NGN represents a fundamental evolution in the design of a mobile switch. A split has been created between the intelligence, or the call control, and the bearer, or the gateway. Where there used to be an integrated switch, there’s now a distributed architecture.

Benefits of a Distributed Architecture
A distributed architecture benefits the mobile service operator (MSP) by enabling major and immediate OPEX and CAPEX reductions. This is achieved in part due to the reduction of switching sites and their associated backhauling costs.

For reasons of scale, traffic in the past would have to be backhauled to another city, and then switched back to the original location. This required the use of costly long-distance backhaul facilities. But with a distributed architecture, switching remains close to the subscriber. This is relevant because 70 percent of mobile traffic occurs in the same region. As a result, a distributed architecture can significantly reduce OPEX.

Moreover, with NGN, mobile operators need only invest in a few, powerful mobile call servers, thus reducing CAPEX. These are distributed through a limited number of centralized control sites located in the operator’s largest traffic zones. To switch the traffic locally, a larger number of lower-cost media gateways are deployed close to the access network.

Seamless Evolution to an All-IP Network
Depending upon the context, NGN means different things. Initially, the 3GPP R4 distributed mobile architecture defines interfaces for GSM/UMTS network deployment. Evolving 3GPP standards (R5/R6/etc.) established the architecture for IMS (IP Multimedia Subsystem) and beyond.

Whatever the context, NGN is designed to permit seamless evolution; first, to a voice-over-packet network, then to IMS – an environment that enables unprecedented speed in launching bandwidth-intensive, revenue-rich services – and finally to an all-IP core.

Simplification of the Transport Network
An NGN architecture also simplifies the transport network. Consolidating voice and data on ATM or IP onto a single transport backbone provides not only more efficient use of network resources, but also delivers savings from a common network management system.

NGN Momentum
For many operators, NGN has become a compelling proposition. In mature markets, MSPs need to gradually increase network capacity, migrate to 3G and IP-based services, modernize their networks and reduce OPEX. And in emerging/growing markets, MSPs - while facing low-ARPU subscriber growth - also need to increase network capacity and reduce OPEX. In fact, ninety percent of the top 20 MSPs are planning to deploy NGN over the next two to three years.