Cross-layer Resource Allocation Scheme for Multi-band High Rate UWB Systems

In this paper, we investigate the use of a cross-layer allocation mechanism for the high-rate ultra-wideband (UWB) systems. The aim of this paper is twofold. First, through the cross-layer approach that provides a new service differentiation approach to the fully distributed UWB systems, we support traffic with quality of service (QoS) guarantee in a multi-user context. Second, we exploit the effective SINR method that represents the characteristics of multiple sub-carrier SINRs in the multi-band WiMedia solution proposed for UWB systems, in order to provide the channel state information needed for the multi-user sub-band allocation. This new approach improves the system performance and optimizes the spectrum utilization with a low cost data exchange between the different users while guaranteeing the required QoS. In addition, this new approach solves the problem of the cohabitation of more than three users in the same WiMedia channel

CROSS-LAYER RESOURCE ALLOCATION SCHEME UNDER HETEROGENEOUS CONSTRAINTS FOR NEXT GENERATION HIGH RATE WPAN

International audienceIn the next generation wireless networks, the growing demand for new wireless applications is accompanied with high expectations for better quality of service (QoS) fulfillment especially for multimedia applications. Furthermore, the coexistence of future unlicensed users with existing licensed users is becoming a challenging task in next generation communication systems to overcome the underutilization of the spectrum. A QoS and interference aware resource allocation is thus of special interest in order to respond to the heterogeneous constraints of the next generation networks. In this work, we address the issue of resource allocation under heterogeneous constraints for unlicensed multi-band ultra-wideband (UWB) systems in the context of Future Home Networks, i.e. WPAN. The problem is first studied analytically using a heterogeneous constrained optimization problem formulation. After studying the characteristics of the optimal solution, we propose a low-complexity suboptimal algorithm based on a cross-layer approach that combines information provided by the PHY and MAC layers. While the PHY layer is responsible for providing the channel quality of the unlicensed UWB users as well as their interference power that they cause on licensed users, the MAC layer is responsible for classifying the unlicensed users using a two-class based approach that guarantees for multimedia services a high-priority level compared to other services. Combined in an efficient and simple way, the PHY and MAC information present the key elements of the aimed resource allocation. Simulation results demonstrate that the proposed scheme provides a good tradeoff between the QoS satisfaction of the unlicensed applications with hard QoS requirements and the limitation of the interference affecting the licensed users

Multi-user cross-layer allocation design for LP-OFDM high-rate UWB

International audienceIn this paper, we investigate a cross-layer design for the packet scheduling and the resource allocation in UWB systems. This design considers the combination of queuing and channel state information (CSI) which provides QoS support for multimedia applications in UWB. For the physical layer, the use of a linear precoded orthogonal division multiplexing (LPOFDM) waveform is proposed because of its significant performance increase compared to the WiMedia proposal. For the medium access control layer, scheduling is performed in order to differentiate between the different users and to satisfy their quality of service constraints. This cross-layer approach optimizes the system spectral efficiency and solves the problem in the WiMedia solution of cohabitation of more than three users sharing the three sub-bands of the same channel. Simulation results show that the proposed scheme leads to a considerable improvement in resource allocation and can guarantee the required quality of service

Cross-Layer Resource Allocation for MB-OFDM UWB Systems

ISBN 978-953-3076461-0International audienc

DIFFERENTIATED MULTIUSER RESOURCE ALLOCATION SCHEME FOR MULTI-BAND UWB SYSTEMS

ISBN: 978-1-4244-3695-8International audienceThis paper considers the dynamic resource allocation in a multiuser context taking into account the quality of service (QoS) requirements for the high-rate ultra-wideband (UWB) systems. The aim of this paper is twofold. First, we exploit the effective SINR method in the multi-band WiMedia solution proposed for UWB systems. This method is based on the exploitation of the characteristics of multiple sub-carrier SINRs in order to provide the channel state information needed for the multiuser sub-band allocation. Second, using the effective SINR as a channel metric, we derive a multiuser convex optimization problem to find the optimal allocation for all users while differentiating between two traffic classes: hard-QoS and soft-QoS. A low-complexity cross-layer allocation algorithm is also proposed. The cross-layer solution is a combination of two simple processes, one working at the PHY level and the other at the MAC level. Simulation results show that the proposed cross-layer solution performance is close to that of the optimal solution and it outperforms the single-user WiMedia solution in the hard-QoS users cas

Multiuser Service Differentiated Spectrum Allocation Scheme for High Rate UWB Systems

International audienceIn this paper, we propose a multiuser spectrum allocation scheme for high-rate UWB systems under QoS requirements. This scheme comes as a solution to the coexistence of multiple users sharing the three sub-bands of the same channel as defined in the WiMedia solution adopted for multiband UWB systems. Indeed, WiMedia solution does not allow more than three users to coexist in the same channel. Based on a constrained multiuser optimization problem, the proposed allocation algorithm allows multiple users to access the medium following a mixed sub-band assignment and priority-based scheduling approach in order to ensure an efficient differentiated spectrum sharing. The resulting time-frequency scheduling algorithm relies on the combination of two main metrics available at PHY and MAC levels: the channel quality of each user provided by the exploitation of the effective SINR method, and the QoS constraint represented by a simple weighting parameter that differentiates between two service classes. Simulation results show the efficiency of the proposed scheme and how it guarantees a good performance level for users having strict QoS requirements

A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks

In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs