<s>
A	O
Push	B-General_Concept
Proxy	I-General_Concept
Gateway	I-General_Concept
is	O
a	O
component	O
of	O
WAP	B-Protocol
Gateways	O
that	O
pushes	O
URL	O
notifications	O
to	O
mobile	O
handsets	O
.	O
</s>
<s>
A	O
push	B-General_Concept
message	I-General_Concept
is	O
sent	O
as	O
an	O
HTTP	B-Protocol
POST	O
to	O
the	O
Push	B-General_Concept
Proxy	I-General_Concept
Gateway	I-General_Concept
.	O
</s>
<s>
The	O
POST	O
will	O
be	O
a	O
multipart	O
XML	O
document	O
,	O
with	O
the	O
first	O
part	O
being	O
the	O
PAP	B-General_Concept
(	O
Push	B-General_Concept
Access	I-General_Concept
Protocol	I-General_Concept
)	O
Section	O
and	O
the	O
second	O
part	O
being	O
either	O
a	O
Service	O
Indication	O
or	O
a	O
Service	O
Loading	O
.	O
</s>
<s>
The	O
PAP	B-General_Concept
XML	O
contains	O
at	O
the	O
minimum	O
,	O
a	O
<pap> element, a <push-message> element, and an <address>	O
element	O
.	O
</s>
<s>
An	O
example	O
of	O
a	O
PAP	B-General_Concept
XML	O
:	O
</s>
<s>
The	O
important	O
parts	O
of	O
this	O
PAP	B-General_Concept
message	O
are	O
the	O
address	O
value	O
and	O
type	O
.	O
</s>
<s>
Additional	O
capability	O
of	O
PAP	B-General_Concept
can	O
be	O
found	O
in	O
the	O
PAP	B-General_Concept
article	O
.	O
</s>
<s>
Once	O
a	O
push	B-General_Concept
message	I-General_Concept
is	O
received	O
from	O
the	O
Push	O
Initiator	O
,	O
the	O
PPG	O
has	O
two	O
avenues	O
for	O
delivery	O
.	O
</s>
<s>
In	O
Connectionless	O
Push	O
,	O
an	O
SMSC	O
BIND	O
is	O
required	O
for	O
the	O
PPG	O
to	O
deliver	O
its	O
push	B-General_Concept
message	I-General_Concept
to	O
the	O
mobile	O
station	O
.	O
</s>
<s>
Since	O
a	O
WAP	B-Protocol
Push	B-General_Concept
message	I-General_Concept
can	O
be	O
larger	O
than	O
a	O
single	O
SMS	O
message	O
can	O
contain	O
,	O
the	O
push	B-General_Concept
message	I-General_Concept
may	O
be	O
broken	O
up	O
into	O
multiple	O
SMS	O
messages	O
,	O
as	O
a	O
multipart	O
SMS	O
.	O
</s>
<s>
Typically	O
,	O
the	O
PPG	O
or	O
another	O
part	O
of	O
the	O
gateway	O
has	O
to	O
receive	O
RADIUS	B-Protocol
or	O
other	O
accounting	O
packets	O
in	O
order	O
to	O
support	O
Connection	O
Oriented	O
Push	O
.	O
</s>
<s>
PPG	O
vendors	O
include	O
Nokia	O
Siemens	O
Networks	O
,	O
Ericsson	O
,	O
Gemini	O
Mobile	O
Technologies	O
,	O
Openwave	B-Application
,	O
Acision	O
,	O
Huawei	O
,	O
,	O
Alcatel	O
,,	O
ZTE	O
,	O
and	O
open	O
source	O
Kannel	B-Language
.	O
</s>
