  This paper is concerned with dynamic resource allocation in a cellular
wireless network with slow fading for support of data traffic having
heterogeneous transmission delay requirements. The multiple-input single-output
(MISO) fading broadcast channel (BC) is of interest where the base station (BS)
employs multiple transmit antennas to realize simultaneous downlink
transmission at the same frequency to multiple mobile users each having a
single receive antenna. An information-theoretic approach is taken for
characterizing capacity limits of the fading MISO-BC under various transmission
delay considerations. First, this paper studies transmit optimization at the BS
when some users have delay-tolerant ``packet'' data and the others have
delay-sensitive ``circuit'' data for transmission at the same time. Based on
the convex optimization framework, an online resource allocation algorithm is
derived that is amenable to efficient cross-layer implementation of both
physical (PHY) -layer multi-antenna transmission and media-access-control (MAC)
-layer multiuser rate scheduling. Secondly, this paper investigates the
fundamental throughput-delay tradeoff for transmission over the fading MISO-BC.
By comparing the network throughput under completely relaxed versus strictly
zero transmission delay constraint, this paper characterizes the limiting loss
in sum capacity due to the vanishing delay tolerance, termed the delay penalty,
under some prescribed user fairness for transmit rate allocation.
