Projects

The primary goal of SatNEx is to achieve long-lasting integration of the European research in satellite communication and to develop a common base of knowledge, thus contributing to the realization of the European Research Area.

Local Website: http://satnex.cosy.sbg.ac.at
Official Website: http://www.satnex.org

• Development of an economical realistic network architecture for the provision of true broadband services for all citizens in Europe.
• Positioning of European industry in the lead for next generation broadband fixed wireless access (BFWA) solutions.
• Motivating advanced utilisation of broadband services at all levels of the society by performing demonstrations and trials in some rural areas.

• Broadband access, network requirements and architecture
• Wireless access systems
• Broadband network utilisation

Hybrid wireless access technologies will offer broadband services to all citizens wherever they may be. Use of the right technology in the right place, as part of a harmonised network architecture, will allow operators to make an affordable, truly broadband offer to fixed and nomadic users in all areas from urban to rural.

The contribution from the Multimedia Communications Group at the Department of Computer Sciences expects impact at several issues, in particular:

• Simple architecture for effective interconnected networks
• New network solutions scalable for varying population densities and user demands
• Fixed and nomadic users have access for all services over a single platform
• Advanced web caching and adaptive video streaming solutions

There are 25 BROADWAN partners comprising operators, industry, academia and consultancy. The partners from 10 countries represent all parts of Europe, both the north and south dimension and the west and east dimension. The significant numbers of SMEs are particularly focussing on broadband service provision.

Consortium Partners

The project has developed a new IP over DVB encapsulation to provide Internet services over DVB broadcast networks. The current standard encapsulation, MultiProtocol Encapsulation (MPE), while providing basic services, adds unnecessary overhead to the IP packet while not fully supporting the IP requirements for current and next generation networks:

• Native support for IP version 6 (IPv6) packets
• Minimal overhead for IP (multicast) packets
• Dynamic address resolution and
• Quality of service.

To provide a full networking solution, the study has also evaluated the encapsulation on the return channel, and performance and quality of service issues have been analysed. Since network performance cannot be abstracted from the network architecture the study has also evaluated a number of realistic end user scenarios. Hence, the result of the study has provided a comprehensive assessment of the new encapsulation and provides a valuable roadmap for future implementations.

Together with Alcatel Space Industries, who designed the new multi-beam transponder, we developed a requirements analysis for multicast traffic signaling in the planned fully-meshed network, taking into account the characteristics of the new transponder generation. In a second project phase after finalizing the requirements and protocol specifications, we adapted existing solutions, such as the Restricted Reliable Multicast Protocol (RRMP) and the DataCast application for use in a multi-beam demonstration setup.

For the purpose of live courses DistLearn was used and the SiMPLE software was used for media-on-demand services. During the project trials numerous live sessions with prominent Austrian lecturers have been transmitted to nearly hundreds schools throughout Austria, and after the live event the recorded videos and related material have been pushed for off-line access.

• A prototype was developed using MPEG-2 in the downlink and an uplink using multiple frequency time division multiple access.
• Time division duplex was studied as an alternative to the frequency division duplex, realised in the hardware prototype.
• Star and mesh networks were studied, allowing for network capacity growth as businesses grow.
• The access network inter-operates and multiplexes effectively with other common networks.
• Solutions allowing for nomadic users and route diversity (switching between two or more base stations) were developed.
• Planning tools were developed that take into account obstruction from the topography and man-made structures, the effects of atmospheric propagation conditions and the antenna radiation patterns.

The general foals of the study were:

• Determine the enabling characteristics, and any possible disadvantageous characteristics of existing security systems with respect to their use in satellites;
• Enable intranets based on the IP protocol (IP);
• Determine the security/cost trade-off in specific solutions;
• Determine the effects of satellite specific characteristics such as delay, asymmetry, footprint exposure on security;
• Determine how emerging security technologies will enable applications using satellite broadcasting;
• Recommend architectures for secure business over satellite links;
• To plan a demonstrator of a corporate intranet application employing satellite links and using a candidate (identified in the study) end-to-end security with strong user authentication.

• High-quality voice/video services
• Asymmetric high-speed interactive Internet services
• Fully-reliable high-speed multimedia multicast push services
• High-speed LAN interconnection via satellite

• Overload of communications links and congestion in routers and switches
• Operation at full capacity with the consequence of severe queueing effects and high delays and packet losses
• New types of applications, in particular multimedia information services and multicast applications (slow scan video and audio) require additional capacities
• A lack of high speed (256 Kbits/sec to 2 Mbits/sec) "delivery networks", particularly for the "last mile" and in rural and less developed areas
• A lack of broadband capacity (100 Mbits/sec to several Gbits/sec) for delivery of multimedia services directly to large groups of end users.

The leader for this project was Telekom Austria.

1. Automatic multicast Web cache content updating,
2. Automatic selection and delivery of content,
3. Decentralised software system for distribution of information and
4. Easy and efficient method of multicasting multimedia Internet content.

In such systems, both the broadcast channels from the Service Providers to the Users and the interaction channels from the Users to the Providers are implemented by means of satellite links. The terminal receives a down-link MPEG-2/DVB stream of around 27.5 Msymbol/s in Ku band and can transmit in up-link at 144 kbit/s or 512 Kbit/s in Ka band adopting MF-TDMA access scheme. The foreseen highest data rate will be 2Mbit/s.

A dual band antenna has been designed in order to best fit the requirements employing a dichroic mirror. The End User PC can be connected with IMMIS User Terminal through an UTOPIA (Universal Test and Operations Physical Interface for ATM) Level 1 standard interface with IP datagrams in forward and ATM (Asynchronous Transfer Mode) cells in Return Path (it complies with Ethernet 10baseT standard). IMMIS has been designed to support some set of services currently offered by the Internet infrastructure. Furthermore such terminal gives the User to a high capacity access to multimedia services and internet, and can be used also in rural areas or without relying on the terrestrial infrastructure. The possible applications and services which have been identified can be grouped in the following categories:

• Entertainment
• Communication Services and Applications
• Electronic Commerce (transactions)

In such systems, both the broadcast channels from the Service Providers to the Users and the interaction channels from the Users to the Providers are implemented by means of satellite links. The terminal receives a down-link MPEG-2/DVB (Motion Picture Expert Group / Digital Video Broadcasting) stream of around 27.5 Msymbol/s in Ku band and can transmit in up-link at 144 kbit/s or 512 Kbit/s in Ka band adopting MF-TDMA (Multi-Frequency Time Domain Multiple Access) access scheme. The foreseen highest data rate will be 2Mbit/s.

ISIS aimed to support some set of Internet and television services and to support high-speed access to multimedia services and internet, and can be used also in rural areas or without relying on the terrestrial infrastructure. The following applications and services have been tested:

• Internet Services and Applications
• Digital Video

The prototype was successfully implemented and demonstrated in the IBM Hawthorne labs (New York) in September 1997. Later on, a successor project was started to demonstrate the feasability of using the high-precision timestamps embedded in DVB video/audio streams for synchronizing IP traffic with live multimedia content.