2,675 research outputs found
Discrete-time queues with zero-regenerative arrivals: moments and examples
In this paper we investigate a single-server discrete-time queueing system with single-slot service times. The stationary ergodic arrival process this queueing system is subject to, satisfies a regeneration property when there are no arrivals during a slot. Expressions for the mean and the variance of the queue content in steady state are obtained for this broad class which includes among others autoregressive arrival processes and M/G/infinity-input or train arrival processes. To illustrate our results, we then consider a number of numerical examples
The effective bandwidth problem revisited
The paper studies a single-server queueing system with autonomous service and
priority classes. Arrival and departure processes are governed by marked
point processes. There are buffers corresponding to priority classes,
and upon arrival a unit of the th priority class occupies a place in the
th buffer. Let , denote the quota for the total
th buffer content. The values are assumed to be large, and
queueing systems both with finite and infinite buffers are studied. In the case
of a system with finite buffers, the values characterize buffer
capacities.
The paper discusses a circle of problems related to optimization of
performance measures associated with overflowing the quota of buffer contents
in particular buffers models. Our approach to this problem is new, and the
presentation of our results is simple and clear for real applications.Comment: 29 pages, 11pt, Final version, that will be published as is in
Stochastic Model
Channel-Aware Random Access in the Presence of Channel Estimation Errors
In this work, we consider the random access of nodes adapting their
transmission probability based on the local channel state information (CSI) in
a decentralized manner, which is called CARA. The CSI is not directly available
to each node but estimated with some errors in our scenario. Thus, the impact
of imperfect CSI on the performance of CARA is our main concern. Specifically,
an exact stability analysis is carried out when a pair of bursty sources are
competing for a common receiver and, thereby, have interdependent services. The
analysis also takes into account the compound effects of the multipacket
reception (MPR) capability at the receiver. The contributions in this paper are
twofold: first, we obtain the exact stability region of CARA in the presence of
channel estimation errors; such an assessment is necessary as the errors in
channel estimation are inevitable in the practical situation. Secondly, we
compare the performance of CARA to that achieved by the class of stationary
scheduling policies that make decisions in a centralized manner based on the
CSI feedback. It is shown that the stability region of CARA is not necessarily
a subset of that of centralized schedulers as the MPR capability improves.Comment: The material in this paper was presented in part at the IEEE
International Symposium on Information Theory, Cambridge, MA, USA, July 201
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