The Project will demonstrate the concepts and schemes proposed for the end to end integrated communications scenarios, with focus on the provisioning of QoS aware communication services across heterogeneous domains.
The key issues are related to the progress in the QoS aware interworking between IP terrestrial networks and satellite systems, the latter utilising DVB-RCS for the return channel interactivity. The project focuses on the functional characterisation of the system and its elements, considering best practice and novel schemes for QoS and traffic management. Approaches are proposed for the definition of mappings among the QoS classes and the relevant parameters on the terrestrial domain and the satellite domain and these are validated via the laboratory test bench.
The project has proposed a technical approach to define interoperable terrestrial and satellite based broadband systems, considering a wide spectrum of end to end architectures and identifying solutions beneficial to several exploitation scenarios, ranging from the upgrade of current commercial offers based on existing satellites, to new generation systems, exploiting mesh connectivity and on board regeneration.
The considered scenarios will suit to institutional and business customers, as well as single users, thanks to the careful selection of the target capabilities for the network equipment, including satellite terminals.
The focus on bearer service definition and mapping rules is, in fact, a missing piece in the current portfolio of network capabilities in integrated terrestrial - satellite systems. These bearer services include traffic management, connection control, medium access control for point to point and point to multipoint communications, which are the key ingredients for true QoS aware communications in a dynamic environment, in which sessions are frequently set up and released.
Overall, the considered functions and their implementation according to the project result will suit to achieve effective communication support in a standard-compliant and bandwidth-efficient environment, with optimisation of communication resource exploitation and reduced, if not even completely abated, need for over-provisioning of resources. It is expected that these results will be extensively applied by future generation QoS aware IP services over satellite.
Two border routers and one core router are set-up with software managing DiffServ procedures powered by GRIP. The core router establishes the DiffServ class of a new connection by inspecting the ToS field of incoming RSVP Path messages and it can then determine if the connection can be accepted based on the traffic congestion level of the selected class. The RSVP signalling is supported up to the border router, which hosts the interworking between the IntServ and DiffServ. This Interworking is performed each time the border router receives a RSVP Path message: the router marks the ToS-field of this packet/message in accordance to the IntServ/DiffServ mapping, so that this RSVP Path message will act as probing packet for the GRIP hosted by the CR and the RSVP Resv message will act as the GRIP ack.
The GRIP Admission Control Procedure is performed by the GRIP module in the core router, which processes GRIP probing packets and verifies the acceptance of this incoming flow to preserve the performance of the existing flows before forwarding the packet to the egress router. If the flow cannot be admitted, the incoming packet is dropped and this results in time expiration in the originating router, which will close the RSVP procedure towards the originating node.
|The interoperation of the Terrestrial and the Satellite networks determines the mapping between the IP level QoS requests and the DVB-RCS satellite network capabilities. The choice for the Profile Class is based on the target traffic characteristics.|
The Project has been structured into 3 technical workpackages and a dissemination task. The WP 1000 identifies and trades off the end to end communication scenarios, based on the current practices by Service Providers and Satellite Providers for QoS services; the QoS requirements will also be identified.
The WP 2000 performs architectural studies on the selected communication scenarios, to define end to end Reference Configurations, Reference Models, and Functional Architectures at system and network element levels.
The WP 3000 proposes and evaluates the performance of QoS-aware Interoperation of Terrestrial and DVB-RCS Satellite segments, considering Hybrid IntServ/DiffServ and DiffServ enhanced with GRIP. The WP also proposes and evaluates mechanisms for On Board QoS support in regenerative satellites.
A laboratory demonstration upgrades an existing test bench with additional core functions for the interworking between DVB-RCS and IP. The dissemination has completed the activities, including presentations to workshops, SatLabs and ETSI BSM WGs. The Project has been concluded in December 2004.
The project has been successfully concluded. The WPs jave delivered all the required technical notes and dissemination has been performed to international conference of Wireless Personal Multimedia Communications (Sept. 2004), at the QoS Workshop organised by ETSI BSM on Sept. 2004 and IETF, the latter through the Internet Draft 'Implicit Signaling over Stateless Networks'. Also, a presentation to SatLabs has been performed in November 2004, as part of the dissemination activities.