In the last decade, the Telecommunications world has taken a turn from the exclusive use of proprietary architectures, towards convergence with the Internet world concepts and technologies. The primary driver for this transformation is the highly innovative and cost-efficient nature of the Internet world with its openness, which has sparked dramatic changes not only to the communication domain itself, but also to the entire world, transforming our societies into connected ones. The Next Generation Networks (NGNs) aim to converge and bring together these technologies and the open innovation model, within the previously closed Telecommunications world, yet without compromising any of the traditional characteristics, like for example high reliability. Besides the technological convergence, the NGN effort also entails radical changes in the business models, as well as transforming the traditional Research and Development (R&D) models.
At the heart of the NGN architectures are the Core Network (CN) control models. These have transformed from closed systems towards open control platforms, where open innovation and competition will cater for best performance. Using Internet traditional protocols, yet specifically improved for higher performance demands, the NGN architectures are designed to provide the ultimate performance, reliability and predictability, as expected from the best network operators today. With flexibility and openness regarded as a primary drivers, service innovation and evolutions would be fast and efficient, providing the lean-factor to operators. Different domains like fixed, mobile or professional communications are all aiming for a common shared core architecture, with various access technologies and service platforms progressing along.
One of the most important catalysts of innovation in the Internet world is represented by the Open Source models, which empower large masses of innovators with the freedom to continuously drive its transformation. Such models have been regarded in the Telecom world first as efficiency increasing means, by replacing legacy non-essential proprietary systems with improved commoditized counterparts. Marking the beginning of the core architectures convergence were the Voice over IP (VoIP) concepts, which proved that similar telephony performance with much better flexibility can also be obtain with Internet world technologies.
The dissertation work starts from the experiences gathered through Open Source projects like the Fraunhofer FOKUS SIP Express Router (SER), which has quickly established itself as one of the best, most known and used signaling routing and processing platform for VoIP. On top of this success, a true NGN software toolkit is built, through the Open Source IMS Core project. The author has led the project and directly developed significant parts, such that today this is known and used as a world-wide reference for IP-Multimedia Subsystem (IMS)/NGN test-beds. Besides the implicit architectural validation and test-bed targets, such toolkits aim to provide solid R&D foundations not only for the industry but also for the academia, to educate and to build innovation bridges.
The primary scope of the dissertation will be to expose the main requirements, design decisions, implementation and exploitation steps which have been used in order to realize this prototype. A second step has already been started, as to better follow the NGN evolution from an IMS centric architecture towards a better generalized connectivity platform with the addition of Evolved Packet Core (EPC).
This provides the opportunity for an incremental step in refining the presented methods. Yet due to the sheer size of each of these projects, the focus will be kept here on the completed IMS toolkit, with the EPC one used mostly to prove that the described methodology, of using Open Source as innovation sparking catalyst in test-beds, is also sound and useful in a more generalized and systematized way.