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Based on the laws of the known mechanisms of the frequency resources scheduling in the download channel, solution of the problem raised in this paper assures QoS by available resources which directly influent on quality of design of the equipment. The WiMAX resource allocation algorithms determine which users to schedule, how to allocate subcarriers to them, and how to determine the appropriate power...
This paper proposes a scheduling approach for mobile uplink WiMAX system that provides a trade-off between delay requirement satisfaction and throughput maximization. The paper starts by introducing three scheduling algorithms each with a different objective. The first aim is to maximize the throughput of the system, while maintaining the user fairness. The second aim is to satisfy the delay requirements...
Quality of Service (QoS) differentiation measurement provides the ability to evaluate different level of QoS support in 4G networks such as Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX). Many research studies around the world have addressed the QoS Differentiation (QoS-Diff) considerations, however, to the best of our knowledge, only a few have attempted to...
In this paper, we focus on a cognitive network scenario, comprised of a WLAN overlaid on a network with time-scheduled primary users. WiMAX is an example of such primary networks. For time-scheduled primary users simple On-Off traffic model with exponential durations is not valid anymore. In this scenario, the cognitive nodes (CNs) hear downlink map (DL-MAP) and thus, know the frequency and time locations...
In 2011, a project under the Japan Ministry of Internal Affairs and Communications (MIC) conducted measurement campaigns for Worldwide Interoperability for Microwave Access (WiMAX) in different scenarios in order to verify and improve the existing deterministic methods for estimating WiMAX system coverage in Japan [1]. Both outdoor urban and outdoor-indoor scenarios were considered in that project...
This paper presents a propagation model for prediction of path loss and performance parameters (throughput and frame loss) on OFDM-based networks. For this study, measurements on a 5.8 GHz Wimax network were carried out. The proposed model parameters have been adjusted by LS (Least Squares) optimization, using measured data as reference. The results show that the proposed model has a good agreement...
In this paper, we propose a general model for the broadcast polling protocol of unsaturated IEEE 802.16 networks in which each subscriber station has a finite buffer. A subscriber station can be modelled as a M/G/1/K queue with its service time determined by the broadcast polling protocol. The buffer overflow probability, network throughput and packet delay performances are analyzed. The proposed...
The main function of relay station is to enhance the network capacity and extend the coverage area. This paper analyses the performance of relay stations in IEEE 802.16j Mobile Multi-hop Relay (MMR) WiMAX for the transparent and non-transparent modes. The performance of these relays is evaluated based on the throughput for the downlink and uplink transmission using National Chiao Tung University -...
WiMAX is an appropriate wireless technology for networked vehicular applications in intelligent transportation system because of its mobility support at vehicular speeds and its inherent wide coverage. In this paper, performance of a WiMAX (IEEE 802.16e Standard) mobile vehicular network is investigated under different existing empirical propagation models, hand-off scenarios and variation of speed...
Adaptive modulation and coding (AMC) is attracting research interest in wireless multicast broadcast services (MBS). AMC increases the system throughput by utilizing possible good channel states instead of using robust modulation and coding schemes. A model for the AMC in an MBS system with multiple MBS groups is provided, and stochastic analysis using Markov chain is also applied for modeling analysis...
Quality of Service (QoS) differentiation in WiMAX networks is a critically important part of QoS support that has not been properly addressed in the literature. Radio Resource Management (RRM) techniques such as packet scheduling and admission control have been studied by many research groups, and although they claim to provide QoS differentiation in their schemes, no studies have truly evaluated...
Microeconomics models are widely used for revenue estimation through utility functions and deployed pricing schemes. Utility functions represent the QoS (Quality of Service) perception of the user for a given service while the pricing schemes denote the provider charging policy for a service. This paper proposes novel approach for utility estimation for data traffic in WiMAX and aims to investigate...
Worldwide interoperability for microwave access (WiMAX) based wireless metropolitan area networks have recently received wide attention as they support high data rates with great quality of service (QoS) capabilities. In order to support QoS, bandwidth request (BW-REQ) mechanisms are suggested in the WiMAX standard for resource reservation. In this letter we propose a simple and accurate analytical...
A vision of future wireless networks is the coexistence of multiple access network technologies. Different access networks will coexist and the Internet Protocol will be the joint layer. Controlling the resources of these networks is very challenging. This paper deals with two data oriented access networks, the worldwide interoperability for microwave access (WiMAX) and the high speed downlink packet...
In IEEE 802.16e mobile WiMAX system, since mobile stations (MSs) send bandwidth request (BR) messages to base station (BS) during contention period when they need uplink channel to transmit data in the case of multicast polling or broadcast polling, the uplink performance is affected by the size of the contention period in the uplink subframe. The access delay will be increased if the size of the...
In this work we aim to present some results to provide useful guidelines for the deployment of IMT-2000 systems like WiMAX and WCDMA, in terms of uplink cell throughput and cell coverage capacities. For this, a simple link level simulations planning tool, based on four established path loss models applicable to three different Brazilian cities were done and the results shown that WiMAX systems, for...
IEEE 802.16 standards define the power saving of class (PSC) II to save energy for voice over IP (VoIP) services. But the system performance, such as throughput and delay, is affected by load imbalance caused by the parameter setting of sleep mode of VoIP users. To solve this problem, we propose a strategy to balance the load. We arrange the sleep cycle of each VoIP user alternately in this strategy...
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