Leandros Tassiulas has revolutionized how scheduling and stability analysis are performed in communications networks, providing dynamic resource allocation tools to improve performance of wireless networks and Internet switches. Developing control algorithms based on a sound mathematical foundation as an alternative to heuristic approaches, Tassiulas introduced the Max-Weight scheduling algorithm for achieving maximum throughput in systems with conflicting resources as well as the Backpressure routing algorithm for end-to-end traffic forwarding. His Maximum Connected Queue algorithm introduced the concept of opportunistic scheduling that became part of most wireless standards since 3G. Together, these three algorithms provide the basis for cross-layer network design in today’s wireless networks.
An IEEE Fellow, Tassiulas is the John C. Malone Professor in the Electrical Engineering Department and the Institute for Network Science at Yale University, New Haven, CT, USA.
A visionary computer-networking expert, Albert G. Greenberg has revolutionized how industry designs and operates large-scale backbone and data-center networks critical to today’s “cloud” services and other applications. Dr. Greenberg’s “fair queuing” scheduling algorithm helped transform AT&T from a voice- to an Internet Protocol-services company. He was instrumental in creating tools for network tomography and Internet Protocol measurement, fault diagnosis, and network management now used in AT&T’s operational systems and networks. He then transformed data-center network operations at Microsoft with virtual networks that operate on shared infrastructures but behave like they are dedicated to individual customers. His VL2 architecture provides an 80-time improvement in cost, availability, and response time over existing designs and is the architecture of choice for Microsoft data-center networks, including Xbox, Bing, and Azure.
An IEEE Member, Dr. Greenberg is a Distinguished Engineer and director of Microsoft Azure, Redmond, WA, USA.
George Varghese’s powerful algorithms for packet-switching networks are an integral part of Internet routers, enabling data transfer that is safer, faster, and more reliable. Dr. Varghese pioneered the development of network algorithmics, which has enabled the proliferation of packet-switched networks. Network algorithmics involves changing hardware and operating systems and applying efficient algorithms to reduce Internet bottlenecks. Dr. Varghese’s Deficit Round Robin packet scheduling algorithm supports real-time audio and video over the Internet and has been incorporated into practically every Internet router used. His algorithms for fast Internet protocol lookups overcame the perception that route lookup was slow.
An Association for Computing Machinery Fellow, Dr. Varghese is currently a principal researcher with Microsoft Research, Mountain View, CA, USA. He was formerly a professor at University of California, San Diego, CA, USA and earlier at Washington University, St. Louis, MO, USA.
Thomas Anderson’s trailblazing network computing research has improved the understanding of Internet routing behavior and provided tools crucial to advancing Internet efficiency, reliability, and security. Anderson has developed novel techniques to understand, diagnose, and repair broken or pathological Internet routes essential to reducing the high number of service outages that occur daily around the world. Working with colleagues, Anderson was able to show that the shortest Internet path from point A to B is often not the direct path but rather one from A to C to B, and he developed a practical tool for identifying router-level paths in the reverse direction back to the source. He has also created protocols for addressing Internet denial-of-service attacks and reducing outages due to route protocol convergence.
An Association for Computing Machinery Fellow, Dr. Anderson is the Robert E. Dinning Professor of Computer Science and Engineering at the University of Washington, Seattle, WA, USA.
Jean Walrand’s research on high-speed switching and network resource allocation has improved performance for more efficient and reliable communication over the Internet. During the 1990s, Dr. Walrand developed quick simulation techniques for queuing networks to estimate the probability of events that can have catastrophic consequences in communications networks. He also developed virtual buffers to improve the marking of data packets to help detect when a router is reaching its maximum capacity. Dr. Walrand’s award-winning work on high-speed switching for queued networks initiated in 1993 investigated a method to allow Internet routers to reach 100% efficiency, overcoming the problem of “head of the line blocking.” Dr. Walrand’s contributions to network resource allocation include the concept of virtual bandwidth and work on fair end-to-end window-based congestion control. His recent research has focused on distributed schemes for resource allocation applied to switches, wireless multihop networks, and allocations in data centers.
An IEEE Fellow, Dr. Walrand is currently a professor with the Electrical Engineering and Computer Sciences Department at the University of California, Berkeley, CA, USA.
Considered the world’s foremost experts on iterative decoding, Thomas J. Richardson and Rüdiger Urbanke have helped optimize data transmission rates for wireless and optical communications and digital information storage. To approach “Shannon’s limit,” which established the maximum rate for communications over a noisy channel, they expanded on low density parity check (LDPC) codes and provided new tools for understanding the complexities of iterative decoding procedures. The result has been reliable data transmission at rates close to channel capacity but with low complexities. Three landmark papers by Drs. Richardson and Urbanke appearing in the February 2001 issue of the IEEE Transactions on Information Theory successfully addressed the obstacles facing the development of capacity-approaching codes. Their work showed that LDPC codes could very closely approach the Shannon limit, showed how to design irregular LDPC codes and provided methods for efficiently encoding LDPC codes. They introduced the density evolution technique, on which practically all subsequent work on LDPC codes is based.
An IEEE Fellow, Dr. Richardson is currently vice president of engineering at Qualcomm Inc., Bridgewater, N.J.
Dr. Urbanke is currently a professor with the Communications and Computer Sciences Department at the École Polytechnique Fédérale de Lausanne, Switzerland.
Larry Peterson, a leader of experimental research that evaluates new ideas through large-scale worldwide deployment studies incorporating real prototypes, has revolutionized networking research. Dr. Peterson’s PlanetLab has provided researchers with the ability to actually deploy and test distributed systems projects that were previously limited to paper studies and simulation. Initially deployed in 2002, it is currently the most widely used and influential platform for networking and distributed systems research. PlanetLab is a set of servers distributed across the Internet on which researchers can install and operate widely distributed systems such as content delivery networks, file sharing protocols, and network measurement tools. Incorporating over 1,000 computers at 485 sites spread among over 40 countries and used by over 4,000 researchers, it has led to major innovations in distributed systems and has inspired many other platforms for network virtualization and distributed networks.
An IEEE Fellow, Dr. Peterson is currently the Robert E. Kahn Professor of Computer Science at Princeton University, Princeton, NJ, USA.
Considered the dominant contributor to both the theory and practice of switching technology, Nick McKeown’s work influenced modern router design, overcoming existing bottlenecks and enabling the phenomenal growth of the Internet during the 1990s. His Bay Bridge router in 1992 was the first example of line-rate processing of data packets by a programmable processor and was considered the world’s fastest router. His work on input-queued switches with virtual output queues in 1995 revolutionized how routers were built and enabled a ten-fold increase in capacity compared to previous routers, becoming the basis for Cisco Systems’ GSR router, which made up 75% of the backbone of the Internet. Dr. McKeown also determined that packet buffers could be made much smaller and developed a new caching system for the routers that allowed the use of less-expensive DRAM chips for “network memory,” saving the industry hundreds of millions of dollars.
An IEEE Fellow, Dr. McKeown is currently an associate professor of electrical engineering and computer science at Stanford University, Palo Alto, California, USA.
One of the world’s leading researchers in cryptography, Don Coppersmith was part of the IBM team that developed the Data Encryption Standard (DES). Used in financial and Internet applications since 1977, DES is an established U.S. government standard for commercial encryption. Currently, Dr. Coppersmith is a research staff member at the Center for Communications Research (CCR), Institute for Defense Analyses, Princeton, N.J. His work with Shmuel Winograd on the complexity of matrix multiplication pushed the boundaries of computational complexity theory and has gained much renown. One of his most significant breakthroughs in cryptanalysis was his ultra-fast algorithm for discrete logarithms. An IEEE Fellow, Coppersmith is a four-time winner of the William Lowell Putnam Mathematical Competition, and past recipient of an IBM Outstanding Innovation Award. He has authored and co-authored more than 100 technical papers and holds a master’s degree and doctorate in mathematics from Harvard University, Cambridge, MA, USA.
Donald Towsley is a distinguished professor in the Department of Computer Science at the University of Massachusetts in Amherst and a leading scholar in developing foundational modeling and analysis techniques used by researchers worldwide to better understand the performance of computer and communication systems and networks. His seminal work includes network tomography, sample path analysis of networks and analytic modeling of the transmission control protocol.
In the 1980s, he was among the first to develop early models of distributed computer systems and parallel processing systems with a particular focus on scheduling. More recently, he developed foundational techniques for analyzing and studying the propagation of Internet viruses and worms, and his work on the analytical evaluation of TCP throughput is among the most notable results obtained in networking research in the last few years.
An IEEE Fellow, he previously received the IEEE Communications Society William Bennett Prize Paper Award. He is editor in chief of IEEE/ACM Transactions on Networking.
A professor at Columbia University in New York and a former department head at Bell Labs Research in Murray Hill, New Jersey, Professor Nicholas F. Maxemchuk is a networking pioneer. His visionary contributions have opened new avenues and led to groundbreaking new systems – sometimes years before their time.
In 1974, Professor Maxemchuk invented Dispersity Routing, a procedure that is still used in wireless ad hoc networks. In 1983, he invented the Reliable Multicast Protocol (RMP), the first reliable multicast protocol for broadcast networks like Ethernet, and has been used extensively on the Internet. That same year, Professor Maxemchuk also developed Homenet, a CATV (community aided television) network that also carried voice and data using a transmission technique enabling Ethernet protocols to be applied over longer distances. All three technologies proved to be more than 20 years ahead of their time. In 1985, he invented the Manhattan Street Network, so named for its design resembling Manhattan streets and avenues. This metropolitan area network required little or no storage, yet could attain throughputs exceeding 90 percent. The technology was incorporated into high-speed routers and ATM switches, and is being used in experimental optical switches
Professor Maxemchuk invented the Movable Slot TDM, a protocol used to transmit telephone-quality voice on Ethernets without the collisions then routinely occurring in conventional networks. He introduced probabilistic protocol verification, which showed that a protocol performs its intended operation most of the time, and ultimately was the basis for testing telephone protocols.
In 1992, this perceptive researcher foresaw the advent not only of electronic commerce and publishing, but also the importance of security and privacy protection. By separating personal information and using cryptographic techniques, he created an anonymous credit card that made it difficult to associate a person’s purchases and their identity. A year later, he developed a simple, practical watermarking method to protect the copyrights of text documents used in online distribution. This technique, which represents one of his 28 patents, was the first such information hiding method used on the Internet.
An IEEE Fellow, Professor Maxemchuk was the editor-in-chief of the IEEE Journal on Selected Areas in Communication. In 1996, the IEEE Communications Society presented him with the William R. Bennett Prize in the Field of Communications Circuits and Techniques, and has twice presented the Leonard G. Abraham Prize in the Field of Communications Systems to him.
He holds a bachelor’s degree from the City College of New York and a master’s degree from the University of Pennsylvania in Philadelphia, both in electrical engineering, and a doctoral degree in systems engineering, also from the University of Pennsylvania.
Professor of Mathematics of Systems at the University of Cambridge in England, Dr. Frank Kelly's critical insight into the performance and behavior of telecommunications networks and his application of the economic theory of pricing to congestion control and fair resource allocation have reshaped how researchers study future directions for the Internet. In the 1980s, Dr. Kelly and his colleagues at Cambridge and at BT Laboratories, in Martlesham, England, developed Dynamic Alternative Routing (DAR), later deployed in the British Telecom network. DAR is a decentralized adaptive call-routing strategy that relies solely on local information and is simple to both implement and manage. The DAR concept and analysis have influenced the design of reliable call-routing strategies around the world.
Along with his academic responsibilities, Dr. Kelly is chief scientific advisor to the British Department of Transport. He has served on the Scientific Board of Hewlett-Packard's Basic Research Institute in Mathematical Sciences and the Conseil Scientifique of France Telecom.
Bruce Hajek's work has significantly furthered the integration of computers and communications systems. His many papers have taken the chaotic field of communication networking and given it a coherence and conceptual structure that it did not have previously. In the early 1980s, he led research that proved the stability of dynamically controlled ALOHA multiple-access. He and his students also developed algorithms for dynamic routing and transmission scheduling. These innovations showed that determinism in service time minimizes waiting time in network queues.
An IEEE Fellow and a member of the U.S. National Academy of Engineering, he has served as
president of the IEEE Information Theory Society and was among eight winners of the USA Mathematical Olympiad in 1973. Dr. Hajek is a professor in the Electrical and Computer Engineering Department at the University of Illinois at Urbana-Champaign.
Van Jacobson is one of the primary contributors to the technological foundations of today’s Internet. While employed at the Lawrence Berkeley Laboratories in Berkeley, Calif., he collaborated with the Computer Science Research Group at the University of California to help solve the problem of computer congestion. His strategy to handle transmission control protocol congestion, which is used in about 90 percent of all Internet hosts, is widely credited with enabling the Internet to expand to support increasing demands of size and speed. He also has developed numerous other Internet tools used in network diagnosis, data compression, and audio and video conferencing.
Chief scientist at Packet Design in Mountain View, Calif., Mr. Jacobson has written or co-authored dozens of papers in the area of networking technology and received the 2001 ACM Sigcomm Award for Lifetime Achievement.