Drexel University - Comprehensive, integrated academics enhanced by co-operative education, technology, and research opportunities. | Drexel University
Drexel University
Search events. View events.

All Categories

Click for help in using calendar displays. Print the contents of the current screen.
Display Format: 
Event Details
Notify me if this event changes.Add this event to my personal calendar.
Go Back
Ph.D. Research Proposal: Nan Xie
Start Date: 11/20/2013Start Time: 11:00 AM
End Date: 11/20/2013End Time: 1:00 PM

Event Description
Title:  Towards a Better Cellular Network: Stability, Delay Performance and Scheduling
Advisor:  Dr. Steven Weber
Date:  Wednesday, November 20, 2013
Time:  11:00 a.m.
Location:  ECE Conference Room 303, 3rd Floor, Bossone Research Enterprise Center

Abstract

This thesis proposal addresses several issues of design and performance analysis in cellular communication networks.  We investigate topics relevant to both uplink and downlink.  For the uplink part, we address the stability region of the slotted Aloha medium access control protocol under the collision channel model, for the case of a finite number of independent users. The stability region (i.e., the set of arrival rate vectors such that the whole queueing system can be made stable) is in general unknown when the number of users is more than three.  We seek to characterize the set of stabilizable rate vectors, whereas most existing work only provides bounds of the region of stabilized rate vectors for given contention probability vectors.

For the downlink part, we seek to characterize the delay when broadcasting random linear combinations of the information packets over independent erasure channels to a finite number of users.  Of interest is the random delay until all the receivers recover all the packets initially queued at the base station (i.e., the sender).  This falls into the study of certain order statistic of random variables. We obtain tight lower and upper bounds, exact expressions and finite-step computational procedures (recurrence) for the moment(s) of the random delay. We also investigate the dependence of the delay on the code blocklength (under random linear combinations of packets as the scheme employed in random linear network coding), and on the number of receivers, respectively.  Our proposed work includes the following two topics.  First, we propose to study the tradeoff between increasing the blocklength (to reduce the overall delay) and meeting the delivery deadline requirements of individual packets.  Second, we will also be interested in the scenario where receivers already have a subset of the packets (i.e., as side information) hosted at the base station, and are interested in only the remaining packets.  Most of the work is related to network coding, which for more than one and a half decade, has successfully generated theoretical and practical interests in information theory, communication theory and networking communities.
Location:
ECE Conference Room 303, 3rd Floor, Bossone Research Enterprise Center
Audience:
  • Current Students
  • Faculty
  • Staff

  • Display Month:

    Advanced Search (New Search)
    Date Range:
    Time Range:
    Category(s):
    Audience: 

    Special Features: 

    Keyword(s):
    Submit
    Select item(s) to Search
    Select item(s) to Search
    Select item(s) to Search
    Select item(s) to Search