<s>
Answer	B-Device
tone	I-Device
is	O
a	O
feature	O
of	O
wireline	O
modems	B-Application
.	O
</s>
<s>
The	O
answer	B-Device
tone	I-Device
is	O
the	O
first	O
signal	O
sent	O
by	O
the	O
answering	O
modem	B-Application
after	O
the	O
billing	O
delay	O
.	O
</s>
<s>
It	O
may	O
also	O
be	O
amplitude	B-Device
modulated	I-Device
by	O
a	O
15	O
Hz	O
signal	O
to	O
indicate	O
ITU-T	O
V.8	O
capability	O
.	O
</s>
