---- dataentry seminar ----
date_dt : 2005-10-31
title : Application-layer FEC erasure codes and cellular multicast/broadcast 
speaker : Dr Michael Luby
affiliation :  Digital Fountain.
time : 
room : 
table : seminars
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template:datatemplates:seminar
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==== abstract ====
There has recently been and continues to be a large amount of work in 
cellular commercial standards that is focused on multimedia delivery using
broadcast and multicast channels.  The reasons for these standardization
efforts are self-evident: while cellular services become ever more popular
and as cellular multimedia applications grow richer, the available bandwidth
for delivering these services remains fairly limited, and thus
broadcast/multicast delivery is the only viable solution operators see to
this obvious revenue-threatening bottleneck.  Examples of such commercial
standardization efforts include 3GPP MBMS, DVB-H IPDatacast, 3GPP2 BCMCS and
DMB. One of the primary challenges in using broadcast/multicast channels for
delivering multimedia is to provide a reliable solution that efficiently
uses the channel.  For cellular unicast delivery, there are a number of
methods to assure reliability and efficiency, including automatic modulation
and error-correction adjustments at the physical layer, automatic
retransmission  of lost radio packets, and automatic adjustments of transmit
power, all based on continual feedback from each individual receiver.  

For   cellular broadcast/multicast delivery, none of these methods are applicable, 
and the primary method of providing reliability instead is the use of   application-layer 
FEC codes. In this talk we describe some of the   broadcast/multicast services to
be offered and specifically how   application-layer FEC codes provide reliability and
channel efficiency for   each of the services.  We also describe in some detail 
Raptor R10, the   application-layer FEC code that has been chosen by 3GPP MBMS 
and DVB-H   IPDatacast, and that is under consideration in all of the remaining cellular
standards that have not yet made a selection.

{{:en:group:seminars:luby1005.pdf|Full presentation}}