Microsoft Word Master master doc

8.1
 
GPRS as a framework for creating end-to-end mobile services 
GPRS provides only a data transport protocol, which means that the service designer 
must select all application level protocols herself. However this is a blade with two edges.
This freedom is unnecessary for creating end-to-end services which are quite simple in 
functionality, like our use case, but still require important properties such as security and 
reliability. But in scenarios where support for proprietary and/or legacy application 
protocols is needed then it is easy to use these with GPRS. 
It seems like a CAMEL application can provide the missing information and events to 
the GPRS TMMS PR, so it can provide a similar service experience as the service based 
on IMS. A disadvantage with this is that the service becomes dependent on the 
operator's network. 
A disadvantage of GPRS is that it does not provide an end-to-end environment, since the 
TMMS PR lives outside of the GPRS network. This makes it harder to achieve e.g. end-
to-end security. 
8.2
 
IMS as a framework for creating end-to-end mobile services 
IMS is almost the opposite of the GPRS environment. There are lots of features available 
and most, if not all, application level protocols have been specified. 
Fortunately, IMS is also easy to extend and adapt to the service designer's needs. E.g. it 
provides support for hosting both OSA and CAMEL application servers by adapting SIP 
to the expected input/output of those frameworks. 
A problem with IMS is the size of the documentation, which is huge in contrast to the 
other frameworks evaluated. It is difficult to say exactly which specifications are 
necessary to know about for a service designer since most of the IMS specifications 
touch this subject. 
Finally, IMS provides a true end-to-end environment in contrast to the other frameworks 
evaluated.