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In cellular OFDMA networks, there exists a fundamental trade-off between the achievable cell capacity and the degree of fairness among the users in the cell. Several scheduling algorithms have been proposed which try to balance this tradeoff. The parameterization of these scheduling algorithms to achieve a certain desired fairness level is non-trivial. We show that the optimal fairness parameter settings...
Received video quality is dependent on the available link rate and the packet loss rate, which are inter-related in a busy network link. Even low packet loss ratios (PLRs) can significantly reduce the video quality. In this paper, a packet level parity FEC is applied to the video stream in order to reduce the video PLR. A constant gross data rate is assumed, such that adding a FEC leads to a decrease...
Coordinated multipoint (CoMP) transmission is being considered in next-generation cellular systems to improve cell-edge throughput. In this paper, we consider open-loop CoMP with L base stations (BSs) where they cooperatively serve a cell-edge user. We first propose antenna selected space-time block code (STBC) to exploit diversity gain for serving the cell-edge user and also support the scenario...
In this paper we propose a novel technique for efficient video distribution over WiMAX networks. The technique incorporates resource distribution, scheduling and content-aware streaming of video taking advantage of a flexible QoS functionality offered by WiMAX. The proposed technique was thoroughly investigated using NS-2 software package under various real-life scenarios which included streaming...
We concentrate on the sum power minimization problem for the uplink of wireless cellular systems in this paper. Given a certain quality-of-service (QoS) constraint per mobile station (MS), the optimal power control and receiver beamforming are jointly considered with adaptive multi base station set (MBS) selection for joint reception. An iterative optimization algorithm is proposed accordingly. Although...
Multiple Input Multiple Output (MIMO) opens new challenges to be exploited in Cognitive Radio (CR) by simultaneously serving several users. The spatial domain that is added through MIMO is another system resource that has to be optimized, and shared when possible. In this paper, we present a spatial sharing approach that is carried out through Zero Forcing beamforming (ZFB). Statistical assessment...
In a heterogeneous cellular networks environment, users behaviour and network deployment configuration parameters have an impact on the overall Quality of Service. This paper proposes a new and simple model that, on the one hand, explores the users behaviour impact on the network by having mobility, multi-service usage and traffic generation profiles as inputs, and on the other, enables the network...
In this paper, we apply distributed optimization dynamics of the mutually connected neural networks to RAN selection in heterogeneous type cognitive wireless networks. We evaluate the performance of the proposed approach by implementing it on an experimental heterogeneous wireless network system called Cognitive Wireless Cloud, which supports vertical handover between different radio access networks...
Cognitive wireless mesh networks have great potential to green communication. One of the critical challenges for realizing such networks is how to adaptively match transmit powers and allocate frequency resources among secondary users of the licensed frequency bands whilst maintaining the quality-of-service (QoS) requirement of the primary users, even in mutually entangled interferences environment...
The IEEE 802.16 standard is a promising technology for 4G mobile networks. Though supporting versatile service classes, best effort (BE) service class is expected to dominate WiMAX networks, due to operational simplicity. One of bandwidth request mechanisms that subscriber stations (SS) can utilize to issue bandwidth requests (BW-REQ) for BE connections is contention-based random access. An SS starts...
WiMAX, based on the IEEE 802.16 standard, is designed to support a variety of applications, including voice and multimedia services, through scalable OFDMA, advanced antenna techniques supporting MIMO, and well-defined quality of service classes. This paper presents WiMAX downlink achievable user goodput and operating range for different modulation and coding schemes for SISO and MIMO (both Space...
In this article, we are interested in improving the handover quality of Host Identity Protocol (HIP) in the case of micro mobility by (i) proposing the Local Rendezvous Server architecture as a first attempt to minimize the handover delay in the mobility process, (ii) introducing an adaptive early update mechanism to improve the handover quality during mobility by introducing early HIP (eHIP) and...
The growing problem of spectrum scarcity and the inefficient spectrum utilization in the licensed bands, are addressed by the emerging Cognitive Radio (CR) paradigm. It is seen that the choice of the spectrum bands, called as spectrum decision, must be organized carefully by considering the challenges in the spectrum availability over time, the short term fluctuations in the availability, and the...
The goal of our work is to limit in-band interference in wireless communication systems. Based on a three-regime interference classifier, we propose a novel distributed inter-cell power allocation algorithm where each cell computes by an iterative process its minimum power budget to meet its local quality of service (QoS) constraints. Analytical results show how our proposal permits to notably reduce...
The spread of novel multimedia services such as audio and video streaming, HDTV and online gaming have become a ordinary in the home networks. Therefore, the possibility to manage the Quality of Service (QoS) within an home environment becomes a crucial factor for the satisfaction of the user. In this paper we propose an enhanced Admission Control and Drop strategies for a UPnP-QoS controlled home...
This paper introduces a technology convergence adaptor for a previously presented Inter-MAC architecture for heterogeneous home area networks. Its main task is to translate technology-dependent link metrics into a machine readable common language. This language allows for the description of various service and application classes and provides means to describe link metrics of underlying MAC protocols...
Cognitive radio (CR) technology has been considered promising to enhance spectrum efficiency via opportunistic transmission at link level. To make CR useful, networking CRs to form a cognitive radio network (CRN) is able to support end-to-end transmission from CR source to CR destination. However, the opportunistic nature of CR link for interference avoidance to primary users degrades the quality-of-service...
Inter-cell interference coordination (ICIC) is one of the key technologies in the multi-cell radio resource management of mobile systems. It plays a vital role in mitigating strong inter cell interference and guaranteeing proper quality of services for in-progress sessions. Because heterogeneous deployment is adopted in LTE-Advanced, and interference problem becomes serious. In this paper, we propose...
The information and communications technologies world is migrating towards the Future Internet (FI) era. Operators will have increased complexity to address in the FI era, compared to today, in the management of their infrastructure and services. This is due to the extended set of applications that should be supported and to the more options offered by the infrastructure. Cognitive management systems...
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