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This paper presents a study on cost/benefit analysis regarding WiMAX in Europe. The first step is the engineering process (the cellular planning to be more accurately) in which the number of base stations needed to provide coverage and to ensure the quality of service in a given environment (rural, suburban or urban) is calculated through mathematical models. Following the engineering process, and...
This paper presents a study on cost/benefit analysis regarding WiMAX in Europe. The first step is the engineering process (the cellular planning to be more accurately) in which the number of base stations needed to provide coverage and to ensure the quality of service in a given environment (rural, suburban or urban) is calculated through mathematical models. Following the engineering process, and...
In fixed Worldwide Interoperability for Microwave Access (WiMAX), the contribution from each transmission mode can be incorporated into an implicit formulation to obtain the supported throughput as a function of the carrier-to-interference ratio. This is done by weighting the physical throughput in each concentric coverage ring by the size of the ring. In this paper, multihop cells are formed by a...
A novel coordinated scheduling algorithm for OFDM-based systems in multi-cell scenario is proposed in this paper. The studied algorithm based on the utility function is general for the downlink of networks. The algorithm coordinates the subcarrier assignment over the BS cluster. We first establish the framework for this inter-cell coordinated optimization problem through utility-based method. The...
In the recent years, the WiMAX cellular system has been greatly deployed worldwide as it can provide high data rate to mobile subscribers. However, a few works has been done to characterize the behavior of the WiMAX network in different deployment scenarios. In this paper, we investigate the performance of the WiMAX system in various morphological scenarios, namely, dense urban, urban, and sub-urban...
This paper studies the joint OFDMA resource allocation and QoS routing problem in a hybrid wireless network, which includes an OFDMA based cellular network and an ad-hoc network with many sensor nodes. In such application, each sensor node generates certain amount of data that need to be sent to cellular base station (BS). The cellular nodes act as gateway to forward all the uplink traffic. We formulate...
This paper presents a system level simulator for the evaluation of WiMAX IEEE 802.16m technologies in a multi-cellular environment. This simulator is a quite powerful tool which allows quantifying the benefits of proposed air interface technologies on overall system performance using several metrics. As a case of study, the paper conducts performance evaluation of WiMAX IEEE 802.16m contiguous and...
The IEEE 802.16j WiMAX standard outlines the method for creating a multi-hop mesh network, which can be deployed as a high speed wide-area wireless network. To realize the full potential of such high-speed mesh networks, an efficient wireless radio resource allocation extension has been developed. Load balancing is a technique to spread work between two or more elements, in order to get optimal resource...
This paper studies OFDMA resource allocation for QoS provision in hybrid wireless network, which includes an infrastructure based cellular network and many ad-hoc nodes. The base station has to consider not only those cellular nodes with direct links but also ad-hoc nodes with multihop connectivity. We formulate the optimization problem to maximize the overall throughput, while satisfying the individual...
Femtocells are a promising solution for the provision of high indoor coverage and capacity. Furthermore, OFDMA-based femtocells have proven to be highly versatile when dealing with cross-layer co-channel interference thanks to the allocation of frequency subchannels. However, concerns still exist related to the impact of the different access methods to femtocells in an overlayed network. Femtocells...
In recent years, smart antenna technologies are of ever-increasing interest to boost the capacity of existing and future wireless systems. Several standards support these techniques such as the wireless metropolitan area network IEEE 802.16 (WiMAX) and IMT-Advanced candidates. In applying smart antenna beamforming and Space Division Multiple Access (SDMA) techniques, adaptive antennas are able to...
Multi-hop relays will be deployed as one of the promising technologies for future cellular networks to enhance the performance of cell boundary users and to reduce deployment and operating cost. However, they have many challenges which include signaling overhead and latency in order to be practically deployed due to a hierarchical multi-hop structure, and the situation is much severer in uplink case...
This article addresses downlink resource allocation in multi-cell OFDMA mobile WiMAX systems using zone switching diversity method. We propose to use fractional frequency reuse for guaranteeing the quality of service for different service flows (SFs) in the system. Our approach includes an architecture which coordinates the allocation of resources in terms of slots (the basic allocation unit in time...
Interference over thermal noise (IoT) level control is crucial to system performance and link quality in interference limited scenarios, especially for cell edge users. This paper proposes a simple and novel technique for IoT control by adopting the concept of load control where load is defined as the total interference impacting on neighbor sectors. The proposed technique is able to control IoT level...
This work centers on the downlink scheduling algorithm for such cellular wireless networks with relays as IEEE802.16j. We propose an efficient algorithm to discover concurrent transmission scenarios under a multihop relay environment, while applying the back-pressure flow control mechanism to reflect the dynamic queue status of each relay station. Then, we develop a linear programming algorithm for...
Relay and RF repeater technologies are considered as an effective means to improve the system throughput and coverage performance of cellular OFDMA systems. In this paper, we provide a comprehensive system level comparison of relay and RF repeater based systems utilizing multiple antenna techniques. For relay-based systems we consider a novel relay mode selection procedure that allows intelligent...
So far we have developed a disaster information network which is very effective and robust using wireless network. In this paper, we introduce a mobile network for disaster communication network by combination of different wireless LANs and mobile network. Currently available wireless LANs such as IEEE802.11b,g,j,n, IEEE802.16 (WiMAX), cellular network are combined with a mobile router and loaded...
Motivated by the advantages of relaying, multi-hop relay (MR) architecture has been considered in the IEEE 802.16 networks, where the relay stations (RSs) were introduced into the conventional cellular networks to exploiting spatial reuse and to combating the shadowing at high radio frequency. In the current MR networks, the communication path has not been optimized, especially for two SSs attached...
This paper investigates the performance and capacity of a WiMAX 802.16e cellular system deployed via High Altitude Platform (HAP WiMAX) through extensive simulations. HAP WiMAX link performance is evaluated for a wide range of channel conditions in terms of elevation angle and signal to noise ratio (SNR) through a comprehensive link level simulator based on 802.16e. The obtained results are then used...
WiMaX is the commercial name for the 4G OFDM based wireless broadband data transmission standard 802.16, developed by IEEE ([1] and [2]). It is currently being deployed in several countries around the world. Sub-channels (which are the basic unit of resource allocation) are formed by grouping together sub-carriers in one of two formats - PUSC or AMC. In PUSC the set of sub-carriers in a sub-channel...
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