Queue Length Analysis Research Articles

ПОРІВНЯЛЬНИЙ АНАЛІЗ ЕФЕКТИВНОСТІ СХЕМ ВИЯВЛЕННЯ ПЕРЕВАНТАЖЕННЯ ТЕЛЕКОМУНІКАЦІЙНОЇ МЕРЕЖІ

The scheme of congestion detection and regulation of input data flow based on the analysis of the sensitivity function of the telecommunication network performance is considered. The gradient of the sensitivity function characterizes the rate of change of this function and provides the optimal direction for adjusting the speed of the data source. To determine the sensitivity function, the use of a simple neural network model of a dynamic system is proposed. Determination of the gradient on the current value of the sign of the sensitivity function of the performance indicator is based on the algorithm of additive increase / multiple decrease. This algorithm is an alternative to the system of overload prediction and flow control, based on the control of the current value of the queue in comparison with a given threshold. The neural model for multi-step prediction of the queue state on the side of the telecommunication network receiver is considered. The results of comparative analysis of congestion control methods based on queue length analysis and sensitivity analysis with 1-step and 3-step horizons predicting network status are presented. The study was conducted for sinusoidal function of the narrow queue. It is shown that the key performance indicators for the sensitivity function-based scheme are better than for the queue length analysis scheme. The queue size-based scheme is more sensitive to changes in queue maintenance speed, and data source speed fluctuations are less sensitive for the sensitivity-based scheme. For systems based on sensitivity function analysis, a 3-step horizon predictor provides better performance and a smaller maintenance queue than a 1-step horizon scheme.

Konsumsi Bahan Bakar Akibat Buka Tutup Arus Lalu Lintas pada Jalan. Jl. Bts. Kota Lhokseumawe, Aceh Utara – Lhoksukon Km. 280 Provinsi Nanggroe Aceh Darussalam

This study aims to determine the effect of vehicle queues on fuel consumption due to the opening and closing of traffic flows caused by drainage channels project throughout October 2020 on. Jalan. Bts. Lhokseumawe City/North Aceh – Lhoksukon Km. 280. The queue length analysis was calculated based on vehicle traffic flow in locations that have not been affected by the existence of open/close traffic flow activities and analysis of fuel consumption based on the length of delay and the number of vehicle queues using LAPI-ITB formula. The results showed that the queue of vehicles due to opening and closing of vehicle lanes for 6 hours (12.00 – 18.00 WIB) on holidays was 23% larger than the queue on weekdays. Vehicle queues for 6 hours on holidays cause additional vehicle fuel consumption for light vehicles (LV) of 424,15 liters, heavy vehicles (HV) of 53,09 liters, and motorcycles (MC) of 203,24 liters and on weekdays causes additional fuel consumption for light vehicles (LV) as much as 342,66 liters, Heavy vehicles (HV) as much as 35,85 liters, and motorcycles (MC) as much as 203,24 liters. Loss of fuel use due to queues caused by opening and closing roads on Jalan. Bts. Lhokseumawe City/North Aceh – Lhoksukon Km. 280 for 6 hours (12.00 – 18.00 WIB) on weekdays is 4.402.185,00 and on holidays it is Rp. 5.541.065,00.

Waiting time and queue length analysis of Markov-modulated fluid priority queues

This paper considers a multi-type fluid queue with priority service. The input fluid rates are modulated by a Markov chain, which is common for all fluid types. The service rate of the queue is constant. Various performance measures are derived, including the Laplace–Stieltjes transform and the moments of the stationary waiting time of the fluid drops and the queue length distributions. An Erlangization-based numerical method is also provided to approximate the waiting time and the queue length distributions up to arbitrary precision. All performance measures are formulated as reward accumulation problems during busy periods of simple Markovian fluid flow models, for which efficient matrix-analytic solutions are provided, enabling us to solve large models with several hundred states.

Mitigation of Packet Loss Using Data Rate Adaptation Scheme in MANETs

Node’s mobility, bursty data traffic, and dynamic nature of the network make congestion avoidance and control a challenging task in Mobile Adhoc Networks (MANETs). Congestion results in high packet loss rate, increased delays, and wastage of network resources due to re-transmissions. In this paper, we propose In-route data rate adaptation to avoid packet loss. Proposed scheme is based on the analysis of queue length of the forwarding nodes, number of data source nodes, and rate of link changes. In proposed technique, queue length of forwarding nodes is communicated periodically to the neighbor nodes using existing control messages of the underlying routing protocol. Keeping in view the queue length of forwarding nodes, number of data source nodes, and rate of link changes, initially the intermediate nodes buffer the incoming data packets upto some threshold and then, gradually shift the effect of congestion to the data source nodes. Then, the source node adapts its sending data rate to avoid congestion and to ensure reliable data communication. We have performed simulations in NS-2 simulator by varying different network metrics such as data rate, number of source nodes, and node speed. Results show that proposed technique improves network performance in terms of packet delivery ratio upto 15 %, reduction of average end-to-end delay and packet loss due to interface queue overflow upto 25 % and 14 % respectively, as compared to the static rate adaptation scheme.

Queue length analysis of a Markov-modulated vacation queue with dependent arrival and service processes and exhaustive service policy

The paper introduces a class of vacation queues where the arrival and service processes are modulated by the same Markov process, hence they can be dependent. The main result of the paper is the probability generating function for the number of jobs in the system. The analysis follows a matrix-analytic approach. A step of the analysis requires the evaluation of the busy period of a quasi birth death process with arbitrary initial level. This element can be useful in the analysis of other queueing models as well. We also discuss several special cases of the general model. We show that these special settings lead to simplification of the solution.

Analysis and optimization of vacation and polling models with retrials

We study a vacation-type queueing model, and a single-server multi-queue polling model, with the special feature of retrials. Just before the server arrives at a station there is some deterministic glue period. Customers (both new arrivals and retrials) arriving at the station during this glue period will be served during the visit of the server. Customers arriving in any other period leave immediately and will retry after an exponentially distributed time. Our main focus is on queue length analysis, both at embedded time points (beginnings of glue periods, visit periods and switch- or vacation periods) and at arbitrary time points.

English

English

DELAY IN A TANDEM QUEUEING MODEL WITH MOBILE QUEUES: AN ANALYTICAL APPROXIMATION

In this paper, we analyze the end-to-end delay performance of a tandem queueing system with mobile queues. Due to state-space explosion, there is no hope for a numerical exact analysis for the joint-queue-length distribution. For this reason, we present an analytical approximation that is based on queue-length analysis. Through extensive numerical validation, we find that the queue-length approximation exhibits excellent performance for light traffic load.

Steady-State Queue Length Analysis of a Batch Arrival Queue under N-Policy with Single Vacation and Setup Times

This paper investigates the steady state property of queue length for a batch arrival queue under N-policy with single vacation and setup times. When the system becomes empty, the server is turned off at once and takes a single vacation of random length . When he returns, if the queue length reaches or exceeds threshold , the server is immediately turned on but is temporarily unavailable due to a random setup time before offering service. If not, the server stays in the system until the queue length at least being . We derive the system size distribution and confirm the stochastic decomposition property. We also derive the recursion expressions of queue length distribution and other performance measures. Finally, we present some numerical examples to show the analytical results obtained. Sensitivity analysis is also performed.

Queue-Length Analysis of Continuous-Time Polling System with Vacations Using M-Gated Services

In this paper we consider the polling system with multiple vacations an bulk arrival using M-gated services in continuous time. By the imbedded Markov chain theory, the generating functions of queue length at the station is obtained. Then computational equations are explicitly determined for the mean queue length. Especially we can obtain some corresponding results under some especial cases. The results reveal that our system model can guarantee better QoS and system stability, and it has better efficiency than that of traditional gated service.

Analysis of a time-limited service priority queueing system with exponential timer and server vacations

We consider a multi-class priority queueing system with a non-preemptive time-limited service controlled by an exponential timer and multiple (or single) vacations. By reducing the service discipline to the Bernoulli schedule, we obtain an expression for the Laplace-Stieltjes transform (LST) of the waiting time distribution via an iteration procedure, and a recursive scheme to calculate the first two moments. It is noted that we have to select embedded Markov points based on the service beginning epochs instead of the service completion epochs adopted for most of M/G/1 queueing analyses. Through the queue-length analysis, we obtain a decomposition form for the LST of the waiting time in each queue having the exhaustive service.

Queue length analysis of batch arrival queues under bilevel threshold control with early set-up

Queue length analysis of batch arrival queues under bilevel threshold control with early set-up

Queue length analysis of batch arrival queues under bilevel threshold control with early set-up

The queue length process of MX/G/1 queues under bilevel threshold control and early set-up withlwithout server vacations is outlined. The stationary probability generating functions of the queue length distributions under a unified framework are also derived. Also derived are the mean queue length of each system.

Queue Length Analysis of Non-Preemptive DiffServ Networks

Abstract Considering that differential services (DiffServ) networking technologies are under development to support diverse quality-of-service (QoS) requirements, this letter provides the upper and lower bounds of the expected queue length for each priority class in a non-preemptive priority queueing system. The results illustrate the possible performance gain in terms of buffer requirement and/or waiting time that Diffserv networks can provide compared to those that do not support service differentiation.

Realistic modeling of clinical laboratory operation by computer simulation

An important objective of laboratory management is to adjust the laboratory's capability to the needs of patients' care as well as economy. The consequences of management may be changes in laboratory organization, equipment, or personnel planning. At present only one's individual experience can be used for making such decisions. We have investigated whether the techniques of operations research could be transferred to a clinical laboratory and whether an adequate simulation model of the laboratory could be realized. First we listed and documented the system design and the process flow for each single laboratory request. These input data were linked by the simulation model (programming language SIMSCRIPT II.5). The output data (turnaround times, utilization rates, and analysis of queue length) were validated by comparison with the current performance data obtained by tracking specimen flow. Congruence of the data was excellent (within +/- 4%). In planning experiments we could study the consequences of changes in order entry, staffing, and equipment on turnaround times, utilization, and queue lengths. We conclude that simulation can be a valuable tool for better management decisions.