Tele-Communication (Telecom) Terms Glossary and Dictionary
Low Tone is a generic tone used with various interruption patterns for the specific tones. Low Tone is 4800 Hz and 620 Hz at -24 dBm0/frequency. On some systems manufactured before 1974, Low Tone was 600 Hz modulated at 120, 133, 140 or 160 Hz at 61-71 dBmc. The following are a list of specific Low Tones: Line Bust Tone, Reorder, Reverting Tone, No Circuit Tone, No Such Number, Vacant Code, Group Busy Tone, Deposit Coin Tone, Dial Off-Normal Tone, Trouble Tone, Dial Jack Tone, Dial Test Signal, Class of Service.