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Worldwide Interoperability for Microwave Access (WiMAX) is a broadband wireless access (BWA) technology. It provides high data rate and multimedia service. It also supports Quality of Service (QoS) for various types of application. In this network, it is important to allocate appropriate resource to different class of service to guarantee the delay of real-time service and avoid the starvation of...
The study of the end-to-end QoS (Quality of Service) features of wireless networks may give to mobile operators ways to manage the network infrastructures from a trustworthy and robustness perspective, to optimize the network usage and guarantee desired quality of services to end user. In this paper a review of studies on end-to-end QoS in LTE networks is presented. The most important features of...
In WiMAX architecture to avoid congestion at the base station, a mechanism namely WiMAX Fair Intelligent Congestion Control (WFICC) was proposed in [11]. WFICC ensures that the traffic is scheduled in such a way that the base station output buffer operates around a target operating point, without violating the Quality of Service (QoS) requirements of connections. However, only preliminary results...
This paper investigates cell zooming and relaying in conjunction with the use of opportunistic sleep modes to save energy at times of low load in WiMAX network deployments. It performs extensive propagation measurements in a hilly area of Covilhã, Portugal, in order to present a realistic and topographically challenging scenario in which to perform dynamic optimizations. It describes these measurements...
Public transportation is vital in everyday life. As a consequence, the increasing need for intelligent surveillance systems over public transportation provides promising areas for wireless vehicular communication research for in-tunnel applications. This paper particularly emphasizes on tunnel implementation regarding to a prototype surveillance system on railway environments based on autonomous,...
The IEEE 802.16j Mobile Multi-hop Relay (MMR) WiMAX networks allow the extension of the coverage area of a WiMAX network by deploying a relay station (RS). In WiMAX, subscriber station (SS) located non Line-of-sight (LOS) with the BS suffers from deterioration in service. In this paper, we investigate the usage of RS in improving the per-user throughput. Simulations are performed using OPNET Modeler...
Decisions for vertical handover in heterogeneous mobile and wireless networks are very important because they impact the QoS of the mobile users and they are also dependent upon the mobility. Choosing the right radio interface at a given moment when mobile terminal has more than one available wireless or mobile network can be based on various factors beside signal strength. In this paper we propose...
In this paper, we have observed that the performance analysis of one of the most challenging security issue for wireless network i.e. Black hole attack. WiMAX-WLAN interface will play a important role in the NGN (Next generation Network) scenario. This attack is possible in WiMAX-WLAN interface network i.e. in current scenarios. In this paper we analyzed the performance analysis of Performance Analysis...
This paper proposes an efficient downlink resource allocation scheme for Orthogonal Frequency Division Multiple Access based WiMAX systems using the Adaptive Modulation and Coding mode operation. Given a set of user requests, the proposed algorithm determines the modulation scheme and allocates a two-dimensional (time and frequency) burst to each user. It is known that finding the optimal solution...
This paper describes field evaluation results on a mobile WiMAX network and network services in Azumino city. An experimental mobile WiMAX network has been deployed in Azumino city so as to improve the sophistication of public services. Overview of the deployed network and field experimental results on both throughput in UDP (User Datagram Protocol) layer and received power are denoted in this paper...
The use of wireless technologies in high voltage environments is increasing with the growing need for monitoring and preventive maintenance in electricity utilities. The feasibility of deploying wireless technologies in high voltage environments such as substations is addressed in this paper. High voltage substations are different from common area due to the presence of many metallic structures causing...
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 this paper, we focus on the bandwidth allocation issue in wireless access networks, which are made up of Ethernet Passive Optical Network (EPON) and Worldwide Interoperability for Microwave Access (WiMAX) networks, i.e., Fiber-Wire (FiWi) networks. Since the bandwidth allocation scheme largely determines the performance of the entire wireless access network, in the past decades, researchers have...
In this paper, we have investigated the use of transparent relay station to improve the throughput of the IEEE 802.16j Mobile Multi-hop Relay (MMR) WiMAX network. Simulations are performed using OPNET Modeler, and only VoIP application is considered. The result shows transparent relay station does improve the throughput of WiMAX network with some coverage extension.
IEEE 802.16e based WIMAX is a promising technology for broadband wireless access (BWA) because of its high scalability, large coverage area, high data rates and low cost of system deployment. Unlike wireless Local Area Networks (LANs), WIMAX network supports Quality of Service (QoS) to different types of network traffic and has introduced several mechanisms at Medium Access Control (MAC) layer to...
LTE (3GPP Release8) and Mobile WiMAX (IEEE 802.16e) are discussed extensively as choices for the next generation of mobile broadband technologies. In this paper, LTE and Mobile WiMAX are analyzed comprehensively from a physical layer performance point of view for different antenna diversity modes in downlink and uplink transmissions. The objective of this study is to fill the current gaps in published...
Layered and cooperative elements such as femto-cells and relays can improve performance or energy efficiency in mobile networks; however, they consume energy per se and their durations in operational state must therefore be minimised. This paper investigates the use of relays in WiMAX network deployments and concentrates on the cost/revenue performance and energy efficiency trade-off in such cases...
WiMAX is the very well known 802.16 technology certified by the WiMAX forum. However, it is not largely known that the IEEE 802.16 standard foresees an option to use the technology on the license-free 5 GHz band. For such a use, the EIRP requirements for the 5 GHz band must be respected. The use of WiMAX technology in that band may be an interesting option for wireless backhauling and wireless mesh...
Wireless mesh networks are at the forefront of the technological drive. Achieving high system throughput in these networks is challenging due to interference which limits concurrent transmissions. In this paper we study routing and link scheduling in time division multiple access networks free of contention. We extend the work in the literature in several ways: (a) we present simple joint routing...
The use of smart antenna systems in WiMAX vehicular communications increases the coverage and throughput thus reducing the infrastructure costs, creates the lower levels support for new high level innovative services and may increase applications security. However, new challenges appear related to interference range, neighbor discovery, mobility management, scheduling issues, in addition to some already...
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