HiBRID-SoC: A Multi-Core SoC Architecture for Multimedia Signal Processing

The HiBRID-SoC multi-core system-on-chip architecture targets a wide range of multimedia applications with particularly high processing demands, including general signal processing applications, video de-/encoding, image processing, or a combination of these tasks. For this purpose, the HiBRID-SoC integrates three fully programmable processors cores and various interfaces onto a single chip, all tied to a 64-Bit AMBA AHB bus. The processor cores are individually optimized to the particular computational characteristics of different application fields, complementing each other to deliver high performance levels with high flexibility at reduced system cost. The HiBRID-SoC is fabricated in a 0.18 μm 6LM standard-cell CMOS technology, occupies about 81 mm², and operates at 145 MHz. An MPEG-4 Advanced Simple Profile decoder in full D1 resolution requires about 120 MHz for real-time operation on the HiBRID-SoC, utilizing only two of the three cores. Together with the third core, a custom region-of-interest (ROI) based surveillance application can be built.Hans-Joachim Stolberg received the Dipl.-Ing. degree in electrical engineering from the University of Hannover, Germany, in 1995.From 1995 to 1996, he was with the NEC Information Technology Research Laboratories, Kawasaki, Japan, working on efficient implementations of video compression algorithms. Since 1996, he has been with the Institute of Microelectronic Systems at the University of Hannover as a Research Assistant. During summer 2001, he was a Monbukagakusho Research Fellow at the Tokyo Institute of Technology, Japan. His current research interests include VLSI architectures for video signal processing, performance estimation of multimedia schemes, and profile-guided memory organization for signal processing and multimedia applications.Mladen Bereković received the Dipl.-Ing. degree in electrical engineering from the University of Hannover, Germany, in 1995.Since then he has been a Research Assistant with the Institute of Microelectronic Systems of the University of Hannover. His current research interests include VLSI architectures for video signal processing, MPEG-4, System-on-Chip (SOC) designs, and simultaneously multi-threaded (SMT) processor architectures.Sören Moch received the Dipl.-Ing. degree in electrical engineering from the University of Hannover, Germany, in 1997.Since then he has been Research Assistant with the Laboratory for Information Technology, University of Hannover. His current research interests are in the area of processor architectures for image, video and multimedia signal processing applications.Lars Friebe studied electrical engineering at the Universities Ulm and Hannover, Germany. In 1999, he worked at the NEC System ULSI Research Laboratory in Kanagawa, Japan. He received the Dipl.-Ing. degree in electrical engineering from the University of Hannover, Germany, in 1999.Since then he has been a Research Assistant with the Laboratory for Information Technology, University of Hannover. His current research interests are in the area of parallel programmable VLSI architectures for real-time image processing.Mark B. Kulaczewski started his studies in electrical engineering at the University of Hannover, Germany. In 1994, he transferred to Purdue University, West Lafayette, USA, and received the M.S. degree in electrical engineering in 1996.Since 1997 he has been a Research Assistant at the Laboratory for Information Technology and the Institute of Microelectronic Systems, University of Hannover. His current research interests include programmable real-time architectures for video coding and image segmentation, and instruction-set extensions for cryptographic applications.Sebastian Flügel was born in Crivitz, Germany, in 1975. He received his Dipl.-Ing. degree from the Department of Electrical Engineering of the University of Rostock in 2001.Since then he has been a Ph.D. candidate at the Institute of Microelectronic Systems at the University of Hannover. He works in the field of architectures and systems for video processing systems. His focus is on algorithms for video encoding and the development of optimized hardware architectures.Heiko Klußmann received the Dipl.-Ing. degree in computer engineering from the University of Hannover, Germany, in 2002.Since then he has been a Research Assistant with the Institute of Microelectronic Systems of the University of Hannover. His current research interests are in the area of programmable architectures for real-time video signal processing.Andreas Dehnhardt was born in Frankfurt am Main, Germany, in 1976. He received his Dipl.-Ing. degree in electrical engineering from the University of Hannover, Germany, in 2002.Since then, he has been a Research Assistant with the Institute of Microelectronic Systems, University of Hannover. His current research interests include programmable architectures for multimedia applications and implementation of real-time MPEG-4 encoding schemes.Peter Pirsch received the Ing. grad. degree from the engineering college in Hannover, Hannover, Germany, in 1966, and the Dipl.-Ing. and Dr.-Ing. degrees from the University of Hannover, in 1973 and 1979, respectively, all in electrical engineering.From 1966 to 1973 he was employed by Telefunken, Hannover, working in the Television Department. He became a Research Assistant at the Department of Electrical Engineering, University of Hannover, in 1973, a Senior Engineer in 1978. During 1979 to 1980 and in Summer 1981 he was on leave, working in the Visual Communications Research Department, Bell Laboratories, Holmdel, NJ. During 1983 to 1986 he was Department Head for Digital Signal Processing at the SEL research center, Stuttgart. Since 1987 he is Professor in the Department of Electrical Engineering, since 2002 in the Department of Computer Science at the University of Hannover. He served as Vice President Research of the University of Hannover from 1998 to 2002. His present research includes architectures and VLSI implementations for image processing applications, rapid prototyping and design automation for DSP applications. He is the author or coauthor of more than 200 technical papers. He has edited a book on VLSI Implementations for Image Communications (Elsevier 1993) and is author of the book Architectures for Digital Signal Processing (John Wiley 1998).Pirsch is a member of the IEEE, the German Institute of Information Technology Engineers (ITG) and the German Association of Engineers (VDI). He was recipient of several awards: the NTG paper price award (1982), IEEE Fellow (1997), IEEE Circuits and Systems Golden Jubilee Medal (1999). He was member or chair of several technical program committees of international conferences and organizer of special sessions and preconference courses. He has held several administrative and technical positions with the IEEE Circuits and Systems Society and other professional organizations. Dr. Pirsch currently serves as Vice President Publications of the IEEE Circuits and Systems Society. Since 2000 he is chairman of the Accreditation Commission for Engineering and Informatics of the Accreditation Agency for Study Programs in Engineering, Informatics, Natural Science and Mathematics (ASIIN). Dr. Pirsch is chair of the VDI committee on Engineering Education.     

A Platform-Independent Methodology for Performance Estimation of Multimedia Signal Processing Applications

A methodological framework for performance estimation of multimedia signal processing applications on different implementation platforms is presented. The methodology derives a complexity profile which is characteristic for an application, but completely platform-independent. By correlating the complexity profile with platform-specific data, performance estimation results for different platforms are obtained. The methodology is based on a reference software implementation of the targeted application, but is, in constrast to instruction-level profiling-based approaches, fully independent of its optimization degree. The proposed methodology is demonstrated by example of an MPEG-4 Advanced Simple Profile (ASP) video decoder. Performance estimation results are presented for two different platforms, a specialized VLIW media processor and an embedded general-purpose RISC processor, showing a high accuracy of he methodology. The approach can be employed to assist in design decisions in the specification phase of new architectures, in the selection process of a suitable target platform for a multimedia application, or in the optimization stage of a software implementation on a specific platform.Hans-Joachim Stolberg received the Dipl.-Ing. degree in electrical engineering from the University of Hannover, Germany, in 1995.From 1995 to 1996, he worked at the NEC Information Technology Research Laboratories, Kawasaki, Japan, on efficient implementation of video compression algorithms. Since 1996, he has been with the Institute of Microelectronic Systems at the University of Hannover as a Research Assistant. During summer 2001, he was a Monbukagakusho Research Fellow at the Tokyo Institute of Technology, Japan. His current research interests include VLSI architectures for video signal processing, performance estimation of multimedia schemes, and profile-guided memory organization approaches for signal processing and multimedia applications.Mladen Bereković received the Dipl.-Ing. degree in electrical engineering from the University of Hannover, Germany, in 1995.Since then he has been a Research Assistant with the Institute of Microelectronic Systems of the University of Hannover. His current research interests include VLSI architectures for video signal processing, MPEG-4, System-on-Chip (SOC) designs, and simultaneously multi-threaded (SMT) processor architectures.Peter Pirsch received the Ing. grad. degree from the engineering college in Hannover, Germany, in 1966, and the Dipl.-Ing. and Dr.-Ing. degrees from the University of Hannover, in 1973 and 1979, respectively, all in electrical engineering.From 1966 to 1973 he was employed by Telefunken, Hannover, working in the Television Department. He became a Research Assistant at the Department of Electrical Engineering, University of Hannover, in 1973, a Senior Engineer in 1978. During 1979 to 1981 he was on leave, working in the Visual Communications Research Department, Bell Laboratories, Holmdel, NJ. During 1983 to 1986 he was Department Head for Digital Signal Processing at the SEL Research Center, Stuttgart, Germany. Since 1987 he is Professor in the Department of Electrical and Computer Engineering at the University of Hannover. He served as Vice President Research of the University of Hannover from 1998 to 2002.His present research includes architectures and VLSI implementations for image processing applications, rapid prototyping and design automation for DSP applications. He is the author or coauthor of more than 200 technical papers. He has edited a book on VLSI Implementations for Image Communications (Elsevier 1993) and is author of the book Architectures for Digital Signal Processing (John Wiley 1998).Dr. Pirsch is a member of the IEEE, the German Institute of Information Technology Engineers (ITG) and the German Association of Engineers (VDI). He was recipient of several awards: the NTG paper price award (1982), IEEE Fellow (1997), IEEE Circuits and Systems Golden Jubilee Medal (1999). He was member or chair of several technical program committees of international conferences and organizer of special sessions and preconference courses. He has held several administrative and technical positions with the IEEE Circuits and Systems Society and other professional organizations. Dr. Pirsch currently serves as Vice President Publications of the IEEE Circuits and Systems Society. Since 2000 he is chairman of the Accreditation Commission for Engineering and Informatics of the Accreditation Agency for Study Programs in Engineering, Informatics, Natural Science and Mathematics (ASIIN). Dr. Pirsch is chair of the VDI committee on Engineering Education.     

Design of Amplitude and Phase Modulated Signals for Differential Space-Time Block Codes

A differential space-time block code (DSTBC) provides full diversity advantage and does not require any radio channel estimation in the receiver, which makes it an attractive alternative to the well-known coherent space-time block code (STBC). However the original design of DSTBC allows only pure phase shift keying (M-PSK) modulation scheme, which are not optimal for M > 4. In this paper a simultaneous amplitude and phase modulation scheme for DSTBC with 2 transmit and several receive antennas is introduced. The performance of the proposed scheme is investigated and compared with DSTBC techniques using pure M-PSK modulation. Alexandre Vanaev received B.Eng. degree in Electrical and Electronic engineering from the St. Petersburg State Polytechnic University, Russia in 1998, and M.Sc. degree in “Information and communication systems” from Technical University Hamburg-Harburg in 2002. He is currently pursuing his Ph.D. in the Technical University Hamburg-Harburg, Department of Telecommunications. His research interests include prospective OFDM-based wireless communication systems and MIMO technology. Prof. Hermann Rohling is with the Technical University Hamburg-Harburg, Germany where he has developed an international reputation for Mobile Communication (4G) and automotive radar systems. Previously Prof. Rohling was with the AEG Research Institute, Ulm as a researcher working in the area of digital signal processing for radar and communications applications. His research interests have includedWideband Mobile Communications especially based on Multicarrier Transmission Techniques (OFDM) for future broadband systems (4G), signal theory, digital radar signal processing, detection, estimation and differential GPS for high precision navigation. Prof. Rohling is a member of Informationstechnische Gesellschaft (ITG), German Institute of Navigation (DGON) and a Fellow of IEEE. He is a chairman of the September 2006 International OFDM Workshop (InOWo 2006) and the International Radar Symposium (IRS 2006) in Krakow, Poland. Prof. Rohling is theVice President of the Technical University Hamburg-Harburg.     

The 802.11n MIMO-OFDM Standard for Wireless LAN and Beyond

An overview is given of the new IEEE 802.11n standard. This is the first wireless LAN standard based on MIMO-OFDM, a technique pioneered by Airgo Networks to give a significant performance increase in both range and rate relative to conventional wireless LAN. Performance results show that net user throughputs over 100 Mbps are achievable, which is about four times larger than the maximum achievable throughput using IEEE 802.11a/g. For the same throughput, MIMO-OFDM achieves a range that is about 3 times larger than non-MIMO systems. This significant improvement in range-rate performance makes MIMO-OFDM the ideal solution not only for wireless LAN, but also for home entertainment networks and 4G networks. Richard van Nee received the M.Sc. degree in Electrical Engineering from Twente University in Enschede, the Netherlands, in 1990. In May 1995, he received the PhD degree from Delft University of Technology. From 1995 to 2000, he worked for Lucent Technologies Bell Labs on wireless LAN transmission techniques. He was one of the original proposers of the CCK and OFDM modulation techniques which were adopted by the IEEE 802.11b and IEEE802.11a wireless LAN standards. In 2001, he cofounded Airgo Networks that developed the first MIMO-OFDM modem for wireless LAN and which techniques form the basis of the IEEE 802.11n standard. Together with Ramjee Prasad, he wrote a book on OFDM, entitled ‘OFDM for Mobile Multimedia Communications.’ In 2002 he received the Dutch Veder award for his contributions to standardization of wireless communications.     

Providing Throughput Guarantees in 802.11e WLAN Through a Dynamic Priority Assignment Mechanism

Supporting real-time and interactive traffic in addition to traditional data traffic with a best-effort nature represents a constantly rising need in any kind of telecommunications environment. The IEEE 802.11 based WLAN (Wireless Local Area Network) environment does not represent an exception. This is why at different protocol layers, and primarily at the MAC layer, many efforts are being put by both the research community and the standardization bodies to design effective mechanisms for user QoS (Quality of Service) differentiation. Although early results are coming into sight, such as, for example, the IEEE 802.11e standard release, still a thorough research activity is required. Aim of the present paper is to contribute to the cited research issue by proposing an improvement to the “static” traffic prioritisation mechanism foreseen by the IEEE 802.11e MAC (Medium Access Control) protocol. This latter shows a twofold drawback. First, there is no certainty that QoS requirements relevant to a given application are always fulfilled by the “statically” associated priority. Second, resource requests of the applications are not adapted to the (usually highly) variable traffic conditions of a distributed WLAN environment. The algorithm we propose is specifically tailored to “dynamically” assign 802.11e MAC priorities, depending on both application QoS requirements and observed network congestion conditions. It is carefully designed, implemented into a system simulation tool, and its highly effective behaviour assessed under variable traffic and system conditions. Antonio Iera graduated in Computer Engineering at the University of Calabria, Italy, in 1991 and received a Master Diploma in Information Technology from CEFRIEL/Politecnico di Milano, Italy, in 1992 and a Ph.D. degree from the University of Calabria, Italy, in 1996. From 1994 to 1995 he has been at the Mobile Network Division Research Center, Siemens AG Muenchen, Germany to participate to the CEC Project “RACE II 2084 ATDMA (Advanced TDMA Mobile Access)” under a “Commission of European Communities Fellowship Contract in RACE Mobility Action”. He has been with the University of Reggio Calabria, Italy, from 1997 to 2000 as Assistant Professor, and from 2001 to 2005 as Associate Professor. Currently, he is Full Professor of Telecommunications at the same University. In 1995 and in 1996 he has been the recipient of an IEEE Paper Award for the papers presented at the IEEE International Conference on Universal Personal Communications ICUPC'95, and an IEICE/IEEE Outstanding Paper Award for the paper presented at the IEEE ATM Workshop'99, respectively. He served as member of Technical Program Committees of several International Conferences, and in 2003 he has been co-Guest Editor for the special issue “QoS in Next-generation Wireless Multimedia Communications Systems” in the IEEE Wireless Communications Magazine. His research interests include QoS control and resource management in Personal Communications Systems and Enhanced Wireless and Satellite Systems. Giuseppe Ruggeri received the degree in electronics engineering from the University of Catania, Italy, in 1998. He received the Ph.D. degree in electronics, computer science and telecommunications engineering with a dissertation on “Advanced Methods to Improve the QoS in VoIP Systems Based on VBR Speech Coders”. His interests include the field of adaptive-rate voice transmission for IP Telephony applications, and support of Quality of Service in heterogeneous wireless networks and WLAN-3G interconnection-integration . He is currently Assistant Professor in the Department of Computer Science, Mathematics, Electronic and transportation systems (DIMET) at the University “Mediterranea” of Reggio Calabria. His mail address is ruggeri@ing.unirc.it. Domenico Tripodi received M.S. degree (cum laude) in electronic engeneering from the University ‘Mediterranea' of Reggio Calabria, Italy in 2003. He won a post-degree scholarship from CNIT in 2004, and he is currently at CNIT Research Unit of Reggio Calabria. His reasearch interest are in the area of QoS provisioning in Mobile Ad-Hoc Networks.     

Localized algorithms for coverage boundary detection in wireless sensor networks

Connected coverage, which reflects how well a target field is monitored under the base station, is the most important performance metric used to measure the quality of surveillance that wireless sensor networks (WSNs) can provide. To facilitate the measurement of this metric, we propose two novel algorithms for individual sensor nodes to identify whether they are on the coverage boundary, i.e., the boundary of a coverage hole or network partition. Our algorithms are based on two novel computational geometric techniques called localized Voronoi and neighbor embracing polygons. Compared to previous work, our algorithms can be applied to WSNs of arbitrary topologies. The algorithms are fully distributed in the sense that only the minimal position information of one-hop neighbors and a limited number of simple local computations are needed, and thus are of high scalability and energy efficiency. We show the correctness and efficiency of our algorithms by theoretical proofs and extensive simulations. Chi Zhang received the B.E. and M.E. degrees in Electrical Engineering from Huazhong University of Science and Technology, Wuhan, China, in July 1999 and January 2002, respectively. Since September 2004, he has been working towards the Ph.D. degree in the Department of Electrical and Computer Engineering at the University of Florida, Gainesville, Florida, USA. His research interests are network and distributed system security, wireless networking, and mobile computing, with emphasis on mobile ad hoc networks, wireless sensor networks, wireless mesh networks, and heterogeneous wired/wireless networks. Yanchao Zhang received the B.E. degree in computer communications from Nanjing University of Posts and Telecommunications, Nanjing, China, in July 1999, the M.E. degree in computer applications from Beijing University of Posts and Telecommunications, Beijing, China, in April 2002, and the Ph.D. degree in electrical and computer engineering from the University of Florida, Gainesville, in August 2006. Since September 2006, he has been an Assistant Professor in the Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark. His research interest include wireless and Internet security, wireless networking, and mobile computing. He is a member of the IEEE and ACM. Yuguang Fang received the BS and MS degrees in Mathematics from Qufu Normal University, Qufu, Shandong, China, in 1984 and 1987, respectively, a Ph.D. degree in Systems and Control Engineering from Department of Systems, Control and Industrial Engineering at Case Western Reserve University, Cleveland, Ohio, in January 1994, and a Ph.D. degree in Electrical Engineering from Department of Electrical and Computer Engineering at Boston University, Massachusetts, in May 1997. From 1987 to 1988, he held research and teaching position in both Department of Mathematics and the Institute of Automation at Qufu Normal University. From September 1989 to December 1993, he was a teaching/research assistant in Department of Systems, Control and Industrial Engineering at Case Western Reserve University, where he held a research associate position from January 1994 to May 1994. He held a post-doctoral position in Department of Electrical and Computer Engineering at Boston University from June 1994 to August 1995. From September 1995 to May 1997, he was a research assistant in Department of Electrical and Computer Engineering at Boston University. From June 1997 to July 1998, he was a Visiting Assistant Professor in Department of Electrical Engineering at the University of Texas at Dallas. From July 1998 to May 2000, he was an Assistant Professor in the Department of Electrical and Computer Engineering at New Jersey Institute of Technology, Newark, New Jersey. In May 2000, he joined the Department of Electrical and Computer Engineering at University of Florida, Gainesville, Florida, where he got early promotion to Associate Professor with tenure in August 2003, and to Full Professor in August 2005. His research interests span many areas including wireless networks, mobile computing, mobile communications, wireless security, automatic control, and neural networks. He has published over one hundred and fifty (150) papers in refereed professional journals and conferences. He received the National Science Foundation Faculty Early Career Award in 2001 and the Office of Naval Research Young Investigator Award in 2002. He also received the 2001 CAST Academic Award. He is listed in Marquis Who’s Who in Science and Engineering, Who’s Who in America and Who’s Who in World. Dr. Fang has actively engaged in many professional activities. He is a senior member of the IEEE and a member of the ACM. He is an Editor for IEEE Transactions on Communications, an Editor for IEEE Transactions on Wireless Communications, an Editor for IEEE Transactions on Mobile Computing, an Editor for ACM Wireless Networks, and an Editor for IEEE Wireless Communications. He was an Editor for IEEE Journal on Selected Areas in Communications:Wireless Communications Series, an Area Editor for ACM Mobile Computing and Communications Review, an Editor for Wiley International Journal on Wireless Communications and Mobile Computing, and Feature Editor for Scanning the Literature in IEEE Personal Communications. He has also actively involved with many professional conferences such as ACM MobiCom’02 (Committee Co-Chair for Student Travel Award), MobiCom’01, IEEE INFOCOM’06, INFOCOM’05 (Vice-Chair for Technical Program Committee), INFOCOM’04, INFOCOM’03, INFOCOM’00, INFOCOM’98, IEEE WCNC’04, WCNC’02, WCNC’00 Technical Program Vice-Chair), WCNC’99, IEEE Globecom’04 (Symposium Co-Chair), Globecom’02, and International Conference on Computer Communications and Networking (IC3N) (Technical Program Vice-Chair).     

Mobile multi-layered IPsec

To achieve high throughput in wireless networks, smart forwarding and processing of packets in access routers is critical for overcoming the effects of the wireless links. However, these services cannot be provided if data sessions are protected using end-to-end encryption as with IPsec, because the information needed by these algorithms resides inside the portion of the packet that is encrypted, and can therefore not be used by the access routers. A previously proposed protocol, called Multi-layered IPsec (ML-IPsec) modifies IPsec in a way so that certain portions of the datagram may be exposed to intermediate network elements, enabling these elements to provide performance enhancements. In this paper we extend ML-IPsec to deal with mobility and make it suitable for wireless networks. We define and implement an efficient key distribution protocol to enable fast ML-IPsec session initialization, and two mobility protocols that are compatible with Mobile IP and maintain ML-IPsec sessions. Our measurements show that, depending on the mobility protocol chosen, integrated Mobile IP/ML-IPsec handoffs result in a pause of 53–100 milliseconds, of which only 28–75 milliseconds may be attributed to ML-IPsec. Further, we provide detailed discussion and performance measurements of our MML-IPsec implementation. We find the resulting protocol, when coupled with SNOOP, greatly increases throughput over scenarios using standard TCP over IPsec (165% on average). By profiling the MML-IPsec implementation, we determine the bottleneck to be sending packets over the wireless link. In addition, we propose and implement an extension to MML-IPsec, called dynamic MML-IPsec, in which a flow may switch between plaintext, IPsec and MML-IPsec. Using dynamic MML-IPsec, we can balance the tradeoff between performance and security. Heesook Choi is a Ph.D. candidate in the Department of Computer Science and Engineering at the Pennsylvania State University. She received her B.S. degree in Computer Science and Statistics and M.S. degree in Computer Science from the Chungnam National University, Korea, in 1990 and 1992 respectively. She was a senior research staff in Electronics and Telecommunications Research Institute (ETRI) in Korea before she enrolled in the Ph.D. program at the Pennsylvania State University in August 2002. Her research interests lie in security and privacy in distributed systems and wireless mobile networks, focusing on designing algorithms and conducting system research. Hui Song is a Ph.D. candidate in the Department of Computer Science and Engineering at the Pennsylvania State University, University Park. He received the M.E. degree in Computer Science from Tsinghua University, China in 2000. His research interests are in the areas of network and system security, wireless ad-hoc and sensor networks, and mobile computing. He was a recipient of the research assistant award of the Department of Computer Science and Engineering at the Pennsylvania State University in 2005. Guohong Cao received his BS degree from Xian Jiaotong University, Xian, China. He received the MS degree and Ph.D. degree in computer science from the Ohio State University in 1997 and 1999 respectively. Since then, he has been with the Department of Computer Science and Engineering at the Pennsylvania State University, where he is currently an Associate Professor. His research interests are wireless networks and mobile computing. He has published over one hundred papers in the areas of sensor networks, wireless network security, data dissemination, resource management, and distributed fault-tolerant computing. He is an editor of the IEEE Transactions on Mobile Computing and IEEE Transactions on Wireless Communications, a guest editor of special issue on heterogeneous wireless networks in ACM/Kluwer Mobile Networking and Applications, and has served on the program committee of many conferences. He was a recipient of the NSF CAREER award in 2001. Thomas F. La Porta received his B.S.E.E. and M.S.E.E. degrees from The Cooper Union, New York, NY, and his Ph.D. degree in Electrical Engineering from Columbia University, New York, NY. He joined the Computer Science and Engineering Department at Penn State in 2002 as a Full Professor. He is the Director of the Networking and Security Research Center at Penn State. Prior to joining Penn State, Dr. La Porta was with Bell Laboratories since 1986. He was the Director of the Mobile Networking Research Department in Bell Laboratories, Lucent Technologies where he led various projects in wireless and mobile networking. He is a Bell Labs Fellow. Dr. La Porta was the founding Editor-in-Chief of the IEEE Transactions on Mobile Computing and served as Editor-in-Chief of IEEE Personal Communications Magazine. He is currently the Director of Magazines for the IEEE Communications Society and is a member of the Communications Society Board of Governors. He has published over 50 technical papers and holds 28 patents. His research interests include mobility management, signaling and control for wireless networks, mobile data systems, and protocol design.     

Dynamic utility and price based radio resource management for rate adaptive traffic

This paper explores analytical Radio Resource Management models where the relationship between users and services is mapped through utility functions. Compared to other applications of these models to networking, we focus in particular on specific aspects of multimedia systems with adaptive traffic, and propose a novel framework for describing and investigating dynamic allocation of resources in wireless networks. In doing so, we also consider economic aspects, such as the financial needs of the provider and the users’ reaction to prices. As an example of how our analytical tool can be used, in this paper we compare different classes of RRM strategies, e.g., Best Effort vs. Guaranteed Performance, for which we explore the relationships between Radio Resource Allocation, pricing, provider’s revenue, network capacity and users’ satisfaction. Finally, we present a discussion about Economic Admission Control, which can be applied in Best Effort scenarios to further improve the performance. Part of this work has been presented at the conference ACM/IEEE MSWiM 2004, Venice (Italy). Leonardo Badia received a Laurea degree (with honors) in electrical engineering and a Ph.D. in information engineering from the University of Ferrara, Italy, in 2000 and 2004, respectively. He was a Research Fellow at the University of Ferrara from 2001 to 2006. During these years, he also had collaborations with the University of Padova, Italy, and Wireless@KTH, Royal Institute of Technology, Stockholm, Sweden. In 2006, he joined the “Institutions Markets Technologies” (IMT) Institute for Advanced Studies, Lucca, Italy, where he is currently a Research Fellow. His research interests include wireless ad hoc and mesh networks, analysis of transmission protocols, optimization tools and economic models applied to radio resource management. Michele Zorzi received a Laurea degree and a Ph.D. in electrical engineering from the University of Padova in 1990 and 1994, respectively. During academic year 1992–1993, he was on leave at UCSD, attending graduate courses and doing research on multiple access in mobile radio networks. In 1993 he joined the faculty of the Dipartimento di Elettronica e Informazione, Politecnico di Milano, Italy. After spending three years with the Center for Wireless Communications at UCSD, in 1998 he joined the School of Engineering of the University of Ferrara, Italy, where he became a professor in 2000. Since November 2003 he has been on the faculty at the Information Engineering Department of the University of Padova. His present research interests include performance evaluation in mobile communications systems, random access in mobile radio networks, ad hoc and sensor networks, energy constrained communications protocols, and broadband wireless access. He was Editor-In-Chief of IEEE Wireless Communications, 2003–2005, and currently serves on the Editorial Boards of IEEE Transactions on Communications, IEEE Transactions on Wireless Communications, Wiley’s Journal of Wireless Communications and Mobile Computing, and ACM/URSI/Kluwer Journal of Wireless Networks, and on the Steering Committee of the IEEE Transactions on Mobile Computing. He has also been a Guest Editor of special issues in IEEE Personal Communications (Energy Management in Personal Communications Systems) and IEEE Journal on Selected Areas in Communications (Multimedia Network Radios).     

MIMO Channel Characterization for Short Range Fixed Wireless Propagation Environments

This paper reports results from wideband MIMO measurements performed in short range fixed wireless environments at 5.2 GHz. The objective is to provide MIMO channel characterization results for the measured environments and contribute to the limited available similar studies. Two kinds of propagation scenarios are investigated, rooftop to rooftop and street to rooftop, at three different sites always under LOS propagation conditions. The analysis of measurement data is performed in the context of non physical modeling, providing insight into the statistics of the measured channels. In particular, the slow time varying nature of the channel is studied and the narrow Doppler spectrum shape is approximated. Furthermore, frequency correlation results are obtained and the typical delay dispersion measures are extracted. Then, the antenna correlation is studied and the error of the Kronecker product approximation is evaluated. Finally, capacity results are provided and the channel measurements are characterized in terms of spatial multiplexing quality and multipath richness through condition number analysis. Nikolaos D. Skentos received his Diploma in Electrical and Computer Engineering from the National Technical University of Athens (NTUA), Greece in October 2000. Since January 2001 he has been a research associate at the Mobile Radio Communications Laboratory at the NTUA, and he is currently working towards the Ph.D. degree. His research interests include channel measurements, MIMO channel characterization, MIMO algorithms and space time processing. He has been active in the IST STINGRAY project, the COST 273 Action and the ACE Network of Excellence. He is also a member of the National Technical Chamber of Greece since 2001. Athanasios G. Kanatas received the Diploma in Electrical Engineering from the National Technical University of Athens, Greece, in 1991, the M.Sc. degree in Satellite Communication Engineering from the University of Surrey, Surrey, UK in 1992, and the Ph.D. degree in Mobile Satellite Communications from the National Technical University of Athens, Greece in February 1997. From 1993 to 1994 he was with National Documentation Center of National Research Institute. In 1995 he joined SPACETEC Ltd. where he was Technical Project Manager for VISA/EMEA VSAT Project in Greece. In 1996 he joined the Mobile Radio Communications Laboratory as a research associate. From 1999 to 2002 he was with the Institute of Communication & Computer Systems. In 2000 he became a member of the Board of Directors of OTESAT S.A. He is an Assistant Professor in the Department of Technology Education and Digital Systems at University of Piraeus. His current research interests include channel characterization and estimation, simulation and modeling for mobile, mobile satellite, and future wireless communication systems. He has been a Senior Member of IEEE since 2002, and is also a member of the Technical Chamber of Greece. In 1999 he was elected Chairman of the Communications Society of the Greek IEEE Section. Panagiotis I. Dallas was born 1967 in Thessaloniki, Greece. He obtained his diploma and Ph.D. degree from the Electrical and Computer Engineering Department of Aristotle University of Thessaloniki, Greece, in 1990 and 1997, respectively. Since 1998 he joined with INTRACOM where he currently is Section Manager of Advanced Communications Technologies branch of Emerging Technologies & Markets department, leading the next generation of broadband wireless access systems for internal and EU projects. He runs the relevant standardization activities (IEEE 802.16 and ETSI/BRAN HIPERMAN) in INTRACOM and he represents the company in WiMAX forum. Finally, he has over 30 publications in international journals and conferences. Philip Constantinou received the Diploma in Physics from the National University of Athens in 1972, the Master of Applied Science in Electrical Engineering from the University of Ottawa, Ontario, Canada in 1976, and the Ph.D. degree in Electrical Engineering in 1983 from Carleton University, Ottawa, Ontario, Canada. From 1976 to 1979 he was with Telesat Canada as a Communications System Engineer. In 1980 he joined the Ministry of Communications in Ottawa, Canada where he was engaged in the area of Mobile Communication. From 1984 to 1989 he was with the National Research Center Demokritos in Athens, Greece where he was involved in several research projects in the area of Mobile Communications. In 1989 he joined the National Technical University of Athens where he is currently a Professor and Director of the Mobile Radio Communications Laboratory. His current research interests include Personal Communications, Mobile Satellite Communications, and Interference Problems on Digital Communications Systems.     

UbiqMuseum: A Bluetooth and Java Based Context-Aware System for Ubiquitous Computing

This paper evaluates the use of Bluetooth and Java based technologies in ubiquitous computing environments. Ubiquitous computing strongly depends on leveraging appropriate contextual information to users, according to their preferences and the environment in which they reside. We present UbiqMuseum – an experimental context-aware application that provides context-aware information to museum visitors. UbiqMuseum combines the productivity of Java with the universal connectivity provided by Bluetooth wireless technology. We describe the overall architecture and discuss the implementation steps taken to create our Bluetooth and Java based context-aware application. We demonstrate practicality of building a context-aware system by using UbiqMuseum as a proof of concept that integrates a combination of Bluetooth, WLAN and Ethernet LAN technologies. Finally we run some experiments in a small testbed to evaluate the performance and system behaviour. We evaluate the impact on throughput with varying packet size, coding types and device separation distance sending both images and text. We also present our findings in term of inquiry delay with respect to distance. Numerical results show that Bluetooth offers a relatively steady throughput up to 10 m while the inquiry delay does not increase significantly with distance. Juan-Carlos Cano is an assistant professor in the Department of Computer Engineering at the Polytechnic University of Valencia (UPV) in Spain. He earned an M.Sc. and a Ph.D. in computer science from the UPV in 1994 and 2002 respectively. Between 1995–1997 he worked as a programming analyst at IBM's manufacturing division in Valencia. His current research interests include power aware routing protocols for mobile ad hoc networks and pervasive computing. You can contact him at jucano@disca.upv.es. Pietro Manzoni received the MS degree in computer science from the “Universitá degli Studi" of Milan, Italy, in 1989, and the Ph.D. degree in computer science from the Polytechnic University of Milan, Italy, in 1995. He is an associate professor of computer science at the Polytechnic University of Valencia, Spain. His research activity is related to wireless networks protocol design, modeling, and implementation. He is member of the IEEE. C.-K. Toh is currently a Professor and Chair in Communication Networks at Queen Mary University of London, UK. He is also the Director of the UK Ad Hoc Wireless Consortium and Director of the Queen Mary/Fudan Joint Research Lab in Mobile Networking and Ubiquitous Computing. Concurrently, he is also an Honorary Professor with the University of Hong Kong and an Adjunct Professor at Fudan University, Shanghai. Previously, he was the Director of Research with TRW Tactical Systems in California, USA (now Northrop Grumman Corporation) and was responsible for DARPA and Army programs in communications and networking. He had also worked for Hughes Research, ALR, HP, and was a professor at GeorgiaTech and University of California, Irvine. CK is the recipient of the 2005 IEEE Kiyo Tomiyasu Technical Medal Award, for “pioneering contributions to communication protocols in ad hoc mobile wireless networks." He is the author of “Wireless ATM & Ad Hoc Networks" (Kluwer Press, 1996) and “Ad Hoc Mobile Wireless Networks" (Prentice Hall Engineering Title Best Seller, 2001–2003). He is a recipient of the ACM Recognition of Service Award, for co-founding ACM MobiHoc Conference. He is a co-recipient of the Korean Science & Engineering Foundation Best Journal paper Award for his work on ad hoc TCP. CK was formerly the Chairman of IEEE Communications Society Technical Committee on Computer Communications and Chairman of IEEE Subcommittee on Ad Hoc Mobile Wireless Networks. He was an IEEE Expert/Distinguished Lecturer and had served as a Steering Committee Member for IEEE WCNC Conference and IEEE Transaction on Mobile Computing. He was a member of IEEE Communications Society Meetings & Conferences Board. CK was an editor for IEEE Networks, IEEE JSAC, IEEE transactions on Wireless Communications, Journal on Communication Networks, and IEEE Distributed Systems. He is a Fellow of four societies: British Computer Society, the IEE, the Hong Kong Institution of Engineers and the New Zealand Computer Society. He received his Ph.D. degree in Computer Science from Cambridge University, England, and his executive education from Harvard.     

Network-Adaptive Video Communication Using Packet Path Diversity and Rate-Distortion Optimized Reference Picture Selection

In this paper, we present error-resilient Internet video transmission using path diversity and rate-distortion optimized reference picture selection. Under this scheme, the optimal packet dependency is determined adapting to network characteristics and video content, to achieve a better trade-off between coding efficiency and forming independent streams to increase error-resilience. The optimization is achieved within a rate-distortion framework, so that the expected end-to-end distortion is minimized under the given rate constraint. The expected distortion is calculated based on an accurate binary tree modeling with the effects of channel loss and error concealment taken into account. With the aid of active probing, packets are sent across multiple available paths according to a transmission policy which takes advantage of path diversity and seeks to minimize the loss rate. Experiments demonstrate that the proposed scheme provides significant diversity gain, as well as gains over video redundancy coding and the NACK mode of conventional reference picture selection. Yi Liang received the Ph.D. degree in Electrical Engineering from Stanford University in 2003. His expertise is in the areas of networked multimedia systems, real-time voice and video communication, and low-latency media streaming over the wire-line and wireless networks. Currently holding positions at Qualcomm CDMA Technologies, San Diego, CA, he is responsible for video and multimedia system design and development for Qualcomm's mobile station modem (MSM) chipsets. From 2000 to 2001, he conducted research with Netergy Networks, Inc., Santa Clara, CA, on voice over IP systems that provide improved quality over best-effort networks. From 2001 to 2003, he had been the lead of the Stanford - Hewlett-Packard Labs low-latency video streaming project, in which he and his colleagues developed error-resilience techniques for rich media communication over IP networks at low latency. In the summer of 2002 at Hewlett-Packard Labs, Palo Alto, CA, he developed an accurate loss-distortion model for compressed video and contributed in the development of the mobile streaming media content delivery network (MSM - CDN) that delivers rich media over 3G wireless. Yi Liang received the B. Eng. degree from Tsinghua University, Beijing, China. Eric Setton received the B.S. degree from Ecole Polytechnique, Palaiseau, France in 2001 and the M.S. degree, in Electrical Engineering from Stanford University in 2003. He is currently a Ph.D. candidate in the department of Electrical Engineering of Stanford University and is part of the Image, Video and Multimedia Systems group. Multimedia communication over wired and wireless networks, video compession and image processing are his main research interests. In 2001, he received the Carnot fellowship and the SAP Stanford Graduate fellowship. In 2003, he received the Sony SNRC fellowship. He has spent time in industry in France at SAGEM and in the United States at HP labs and at Sony Electronics. He has 4 patents pending. Bernd Girod is Professor of Electrical Engineering in the Information Systems Laboratory of Stanford University, California. He also holds a courtesy appointment with the StanfordDepartment of Computer Science and he serves as Director of the Image Systems Engineering Program at Stanford. His research interests include networked media systems, video signal compression and coding, and 3-d image analysis and synthesis. He received his M.S. degree in Electrical Engineering from Georgia Institute of Technology, in 1980 and his Doctoral degree “with highest honours” from University of Hannover, Germany, in 1987. Until 1987 he was a member of the research staff at the Institut fur Theoretische Nachrichtentechnik und Informationsverarbeitung, University of Hannover, working on moving image coding, human visual perception, and information theory. In 1988, he joined Massachusetts Institute of Technology, Cambridge, MA, USA, first as a Visiting Scientist with the Research Laboratory of Electronics, then as an Assistant Professor of Media Technology at the Media Laboratory. From 1990 to 1993, he was Professor of Computer Graphics and Technical Director of the Academy of Media Arts in Cologne, Germany, jointly appointed with the Computer Science Section of Cologne University. He was a Visiting Adjunct Professor with the Digital Signal Processing Group at Georgia Institute of Technology, Atlanta, GA, USA, in 1993. From 1993 until 1999, he was Chaired Professor of Electrical Engineering/Telecommunications at University of Erlangen-Nuremberg, Germany, and the Head of the Telecommunications Institute I, co-directing the Telecommunications Laboratory. He has served as the Chairman of the Electrical Engineering Department from 1995 to 1997, and as Director of the Center of Excellence “3-D Image Analysis and Synthesis” from 1995-1999. He has been a Visiting Professor with the Information Systems Laboratory of Stanford University, Stanford, CA, during the 1997/98 academic year. As an entrepreneur, Prof. Girod has worked successfully with several start-up ventures as founder, investor, director, or advisor. Most notably, he has been a co-founder and Chief Scientist of Vivo Software, Inc., Waltham, MA (1993–98); after Vivo's aquisition, 1998-2002, Chief Scientist of RealNetworks, Inc. (Nasdaq: RNWK); and, from 1996–2004, an outside Director of 8 × 8, Inc. (Nasdaq: EGHT). Prof. Girod has authored or co-authored one major text-book, two monographs, and over 250 book chapters, journal articles and conference papers in his field, and he holds about 20 international patents. He has served as on the Editorial Boards or as Associate Editor for several journals in his field, and is currently Area Editor for Speech, Image, Video and Signal Processing of the “IEEE Transactions on Communications.” He has served on numerous conference committees, e.g., as Tutorial Chair of ICASSP-97 in Munich and ICIP-2000 in Vancouver, as General Chair of the 1998 IEEE Image and Multidimensional Signal Processing Workshop in Alpbach, Austria, and as General Chair of the Visual Communication and Image Processing Conference (VCIP) in San Jose, CA, in 2001. Prof. Girod has been a member of the IEEE Image and Multidimensional Signal Processing Committee from 1989 to 1997 and was elected Fellow of the IEEE in 1998 ‘for his contributions to the theory and practice of video communications.’ He has been named ‘Distinguished Lecturer’ for the year 2002 by the IEEE Signal Processing Society. Together with J. Eggers, he is recipient of the 2002 EURASIP Best Paper Award.     

Enabling SIP-based sessions in ad hoc networks

The deployment of infrastructure-less ad hoc networks is suffering from the lack of applications in spite of active research over a decade. This problem can be solved to a certain extent by porting successful legacy Internet applications and protocols to the ad hoc network domain. Session Initiation Protocol (SIP) is designed to provide the signaling support for multimedia applications such as Internet telephony, Instant Messaging, Presence etc. SIP relies on the infrastructure of the Internet and an overlay of centralized SIP servers to enable the SIP endpoints discover each other and establish a session by exchanging SIP messages. However, such an infrastructure is unavailable in ad hoc networks. In this paper, we propose two approaches to solve this problem and enable SIP-based session setup in ad hoc networks (i) a loosely coupled approach, where the SIP endpoint discovery is decoupled from the routing procedure and (ii) a tightly coupled approach, which integrates the endpoint discovery with a fully distributed cluster based routing protocol that builds a virtual topology for efficient routing. Simulation experiments show that the tightly coupled approach performs better for (relatively) static multihop wireless networks than the loosely coupled approach in terms of the latency in SIP session setup. The loosely coupled approach, on the other hand, generally performs better in networks with random node mobility. The tightly coupled approach, however, has lower control overhead in both the cases. This work was partially done while the author was a graduate student in CReWMaN, University of Texas at Arlington. Dr. Nilanjan Banerjee is a Senior Research Engineer in the Networks Research group at Motorola India Research Labs. He is currently working on converged network systems. He received his Ph.D. and M.S. in computer science and engineering from University of Texas at Arlington. He received his B.E. degree in the same discipline from Jadavpur University, India. His research interests include telecom network architectures and protocols, identity management and network security, mobile and pervasive computing, measures for performance, modeling and simulation, and optimization in dynamic systems. Dr Arup Acharya is a Research Staff Member in the Internet Infrastructure and Computing Utilities group at IBM T.J. Watson Research Center and leads the Advanced Networking micropractice in On-Demand Innovation Services. His current work includes SIP-based services such as VoIP, Instant Messaging and Presence, and includes customer consulting engagements and providing subject matter expertise in corporate strategy teams. Presently, he is leading a IBM Research project on scalability and performance of SIP servers for large workloads. In addition, he also works on different topics in mobile/wireless networking such as mesh networks. He has published extensively in conferences/journals and has been awarded seven patents. Before joining IBM in 2000, he was with NEC C&C Research Laboratories, Princeton. He received a B.Tech degree in Computer Science from the Indian Institute of Technology, Kharagpur and a PhD in Computer Science from Rutgers University in 1995. Further information is available at Dr. Sajal K. Das is a Professor of Computer Science and Engineering and also the Founding Director of the Center for Research in Wireless Mobility and Networking (CReWMaN) at the University of Texas at Arlington (UTA). His current research interests include sensor networks, resource and mobility management in wireless networks, mobile and pervasive computing, wireless multimedia and QoS provisioning, wireless internet architectures and protocols, grid computing, applied graph theory and game theory. He has published over 400 research papers in these areas, holds four US patents in wireless internet and mobile networks. He received Best Paper Awards in IEEE PerCom’06, ACM MobiCom’99, ICOIN’02, ACM MSwiM’00 and ACM/IEEE PADS’97. He is also recipient of UTA’s Outstanding Faculty Research Award in Computer Science (2001 and 2003), College of Engineering Research Excellence Award (2003), the University Award for Distinguished record of Research (2005), and UTA Academy of Distinguished Scholars Award (2006). He serves as the Editor-in-Chief of Pervasive and Mobile Computing journal, and as Associate Editor of IEEE Transactions on Mobile Computing, ACM/Springer Wireless Networks, IEEE Transactions on Parallel and Distributed Systems. He has served as General or Program Chair and TPC member of numerous IEEE and ACM conferences. He is a member of IEEE TCCC and TCPP Executive Committees.     

Physical-layer air interface solutions for broadband high-speed wireless cellular systems

We propose the physical-layer (PHY) air interface solutions for downlink and uplink transmissions in broadband high-speed wireless cellular systems. A system based on low-density parity-check (LDPC) coded multiple-input-multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) time-division multiple-accessing (TDMA) (with scheduling) is proposed for downlink transmission; and a system based on orthogonal space-time block coded (STBC) multi-carrier code-division multiple-accessing (MC-CDMA) is proposed for uplink transmission. The proposed scheme can support ∼100 Mbps peak rate over 25 MHz bandwidth downlink channels and ∼30 Mbps sum rate of multiple users over 25 MHz uplink channels. Moreover, the proposed solutions provide excellent performance and reasonable complexity for mobile station and for base station. Ben Lu received the B.S. and M.S. degrees in electrical engineering from Southeast University, Nanjing, China, in 1994 and 1997; the Ph.D. degree from Texas A & M University in 2002. From 1994 to 1997, he was a Research Assistant with National Mobile Communications Research Laboratory at Southeast University, China. From 1997 to 1998, he was with the CDMA Research Department of Zhongxing Telecommunication Equipment Co., Shanghai, China. From 2002 to 2004, he worked for the project of high-speed wireless packet data transmission (4G prototype) at NEC Laboratories America, Princeton, New Jersey. He is now with Silicon Laboratories. His research interests include the signal processing and error-control coding for mobile and wireless communication systems. Xiaodong Wang received the B.S. degree in Electrical Engineering and Applied Mathematics (with the highest honor) from Shanghai Jiao Tong University, Shanghai, China, in 1992; the M.S. degree in Electrical and Computer Engineering from Purdue University in 1995; and the Ph.D degree in Electrical Engineering from Princeton University in 1998. From July 1998 to December 2001, he was an Assistant Professor in the Department of Electrical Engineering, Texas A&M University. In January 2002, he joined the faculty of the Department of Electrical Engineering, Columbia University. Dr. Wang’s research interests fall in the general areas of computing, signal processing and communications. He has worked in the areas of digital communications, digital signal processing, parallel and distributed computing, nanoelectronics and bioinformatics, and has published extensively in these areas. Among his publications is a recent book entitled “Wireless Communication Systems: Advanced Techniques for Signal Reception”, published by Prentice Hall, Upper Saddle River, in 2003. His current research interests include wireless communications, Monte Carlo-based statistical signal processing, and genomic signal processing. Dr. Wang received the 1999 NSF CAREER Award, and the 2001 IEEE Communications Society and Information Theory Society Joint Paper Award. He currently serves as an Associate Editor for the IEEE Transactions on Communications, the IEEE Transactions on Wireless Communications, the IEEE Transactions on Signal Processing, and the IEEE Transactions on Information Theory. Mohammad Madihian (S’78-M’83-SM’88-F’98) received his Ph.D in electronic engineering from Shizuoka University, Hamamatsu, Japan, in 1983. He is presently the Chief Patent Officer and Department Head, NEC Laboratories America, Inc., Princeton, New Jersey, where he conducts Microwave as well as PHY/MAC layer signal processing activities for high-speed wireless networks and personal communications applications. He holds 35 Japan/US patents and has authored/co-authored more than 130 technical publications including 25 invited talks. He has received 8 NEC Distinguished R&D Achievement Awards, the 1988 IEEE MTT-S Best Paper Microwave Prize, and 1998 IEEE Fellow Award. He has served as Guest Editor to the IEEE Journal of Solid-State Circuits, Japan IEICE Transactions on Electronics, and IEEE Transactions on Microwave Theory and Techniques. He is currently serving on the IEEE Speaker’s Bureau, IEEE Compound Semiconductor IC Symposium Executive Committee, IEEE Radio and Wireless Symposium Executive Committee, IEEE International Microwave Symposium Technical Program Committee, IEEE MTT-6 Subcommittee, IEEE MTT Editorial Board, and Technical Program Committee of International Conference on Solid State Devices and Materials. Dr. Madihian is an Adjunct Professor at Electrical and Computer Engineering Department, Drexel University, Philadelphia, Pennsylvania.     

A Virtual MAC Address Scheme for Mobile Ethernet

Heterogeneous wireless access is being integrated into IP networks to support future wireless systems. The enhanced IP technologies being developed must address both handover issues related to mobility management and security issues related to wireless access. We previously proposed a network architecture, Mobile Ethernet, based on wide area Ethernet technologies, that reduces overhead involving handover by managing mobility in the IEEE802 MAC layer. We also proposed a virtual MAC address scheme that introduces a host identifier into layer 2 to accommodate heterogeneous wireless access, manage handover between wireless accesses, provide scalability, and ensure security. In this paper, we design the virtual MAC address scheme for Mobile Ethernet and describe the sequence diagrams of the scheme. We also clarify the effect of our proposed scheme from the viewpoint of scalability by comparing the simulated signaling traffic load at handover with that using FMIPv6. Yoshia Saito received his B.E. and M.E. degrees from Shizuoka University, Shizuoka, Japan, in 2002 and 2003 respectively. He is currently a student in Ph.D. course in the university. From January 2004, he is also working as a visiting researcher at National Institute of Information and Communications Technology, Yokosuka, Japan. His research interests include mobile computing and next generation wireless systems. Masahiro Kuroda received the M.E. degree in systems science from the Tokyo Institute of Technology, Japan, in 1980, the M.S. degree in computer science from University of California, Santa Barbara, CA, in 1989, and received the Ph.D. degree in computer science from Shizuoka University, Japan, in 2000. He joined Mitsubishi Electric Corporation, Kamakura, Japan in 1980. Since then, he was engaged in OS/network developments, mobile network computing R&D, and cellular Java standardizations. He is currently working as a group leader at National Institute of Information and Communications Technology, Yokosuka, Japan. His current research interests includes wireless network, wireless security, mobile systems, ubiquitous systems, and next generation wireless systems architecture. He is a member of the IEEE Computer Society. Tadanori Mizuno received the B.E. degree in industrial engineering from the Nagoya Institute of Technology in 1968 and received the Ph.D. degree in computer science from Kyushu University, Japan, in 1987. In 1968, he joined Mitsubishi Electric Corp. Since 1993, he is a Professor of Faculty of Engineering, Shizuoka University, Japan. He moved to the Faculty of Information, Shizuoka University in 1995. His research interests include mobile computing, distributed computing, computer networks, broadcast communication and computing, and protocol engineering. He is a member of Information Processing Society of Japan, the institute of electronics, information and Communication Engineers, the IEEE Computer Society and ACM.     

Effective Capacity-Based Quality of Service Measures for Wireless Networks

An important objective of next-generation wireless networks is to provide quality of service (QoS) guarantees. This requires a simple and efficient wireless channel model that can easily translate into connection-level QoS measures such as data rate, delay and delay-violation probability. To achieve this, in Wu and Negi (IEEE Trans. on Wireless Communications 2(4) (2003) 630–643), we developed a link-layer channel model termed effective capacity, for the setting of a single hop, constant-bit-rate arrivals, fluid traffic, and wireless channels with negligible propagation delay. In this paper, we apply the effective capacity technique to deriving QoS measures for more general situations, namely, (1) networks with multiple wireless links, (2) variable-bit-rate sources, (3) packetized traffic, and (4) wireless channels with non-negligible propagation delay. Dapeng Wu received B.E. in Electrical Engineering from Huazhong University of Science and Technology, Wuhan, China, in 1990, M.E. in Electrical Engineering from Beijing University of Posts and Telecommunications, Beijing, China, in 1997, and Ph.D. in Electrical and Computer Engineering from Carnegie Mellon University, Pittsburgh, PA, in 2003. From July 1997 to December 1999, he conducted graduate research at Polytechnic University, Brooklyn, New York. During the summers of 1998, 1999 and 2000, he conducted research at Fujitsu Laboratories of America, Sunnyvale, California, on architectures and traffic management algorithms in the Internet and wireless networks for multimedia applications. Since August 2003, he has been with Electrical and Computer Engineering Department at University of Florida, Gainesville, FL, as an Assistant Professor. His research interests are in the areas of networking, communications, multimedia, signal processing, and information and network security. He received the IEEE Circuits and Systems for Video Technology (CSVT) Transactions Best Paper Award for Year 2001. Currently, he is an Associate Editor for the IEEE Transactions on Vehicular Technology and Associate Editor for International Journal of Ad Hoc and Ubiquitous Computing. He served as Program Chair for IEEE/ACM First International Workshop on Broadband Wireless Services and Applications (BroadWISE 2004); and as TPC member of over 20 conferences such as IEEE INFOCOM'05, IEEE ICC'05, IEEE WCNC'05, and IEEE Globecom'04. He is Vice Chair of Mobile and wireless multimedia Interest Group (MobIG), Technical Committee on Multimedia Communications, IEEE Communications Society. He is a member of the Award Committee, Technical Committee on Multimedia Communications, IEEE Communications Society. He is also Director of Communications, IEEE Gainesville Section. Rohit Negi received the B.Tech. degree in Electrical Engineering from the Indian Institute of Technology, Bombay, India in 1995. He received the M.S. and Ph.D. degrees from Stanford University, CA, USA, in 1996 and 2000 respectively, both in Electrical Engineering. He has received the President of India Gold medal in 1995. Since 2000, he has been with the Electrical and Computer Engineering department at Carnegie Mellon University, Pittsburgh, PA, USA, where he is an Assistant Professor. His research interests include signal processing, coding for communications systems, information theory, networking, cross-layer optimization and sensor networks.     

A secure authentication and billing architecture for wireless mesh networks

Wireless mesh networks (WMNs) are gaining growing interest as a promising technology for ubiquitous high-speed network access. While much effort has been made to address issues at physical, data link, and network layers, little attention has been paid to the security aspect central to the realistic deployment of WMNs. We propose UPASS, the first known secure authentication and billing architecture for large-scale WMNs. UPASS features a novel user-broker-operator trust model built upon the conventional certificate-based cryptography and the emerging ID-based cryptography. Based on the trust model, each user is furnished with a universal pass whereby to realize seamless roaming across WMN domains and get ubiquitous network access. In UPASS, the incontestable billing of mobile users is fulfilled through a lightweight realtime micropayment protocol built on the combination of digital signature and one-way hash-chain techniques. Compared to conventional solutions relying on a home-foreign-domain concept, UPASS eliminates the need for establishing bilateral roaming agreements and having realtime interactions between potentially numerous WMN operators. Our UPASS is shown to be secure and lightweight, and thus can be a practical and effective solution for future large-scale WMNs. Yanchao Zhang received the B.E. degree in Computer Communications from Nanjing University of Posts and Telecommunications, Nanjing, China, in July 1999, and the M.E. degree in Computer Applications from Beijing University of Posts and Telecommunications, Beijing, China, in April 2002. Since September 2002, he has been working towards the Ph.D. degree in the Department of Electrical and Computer Engineering at the University of Florida, Gainesville, Florida, USA. His research interests are network and distributed system security, wireless networking, and mobile computing, with emphasis on mobile ad hoc networks, wireless sensor networks, wireless mesh networks, and heterogeneous wired/wireless networks. Yuguang Fang received the BS and MS degrees in Mathematics from Qufu Normal University, Qufu, Shandong, China, in 1984 and 1987, respectively, a Ph.D degree in Systems and Control Engineering from Department of Systems, Control and Industrial Engineering at Case Western Reserve University, Cleveland, Ohio, in January 1994, and a Ph.D degree in Electrical Engineering from Department of Electrical and Computer Engineering at Boston University, Massachusetts, in May 1997. From 1987 to 1988, he held research and teaching position in both Department of Mathematics and the Institute of Automation at Qufu Normal University. From September 1989 to December 1993, he was a teaching/research assistant in Department of Systems, Control and Industrial Engineering at Case Western Reserve University, where he held a research associate position from January 1994 to May 1994. He held a post-doctoral position in Department of Electrical and Computer Engineering at Boston University from June 1994 to August 1995. From September 1995 to May 1997, he was a research assistant in Department of Electrical and Computer Engineering at Boston University. From June 1997 to July 1998, he was a Visiting Assistant Professor in Department of Electrical Engineering at the University of Texas at Dallas. From July 1998 to May 2000, he was an Assistant Professor in the Department of Electrical and Computer Engineering at New Jersey Institute of Technology, Newark, New Jersey. In May 2000, he joined the Department of Electrical and Computer Engineering at University of Florida, Gainesville, Florida, where he got early promotion to Associate Professor with tenure in August 2003, and to Full Professor in August 2005. His research interests span many areas including wireless networks, mobile computing, mobile communications, wireless security, automatic control, and neural networks. He has published over one hundred and fifty (150) papers in refereed professional journals and conferences. He received the National Science Foundation Faculty Early Career Award in 2001 and the Office of Naval Research Young Investigator Award in 2002. He also received the 2001 CAST Academic Award. He is listed in Marquis Who’s Who in Science and Engineering, Who’s Who in America and Who’s Who in World. Dr. Fang has actively engaged in many professional activities. He is a senior member of the IEEE and a member of the ACM. He is an Editor for IEEE Transactions on Communications, an Editor for IEEE Transactions on Wireless Communications, an Editor for IEEE Transactions on Mobile Computing, an Editor for ACM Wireless Networks, and an Editor for IEEE Wireless Communications. He was an Editor for IEEE Journal on Selected Areas in Communications: Wireless Communications Series, an Area Editor for ACM Mobile Computing and Communications Review, an Editor for Wiley International Journal on Wireless Communications and Mobile Computing, and Feature Editor for Scanning the Literature in IEEE Personal Communications. He has also actively involved with many professional conferences such as ACM MobiCom’02 (Committee Co-Chair for Student Travel Award), MobiCom’01, IEEE INFOCOM’06, INFOCOM’05 (Vice-Chair for Technical Program Committee), INFOCOM’04, INFOCOM’03, INFOCOM’00, INFOCOM’98, IEEE WCNC’04, WCNC’02, WCNC’00 (Technical Program Vice-Chair), WCNC’99, IEEE Globecom’04 (Symposium Co-Chair), Globecom’02, and International Conference on Computer Communications and Networking (IC3N) (Technical Program Vice-Chair).     

RObust Header Compression (ROHC) Performance for Multimedia Transmission over 3G/4G Wireless Networks

RObust Header Compression (ROHC) has recently been proposed to reduce the large protocol header overhead when transmitting voice and other continuous media over IP based protocol stacks in wireless networks. In this paper we evaluate the real-time transmission of GSM encoded voice and H.26L encoded video with ROHC over a wireless link. For the voice transmission we examine the impact of ROHC on the consumed bandwidth, the voice quality, and the delay jitter in the voice signal. We find that for a wide range of error probabilities on the wireless link, ROHC roughly cuts the bandwidth required for the transmission of GSM encoded voice in half. In addition, ROHC improves the voice quality compared to transmissions without ROHC, especially for large bit error probabilities on the wireless link. The improvement reaches 0.26 on the 5-point Mean Opinion Score for a bit error probability of 10^–3. For the video transmission we examine the impact of ROHC on the consumed bandwidth. We find that the bandwidth savings with ROHC depend on the quantization scale used for the video encoding and the video content and ranges between 5–40% for typical scenarios.Frank H.P. Fitzek is an Associate Professor in the Department of Communication Technology, University of Aalborg, Denmark heading the Future Vision group. He received his diploma (Dipl.-Ing.) degree in electrical engineering from the University of Technology – Rheinisch-Westflische Technische Hochschule (RWTH) – Aachen, Germany, in 1997 and his Ph.D. (Dr.-Ing.) in Electrical Engineering from the Technical University Berlin, Germany in 2002. As a visiting student at the Arizona State University he conducted research in the field of video services over wireless networks. He co-founded the start-up company acticom GmbH in Berlin in 1999. In 2002 he was Adjunct Professor at the University of Ferrara, Italy giving lectures on wireless communications and conducting research on multi-hop networks. His current research interests are in the areas of 4G wireless communication, QoS support for multimedia services, access techniques, security for wireless communication, and the integration of multi hop networks in cellular systems. Dr. Fitzek serves on the Editorial Board of the IEEE Communications Surveys and Tutorials. He is the program chair for the International Conference on Advances in Computer Entertainment Technology (ACE2004) and serves in the program committee for VTC2003, VTC2004, ACE2004, and IEEE MWN2004.Stephan Rein studied Electrical Engineering at the Technical University of Aachen, Germany, and the Technical University of Berlin (TUB), Germany. He received the Dipl.-Ing. degree in electrical engineering from the TUB in 2003. From March 2003 to October 2003 he visited the multimedia networking group in the Department of Electrical Engineering at Arizona State University, Tempe. He is currently pursuing the Ph.D. degree at the Institute for Energy and Automation Technology, Technical University of Berlin. His current research interests include data compression and digital signal processing with emphasis on wavelet theory.Patrick Seeling received the Dipl.-Ing. degree in industrial engineering and management (specializing in electrical engineering) from the Technical University of Berlin (TUB), Germany, in 2002. Since 2003 he has been a Ph.D. student in the Department of Electrical Engineering at Arizona State University. His research interests are in the area of video communications in wired and wireless networks. He is a student member of the IEEE and the ACM.Martin Reisslein is an Assistant Professor in the Department of Electrical Engineering at Arizona State University, Tempe. He received the Dipl.-Ing. (FH) degree from the Fachhochschule Dieburg, Germany, in 1994, and the M.S.E. degree from the University of Pennsylvania, Philadelphia, in 1996. Both in electrical engineering. He received his Ph.D. in systems engineering from the University of Pennsylvania in 1998. During the academic year 1994–1995 he visited the University of Pennsylvania as a Fulbright scholar. From July 1998 through October 2000 he was a scientist with the German National Research Center for Information Technology (GMD FOKUS), Berlin. While in Berlin he was teaching courses on performance evaluation and computer networking at the Technical University Berlin. He is editor-in-chief of the IEEE Communications Surveys and Tutorials and has served on the Technical Program Committees of IEEE Infocom, IEEE Globecom, and the IEEE International Symposium on Computer and Communications. He has organized sessions at the IEEE Computer Communications Workshop (CCW). He maintains an extensive library of video traces for network performance evaluation, including frame size traces of MPEG-4 and H.263 encoded video, at . He is co-recipient of the Best Paper Award of the SPIE Photonics East 2000 – Terabit Optical Networking conference. His research interests are in the areas of Internet Quality of Service, video traffic characterization, wireless networking, and optical networking.     

Performance Analysis of Header Compression Schemes in Heterogeneous Wireless Multi–Hop Networks

Wireless multi–hop networks are becoming more popular and the demand for multimedia services in these networks rises with the number of their implementations. Header compression schemes that compress the IP/UDP/RTP headers to save bandwidth for multimedia streams were typically evaluated only for individual links, not taking into account the savings that can be achieved using header compression over a complete path. In this paper, we evaluate the performance of three categories of header compression schemes: (i) delta coding, (ii) framed delta coding, and (iii) framed referential coding. We evaluate the performance for these schemes on reliable and unreliable links. We then extend our evaluations to several links constituting a path. As nodes in multi–hop ad-hoc and mesh networks may differ with respect to their capabilities, we assume in our evaluation that (forwarding) nodes may not be able or choose not to perform header compression. We find that the framed referential header compression scheme is the most suitable scheme in case that no or long-delay feedback channels exist. We additionally compare the packet drop savings due to header compression and the combined savings of compression and drops. We again find that the framed referential coding scheme exhibits good performance that can lead to significant header compression and packet drop savings for reasonable bit error rates. Patrick Seeling is a Faculty Research Associate in the Department of Electrical Engineering at Arizona State University (ASU), Tempe. He received the Dipl.-Ing. degree in Industrial Engineering and Management (specializing in electrical engineering) from the Technical University of Berlin (TUB), Germany, in 2002. He received his Ph.D. in electrical engineering from Arizona State University, Arizona, in 2005. His research interests are in the area of multimedia communications in wired and wireless networks and engineering education. He is a member of the IEEE and the ACM. Martin Reisslein is an Associate Professor in the Department of Electrical Engineering at Arizona State University (ASU), Tempe. He received the Dipl.-Ing. (FH) degree from the Fachhochschule Dieburg, Germany, in 1994, and the M.S.E. degree from the University of Pennsylvania, Philadelphia, in 1996. Both in electrical engineering. He received his Ph.D. in systems engineering from the University of Pennsylvania in 1998. During the academic year 1994–1995 he visited the University of Pennsylvania as a Fulbright scholar. From July 1998 through October 2000 he was a scientist with the German National Research Center for Information Technology (GMD FOKUS), Berlin and lecturer at the Technical University Berlin. From October 2000 through August 2005 he was an Assistant Professor at ASU. He is editor-in-chief of the IEEE Communications Surveys and Tutorials and has served on the Technical Program Committees of IEEE Infocom, IEEE Globecom, and the IEEE International Symposium on Computer and Communications. He has organized sessions at the IEEE Computer Communications Workshop (CCW). He maintains an extensive library of video traces for network performance evaluation, including frame size traces of MPEG-4 and H.263 encoded video, at http://trace.eas.asu.edu. He is co-recipient of the Best Paper Award of the SPIE Photonics East 2000 – Terabit Optical Networking conference. His research interests are in the areas of Internet Quality of Service, video traffic characterization, wireless networking, optical networking, and engineering education. Tatiana K. Madsen has received her M.Sc. and Ph.D. degrees in Mathematics from Moscow State University, Russia in 1997 and 2000, respectively. In 2001 she joined Dept. of Communication Technology, Aalborg University, Denmark where she is currently an Assistant Professor. Her research interests lie within the areas of wireless networking with the focus on IP header compression techniques and mathematical modeling of wireless protocols behavior. Frank Fitzek is an Associate Professor in the Department of Communication Technology, Unversity of Aalborg, Denmark heading the Future Vision gorup. He received his diploma (Dipl.-Ing.) degree in electrical engineering from the University of Technology – Rheinish-Westflische Technische Hochschule (RWTH) – Aachen, Germany, in 1997 and his Ph.D. (Dr.-Ing.) in Electrical Engineering from the Technical Univeristy Berlin, Germany in 2002 for quality of service support in wireless CDMA networks. As a visiting student at the Arizona State University he conducted research in the field of video services over wireless networks. He co-founded the start-up company acticom GmbH in Berlin in 1999. In 2002 he was Adjunct Professor at the University of Ferrara, Italy giving lectures on wireless communications and conducting research on multi-hop networks. In 2005 he won the YRP award for the work on MIMO MDC. His current research interests are in the areas of 4G wireless communication networks and cooperative networking. Dr. Fitzek serves on the Editorial Board of the IEEE Communications Surveys and Tutorials.     

Analytical Study of TCP Performance over IEEE 802.11e WLANs

IEEE 802.11 Wireless LAN (WLAN) has become a prevailing solution for broadband wireless Internet access while the Transport Control Protocol (TCP) is the dominant transport-layer protocol in the Internet. Therefore, it is critical to have a good understanding of the TCP dynamics over WLANs. In this paper, we conduct rigorous and comprehensive modeling and analysis of the TCP performance over the emerging 802.11e WLANs, or more specifically, the 802.11e Enhanced Distributed Channel Access (EDCA) WLANs. We investigate the effects of minimum contention window sizes and transmission opportunity (TXOP) limits (of both the AP and stations) on the aggregate TCP throughput via analytical and simulation studies. We show that the best aggregate TCP throughput performance can be achieved via AP’s contention-free access for downlink packet transmissions and the TXOP mechanism. We also study the effects of some simplifying assumptions used in our analytical model, and simulation results show that our model is reasonably accurate, particularly, when the wireline delay is small and/or the packet loss rate is low.

Coordinated load balancing, handoff/cell-site selection, and scheduling in multi-cell packet data systems

We investigate a wireless system of multiple cells, each having a downlink shared channel in support of high-speed packet data services. In practice, such a system consists of hierarchically organized entities including a central server, Base Stations (BSs), and Mobile Stations (MSs). Our goal is to improve global resource utilization and reduce regional congestion given asymmetric arrivals and departures of mobile users, a goal requiring load balancing among multiple cells. For this purpose, we propose a scalable cross-layer framework to coordinate packet-level scheduling, call-level cell-site selection and handoff, and system-level cell coverage based on load, throughput, and channel measurements. In this framework, an opportunistic scheduling algorithm—the weighted Alpha-Rule—exploits the gain of multiuser diversity in each cell independently, trading aggregate (mean) downlink throughput for fairness and minimum rate guarantees among MSs. Each MS adapts to its channel dynamics and the load fluctuations in neighboring cells, in accordance with MSs’ mobility or their arrival and departure, by initiating load-aware handoff and cell-site selection. The central server adjusts schedulers of all cells to coordinate their coverage by prompting cell breathing or distributed MS handoffs. Across the whole system, BSs and MSs constantly monitor their load, throughput, or channel quality in order to facilitate the overall system coordination. Our specific contributions in such a framework are highlighted by the minimum-rate guaranteed weighted Alpha-Rule scheduling, the load-aware MS handoff/cell-site selection, and the Media Access Control (MAC)-layer cell breathing. Our evaluations show that the proposed framework can improve global resource utilization and load balancing, resulting in a smaller blocking rate of MS arrivals without extra resources while the aggregate throughput remains roughly the same or improved at the hot-spots. Our simulation tests also show that the coordinated system is robust to dynamic load fluctuations and is scalable to both the system dimension and the size of MS population. Aimin Sang received a Ph.D. from the University of Texas at Austin in 2001. His Ph.D. dissertation is on the measurement-based traffic management for QoS guarantee in multi-service networks. From May 2000 to July 2002, he was a member of technical staff and software engineer at Santera System Inc., a startup company in designing and implementing the next-generation multi-service gateway. His duty was to design, implement, and test core traffic management algorithms on the switch fabric and control boards, integrating IP routing, ATM switching, and Class 4 and 5 telephony switching functionalities for multi-service Internet access at the Central Offices. From July 2002 to Nov. 2002, he was a post-doc at UT-Austin, researching on VPN provisioning and ad hoc sensor networks. He joined NEC Lab America in Nov. 2002. Dr. Sang is currently a research staff member in Broadband & Mobile Networking Department, NEC Lab. America, focusing on cross-layer design of 4G wireless systems, such as 4G Cellular base station, WiMax/WLAN systems, and their inter-networking architecture. His duty is to develop the core technologies including the radio resource management and QoS schemes over an IP-optimized MC-CDMA or OFCDM/MIMO air interfaces. He is also interested in ad hoc sensor networks and personal area networks. Xiaodong Wang received the B.S. degree in Electrical Engineering and Applied Mathematics (with the highest honor) from Shanghai Jiao Tong University, Shanghai, China, in 1992; the M.S. degree in Electrical and Computer Engineering from Purdue University in 1995; and the Ph.D degree in Electrical Engineering from Princeton University in 1998. From July 1998 to December 2001, he was an Assistant Professor in the Department of Electrical Engineering, Texas A&M University. In January 2002, he joined the faculty of the Department of Electrical Engineering, Columbia University. Dr. Wang’s research interests fall in the general areas of computing, signal processing and communications. He has worked in the areas of digital communications, digital signal processing, parallel and distributed computing, nanoelectronics and bioinformatics, and has published extensively in these areas. Among his publications is a recent book entitled “Wireless Communication Systems: Advanced Techniques for Signal Reception”, published by Prentice Hall, Upper Saddle River, in 2003. His current research interests include wireless communications, Monte Carlo-based statistical signal processing, and genomic signal processing. Dr. Wang received the 1999 NSF CAREER Award, and the 2001 IEEE Communications Society and Information Theory Society Joint Paper Award. He currently serves as an Associate Editor for the IEEE Transactions on Communications, the IEEE Transactions on Wireless Communications, the IEEE Transactions on Signal Processing, and the IEEE Transactions on Information Theory. Mohammad Madihian received the Ph.D. Degree in Electronic Engineering from Shizuoka University, Japan, in 1983. He joined NEC Central Research Laboratories, Kawasaki, Japan, where he worked on research and development of Si and GaAs device-based digital as well as microwave and millimeter-wave monolithic IC’s. In 1999, he moved to NEC Laboratories America, Inc., Princeton, New Jersey, and is presently the Department Head and Chief Patent Officer. He conducts PHY/MAC layer signal processing activities for high-speed wireless networks and personal communications applications. He has authored or co-authored more than 130 scientific publications including 20 invited talks, and holds 35 Japan/US patents. Dr. Madihian has received the IEEE MTT-S Best Paper Microwave Prize in 1988, and the IEEE Fellow Award in 1998. He holds 8 NEC Distinguished R&D Achievement Awards. He has served as Guest Editor to the IEEE Journal of Solid-State Circuits, Japan IEICE Transactions on Electronics, and IEEE Transactions on Microwave Theory and Techniques. He is presently serving on the IEEE Speaker’s Bureau, IEEE Compound Semiconductor IC Symposium (CSICS) Executive Committee, IEEE Radio and Wireless Conference Steering Committee, IEEE International Microwave Symposium (IMS) Technical Program Committee, IEEE MTT-6 Subcommittee, IEEE MTT Editorial Board, and Technical Program Committee of International Conference on Solid State Devices and Materials (SSDM). Dr. Madihian is an Adjunct Professor at Electrical and Computer Engineering Department, Drexel University, Philadelphia, Pennsylvania. Richard D. Gitlin Is currently President of Innovatia Networks a wireless startup company and a member of the Board of Directors of PCTEL [NASDAQ: PCTI]. Previously he was Visiting Professor of Electrical Engineering at Columbia University and Vice President, Technology of NEC Laboratories America. After receiving his doctorate from Columbia University, he was with Lucent Technologies (Bell Labs), where for more than 32 years he held several research and executive positions, including Senior Vice President, Communications Systems Research and Chief Technical Officer and VP of R&D of Lucent’s Data Networking Business Unit. Throughout his career Dr. Gitlin has both personally conducted and led pioneering research and development in digital communications and networking, digital signal processing, wireless systems, and broadband networking that has resulted in many innovative products, including: the industry leading ATLANTA ATM Chipset, the world’s first 20 gigabit/sec ATM switch, wire-speed and quality of service [QoS]-aware IP switches, multicode CDMA (IS-95B), and the record-setting BLAST broadband fixed-wireless loop system based on advanced spatial domain (smart antenna) processing. Earlier in his career he led the team that pioneered the V.32/V.34 voice-band modems, and in 1986 he was a co-inventor of the DSL technology. He has more than 90 referred publications, is the recipient of three prize papers, has delivered numerous keynotes, and he holds 43 US patents, and co-author of the text Data Communications. He currently serves on the Editorial Boards of Mobile Networks and Applications and the Journal of Communications Networks (JCN). Dr. Gitlin has been elected as a member of the US National Academy of Engineering, is a Fellow of the IEEE, and is a Bell Laboratories Fellow. Dr. Gitlin has served as Chair of the Communication Theory Committee of the IEEE Communications Society, as a member of the COMSOC Awards Board, as Editor for communication theory of the IEEE Transactions on Communications, as a member of the Board of Governors of the IEEE Communications Society, and a member of the Nominations and Elections Board. He has served on the Advisory Committee for Computer Science and Engineering (CISE) of the National Science Foundation.