How does IMS architecture differ from traditional wireless network architecture?
Prior to the establishment of IMS, services were specified and supported by a single logical node or set of nodes that perform specialized features for the service. Each service appears as an island, with its own service or specific node(s). The only possible way to interface between services – for example, for service composition – is through protocols. In the absence of any common service framework, each service may have to be designed and implemented from scratch.
