Filtering

Using computer intelligence to filter out unwanted messages (this is context and content dependent).

Users can instruct their computer to give top priority to urgent messages from family members and to reroute all calls from a particularly obnoxious sales representative to /dev/null!

"Creating a semipermeable wall between work and your private life."
"Some calls from my boss are important, but some are not simply filtering on caller ID is not sufficient."

Filtering is very important:

limits what information must be sent over the wireless link
limits load on the user