I would say that it depends on the criterions you need for you transmission.

1. Should it be reliable ? (from your Failure Mode Effect Analysis - FMEA)
If yes, you may design both hardware and software to achieve this. Report on my 'Design Rules' pages in my website to learn more on FMEA. (URL in my user profile)

2. Should it be cost effective or not ?
This may let you to choose between differents components or technologies.
It's possible to build some very cost effective system but check the reliability, severity, detectability and frequency of failures.

3. What is the bitrate needed ? What is the amount and the frequency sampling of datas to transmit.

4. Is it Master-Slave mode or multi-master mode ?

According to these points you may decide the hardware and the protocol to design.



Regards
Stephane