Main Focus
The HDVIPER project mainly addresses the Multimedia focus of the CELTIC program, as stated in the “CELTIC Purple Book”.
In more detail, the main focus of the HDVIPER project is to design an open and scalable high-definition video conferencing platform based on a new application called Snake that will allow to access the HD video conferencing services. This application will be integrated in a set-top-box and in a PC environment (pre-commercial prototype) , which will be the final, visible outcome of the project.
The application will be based on a Service Oriented Architecture (SOA) paradigm. This term expresses a software architecture that defines the use of services to support the requirements of software users. In other words, in a SOA environment resources on a network are made available as independent services that can be accessed without knowledge of their underlying platform implementation. SOA is usually based on Web services standards (e.g., SOAP) that have gained broad industry acceptance.
As far as session control is concerned, the open standard SIP (Session Initiation Protocol) from IETF (Internet Engineering Task Force) will be used to establish real-time HD sessions.
Last but not least, the project will address those solutions aimed at requesting the allocation of resources in the network so that the desired Quality of Service (QoS) can be provided to the Snake application. In particular, the approach based on the joint use of MPLS (Multi-Protocol Label Switching) and DiffServ (Differentiated Services) will be addressed.
Technological innovation and strategic relevance.
In a nutshell, the HDVIPER project will introduce innovation in the following two aspects.
- Web Services. Implementation of a service-based architecture (SOA) for all non-real-time services specified in the project, such as search or directory services, accounting services and services providing the required network parameters (QoS, establishment of the optical path, etc.). At the present time, there is no commercial or pre-commercial solution providing this kind of video conference services, including both the middle-ware and the network layer.
- SIP services. SIP utilization will allow to setup, to maintain and to release video conference sessions of any quality, starting from the traditional standard definition (H.263 at 200 Kbps), going through high resolution video-conferences (that now appear in the market codified with H.264 at 1 Mbps), following with the DV video conferences that are used at the moment in research networks laboratories, and arriving to the maximum quality that can be currently transmitted following SMPTE standards, that is HD-SDI (SMPTE 292-M) at 1,485 Gbps. Currently, commercial or pre-commercial solutions, aside from only dealing with a small set of these qualities, are proprietary and closed solutions that do not permit further development and improvement by other specialized actors.
As far as point-to-point video conference is concerned, the proposed architecture for the Snake application is the following.
The above scheme clearly shows the decoupling of the signalling layer from the transport layer in the real-time services implemented by the application. To practical effects, this allows any existing quality that can be transmitted over the Internet to be incorporated into the system.
As far as multi conference is concerned, the architecture of the Snake application also permits the inclusion of a module gathering the different flows from audio and video, in a way similar to classical MCU (Multi-point Control Unit), but with the difficulty (unsolved before HDVIPER) to support qualities greater than 10 Mbps. Currently, there is no commercial MCU able to handle these qualities.
The above scheme shows the flexibility of the HDVIPER architecture: it allows the multi-conference module to be integrated in the same Snake client or to be implemented as an independent module, in case of stringent requirements.
