Dr John Schormans, BSc(Eng) PhD CEng MIET SFHEA
Senior Lecturer
Email: j.schormans@qmul.ac.ukTelephone: +44 20 7882 5351Room Number: Engineering, Eng E301Website: http://www.elec.qmul.ac.uk/people/johns/Office Hours: Tuesday 10:00-11:00, Friday 10:00-11:00
Teaching
Communications Systems (Undergraduate)
This module provides a broad background to communications systems and the associated underlying theory. The module will provide an introduction to the generic communication system model, and how it is affected by noise. This will also include switching networks, PCM and SQNR, voice over packet. It will cover and introduction to information: the information measure, entropy and the binary symmetric channel model; coding: for compression and for error detection and correction.
Network Modeling and Performance (Undergraduate/Postgraduate)
This module develops probabilistic solutions to the problems of information loss and delay in modern, broadband packetised networks. It should be of interest to all students interested in networking and communications, with a particular emphasis on Internet performance and design. The module stresses the appreciation and use of queueing theory, but develops the subject in a simple and intuitive manner, avoiding transform techniques. The use of queueing network simulation as a tool for network performance modelling is also addressed using Opnet Modeler. This module aims to give participants an understanding of basic probabilistic and queueing theoretic techniques and solutions, simulation methods, and detailed methods for broadband traffic control in packetised networks.
Signals and Information (Undergraduate)
This first year module introduces the fundamentals of signals, Fourier Series, information theory and signal statistics. Topics covered include: signal fundamentals such as discrete versus continuous time signals; signal average, energy and power; orthogonality; Fourier Series. The module also provides an introduction to information theory, including the information measure, entropy and the binary symmetric channel. Basic ideas in statistics will also be introduced. It will be taught by a combination of lectures, tutorials and labs.
Research
Research Interests:
My main focus is on analysis, simulation and measurement of packet?based networks, in wired and wireless scenarios. This includes evaluat ing QoE as well as more traditional network performance metrics.
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Current and recent PhD students
Current:
Adrian Woodrough - A network-centric vertical handover algorithm for Mobile Satellite Services
Tianhao Guo - User-Experience Informed Resource Allocation in Wireless Networks
Abdul Wahab - error propagation in measuring QoE from QoS metrics
Nafi Ahmad
Completed
Mujtaba Roshan - Experimenting with network measurements and evaluating user QoE
Amna Wahid - Measurement of Overflow Probability in a Packet Buffer
Xingyu Han - Channel Adaptive Analy sis in Wireless Networks with Application to Routing
Zhong Bo - Heterogeneous Traffic Cross-Layer QoS Provision with Dynamic Spectrum A llocation in OFDM-Based Cognitive Radio Networks
Amna Wahid - Optimising the sampling rate when measuring packet-level performance in p acket networks
Adrian Woodrough (part time, while working for Inmarsat, London, UK) - Analysis of hand-over strategies in satellite net works
Ling Xu - Planning Simulation Run Length in Packet Queues
Vindya Amaradasa - Traffic aggregation techniques for non-FIFO schedulers, 2009
Syeda Samana Naqvi - packet level measurements over wireless MPhil, 2008
Maheen HASIB: Analysis of packet loss probing in packet networks . June 2006
Shaowen LU: A systematic multi-level abstraction approach to error constrained time-stepped accelerated simulation for MANETs . 2006
Sharifah ARIFFIN: Accelerated simulation of a packet buffer with a non-FIFO scheduler . March 2006
Ali RAZA: Layered Space Time Architectures For Mimo Wireless Channels . 2006
Chi Ming LEUNG: Non-Intrusive Measurement in Packet Networks and its Applications . February 2004
Ho I (Athen) MA: Accelerated Simulation of Power-Law Traffic in Packet Networks . September 2003
Robert STEWART, End-toEnd Delay Analysis for Small/Medium Scale IP Networks November 2002
Arif AL-HAMMADI Intel ligent Techniques for VBR Traffic Control in ATM Networks . March 2000
Tijana TIMOTIJEVIC System Level Performance of ATM Transmission over a DS-CDMA Satellite Link April 1999
Sufian YOUSEF, APU, 1995
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ATM NETWORKS: MANAGING THE RESOURCES AND CONTROLLING THE TRAFFIC
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My previous UK government EPSRC research support: |
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IPv4 and IPv6 Performance and QoS - 46PaQ |
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IPv4 and IPv6 Performance and QoS - 46 PaQ |
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Whole System Modelling Of Large-Scale Communication Networks For What-If Evaluation |
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ATM NETWORKS: MANAGING THE RESOURCES AND CO NTROLLING THE TRAFFIC. |
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Focusing on EP/G012628/1< span style="box-sizing: border-box; font-weight: 700;"> Optimal design of performance measurement experiments for complex, large-scale networks, Key Findings:
Broadband packet communications networks, exemplified by the internet, are supporting virtually all information exchange internationally. Packet-lev el performance (packet loss and delay) is the dominant factor controlling user experience of these networks, and as user experience is ultimately the key factor driving commercial success, the key network performance measures must be accurately monitored.
A challenging unsolved problem in packet networking has lo ng been: how do we monitor packet level performance in an optimal fashion? This is equivalent to asking how we can ensure that the samples of loss and delay taken from a network c ontain the maximum amount of information (or that they have minimum variance and bias).
In this project we addressed this question. By modelling networks using Markov state models we have been able to treat network measurement and monitoring as numerical experiments. This crucial step then allowed us to optimise these measurement experiments using the Statistical Theory of the Design Of Experiments (DOE).
The major results of this project includ e a utility based framework for optimisation of packet network measurement, and a new approach to optimal sampling based on the maximisation of Fisher Information. This latter bre akthrough led directly to the development of framework for a new science of DOE that allows the ?items? in any experiment to be inter-connected. This is new, and has the potential to revolutionise the use of DOE across a wide range of domains, including agriculture, drug development, viral-marketing techniques, and social policy research as well as in comm unications networking.
Potential use in non-academic contexts
Potential use in non-academic contexts: Network and Service Providers have an urgent need to accurately monitor the performance of their networks, essentially to ensure that they are meeting the guarantees th at are written into their Service Level Agreements (SLAs). Our research can be used directly to set-up pre-existing network monitoring equipment to ensure that best possible use i s made of the monitoring equipment.
KEY RECENT PAPERS:
Holistic assessment of call centre performance
Smith EA, Schormans JA QoS-Aware Energy-Efficient Cooperative Scheme for Cluster-Based IoT Systems
Song L, Chai KK, Chen Y, Schormans J, Loo J, Vinel A Optimal design of experiments on connected units with application to social networks
Parker BM, Gilmour SG, Schormans J Self-organising cluster-based cooperative load balancing in OFDMA cellular networks
Xu L, Chen Y, Chai KK, Schormans J, Cuthbert L
Optimal design of measurements on queueing systems
Parker BM, Gilmour S, Schormans J, Maruri-Aguilar H
QUEUEING SYSTEMS 79(3-4):365-390 Apr 2015
Increasing throughput in IEEE 802.11 by optimal selection of backoff parameters
Gilmour SG, Schormans JA, Parker BM
IET Networks 4(1):21-29 01 Jan 2015 DOI for this publication
Utility based framework for optimal network measurement
Schormans J, Parker BM, Gilmour SG
IET Networks 4(1):10-20 01 Jan 20 15 DOI for this publication
Evaluating QoE in Cognitive Radio Networks for Improved Network and User Performance
Zhong B, Schormans J, Bodanese E
< p style="box-sizing: border-box; margin-top: 0px; margin-bottom: 10px; color: rgb(51, 51, 51); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; font-size: 14 px;">IEEE COMMUNICATIONS LETTERS 17(12):2376-2379 Dec 2013 Author URL DOI for this publication
Performance comparisons between cellular-only and cellular/WLAN integrated systems based on analytical models
Song G, Yang L, Wu J, Schormans J
Frontiers of Computer Science 7(4):486-495 01 Aug 2013 DOI for this publication
Self-organising cluster-based cooperative load balancing in OFDMA cellular networks
Xu L, Chen Y, Chai KK, Schormans J, Cuthbert L
Wireless Co mmunications and Mobile Computing 2013 DOI for this publication
A Performance Study of Hierarchical Heterogeneous Wireless Integrated Networks
Song G, Wu J, Schormans J, Yang L, Cuthbert L
APPLIED MATHEMATICS & INFORMATION SCIENCES 6(2):497S-504S Apr 2012 Author URL
Erlang's fixed-point approxim ation for performance analysis of HetNets
Song G, Wu J, Schormans J, Cuthbert L
Journal of Applied Mathematics 2012 20 Jun 2012 DOI for this publication
Design of Experiments for Categorical Repeated Measurements in Packet Communication Networks
Parker BM, Gilmour SG, Schormans JA
TECHNOMETRICS 53(4): 339-352 Nov 2011 Author URL DOI for this publication
Publications
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Dai Y, Wijeratne V, Chen Y et al. (2018). User experience aware active queue management in cellular networks. nameOfConference
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Song L, Chai KK, Chen Y et al. (2018). Cooperative Coalition Selection for Quality of Service Optimization in Cluster-Based Capillary Networks. nameOfConference
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Guo T, Huang G, Schormans J et al. (2017). CAP: A ContAct based Proximity service via opportunistic device-to-device relay. nameOfConference
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SCHORMANS JA (2017). Channel Quality Aware Active Queue Management. Computer Science and Electronic Engineering (CEEC), 2017
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Smith EA, Schormans JA (2017). Holistic assessment of call centre performance. nameOfConference
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Song L, Chai KK, Chen Y et al. (2017). QoS-Aware Energy-Efficient Cooperative Scheme for Cluster-Based IoT Systems. nameOfConference
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Wang Y, Chai KK, Chen Y et al. (2017). Energy-aware Restricted Access Window control with retransmission scheme for IEEE 802.11ah (Wi-Fi HaLow) based networks. nameOfConference
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Parker BM, Gilmour SG, Schormans J (2017). Optimal design of experiments on connected units with application to social networks. nameOfConference
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Zhao J, Chai KK, Chen Y et al. (2017). Joint mode selection and resource allocation for machine-type D2D links. nameOfConference
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Song L, Chai KK, Chen Y et al. (2016). Energy efficiency cooperative scheme for cluster-based capillary networks in Internet of Things systems. nameOfConference
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Han X, Schormans J (2016). Cross-layer queueing analysis for aggregated ON-OFF arrivals with adaptive modulation and coding. nameOfConference
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Song L, Chai KK, Chen Y et al. (2016). QPSO-based energy-Aware clustering scheme in the capillary networks for Internet of Things systems. nameOfConference
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Zhao J, Chai KK, Chen Y et al. (2016). Two-level game for relay-based throughput enhancement via D2D communications in LTE networks. nameOfConference
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Wang Y, Li Y, Chai KK et al. (2016). Energy-Aware adaptive restricted access window for IEEE 802.11ah based smart grid networks. nameOfConference
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Wang Y, Chai KK, Chen Y et al. (2016). Energy-delay aware restricted access window with novel retransmission for IEEE 802.11ah networks. nameOfConference
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Wang Y, Li Y, Chai KK et al. (2015). Energy-aware adaptive restricted access window for IEEE 802.11ah based networks. nameOfConference
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Wahid AA, Schormans JA (2015). Bounds on accuracy when estimating the loss probability in a packet buffer. nameOfConference
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SCHORMANS JA (2015). QoS-aware Energy Efficient Cooperative Scheme for Cluster-based IoT Systems. nameOfConference
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Parker BM, Gilmour S, Schormans J et al. (2015). Optimal design of measurements on queueing systems. nameOfConference
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Xu L, Luan Y, Chao K et al. (2015). Channel-aware optimised traffic shifting in LTE-Advanced relay networks. nameOfConference
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Song L, Chai KK, Chen Y et al. (2015). Energy efficient cooperative MISO scheme for cluster-based M2M capillary networks. nameOfConference
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Gilmour SG, Schormans JA, Parker BM (2015). Increasing throughput in IEEE 802.11 by optimal selection of backoff parameters. nameOfConference
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Xu L, Chen Y, Chai KK et al. (2015). Self-organising cluster-based cooperative load balancing in OFDMA cellular networks. nameOfConference
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Schormans J, Parker BM, Gilmour SG (2015). Utility based framework for optimal network measurement. nameOfConference
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Xu L, Luan Y, Chao K et al. (2014). Channel-aware optimised traffic shifting in LTE-Advanced relay networks. nameOfConference
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Wahid AA, Schormans J (2013). Bounding the maximum sampling rate when measuring PLP in a packet buffer. nameOfConference
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Zhong B, Schormans J, Bodanese E (2013). Evaluating QoE in Cognitive Radio Networks for Improved Network and User Performance. nameOfConference
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Song G, Yang L, Wu J et al. (2013). Performance comparisons between cellular-only and cellular/WLAN integrated systems based on analytical models. nameOfConference
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Xu L, Chen Y, Chai KK et al. (2013). Self-organising cluster-based cooperative load balancing in OFDMA cellular networks. nameOfConference
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Xu L, Chen Y, Chai KK et al. (2013). User Relay assisted Traffic Shifting in LTE-Advanced Systems. 77th IEEE Vehicular Technology Conference (VTC2013-Spring)
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Song G, Wu J, Schormans J et al. (2012). Erlang's fixed-point approximation for performance analysis of HetNets. nameOfConference
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Parker BM, Gilmour SG, Schormans JA (2011). Design of Experiments for Categorical Repeated Measurements in Packet Communication Networks. nameOfConference
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SCHORMANS JA, Parker BM, Gilmour SG (2011). Design of Experiments for Categorical Repeated Measurements in Packet Communication Networks. nameOfConference
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Xu L, Chen Y, Schormans J et al. (2011). User-Vote Assisted Self-Organizing Load Balancing for OFDMA Cellular Systems. nameOfConference
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Mondragon R, Moore A, Pitts J et al. (2009). Analysis, simulation and measurement in large-scale packet networks. nameOfConference
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Ariffin SHS, Schormans JA, Ma AHI (2009). Application of the generalised ballot theorem for evaluation of performance in packet buffers with non-first in first out scheduling. nameOfConference
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Parker BM, Gilmour SG, Schormans J (2009). Measurement of packet loss probability by optimal design of packet probing experiments. nameOfConference
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Schormans J (2009). Simulation, Analysis and Measurement of Broadband Network Traffic. nameOfConference
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Amaradasa V, Schormans J, Pitts J et al. (2009). Evaluating overflow probability for voice over internet protocol buffer dimensioning. nameOfConference
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Lu S, Schormans JA (2008). Time-stepped approach for accelerated simulation of mobile ad hoc networks. nameOfConference
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Pitts JM, Schormans JA (2008). AN ANALYTICAL STUDY OF PRECEDENCE AND QOE FOR VOICE SERVICE IN DEGRADED IP NETWORKS. nameOfConference
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Song GZ, Cuthbert L, Schormans J (2008). Modelling Cellular/Wireless LAN Integrated Systems with Multi-Rate Traffic Using Queueing Network. nameOfConference
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Song GZ, Cuthbert L, Schormans J (2008). Open Networks of Loss Systems in the Modelling of Tow-Tier Heterogeneous Hierarchical Overlay Wireless Networks. nameOfConference
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Hasib M, Schormans J, Timotijevic T (2007). Accuracy of packet loss monitoring over networked CPE. nameOfConference
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Stewart R, Xiaoguang L, Schormans JA et al. (2007). A cross layer analysis for voice over WiFi communications in multihop wireless networks. nameOfConference
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Pitts JM, Yang Q, Schormans JA (2007). Using AF-PHB BOUDICCA configuration for reliable real-time precedence-based SLAs in degraded IP networks. nameOfConference
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Pitts JM, Wang X, Yang Q et al. (2006). Excess-rate queuing theory for M/M/1/RED with application to VolP QoS. nameOfConference
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SCHORMANS JA, Chen X, Raza A (2006). Advanced Receiver Algorithms for Multi-Layered Space-Time Block Codes. Ultra Wideband Systems, Technologies and Applications, 2006. The Institution of Engineering and Technology Seminar on April 2006
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Pitts JM, Schormans JA (2006). Configuring IP QoS mechanisms for graceful degradation of real-time services. nameOfConference
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Hasib M, Schormans J, Pitts J (2005). Probing limitations for packet loss probability measurement on buffered access links (vol 40, pg 1315, 2004). nameOfConference
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Ma AHI, Schormans JA (2005). Fast, stable simulation of power-law packet traffic using concatenated acceleration techniques. nameOfConference
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Schormans J (2005). Ubiquitous packet networking and data compression. nameOfConference
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Leung CM, Schormans JA (2005). Measurement-based end to end latency performance prediction for SLA verification. nameOfConference
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Hasib M, Schormans J, Pitts J (2004). Probing limitations for packet loss probability measurement on buffered access links. nameOfConference
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Raza A, Schormans JA, Chen X (2004). KIL-BLAST: diversity and multiplexing trade-off for layered space-time architectures with channel estimation error. nameOfConference
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Timotijevic T, Leung CM, Schormans J (2004). Accuracy of measurement techniques supporting QoS in packet-based intranet and extranet VPNs. nameOfConference
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Schormans J (2004). Superhighways technology and broadband VPN. nameOfConference
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Ariffin SHS, Schormans JA (2004). Efficient accelerated simulation technique for packet switched networks: A buffer with two priority inputs.. nameOfConference
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Schormans J, Liu E, Stewart R et al. (2003). Analytical technique for accelerating the simulation of packet networks. nameOfConference
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Ma A, Schormans J, Cuthbert L (2003). Aggregation technique for networks with power law traffic and application to accelerated simulation. nameOfConference
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Timotijevic T, Schormans J (2003). Bandwidth overhead of probe technology guaranteeing QoS in packet networks. nameOfConference
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Leung CM, Schormans JA, Pitts JM et al. (2003). Accurate decay rate prediction for burst-scale queueing in packet buffers. nameOfConference
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Leung CM, Schormans JA, Ma AHI (2002). Measurement-based queue length distribution estimation for power-law traffic. nameOfConference
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Ma AHI, Schormans JA (2002). Hybrid technique for analysis of multiplexed power-law traffic in broadband networks. nameOfConference
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Miah B, Scharf EM, Cuthbert LG et al. (2002). A new charging scheme for ATM based on QoS. nameOfConference
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Pitts JM, ARROWSMITH DK, Schormans JA et al. (2002). End-to-end performance in real time IP networks with self-similar behavior.. nameOfConference
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Leung CM, Schormans JA (2002). Measurement-based end to end latency performance prediction for SLA verification. nameOfConference
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SCHORMANS J, Pitts JM (2002). Overflow Probability in Shared Cell Switched Buffers. nameOfConference
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Pitts JM, Schormans JA, Scharf EM et al. (2001). Tight bounds for the tail of the packet waiting time distribution in buffered networks. nameOfConference
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Cuthbert LG, Pitts JM, SCHORMANS JA et al. (2001). A Hybrid Technique for Accelerated Simulation of ATM Networks and Network Elements. nameOfConference
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Al-Hammadi A, Schormans J (2001). Fuzzy congestion controller in a prioritised ATM switch. nameOfConference
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Pitts JM, Schormans JA, Phillips CI et al. (2001). Accurate delay bounds for real-time IP services in presence of variable packet size. nameOfConference
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SCHORMANS JA, Stewart R, Pitts JM et al. (2000). Analysis of local internet / enterprise networking multiplexer for on-off VoIP sources. nameOfConference
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Liu EJ, Schormans J, Cuthbert L et al. (2000). A novel fast simulation method for ATM networks. nameOfConference
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SCHORMANS JA, Pitts JM, Scharf E et al. (2000). Buffer Overflow Probability for Multiplexed On-Off VoIP Sources. nameOfConference
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SCHORMANS J, Pitts JM, Mondragon R et al. (2000). Design rules for buffering overlapping Pareto processes in packetised networks. nameOfConference
