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Exclusive-Region Based Scheduling Algorithms for UWB WPAN
"... Abstract — With the capability of supporting very high data rate services in a short range, Ultra-Wideband (UWB) technology is appealing to multimedia applications in future wireless personal area networks (WPANs) and broadband home networks. However, the WPAN Medium Access Control (MAC) protocol in ..."
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Abstract — With the capability of supporting very high data rate services in a short range, Ultra-Wideband (UWB) technology is appealing to multimedia applications in future wireless personal area networks (WPANs) and broadband home networks. However, the WPAN Medium Access Control (MAC) protocol in IEEE 802.15.3 standard was originally designed for narrowband communication networks, without considering any specific features of UWB. In this paper, we explore the unique characteristics of UWB communications from which a sufficient condition for scheduling concurrent transmissions in UWB networks is derived: concurrent transmissions can improve the network throughput if all senders are outside the exclusive regions of other flows. We also study the optimal exclusive region size for a UWB network where devices are densely and uniformly located. Since the optimal scheduling problem for peer-to-peer concurrent transmissions in a WPAN is NP-hard, the induced computation load for solving the problem may not be affordable to the network coordinator, commonly a normal UWB device with limited computational power. We propose two simple heuristic scheduling algorithms with polynomial time complexity. Extensive simulations with random network topology demonstrate that, by exploiting the unique characteristics of UWB communications and allowing concurrent transmissions appropriately, the proposed exclusive-region based scheduling algorithms can significantly increase the network throughput.
Cross-layer Design for Efficient Resource Utilization
"... Ultra-wideband (UWB) communications has emerged as a promising technology for high data rate wireless personal area networks (WPANs). In this paper, we address two key issues that impact the performance of a multi-hop UWB-based WPAN: throughput and transmission range. Arbitrary selection of routes i ..."
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Ultra-wideband (UWB) communications has emerged as a promising technology for high data rate wireless personal area networks (WPANs). In this paper, we address two key issues that impact the performance of a multi-hop UWB-based WPAN: throughput and transmission range. Arbitrary selection of routes in such a network may result in reserving an unnecessarily long channel time, and hence low network throughput and high blocking rate for prospective reservations. To remedy this situation, we propose a novel cross-layer resource allocation design. At the core of this design is a routing technique (called RTERU) that uses the allocated channel time as a routing metric. RTERU exploits the dependence of this metric on the multiple-rate capability of an UWB system. We show that selecting the route that consumes the minimum channel time while satisfying a target packet delivery probability over the selected route is an NP-hard problem. Accordingly, RTERU resorts to approximate path selection algorithms (implemented proactively and reactively) to find near-optimal solutions at reasonable computational/communication overhead. We further enhance the performance of RTERU by integrating into its design a packet overhearing capability. Simulations are used to demonstrate the performance of our proposed solutions.
Author manuscript, published in "International Symposium for Wireless Communication Systems, Reykjavik: Iceland (2008)" DOI: 10.1109/ISWCS.2008.4726007 Multi-user Cross-layer Allocation Design for LP-OFDM High Data Rate UWB Systems
, 2008
"... Abstract—In 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 ..."
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Abstract—In 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 (LP-OFDM) 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. I.
Author manuscript, published in "International Conference On Communications And Mobile Computing, Allemagne (2009)" DOI: 10.1145/1582379.1582448 Cross-layer Resource Allocation Scheme for Multi-band High Rate UWB Systems
, 2009
"... Abstract- In this paper, we investigate the use of a crosslayer 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 ..."
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Abstract- In this paper, we investigate the use of a crosslayer 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 subcarrier 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. I.
WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. (2011) Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/wcm.1159 RESEARCH ARTICLE
"... In this paper, we study the multichannel exposed terminal problem in multihop wireless networks. We propose a multichannel medium access control (MAC) protocol, called multichannel MAC protocol with hopping reservation (MMAC-HR), to resolve the multichannel exposed terminal problem. MMAC-HR uses two ..."
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In this paper, we study the multichannel exposed terminal problem in multihop wireless networks. We propose a multichannel medium access control (MAC) protocol, called multichannel MAC protocol with hopping reservation (MMAC-HR), to resolve the multichannel exposed terminal problem. MMAC-HR uses two radio interfaces; one interface is fixed over the control channel, and the other interface switches dynamically between data channels. The fixed interface supports broadcast information and reserves a data channel for any data transmission. The switchable interface, on other hand, is for data exchanges and follows independent slow hopping without requiring clock synchronization. In addition, the proposed protocol is a distributed one. By using the ns-2 simulator, extensive simulations are performed to demonstrate that MMAC-HR can enhance the network throughput and delay compared with existing multichannel MAC protocol. Copyright © 2011
(www.interscience.wiley.com) DOI: 10.1002/wcm.771
"... In this paper, a rate-based admission control scheme for a single shared wireless base station with opportunistic scheduling and adaptive modulation and coding (AMC) is proposed. The proposed admission scheme maintains minimum average rates of the admitted users, i.e., new users will be admitted if ..."
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In this paper, a rate-based admission control scheme for a single shared wireless base station with opportunistic scheduling and adaptive modulation and coding (AMC) is proposed. The proposed admission scheme maintains minimum average rates of the admitted users, i.e., new users will be admitted if the base station has enough resources to support the required minimum average transmission rates of all users. The proposed scheme relies on an analytical model for the average per-user rates of an opportunistic scheduling in an unsaturated scenario, where some queues may be empty for certain periods of time. We provide extensive simulation results to demonstrate the accuracy of the base analytical model on which our admission scheme relies. Copyright © 2009 John Wiley & Sons, Ltd. KEY WORDS: call admission control; opportunistic scheduling; quality of service 1.
Research Supervisor: CROSS LAYER DESIGN FOR ULTRA WIDEBAND MULTIHOP ADHOC WIRELESS NETWORKS
"... The abstract is given below. Doctoral Committee members, members of the faculty, research ..."
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The abstract is given below. Doctoral Committee members, members of the faculty, research
Contents lists available at ScienceDirect Computer Networks
"... journal homepage: www.elsevier.com/locate/comnet Interference aware resource allocation for hybrid hierarchical ..."
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journal homepage: www.elsevier.com/locate/comnet Interference aware resource allocation for hybrid hierarchical
MECHANISMS AND PROTOCOLS FOR INTERFERENCE MANAGEMENT AND RESOURCE UTILIZATION IN UWB NETWORKS
, 2010
"... Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the aut ..."
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Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
