1,676 research outputs found

    Efficient Resource Management Mechanism for 802.16 Wireless Networks Based on Weighted Fair Queuing

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    Wireless Networking continues on its path of being one of the most commonly used means of communication. The evolution of this technology has taken place through the design of various protocols. Some common wireless protocols are the WLAN, 802.16 or WiMAX, and the emerging 802.20, which specializes in high speed vehicular networks, taking the concept from 802.16 to higher levels of performance. As with any large network, congestion becomes an important issue. Congestion gains importance as more hosts join a wireless network. In most cases, congestion is caused by the lack of an efficient mechanism to deal with exponential increases in host devices. This can effectively lead to very huge bottlenecks in the network causing slow sluggish performance, which may eventually reduce the speed of the network. With continuous advancement being the trend in this technology, the proposal of an efficient scheme for wireless resource allocation is an important solution to the problem of congestion. The primary area of focus will be the emerging standard for wireless networks, the 802.16 or “WiMAX”. This project, attempts to propose a mechanism for an effective resource management mechanism between subscriber stations and the corresponding base station

    On analyzing the intra-frame power saving potentials of the IEEE 802.16e downlink vertical mapping

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    Worldwide Interoperability for Microwave Access (WiMAX) is generally considered as a competitive candidate networking technology for the realization of the 4G vision. Among the key factors towards its successful and widespread deployment are the effective support of mobility and the provision of mechanisms for enabling service access at a high quality level in an efficient and cost-effective manner. Nonetheless, this effort should take into account and adequately address strict and severe energy limitations that the mobile devices are currently facing. Power saving constitutes an issue of vital importance, as mobile terminals continue to incorporate more and more functionalities and energy-hungry features in order to support the ever increasing user requirements and demands. The standard employs variations of power saving classes in a frame-to-frame basis, while recent power saving mechanisms proposed in related research literature limit their activity in whole frames, neglecting, thus, the intra-frame power saving capabilities. In this work, the intra-frame energy conservation potentials of the mobile WiMAX network are studied and a novel analytical approach is provided, focusing on the downlink direction where the bandwidth allocation involves idle intervals and dynamic inactivity periods. Specifically, we endeavour to accurately analyse the potential energy conservation capabilities in an intra-frame point of view, applying the well-known simple packing algorithm to distribute the available bandwidth to the various subscribers. Our analytical findings are thoroughly cross-validated via simulation, providing clear insights into the intra-frame energy reduction capabilities

    Multicast broadcast services support in OFDMA-based WiMAX systems [Advances in mobile multimedia]

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    Multimedia stream service provided by broadband wireless networks has emerged as an important technology and has attracted much attention. An all-IP network architecture with reliable high-throughput air interface makes orthogonal frequency division multiplexing access (OFDMA)-based mobile worldwide interoperability for microwave access (mobile WiMAX) a viable technology for wireless multimedia services, such as voice over IP (VoIP), mobile TV, and so on. One of the main features in a WiMAX MAC layer is that it can provide'differentiated services among different traffic categories with individual QoS requirements. In this article, we first give an overview of the key aspects of WiMAX and describe multimedia broadcast multicast service (MBMS) architecture of the 3GPP. Then, we propose a multicast and broadcast service (MBS) architecture for WiMAX that is based on MBMS. Moreover, we enhance the MBS architecture for mobile WiMAX to overcome the shortcoming of limited video broadcast performance over the baseline MBS model. We also give examples to demonstrate that the proposed architecture can support better mobility and offer higher power efficiency

    NS-3 Simulation of WiMAX Networks

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    Simulation is a powerful tool for analysis and improvement of networking technologies, and many simulation packages are available. One that is growing in popularity is NS-3, the successor to the popular NS-2. It is a significant departure from NS-2, and offers many advantages and disadvantages. In this thesis, we translate and update a sophisticated WiMAX simulation model from NS-2 to NS-3, and use this experience to investigate the major differences between NS-2 and NS-3, and the relative strengths of each package. We then use the NS-3 simulation model to provide analysis on a new WiMAX OFDMA downlink subframe mapping algorithm

    WIMAX LINK PERFORMANCE ANALYSIS FOR WIRELESS AUTOMATION APPLICATIONS

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    Wireless broadband access technologies are rapidly growing and a corresponding growth in the demand of its applicability transcends faster internet access, high speed file download and different multimedia applications such as voice calls, video streaming, teleconferencing etc, to industrial operations and automation. Industrial and automation systems perform operations that requires the transmission of real time information from one end to another through high-performance wireless broadband communication links. WiMAX, based on IEEE 802.16 standard is one of the wireless broadband access technologies that has overcome location, speed, and access limitations of the traditional Digital Subscriber Line and Wireless Fidelity, and offers high efficient data rates. This thesis presents detailed analysis of operational WiMAX link performance parameters such as throughput, latency, jitter, and packet loss for suitable applicability in wireless automation applications. The theoretical background of components and functionalities of WiMAX physical and MAC layers as well as the network performance features are presented. The equipment deployed for this field experiment are Alvarion BreeZeMAX 3000 fixed WiMAX equipment operating in the 3.5 GHz licensed band with channel bandwidth of 3.5 MHz. The deployed equipment consisting of MBSE and CPE are installed and commissioned prior to field tests. Several measurements are made in three link quality scenarios (sufficient, good and excellent) in the University of Vaasa campus. Observations and results obtained are discussed and analyzed.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format
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