  In this paper two scheduling models are addressed. First is the standard
model (unicast) where requests (or jobs) are independent. The other is the
broadcast model where broadcasting a page can satisfy multiple outstanding
requests for that page. We consider online scheduling of requests when they
have deadlines. Unlike previous models, which mainly consider the objective of
maximizing throughput while respecting deadlines, here we focus on scheduling
all the given requests with the goal of minimizing the maximum {\em delay
factor}.We prove strong lower bounds on the achievable competitive ratios for
delay factor scheduling even with unit-time requests.For the unicast model we
give algorithms that are $(1 + \eps)$-speed $O({1 \over \eps})$-competitive in
both the single machine and multiple machine settings. In the broadcast model
we give an algorithm for similar-sized pages that is $(2+ \eps)$-speed $O({1
\over \eps^2})$-competitive. For arbitrary page sizes we give an algorithm that
is $(4+\eps)$-speed $O({1 \over \eps^2})$-competitive.
