<s>
An	O
A-law	B-Algorithm
algorithm	I-Algorithm
is	O
a	O
standard	O
companding	B-Algorithm
algorithm	O
,	O
used	O
in	O
European	O
8-bit	O
PCM	B-Algorithm
digital	B-General_Concept
communications	O
systems	O
to	O
optimize	O
,	O
i.e.	O
</s>
<s>
It	O
is	O
one	O
of	O
two	O
versions	O
of	O
the	O
G.711	B-Algorithm
standard	O
from	O
ITU-T	O
,	O
the	O
other	O
version	O
being	O
the	O
similar	O
μ-law	B-Algorithm
,	O
used	O
in	O
North	O
America	O
and	O
Japan	O
.	O
</s>
<s>
For	O
a	O
given	O
input	O
,	O
the	O
equation	O
for	O
A-law	B-Algorithm
encoding	O
is	O
as	O
follows	O
:	O
</s>
<s>
A-law	B-Algorithm
expansion	O
is	O
given	O
by	O
the	O
inverse	O
function	O
:	O
</s>
<s>
The	O
reason	O
for	O
this	O
encoding	O
is	O
that	O
the	O
wide	O
dynamic	O
range	O
of	O
speech	O
does	O
not	O
lend	O
itself	O
well	O
to	O
efficient	O
linear	O
digital	B-General_Concept
encoding	O
.	O
</s>
<s>
A-law	B-Algorithm
encoding	O
effectively	O
reduces	O
the	O
dynamic	O
range	O
of	O
the	O
signal	O
,	O
thereby	O
increasing	O
the	O
coding	O
efficiency	O
and	O
resulting	O
in	O
a	O
signal-to-distortion	O
ratio	O
that	O
is	O
superior	O
to	O
that	O
obtained	O
by	O
linear	O
encoding	O
for	O
a	O
given	O
number	O
of	O
bits	O
.	O
</s>
<s>
The	O
μ-law	B-Algorithm
algorithm	I-Algorithm
provides	O
a	O
slightly	O
larger	O
dynamic	O
range	O
than	O
the	O
A-law	B-Algorithm
at	O
the	O
cost	O
of	O
worse	O
proportional	O
distortion	O
for	O
small	O
signals	O
.	O
</s>
<s>
By	O
convention	O
,	O
A-law	B-Algorithm
is	O
used	O
for	O
an	O
international	O
connection	O
if	O
at	O
least	O
one	O
country	O
uses	O
it	O
.	O
</s>
