Ringback Tone: The sound tone you hear when you are placing a call and are waiting for the phone to be answered. The standard tone is an on and off ringing sound. On some phones users have the ability to choose the tone.

Ringtone: A sound from your phone used to signal an incoming call or message. On most newer phones additional sounds can be downloaded from the wireless system or by data cable. These sounds can take the form of anything you want, the most popular sounds are music.

Roaming: The ability to use a cellular phone outside of a usual service area - when traveling, for example.

RSA (rural service area): One of the 428 FCC designated rural markets across the United States.

Service plan: A rate plan selected by subscribers when they start up cellular service, usually consisting of a base rate for system access and a per-minute rate for usage. Service plans are designed to provide the most cost-effective rates for different types and amounts of usage by the cellular subscriber.

SMS (Short Messaging System): A feature of some cellphones that allows users to receive and transmit short text messages using their wireless phone. Also called "text messaging."