14,589 research outputs found
Scheduling delay-sensitive and best-effort traffics in wireless networks
In this paper we propose a novel wireless scheduling algorithm for delay-sensitive (DS) and best-effort (BE) traffics. Unlike the majority of the previous wireless scheduling, where the wireless links are modeled as having only two states, our algorithm is applicable to links with multiple states. For DS flows, the algorithm is capable of providing statistical delay violation bounds. Such bounds are derived, analytically, using the idea of the statistical service envelope. For BE flows, we propose a new notion of fairness, called long-term link-quality-weighted outcome-fair, which we believe is more suited to wireless networks than pure outcome-fair or effortfair. The algorithm achieves a balance between bandwidth efficiency requirement and fairness requirement, and guarantees minimal goodput levels for BE flows.published_or_final_versio
Statistical Delay Bound for WirelessHART Networks
In this paper we provide a performance analysis framework for wireless
industrial networks by deriving a service curve and a bound on the delay
violation probability. For this purpose we use the (min,x) stochastic network
calculus as well as a recently presented recursive formula for an end-to-end
delay bound of wireless heterogeneous networks. The derived results are mapped
to WirelessHART networks used in process automation and were validated via
simulations. In addition to WirelessHART, our results can be applied to any
wireless network whose physical layer conforms the IEEE 802.15.4 standard,
while its MAC protocol incorporates TDMA and channel hopping, like e.g.
ISA100.11a or TSCH-based networks. The provided delay analysis is especially
useful during the network design phase, offering further research potential
towards optimal routing and power management in QoS-constrained wireless
industrial networks.Comment: Accepted at PE-WASUN 201
On the Effective Capacity of Two-Hop Communication Systems
In this paper, two-hop communication between a source and a destination with
the aid of an intermediate relay node is considered. Both the source and
intermediate relay node are assumed to operate under statistical quality of
service (QoS) constraints imposed as limitations on the buffer overflow
probabilities. It is further assumed that the nodes send the information at
fixed power levels and have perfect channel side information. In this scenario,
the maximum constant arrival rates that can be supported by this two-hop link
are characterized by finding the effective capacity. Through this analysis, the
impact upon the throughput of having buffer constraints at the source and
intermediate-hop nodes is identified.Comment: submitted to ICC 201
Dynamic Scheduling for Delay Guarantees for Heterogeneous Cognitive Radio Users
We study an uplink multi secondary user (SU) system having statistical delay
constraints, and an average interference constraint to the primary user (PU).
SUs with heterogeneous interference channel statistics, to the PU, experience
heterogeneous delay performances since SUs causing low interference are
scheduled more frequently than those causing high interference. We propose a
scheduling algorithm that can provide arbitrary average delay guarantees to SUs
irrespective of their statistical channel qualities. We derive the algorithm
using the Lyapunov technique and show that it yields bounded queues and satisfy
the interference constraints. Using simulations, we show its superiority over
the Max-Weight algorithm.Comment: Asilomar 2015. arXiv admin note: text overlap with arXiv:1602.0801
Energy and bursty packet loss tradeoff over fading channels: a system-level model
Energy efficiency and quality of service (QoS) guarantees are the key design goals for the 5G wireless communication systems. In this context, we discuss a multiuser scheduling scheme over fading channels for loss tolerant applications. The loss tolerance of the application is characterized in terms of different parameters that contribute to quality of experience (QoE) for the application. The mobile users are scheduled opportunistically such that a minimum QoS is guaranteed. We propose an opportunistic scheduling scheme and address the cross-layer design framework when channel state information (CSI) is not perfectly available at the transmitter and the receiver. We characterize the system energy as a function of different QoS and channel state estimation error parameters. The optimization problem is formulated using Markov chain framework and solved using stochastic optimization techniques. The results demonstrate that the parameters characterizing the packet loss are tightly coupled and relaxation of one parameter does not benefit the system much if the other constraints are tight. We evaluate the energy-performance tradeoff numerically and show the effect of channel uncertainty on the packet scheduler design
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