ring again

A CLASS service feature of the public switched telephone network (PSTN). The feature

allows a calling party who encounters a busy signal to request network notification when the called line becomes available.When both lines become available, the network calls the calling party back with a distinctive ring tone. When the caller lifts the handset, the network automatically redials the call. See also CLASS and PSTN.

• 1-persistent carrier sense multiple access (1-Persistent CSMA)
• 1-Persistent CSMA (1-Persistent Carrier Sense Multiple Access)
• 1+ WATS
• 1xEV-DO (one carrier EVolution-Data Optimized)
• 1xRTT (one times Radio Transmission Technology)
• 2
• 20
• 2:1
• 2:1
• 2:1
• 218–219 MHz Service
• 22
• 23B+D
• 23B+D
• 24
• 256-QAM
• 2.5 Gbps
• 2.5 Gbps
• 2.5 Gbps
• 2.5G (Two point Five Generation)
• 26
• 28
• 2B1Q (2 Binary 1 Quaternary)
• 2B+D
• 2 Binary 1 Quaternary (2B1Q)