Verilink AS2000: The Basics (880-502981-001) Product Manual - Manual (Page 123)

Acronyms and Definitions
Verilink Access System 2000: Basics Glossary-3
ATM See asynchronous transfer
mode (ATM) .
attenuation The decrease or loss in signal
power (decrease in the amplutide
of a signal).
available second Any second that is not a failed or
an unavailable second (UAS).