- RESEARCH - CLASSES
Brief Overview of Selective Research Areas and Breakthrough
- Stochastic Modeling
and Detection of Stochastic Point and Jump Processes.
Development of fundamental stochastic models and
likelihood ratios for the detection and processing of information processes
that are modeled as stochastic point and jump processes.
- Information Rates
and Data Compression for Poisson Sequences and Processes
Derivation of the Rate-Distortion functions for
Poisson sequences and processes, identifying the performance of the ‘best’
compression mechanism for information streams that are modeled as such
- Basic Queueing
Delay Analysis for Communications Network Systems
Breakthrough development of methods for the modeling
and calculation of packet and message queueing delay distributions in
- Delay Capacity
Product for packet-Switching Computer Communications Networks
Development of conservation and separation principles
for the synthesis of packet switching networks relating to the network’s
product of overall capacity and message delay performance.
- Synthesis of
Reliable Topologies for Communications Networks
Synthesis of optimal network topologies under diameter
(delay), total link (capacity) and connectivity constrains.
- ARQ Error-control
for TDMA Multiple Access Communications Channels
Analysis and design of stop-and-wait, Go-Back-N
(window based) and Selective-Repeat ARQ schemes.
- Modeling, Analysis
and Design of Medium Access Control (MAC) Protocols and Algorithms for
Multiple Access Communications Channels
Extensive on-going developments of new architectures,
algorithms and protocols to control the operation of a multiple access
communications channels and network.
Classes of algorithms include: fixed assigned (TDMA, FDMA, CDMA, SDMA);
demand assigned: polling and reservation based; random access: pure and dynamic
group random access, CSMA and CSMA/CA based, and many others; Hybrid protocols.
- Modeling and
Analysis of Communications Network Systems when subjected to Fluctuating
Traffic Processes and to Traffic Characterized by Long Range
Analysis of queueing systems under bursty traffic
conditions; modeling of LRD traffic by Multi-Fractal processes; performance behavior
and design of communications network systems when subjected to traffic that is
modeled by the latter processes.
Data/Voice and Multimedia Multiplexers and Multiple Access Networks
Mechanisms and analytical modeling and evaluation
methods for multiplexing and multiple access systems that are shared by data,
voice and video processes as well as by
other multimedia traffic flows.
- Network Management
and Integrated System Management
Fundamental concepts, models and architectures
involving monitoring and control management operations in communications
networks. Tradeoffs involving monitoring
precision, capacity utilization and control responsiveness and efficacy. Integrated system management for ad hoc
wireless network systems that involve combined resource allocations for
communications and sensor subsystems.
- Input-Rate Flow
Control for Communications Networks and QoS based operations. Modeling and Analysis of ATM switching
Systems and Networks
Analysis and design of input-rate flow control
mechanism under desired user-perceived performance measures. ATM switching systems.
- Modeling, Analysis and Design of Cellular
Wireless Network Systems
Analysis and design of networking protocols and
algorithms for cellular wireless networks, including multiple access
mechanisms, handoff methods, optimal selection of the Location Update zones;
forward and reverse signaling channels.
- Analysis and Design
of Load Adaptive Networking Protocols and Algorithms for Wideband Packet
Load adaptive TDMA procedures and algorithms for
efficient operation of packet based satellite networks. Development of the theory of capacity varying
networks and its application to the analysis and design of low altitude satellite
networks (including best paper award).
- Analysis and Design
of Local Area Networks
Modeling and analysis of random access, token ring,
FDDI and other local area networks.
Information Theory and Network Theory based models and Congestion Adaptive
Compression Processing Ideally Characterized by the Delay-Distortion
Development of approaches for the design of
communications network systems integrating and combining the use of information
theory to characterize the error-rate vs. information rate behavior, and
incorporating queueing theory to exhibit the system’s delay-throughput
behavior. Definition and
characterization of the Delay-Distortion function that described the ideally
best combined compression (via a distortion measure) and congestion (via a
packet delay measure) operation.
Congestion state adaptive voice and video compression algorithms.
Development of fundamental concepts and architectures
for all optical circuit and packet switched operations across network systems,
including ring and meshed ring network systems.
Development of the concept of shuttle networking for all-optical
operation across such network systems.
Synthesis of all-optical ring and meshed ring networks.
Concepts for networking operations that require
reduced processing at the routers and switches.
- Ad Hoc Wireless
Networking using Mobile Backbones: Mobile Backbone Networks (MBNs)
New mechanisms for ad hoc wireless networking based on
the dynamic formation of mobile backbones.
On-going innovative developments include: topology synthesis algorithms for the
backbone networks; robust routing; on-demand MBN based routing using flow
control schemes to provide for guaranteed QoS support; hybrid backbone and non-backbone
operation. Cross MAC/network layer
- Unmanned Vehicle
Aided Multi-tier Ad Hoc Wireless Networks
Use of unmanned ground vehicles (UGVs) and unmanned
airborne vehicles (UAVs) to best support the operation of MBN based ad hoc
wireless networks. UAV swarm
networks. Development of new measures
for characterizing the desired performance of user streams and flows when
served by mobile ad hoc wireless networks.
Use of the new measures to control and guide the placement of UGVs and
UAVs to best support client message flows and streams.
Spatial-Reuse Scheduling and combined Routing/Scheduling MAC Algorithms
for Multiple Access Channels and Ad Hoc Wireless Networks
Development of fundamental results of key theoretical
and practical importance for the derivation of MAC schedules (channel resource
allocations) and transmit power assignments based on realistic SINR based
interference models. Substantial
throughput upgrade of current scheduling oriented (such as TDMA and CDMA based)
MAC operations. Proofs that higher power
operations, and not lower transmit power ones, can yield substantial
performance improvement. New partial
coloring oriented scheduling algorithms.
Centralized and distributed network operations.
Spatial-Reuse CSMA based MAC Algorithms for Multiple Access Channels and
for Multi-Hop Ad Hoc Wireless Networks
algorithms for the joint MAC scheduling and selection of transmit power
levels in a IEEE 802.11 CSMA/CA type MAC system based on monitored channel
congestion state. Significant
improvement of throughput and fairness oriented behavior.
- Use of UAV Swarms
for Enhanced Search Operations
Synthesis and performance evaluation of area search
layouts for UAV swarm teams. Comparisons
with random search operations.