Sanyo SCP-7050 User Manual page 240

When is my data connection dormant?
If no data is received for 10 seconds, the connection goes
dormant. When the connection is dormant, voice calls are
allowed. (The connection may become active again quickly.)
If no data is received for an extended period of time, the
connection will be terminated.
Can I sign out of data services?
You can sign out without turning off your phone; however, you
will not be able to browse the Web or use other Sprint Vision
services. While signed out, you can still place or receive phone
calls, check voicemail, and use other voice services. You may
sign in again at any time. To sign out, go to Settings > Data >
Disable Data in your phone's menu.
224 Section 3B: Sprint Vision