which frequency to use (433 or 315) ?

[Rodo]

Hi all...

For a project (primarily in the USA), which frequency would be better to use
433 or 315 MHz ?

I'm looking at the microchip part rfPIC675, which uses either ASK or FSK
The antenna length is the only main difference I know. I don't know much
about RF.

What about FCC approval ? Is one easier to get than the other ?. The project
needs to qualify under FCC part 15. No high speed data transmission needed.
I'll be sending something like temperature info. It will not be periodic.
The info will be sent only when there is a difference of ...say 7.....
degrees.

No need to get too detailed but if you could point me in the right
direction, that's very much appreciated.

Thanks

 

[Frank Raffaeli]

Hi all...

For a project (primarily in the USA), which frequency would be better to use
433 or 315 MHz ?

What's the application? Maybe a different band is more appropriate.
The temperature data application you mentioned may not qualify for
these bands. The signal must be intermittent, with limited on / off
cycle times.

I'm looking at the microchip part rfPIC675, which uses either ASK or FSK
The antenna length is the only main difference I know. I don't know much
about RF.

Try Infineon, Atmel, Toshiba, NEC.

What about FCC approval ? Is one easier to get than the other ?. The project
needs to qualify under FCC part 15. No high speed data transmission needed.

The formulas for maximum power and measurement methods are in the FCC
rules:
http://www.fcc.gov/
You can use more tx power at 434 MHz. The propagation charactaristics
are better at 315 MHz, presuming you are in the antenna's far field.

Frank Raffaeli
http://www.aomwireless.com/