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Our research activities are primarily focused on the boundary area between broadcast-based systems (such as DVB/MPEG-2), and network systems based on the open Internet standards. We integrate traditional broadcast content, such as video and audio, with novel interactive data and multimedia services. Our focus is not only on creating working solutions, but also beautiful and sustainable ones which are efficient and use as little resources and bandwidth as possible. By creating complete solutions which may involve both hardware and software components, we have the full range of possibilities to explore new chances and visions. Developing these ideas into full products, we take special care to comply with international standards, to stay compatible with popular hardware and software platforms, and to provide a clear, convenient, and enjoyable experience to users and operators. Our customers receive complete and well-rounded turn-key systems and applications for data and interactive multimedia transmissions - "Internet Broadcast Solutions". IP/DVBFor more than a decade, gcs has been developing hardware and software for IP-over-DVB applications. Our focus is on selecting the best protocols and instances for the problem at hand, providing highest efficiency and lowest protocol overhead, with optimal cost of implementation. One technology in our tool set is IP multicast, which makes it possible to distribute IP data with extremely low or no return link capacity requirements. Techniques such as location-based filtering and reliable multicast ensure that data transmissions arrive at the place where they are required. DVB-specified protocols are widely and globally employed for distributing broadcasts via satellite, terrestrial, and cable delivery networks. Leveraging this existing infrastructure makes ubiquitous access to information only a matter of the economy of scale: minimal enhancements and investments on the server side can facilitate huge numbers of receivers and clients who benefit from the services. For example, many customers have already realised the benefits of automatic high-speed on-demand push services and redefine the roles of networks, switching to IP over DVB technology for mission critical services. Also, due to the utilization of existing infrastructure, low-cost receiver equipment for home PCs and networks is widely available, which facilitate cheap clients providing high-speed IP multicast reception. IP Multicast (Reliable Multicasting)Reliable IP-multicast software is responsible for delivering multimedia data to subscribed receive stations with high efficiency and reliability. This is achieved by adding a reliable multicast layer on top of the IP/DVB based transmission system. Reliable IP-multicast shortens transaction times, reduces bandwidth requirements and, hence, leads to faster services if it is combined with an appropriate group management and error handling transport protocol. gcs and University of Salzburg have developed a light-weight reliable multicast protocol, called Restricted Reliable Multicast Protocol (RRMP), which provides end-to-end reliable data delivery service to higher layer entities. It implements Forward Error Correction (FEC) as an appealing approach to avoid feedback implosion for reliable multicast transport. FEC techniques transmit additional redundant information to enable the receivers to correct a certain amount of lost data, without requiring retransmission. To provide guaranteed full reliable transmission RRMP requires a low bandwidth return link for requests to retransmit the FEC information of lost packets. A proactive mode allows to reduce the number of retransmissions in permanently sending FEC and only those FEC information for packets have to be retransmitted where lost packets could not be corrected. gcs has integrated RRMP into its light-weight IP-multicast program DataCast sender/receiver to easy integration of IP-multicast file delivery into existing environments. The performance and reliability of DataCast and RRMP was the key issue that DataCast/RRMP was decided to become the IP-multicast software for the ENVISAT data dissemination system. RRMP also is a key component of our SiMPLE technology. Web CachingBased on an idea named SiMPLE, born nearly ten years ago, an ESA funded project called YouCache aimed to successfully integrate SiMPLE technology in already deployed two-way satellite systems. SiMPLE addresses the observation that more than 90 per cent of the web traffic stems from less than 10 per cent of web servers with a satellite based multicast web caching system. Repetitious content is cached and served to the users without latency and each request served from the client cache consequently saves costly satellite bandwidth. ASTRA2Connect is an already deployed commercial two-way satellite system operated by the project partner SES ASTRA, serving the end-user market at DSL-like costs Efficient use of the satellite capacity is of utmost commercial importance, because less capacity consumption per user means more users per transponder. Consequently, the integration of SiMPLE into the ASTRA2Connect system, as the initial target, for exploiting the effectiveness and efficiency of web caching is considered a commercially attractive solution, that may well be adapted to other two-way satellite systems addressing the residential market. Projectsgcs has led and/or participated to a variety of projects over more than 10 years:
ESA
National - Austria
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