Fabio Mesiti

Saturation throughput analysis of IEEE 802.11 in the presence of non ideal transmission channel and capture effects

In this paper, we provide a throughput analysis of the IEEE 802.11 protocol at the data link layer in non-saturated traffic conditions taking into account the impact of both transmission channel and capture effects in Rayleigh fading environment. The impact of both non-ideal channel and capture become important in terms of the actual observed throughput in typical network conditions whereby traffic is mainly unsaturated, especially in an environment of high interference. We extend the multi-dimensional Markovian state transition model characterizing the behavior at the MAC layer by including transmission states that account for packet transmission failures due to errors caused by propagation through the channel, along with a state characterizing the system when there are no packets to be transmitted in the buffer of a station. Finally, we derive a linear model of the throughput along with its interval of validity. Simulation results closely match the theoretical derivations confirming the effectiveness of the proposed model.

On the throughput performance of multirate IEEE 802.11 networks with variable-loaded stations: analysis, modeling, and a novel proportional fairness criterion

This paper focuses on multirate IEEE 802.11 Wireless LAN employing the mandatory Distributed Coordination Function (DCF) option. Its aim is threefold. Upon starting from the multi-dimensional Markovian state transition model proposed by Malone et.al. for characterizing the behavior of the IEEE 802.11 protocol at the Medium Access Control layer, it presents an extension accounting for packet transmission failures due to channel errors. Second, it establishes the conditions under which a network constituted by N stations, each station transmitting with its own bit rate, Rd(s), and packet rate, λs, can be assumed loaded. Finally, it proposes a modified Proportional Fairness (PF) criterion, suitable for mitigating the rate anomaly problem of multirate loaded IEEE 802.11 Wireless LANs, employing the mandatory DCF option. Compared to the widely adopted assumption of saturated network, the proposed fairness criterion can be applied to general loaded networks. The throughput allocation resulting from the proposed algorithm is able to greatly increase the aggregate throughput of the DCF, while ensuring fairness levels among the stations of the same order as the ones guaranteed by the classical PF criterion. Simulation results are presented for some sample scenarios, confirming the effectiveness of the proposed criterion for optimized throughput allocation.

On the Linear Behaviour of the Throughput of IEEE 802.11 DCF in Non-Saturated Conditions

We propose a linear model of the throughput of the IEEE 802.11 distributed coordination function (DCF) protocol at the data link layer in non-saturated traffic conditions. We show that the throughput is a linear function of the packet arrival rate (PAR) lambda with a slope depending on both the number of contending stations and the average payload length. We also derive the interval of validity of the proposed model by showing the presence of a critical lambda, above which the station begins operating in saturated traffic conditions. The analysis is based on the multi-dimensional Markovian state transition model proposed by Liaw et al. with the aim of describing the behaviour of the MAC layer in unsaturated traffic conditions. Simulation results closely match the theoretical derivations, confirming the effectiveness of the proposed linear model.

A Model of the IEEE 802.11 DCF in Presence of Non Ideal Transmission Channel and Capture Effects

In this paper, we provide a throughput analysis of the IEEE 802.11 protocol at the data link layer in non- saturated traffic conditions taking into account the impact of both transmission channel and capture effects in Rayleigh fading environment. Impacts of both non-ideal channel and capture become important in terms of the actual observed throughput in typical network conditions whereby traffic is mainly unsaturated, specially in an environment of high interference. We extend the multi-dimensional Markovian state transition model characterizing the behavior at the MAC layer by including transmission states that account for packet transmission failures due to errors caused by propagation through the channel, along with a state characterizing the system when there are no packets to be transmitted in the buffer of a station.

Modelling and Analysis of the Distributed Coordination Function of IEEE 802.11 with Multirate Capability

The aim of this paper is twofold. On one hand, it presents a multi-dimensional Markovian state transition model characterizing the behavior at the medium access control (MAC) layer by including transmission states that account for packet transmission failures due to errors caused by propagation through the channel, along with a state characterizing the system when there are no packets to be transmitted in the queue of a station (to model non-saturated traffic conditions). On the other hand, it provides a throughput analysis of the IEEE 802.11 protocol at the data link layer in both saturated and non-saturated traffic conditions taking into account the impact of both transmission channel and multirate transmission in Rayleigh fading environment. Simulation results closely match the theoretical derivations confirming the effectiveness of the proposed model.

Novel Techniques for Information Reconciliation, Quantum Channel Probing and Link Design for Quantum Key Distribution

In this manuscript, a novel technique for forward error correction based information reconciliation is proposed, exploiting capacity achieving soft-metric based iteratively decoded block codes. The availability of soft metric and information bits reliability is also employed to efficiently perform channel probing and privacy amplification.

On the Throughput Allocation for Proportional Fairness in Multirate IEEE 802.11 DCF

This paper presents a modified proportional fairness (PF) criterion suitable for mitigating the \textit{rate anomaly} problem of multirate IEEE 802.11 Wireless LANs employing the mandatory Distributed Coordination Function (DCF) option. Compared to the widely adopted assumption of saturated network, the proposed criterion can be applied to general networks whereby the contending stations are characterized by specific packet arrival rates,

Soft-metric-based information reconciliation techniques for QKD

\lambda_s

Capacity-Approaching Channel Codes for Discrete Variable Quantum Key Distribution (QKD) Applications

, and transmission rates

Analysis and design of parallel concatenated channel codes for Quantum Key Distribution (QKD) applications

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