Bell Telephone Laboratories

During his thirteen-year tenure, Dr. Lucantoni was involved in several projects dealing with leading edge technology, including:

• As discussed elsewhere, Dr. Lucantoni’s patents on ATM congestion control have been incorporated into the international standards for ATM equipment manufacturers. These have resulted in over 100 million dollars for Lucent Technologies’ patent licensing program and were recognized with the Lucent Technologies’ Patent Recognition Award in 2000.
• Defined overall control architecture, incorporating end-to-end flow control, traffic shaping capabilities and higher layer control functions; portions have been incorporated into inter-national standards.
• Using exact and approximate models quantified the multiplexing gain for a large number of bursty sources and the impact on engineering of ATM networks.
• Using exact models demonstrated that predictions based on the popular notions of “effective bandwidth” could be arbitrarily poor; proposed more accurate approximations.
• Derived and solved analytically tractable models for quantifying the effectiveness of the “throughput-burstiness filter.”
• Performed analytic modeling to assess the effectiveness of several selective cell discard mechanisms for congestion control in broadband networks using models and analysis, formulated specific recommendations for switched virtual circuit call acceptance/denial algorithms and for bandwidth-on-demand negotiation algorithm.

• Developed algorithms for numerically computing an arbitrary number of moments as well as the exact asymptotic behavior of a distribution function from its transform.
• Contributed to the development of algorithms for numerically inverting multidimensional Laplace-Stieltjes transforms and/or probability generating functions (with an important application of allowing numerical computations to be performed for various transient queueing models).
• Drastically simplified analysis and algorithms for a large class of complex queueing models (BMAP/G/1 queue), which also include multiplexed, highly correlated arrival streams.
• Derived exact solutions and numerical algorithms for computing the transient performance measures of the above class of models; this framework allows new insights into the problems of overload control and call acceptance algorithms for broadband networks.
• Combined transform/eigen-analysis approach with the matrix-geometric method to solve important class of voice and data queueing models.
• Introduced the, now popular, Markovian Arrival Process (MAP) as a versatile and tractable class which includes both renewal and non-renewal point processes.
• Solved the queue with vacations using above model; generalized known factorization results to the non-renewal case and obtained new factorization results.
• Derived an enormously improved approach for solving the nonlinear matrix functional equation arising in the matrix analytic solution to phase-type queues.
• Provided the first general proof that the key transform matrix involved in solving stochastic models of the “M/G/1 Type” was the unique minimal solution to a non-linear, matrix functional equation.

• Developed Markov renewal model for sizing leaky bucket parameters for call setup algorithms.
• Defined two novel measures of goodness-of-fit of a model to data.

• Derived powerful, and widely used, methodology for approximating superposition’s of complicated arrival streams (such as packetized voice) by simpler, tractable processes (e.g., Markov modulated Poisson processes)
• Derived analytic model of bit-dropping in packetized voice which demonstrated (and explained why) a Poisson process was an accurate model for predicting performance.

• Derived and solved (using state-of-the-art solution techniques) an analytic model of the LAPD protocol incorporating timers, retransmissions, polls, etc., in conjunction with a variety of end-terminal window adaptation procedures and network throughput enforcement controls.

• Assisted in design of terminal adapters for frame-relay networks by identifying performance degradations resulting from interactions of pipelining and protocol windowing.

• Derived matrix-analytic performance assessment methodology for a synchronous self-routing packet switching fabric, which quantified impact of traffic burstiness and effects of switch parameters.

• Responsible for performance of new modules required to support ISDN on existing digital switches (e.g., the 5ESS).
• Provided developers with a variety of performance inputs which affected microprocessor selections, buffer sizing, capacity planning, etc.

• Designed and analyzed a system level overload control; potential system throughput degradation under overload was identified; proposed a simple fix which was implemented in the system.