Telecommunication companies definitely have a different business model, and it??™s
this difference that requires major changes in the architecture and the implementation
of IP architectures prior to offering network-wide services on IP. This is what the
3GPP set out to change.
The 3GPP community has learned from many earlier mistakes of implementing
wireless technologies. Just look at the evolution of GSM and you can see the numerous
improvements made over the years making GSM more robust and more secure. As
issues arose (such as handset cloning), the GSM community devised new tactics to
solve the problem (such as encryption over the air interface). So why IMS?
First, providing multiple services with multimedia requires management of the
Quality of Service (QoS). This means being able to assign new facilities to support
bandwidth needed when a new media type is added, for example. Providing this level of
QoS management is best suited for a model such as the IMS. However, there is another
very key function that the IMS brings that traditional IP networks could not support.
As the 3GPP began looking at ways to implement IP in their networks, they found
a need to standardize first of all on one common protocol for call and session control.
This was missing from any standards and is the reason why today you see many companies
with multiple versions of VoIP protocols in their networks.
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