Title:

Delay-optimal Fair Scheduling and Resource Allocation in Multi-user Wireless Relay Networks

Date:

Monday, December 19, 2011 at 10:00am

Location:

Room E2-361, EITC, University of Manitoba, Fort Garry Campus

Speaker:

Mohammad Moghaddari
Department of Electrical and Computer Engineering
University of Manitoba, Canada

Abstract:

We consider fair delay-optimal user selection and power allocation for a relay-based cooperative wireless network. Each user (mobile station) has an uplink queue with heterogeneous packet arrivals and delay requirements. Our system model consists of a base station, a relay station, and multiple users working in a time-division multiplexing (TDM) fashion, where per-user queuing is employed at the relay station to make the analysis of such system tractable. We model the problem as an infinite horizon average reward Markov decision problem (MDP) where the control actions are functions of the instantaneous channel state information (CSI) as well as the joint queue state information (QSI) at the mobile and relay stations. To address the challenge of centralized control and huge complexity of MDP problems, we introduce a distributive and low complexity solution. A linear structure is employed which approximates the value function of the associated Bellman equation by the sum of per-node value functions. Our online stochastic value iteration solution converges to the optimal solution almost surely (with probability 1) under some realistic conditions.

Speaker Bio:

Mohammad Moghaddari received his B.Sc. degree in 2006 and M.Sc. degree in 2009, both in Electrical Engineering from Ferdowsi University of Mashhad (FUM), Iran. He began his Ph.D. program in Sept. 2009 where he is currently a Ph.D. student in the Electrical and Computer Engineering at the University of Manitoba, Canada. His research interests lie in cooperative communication networks, queuing analysis, resource allocation and management, wireless MIMO-OFDM systems. He is a Student Member of the IEEE.

Contact:

For questions or more information: Ekram Hossain 474-8908.

Title:

Distributed Scheduling and Power Control for Cognitive Spatial-Reuse TDMA Networks

Date:

Tuesday, December 13, 2011 at 1:00pm

Location:

Room E2-361, EITC, University of Manitoba, Fort Garry Campus

Speaker:

Phond Phunchongharn
Department of Electrical and Computer Engineering
University of Manitoba, Canada

Abstract:

We investigate the problem of distributed scheduling and power control for vertical spectrum sharing in spatial-reuse time division multiple access (STDMA) networks. The objective is to minimize the transmission length (in term of time slots) of secondary users subject to the interference-limit constraint for primary users and quality-of-service (QoS) guarantee of secondary users. This problem is known to be NP-complete. We therefore propose a novel distributed two-stage algorithm based on the distributed column generation method to find the near-optimal solution for the transmission schedule. In the first stage, the Lagrangian dual problem corresponding to the transmission length minimization problem subject to the minimum bandwidth requirement of secondary users, called the restricted master problem, is solved to obtain a dual optimal solution at each secondary transmitter. The dual optimal variables are passed to the second stage to solve the pricing problem. The pricing problem here finds a feasible channel access pattern such that the sum of dual optimal variables is greater than one subject to the interference constraints for primary users and the signal-to-interference-plus-noise ratio (SINR) constraints for secondary users so that the solution of the master restricted problem can be improved. We also develop a distributed algorithm for solving the pricing problem based on local measurement at each secondary transmitter and a limited number of message exchanges. The proposed algorithm is compared with a previously proposed method and is evaluated in terms of the schedule length, complexity, and the number of message exchanges.

Speaker Bio:

Phond Phunchongharn received her B.E. degree in 2005 and M.E. degree in 2007, both in Computer Engineering from King Mongkut’s University of Technology Thonburi (KMUTT), Thailand. She is currently a Ph.D. candidate in the Electrical and Computer Engineering at the University of Manitoba, Canada. Phond is working as a Student Researcher in TRLabs, Winnipeg. Her research interests lie in cognitive radio networks, dynamic wireless access techniques, resource allocation and management, and wireless network optimization.

Contact:

For questions or more information: Ekram Hossain 474-8908.

Title:

Scheduling in Wireless Networks with Flow Arrivals and Departures

Date:

Wednesday, November 16, 2011 at 10am

Location:

Room E2-361, EITC, University of Manitoba, Fort Garry Campus

Speaker:

R. Srikant, Fellow IEEE
Fredric G. and Elizabeth H. Nearing Endowed Professor
Department of Electrical and Computer Engineering
University of Illinois at Urbana-Champaign, IL, USA

Abstract:

Throughput-maximizing scheduling algorithms have been well-studied for wireless networks under the assumption that the number of flows in the network is fixed. In this talk, we will consider the impact of flow-level dynamics on the throughput and delay performance of wireless networks. First, we will describe traditional scheduling algorithms and identify the reasons for their poor performance in the presence of flow-level dynamics. Then, we will present new scheduling algorithms which significantly improve upon the throughput and/or delay performance of the traditional algorithms.

Speaker Bio:

R. Srikant is with the University of Illinois at Urbana-Champaign, where he is the Fredric G. and Elizabeth H. Nearing Endowed Professor of Electrical and Computer Engineering and a Research Professor in the Coordinated Science Lab. His research interests include communication networks, stochastic processes and queueing theory. He is the author of the book “Mathematics of Internet Congestion Control” and a co-author of the monograph “Network Optimization and Control.” He is a Fellow of the IEEE and a Distinguished Lecturer of the IEEE Communications Society for 2011-2012.

Contact:

For questions or more information: Ekram Hossain 474-8908.

Title:

Virtual Intensive Course on Wireless Communications Engineering

Date:

Course runs from September 26-30, 2011
IEEE Wireless Communications Engineering Technologies (IEEE WCET®) Certification Exam held from October 2-29, 2011.

Location:

Online at www.comsoc.org/training

Speaker:

Javan Erfanian and Daniel Wong

Abstract:

NEW YORK, NY (September 7, 2011) – The IEEE Communications Society (ComSoc), the leading worldwide professional organization dedicated to the advancement of communications technologies, will hold its next “Virtual Intensive Course on Wireless Communications Engineering” from 26 – 30 September 2011. Registration and detailed course information is available at www.comsoc.org/training. Group rates are available for companies interested in registering employees in either or both the five-day online course and the IEEE Wireless Communication Engineering Technologies (IEEE WCET®) Certification Exam to be held 2 – 29 October 2011 at Prometric testing centers worldwide.

The “Virtual Intensive Course on Wireless Communications Engineering” was developed by IEEE ComSoc Training to provide communications engineering professionals with a comprehensive overview of the latest developments in wireless communications, including network operations, technology implementations and overall system design. It can also help IEEE WCET Certification Program candidates identify “need areas” in preparation of the exam held bi-annually in the spring and fall. Individuals who register for the five-day online course by 9 September 2011 will save $100 on the fee, which is $625 for IEEE ComSoc members and $725 for non-members. Information on multi-seat package rates can be obtained by emailing m.catis@comsoc.org.

Scheduled from 9:00 a.m. to 3:00 p.m. EDT on Monday, 26 September through Friday 30 September, the “Virtual Intensive Course on Wireless Communications Engineering” touches on the seven key subject areas covered within the IEEE WCET examination. It does not specifically teach the exam, but rather it was developed for professionals with a broad engineering and/or technology background, who would also like to achieve a deeper understanding of current technologies, operations and future developments.

The course is taught by Javan Erfanian, an IEEE Communications Society Distinguished Lecturer, and Daniel Wong, president of Daniel Wireless, LLC, both of whom are editors of theWireless Engineering Body of Knowledge survey text. Each daily session includes two, two-hour lectures separated by a two-hour break designed to facilitate learning and allow registrants to prepare instructor questions. The weeklong training covers access technologies, network & service architecture, network management & security, facilities infrastructure, and agreements, standards and policies. In addition to the course handout and a copy of the Wireless Engineering Body of Knowledge, each course registrant will earn two IEEE Continuing Education Units upon completion.

Other upcoming learning opportunities include the “The Future of Wireless: Nanotechnology and Practical Wireless Communications,” a one-day course to be held from 9:00 a.m. to 5:00 p.m. CDT on Tuesday, 25 October at 4G World in Chicago, Illinois. Taught by Javan Erfanian, this in-person lecture explores the anatomy of future wireless systems and networks, M2M communications and sensing, e-health care, smart transportation and the impact of nanotechnology on wireless communications engineering. Individuals who register by 30 September will receive a $100 rebate on the $1,195 registration fee.

For more information on any and all online and in-person IEEE ComSoc Training sessions visitwww.comsoc.org/training. Customized corporate learning programs are available for development by IEEE ComSoc Training to address specific areas within the wireless communications industry. General inquiries can also be emailed to Marilyn Catis of IEEE ComSoc at m.catis@comsoc.org.

Contact:

For questions or more information: Ekram Hossain 474-8908.

Title:

Network Modulation: A New Dimension to Enhance Wireless Network Performance

Date:

Friday, September 16, 2011 at 1:00 pm

Location:

Room E2-361, EITC, University of Manitoba, Fort Garry Campus

Speaker:

Dr. Lin Cai
Associate Professor
Department of Electrical and Computer Engineering
University of Victoria, Canada
Web: http://www.ece.uvic.ca/~cai

Abstract:

We have witnessed the explosive growth of the Internet, and the growth will even accelerate in the coming few decades, thanks to the ever-increasing demand for ubiquitous network services, anywhere, anytime, and with any devices. New applications, communication technologies and paradigms are the main driven forces, and they also bring many new challenges. Cross-layer protocol design and optimization is a promising direction for next generation wireless networks. In this talk, we introduce an approach called network modulation which gives us a new dimension to improve wireless network throughput and save energy. In current wireless systems, when a source transmits data to the receiver through a single-hop or multi-hop wireless path, the physical layer modulates and demodulates the information bits hop-by-hop, and the transmission over each hop is treated the same as in a point-to-point communication link. Given the broadcast nature of wireless medium and the wide variation of wireless channel quality, we let a sender transmit messages to multiple receivers simultaneously, using a software mapping technology, called network modulation, to redefine the constellation of typical quadrature amplitude modulation (QAM) schemes. Network modulation can be used to improve network performance in a wide range of scenarios, for anycast (broadcast, multicast and unicast) services, one-way or two-way traffic, and single-hop or multi-hop wireless paths, in infrastructure or ad hoc networks.

Speaker Bio:

Lin Cai received her M.A.Sc. and PhD degrees (awarded Outstanding Achievement in Graduate Studies) in electrical and computer engineering from the University of Waterloo, Waterloo, Canada, in 2002 and 2005, respectively. Since 2005, she has been an Assistant Professor and then an Associate Professor with the Department of Electrical & Computer Engineering at the University of Victoria. Her research interests span several areas in wireless communications and networking, with a focus on network protocol and architecture design supporting emerging multimedia traffic over wireless, mobile, ad hoc, and sensor networks. She has been a recipient of the NSERC Discovery Accelerator Supplement Grant in 2010, the best paper award of IEEE ICC 2008, and the best academic paper award of IEEE WCNC 2011. She has served as a TPC symposium co-chair for IEEE Globecom’10, and the Associate Editor for IEEE Transactions on Wireless Communications, IEEE Transactions on Vehicular Technology, EURASIP Journal on Wireless Communications and Networking, International Journal of Sensor Networks, and Journal of Communications and Networks (JCN).

Contact:

For questions or more information: Ekram Hossain 474-8908.