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We investigate the delay of the discrete-time slotted ALOHA network where the sources are distributed as a Poisson point process. Each of the sources is paired with a destination at a given distance and a buffer of infinite capacity. The network is assumed to be static, i.e., the sources and the destinations are generated at first and remain static during all the time slots. Employing tools from queueing...
This paper proposes the performance comparison for optimal traffic signal controls based on the following two frameworks: M/M/1 and D/D/1 queueing models, and Q-learning approach. Firstly, using the M/M/1 and D/D/1 models, the optimal split derivation has been obtained to minimise the mean waiting time of an intersection. Additionally, the Q-learning framework has been proposed in conjunction with...
Wireless sensor networks usually consist of a large number of very small, energy-constrained sensor nodes. The nodes capture information from their immediate environment to send it to a destination node (sink) in a timely manner.
In a wireless multi-hop or mesh network, stations which are connected to Mesh Access Point (MAP) lesser hops from the gateway are expected to enjoy higher throughput and lower delay than stations connected to the MAP further hops away. To solve this issue, we introduce a technique to determine network layer queue size limit of ingress radio interfaces in the multi-radio MAPs. The intention is to partially...
Wireless Sensor Networks (WSNs) usually consist of hundreds of sensor nodes scattered in a geographical area and one or multiple sink(s) collecting information. The special design and character of sensors and their applications make WSNs different from traditional networks. These characteristics pose great challenges for architecture and protocol design, performance modeling and implementation. Accurately...
This paper presents a problem of queueing theoretic performance modeling and analysis of Orthogonal Frequency Division Multiple Access (OFDMA) under broad-band wireless networks. We consider a single-cell WiMAX environment in which the base station allocates subchannels to the subscriber stations in its coverage area. The subchannels allocated to a subscriber station are shared by multiple connections...
Low Earth Orbit (LEO) satellite networks are expected to provide a variety of multimedia applications. In order to satisfy different QoS requirements and optimize utilization of network resources, a novel traffic classification routing algorithm (TCR) is proposed. The key technique of TCR is investigating the traffic classification link-cost metrics (TCM) for different traffic classes, which selects...
This paper presents the results of the performance evaluation concerning 3G/3GPP IP Multimedia Subsystem (IMS) applications deployed in a wireless multi-hop network controlled by the Delay-Aware Network Utility Maximization System (DANUMS). The main purpose of the DANUM system is simultaneous service of files and multimedia streams, i.e., types of traffic of different delay requirements. DANUMS combines...
In this study, we aim to analyse the relationship between various characteristics of a communication system with data and voice call requests. Queuing theory and Markov chain analysis are effectively used for this purpose. Such a study is useful for understanding how the proposed mathematical models behave which represents a system with integrated voice and data calls in homogenous wireless networks...
In this paper we study WRR-based scheduling algorithms. According to whether packet information is used, we classify them into three classes: Queue-based WRR, Packet-based WRR and Hierarchical WRR. Based on UIWRR (Uniformly Interleaved WRR) which is a kind of Queue-based WRR, we propose a new algorithm called TIIWRR(Interleaved WRR based on ideal Time Interval) in order to overcome collision when...
In order to optimize pedestrian signal cycle, queuing theory and probability theory were used to build delay model of pedestrian-vehicle system, and then put forward the calculation method of conversion coefficient of pedestrian crowd and vehicles. The delays of pedestrian and vehicle were calculated by equilibrium phase delay formula. The critical volume curves of pedestrian signal for pedestrian...
This paper presented the method of determining critical traffic volume for installing traffic signal based on actual traffic situation in China. Considering the condition that all approach traffic streams have equal right to pass through at some special unsignalized intersections, the model of Motorcade Analysis Method was improved by introducing the lost time of saturated discharging, and then the...
We study a multiple-access system with a primary user (PU) and a secondary user (SU) utilizing the same frequency band and communicating with a common receiver. Both users transmit with a fixed transmission rate by employing a channel inversion power control scheme. The SU transmits with a certain probability that depends on the sensing outcome, its queue length and whether it has a new packet arrival...
This article examines the impact of event values (restaurant or dental hospital) on the length of waiting time or waiting time Information effect. Experiment 1 (focuses on pre-process waiting) finds the effect of the length of waiting time or waiting time Information on mood states will be moderated by the event values. Experiment 2 (focuses on post-process waiting) further identified the effect of...
In this paper, a unified analytical model is established to analyze the performance of backoff schemes in IEEE 802.11 DCF networks under saturation condition. It is shown that BEB suffers from deteriorated queueing performance due to a large second moment of access delay, and a key to reduce the second moment lies in the growth rate of the backoff window size. Quadratic Backoff (QB) is further proposed,...
A learning automata (LA) is an automaton that interacts with a random environment, having as its goal the task of learning the optimal action based on its acquired experience. here, we present a ERQD algorithm for congestion avoidance in wired networks. The main aim of this algorithm is to optimize the value of the average size of the queue used for congestion avoidance and to consequently reduce...
Cognitive radio network (CRN) users are inherently expected to experience widely-varied delays due to the uncertainty in wireless channel availability. Supporting delay sensitive real-time services through CRNs, so that visitors are allowed to experience full-scale networking services by opportunistically sharing the spectrum from a number of existing networks without impacting on the primary users,...
We study the privacy compromise due to a queuing side channel which arises when a resource is shared between two users in the context of packet networks. The adversary tries to learn about the legitimate users activities by sending a small but frequent probe stream to the shared resource (e.g., a router). We show that for current frequently used scheduling policies, the waiting time of the adversary...
In this paper, we study the performance of a two-tier primary-secondary network based on IEEE 802.11 broadcast scheme. We assume that a number of primary and secondary users coexist in the radio environment and share a single band. To protect the primary users' priority, the secondary users are allowed to contend for the channel only if they sense it idle for a certain sensing time. Considering an...
This paper presents S-SFQ which is a single queue design and implementation of the well-known Start-time Fair Queueing (SFQ). This aggregate queue orders packets based on their timestamps rather than order of arrivals. Through simulation, we show the performance gains of S-SFQ over other default single-queue schemes such as RED and FIFO in terms of link utilization and flow fairness. When sources...
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