<s>
Map	B-Application
database	I-Application
management	I-Application
systems	O
are	O
software	O
programs	O
designed	O
to	O
store	O
and	O
recall	O
spatial	O
information	O
for	O
navigation	B-Application
applications	I-Application
,	O
and	O
are	O
thus	O
a	O
form	O
of	O
Geographic	B-Application
information	I-Application
system	I-Application
.	O
</s>
<s>
Moreover	O
,	O
they	O
are	O
playing	O
an	O
increasingly	O
important	O
role	O
in	O
the	O
emerging	O
areas	O
of	O
location-based	B-Application
services	I-Application
,	O
active	O
safety	O
functions	O
and	O
advanced	O
driver-assistance	O
systems	O
.	O
</s>
<s>
These	O
are	O
usually	O
formed	O
by	O
a	O
closed	O
polygon	B-General_Concept
,	O
which	O
are	O
shapes	O
that	O
indicated	O
an	O
object	O
over	O
a	O
map	O
has	O
to	O
have	O
a	O
close	O
boundary	O
,	O
meaning	O
the	O
first	O
polygon	B-General_Concept
should	O
be	O
same	O
as	O
a	O
last	O
polygon	B-General_Concept
.	O
</s>
<s>
(	O
For	O
example	O
,	O
to	O
plot	O
a	O
square	O
object	O
on	O
a	O
map	O
,	O
the	O
polygons	B-General_Concept
are	O
1	O
,	O
2	O
,	O
3	O
,	O
4	O
,	O
1	O
.	O
)	O
</s>
<s>
Another	O
point	O
for	O
validation	O
on	O
data	O
is	O
the	O
point	O
in	O
polygon	B-General_Concept
,	O
which	O
helps	O
in	O
finding	O
points	O
lying	O
outside	O
a	O
polygon	B-General_Concept
.	O
</s>
<s>
E.g.	O
,	O
for	O
a	O
particular	O
lon-lat	O
coordinates	O
in	O
a	O
city	O
,	O
if	O
the	O
point	O
is	O
intersecting	O
the	O
polygon	B-General_Concept
in	O
an	O
odd	O
number	O
,	O
then	O
it	O
is	O
inside	O
the	O
polygon	B-General_Concept
and	O
a	O
valid	O
point	O
;	O
otherwise	O
it	O
is	O
outside	O
the	O
polygon	B-General_Concept
and	O
invalid	O
.	O
</s>
<s>
It	O
is	O
usually	O
in	O
a	O
plain-text	O
form	O
(	O
ASCII	B-Protocol
)	O
consisting	O
of	O
fields	O
that	O
are	O
easily	O
parsed	O
and	O
interpreted	O
by	O
the	O
various	O
parties	O
who	O
will	O
handle	O
it	O
.	O
</s>
<s>
However	O
a	O
new	O
initiative	O
called	O
Navigation	O
Data	O
Standard	O
(	O
NDS	O
)	O
is	O
an	O
industry	O
grouping	O
of	O
car	O
manufacturers	O
,	O
navigation	O
system	O
suppliers	O
and	O
map	O
data	O
suppliers	O
whose	O
objective	O
is	O
the	O
standardization	O
of	O
the	O
data	O
format	O
used	O
in	O
car	B-Application
navigation	I-Application
systems	I-Application
.	O
</s>
<s>
The	O
wireless	O
channel	O
might	O
be	O
bi-directional	O
,	O
such	O
as	O
Wi-Fi	O
and	O
cellular	O
phone	O
,	O
broadcast	B-Operating_System
,	O
such	O
as	O
satellite	O
radio	O
,	O
FM	O
sub-carrier	O
or	O
ATSC	B-Device
datacasting	O
,	O
or	O
a	O
combination	O
of	O
both	O
.	O
</s>
<s>
Various	O
navigational	O
functions	O
,	O
involving	O
active	O
safety	O
,	O
driver	O
assistance	O
and	O
location-based	B-Application
services	I-Application
require	O
data	O
that	O
is	O
not	O
considered	O
to	O
be	O
part	O
of	O
a	O
map	O
database	O
and	O
is	O
likely	O
supplied	O
by	O
a	O
vendor	O
other	O
than	O
that	O
of	O
the	O
map	O
provider	O
.	O
</s>
<s>
Such	O
a	O
table	O
is	O
collaboratively	O
produced	O
to	O
support	O
a	O
specific	O
function	O
or	O
class	O
of	O
functions	O
involving	O
location-based	B-Application
service	I-Application
,	O
active-safety	O
or	O
advanced	O
driver	O
assistance	O
.	O
</s>
<s>
TMC	O
,	O
which	O
stands	O
for	O
Traffic	O
Message	O
Channel	O
,	O
is	O
part	O
of	O
the	O
Radio	O
Data	O
System	O
(	O
RDS	O
)	O
,	O
which	O
is	O
implemented	O
as	O
a	O
sub-carrier	O
modulation	O
of	O
a	O
commercial	O
FM	O
broadcast	B-Operating_System
signal	O
.	O
</s>
<s>
They	O
resolve	O
this	O
by	O
using	O
an	O
open	O
intermediate	O
map	O
format	O
expressed	O
with	O
XML	B-Protocol
and	O
based	O
on	O
the	O
concepts	O
of	O
the	O
ISO	O
standard	O
GDF	O
4.0	O
.	O
</s>
