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Broadband Asynchronous Transfer Mode / Synchronous Transfer
Mode (ATM/STM) switching networks are expected to provide
multimedia services using available network resources. One of
the critical resources is the ATM/STM switching. To support the
offered traffic at an acceptable Quality-of-Service (QoS), it is
important to control access to the switching. Toward this goal,
we develop high-performance access control and bandwidth
allocation for ATM and STM switching, respectively. With
respect to access control for ATM switching, we propose an input
access scheme for input-queued ATM multicast switches, achieving
high system throughput, low packet delay and packet loss
probability. Multicast and unicast packets of each input port
are separately queued. Multicast queues take priority over the
unicast queues, and both types of queues are fairly served based
on a cyclic-priority access discipline. In particular, each
unicast queue is handled on a window-service basis, and each
multicast packet is switched in a one-shot scheduling manner. To
evaluate the performance of the access scheme, we propose
approximate analyses based on a simplified cyclic-priority model
for finite-buffer unichannel and multichannel switches
possessing Bernoulli multicast and unicast arrivals, with
window-service (for unicasting) and one-shot scheduling (for
multicasting) both taken into account. We also show simulation
results to demonstrate the accuracy of the approximate analyses
and the superiority of the scheme over existing schemes with
respect to normalized system throughput, mean packet delay, and
packet loss probability. As for bandwidth allocation for STM
switching, we focus on the bandwidth assignment to voice and
data traffic. Our goal is to analytically determine optimal
bandwidth allocated to voice and data traffic by means of a
queueing model with heterogeneous arrivals and multiple
designated channels. The accuracy of analytical results is
confirmed by simulation results. On the basis of the analysis,
we propose a polynomial-bounded algorithm to construct the
bandwidth assignment paradigms for the assignment of network
bandwidth to voice and data traffic in an effort to guarantee
minimal data delay and voice call blocking probability.
Therefore, the resulting bandwidth assignment assures QoSs in
terms of data delay and voice-call blocking probability under
various network loads. Consequently, we can combine the input
access scheme and the bandwidth assignment paradigms in an
integrated and efficient manner to achieve improved network
utilization and satisfy diverse QoS requirements.
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