Overview
In satellite modem technology, the same transponder that is used
to deliver TV, is used to deliver Internet access. Satellite modems
have performance problems because they are used over shared media
and the high data rate is unidirectional, because the return channel
is via a 56K analog modem.
Transmission mechanism: In a DVB (digital video broadcasting) system,
the satellite transmits data to the dish at 6-33 Mbps. This dish
is connected to the PC through a DVB card. The PC is connected to
the Internet by an analog 56 Kbps modem. The service provider connects
the PC with the information provider and the satellite operator.
Spare transponder space on the satellite allows data to be broadcast
alongside normal digital programming in DVB/MPEG-2 multiplex mode.
Some of the different standards are DSS (Hughes proprietary), DVB
(ETS 300-421, an open standards consortium), and Primestar (ITU-R
217/11, being phased out).
Market Research
There were an estimated $100M in satellite modem sales in 1999.
Xilinx Solutions
Xilinx products provide significant value in a satellite modems
when used to interface various ASSPs together, resolving differences
in their interface control signals. The in-system programming capability
of Xilinx devices enables features to be upgraded while the product
is in the field, as well as decreasing the time-to-market for the
product. The Spartan™-II FPGA or XC9500XL CPLD devices are ideal
candidates for this low-cost application.
As satellite modems evolve into residential gateways they will
support multiple home networking interfaces. Spartan-II FPGAs provide
system integration and interconnectivity to these interfaces, hence
providing decreased time-to-market, increased time-in-market and
the rapid product proliferation in this market. Please view the
presentation to see
how Xilinx solutions can help you build products for this fast evolving
market place.
Analog
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Cable
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ISDN
Satellite
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