  We consider the problem of broadcasting data streams over a wireless network
for multiple receivers with reliability and timely delivery guarantees. In our
framework, we consider packets that need to be delivered within a given time
interval, after which the packet is no longer useful at the application layer.
We set the notion of critical packet and, based on periodic feedback from the
receivers, we propose a retransmission scheme that will guarantee timely
delivery of such packets, as well as packets that are innovative for other
receivers. Our solution provides a trade-off between packet delivery ratio and
bandwidth use, which contrasts with existing approaches such as FEC and ARQ,
where the focus is on ensuring reliability first, offering no guarantees of
timely delivery of data. We evaluate the performance of our proposal in a
802.11 wireless network testbed.
