Showing papers by "Theodore S. Rappaport published in 2007"
TL;DR: The current status and direction of future development of UWB, emerging 60 GHz millimeter-wave PAN, and low data rate ZigBee are described and wireless MAC protocol issues of 60 GHz multigigabit PAN are addressed.
Abstract: This article presents standardization, regulation, and development issues associated with short-range wireless technologies for next-generation personal area networks (PAN). Ultra-wideband (UWB) and 60 GHz millimeter-wave communication technologies promise unprecedented short-range broadband wireless communication and are the harbingers of multigigabit wireless networks. Despite the huge potential for PAN, standardization and global spectrum regulations challenge the success of UWB. On the other hand, ZigBeetrade is expected to be a crucial short-range technology for low throughput and ultra low-power consumption networks. The current status and direction of future development of UWB, emerging 60 GHz millimeter-wave PAN, and low data rate ZigBee are described. This article also addresses wireless MAC protocol issues of 60 GHz multigigabit PAN.
390 citations
26 Dec 2007
TL;DR: This paper presents three algorithms that outperform all other published work for allocating a limited number of orthogonal frequency channels to access points (APs) in wireless networks, and minimize interference seen by both users and APs, and mitigate the impact of rogue RF interference.
Abstract: This paper presents three algorithms that outperform all other published work for allocating a limited number of orthogonal frequency channels to access points (APs) in wireless networks. Unlike other work, we minimize interference seen by both users and APs, we use a physical rather than binary model for interference, and we mitigate the impact of rogue RF interference. Our three algorithms have different mechanisms of switching the channels of APs based on the in- situ interference measured at clients and/or APs. The convergence of the algorithms is proven and characterized. Our algorithms consistently yield high throughput gains irrespective of network topology, the level of AP activity, and the number of controlled APs, rogue interferers, and available channels. We outperform the best published work by 15% and 18% for mean and median user throughputs respectively, and 81%, 168%, and 1011% for 25, 20, and 15 percentiles of user throughputs, respectively.
34 citations
15 Oct 2007
TL;DR: This paper presents novel on-chip antenna structures and provides new on- chip circuit concepts that may be implemented as part of standard integrated circuit fabrication processes for wireless integrated circuits of the future.
Abstract: This paper presents novel on-chip antenna structures and provides new on-chip circuit concepts that may be implemented as part of standard integrated circuit fabrication processes for wireless integrated circuits of the future. As wavelengths of wireless local area networks (WLANs) and personal area networks (PANs) shrink to millimeter lengths at 60 GHz and above, interconnectivity issues and cost/scale requirements will require these new approaches for built-in on- chip antennas. This paper highlights advancements in both the integrated circuits and microwave technology research communities, and presents a number of promising areas of research. Finally, we describe an experimental probe station that has been developed at The University of Texas for the testing and characterization of novel on-chip antennas and distributed components.
22 citations
15 Oct 2007
TL;DR: This paper is the first analytical work to exhibit the substantial gains resulting from applying site specific knowledge to frequency allocation in wireless networks, and two new site-specific knowledge-based frequency allocation algorithms are shown to outperform all other published work.
Abstract: This paper is the first analytical work to exhibit the substantial gains resulting from applying site specific knowledge to frequency allocation in wireless networks. Two new site-specific knowledge-based frequency allocation algorithms are shown to outperform all other published work. Site specific knowledge refers to knowledge of building layouts, the locations and electrical properties of APs, users, and physical objects. We assume that a central network controller communicates with all APs, and has site specific knowledge which enables the controller to predict, a priori, the received power from any transmitter to any receiver. Optimal frequency assignments are based on predicted powers to minimize interference and maximize throughput. Our algorithms consistently yield high throughput gains irrespective of network topology, AP activity level, and the number of APs, rogue interferers, and available channels. Our algorithms outperform the best published algorithm by up to 3.68%, 8.95%, 13.6%, 15.1%, 25.8%, and 84.9% for 50, 25, 20, 15, 10, and 5 percentiles of user throughputs, respectively.
5 citations