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| Platform |
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| Basic Considerations |
| The SatNEx satellite platform was designed and deployed
during the first phase of SatNEx to provide a pan-European multimedia collaboration
and dissemination multimedia tools among all SatNEx partners (and, possibly,
beyond ... in the future). Objective is to demonstrate "by example" how
traditional videoconferencing services can be efficiently enhanced by satellite-based
solutions to foster international collaboration and dissemination between
scientific partners. |
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| Interactive session scenario |
| Commercially available IP based videoconferencing
devices (Polycom H.323 terminals) and IP over DVB-S equipment (receive-only
antennae and IPricot DVB-S routers) were purchased by each partner. The
H.323 terminals natively provide audio (microphone, loud speakers), video
(camera, external S-Video input) and network interfaces. In the context
of SatNEx community, most partners are connected to academic research Internet
networks providing ground bandwidth used to establish H.323 access to the
central satellite platform service provider (Fraunhofer FOKUS in Birlinghoven, Germany). |
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| Polycom H.323 terminal |
IPricot DVB-S router |
| A central Multipoint Conferencing Unit (Codian
MCU hosted by partner Fraunhofer FOKUS) acts as permanent "virtual room" that
SatNEx partners can reserve and access 24h/day. The MCU provides "unicast(s)
to unicast(s)" ground reflector capabilities (limited to 8 simultaneous
members) plus an interesting and valuable "unicast(s) to multicast" live
re-encoding process used to feed an IP-over-DVB satellite stream compatible
with standard Quicktime players. |
| The SatNEx satellite channel can reliably deliver
an 1 MBit/s IP stream with equitable quality of service to all partners,
extending MCU limitations in number of remote attendees. Thanks to this
satellite multicast extension a large amount of ground network bandwidth
can be saved, geographic barriers are removed and dissemination becomes
possible all over Europe. |
| Using such a hybrid configuration (ground contribution(s)
+ satellite reception(s)), SatNEx partners can run face-to-face sessions,
broadcast specific lectures/events or organize multi-party interactive
virtual meetings. |
| (1 to 1), (1 to N) and (p to N) topologies are accessible
to hundreds of SatNEx researchers distributed over 24 separate locations
in 10 European countries. |
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| Example of multi-parties distributed
interactive session |
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| Channel Reservation and Sessions Announcements |
| To inform partners and to avoid ressource reservation
collision, session initiators are invited to announce and register their
upcoming sessions on the SatNEx calendar (only available in the private
area of this web site) This is a basic (but highly recommended) procedure
to identify (and reserve) available time slots. |
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| Channel reservation with SatNEx calendar |
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EUROPEAN SATELLITE COMMUNICATIONS
NETWORK OF EXCELLENCE (SatNEx)
Coordination: DLR Oberpfaffenhofen []
© ,
Rosenheim 2004 |
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