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DATA REPLICATION AND SCHEDULING
FOR CONTENT AVAILABILITY
IN VEHICULAR NETWORKS
by
Shyam N Kapadia
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Ful¯llment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(COMPUTER SCIENCE)
January 2007
Copyright 2007 Shyam N Kapadia
Object Description
| Title | Data replication and scheduling for content availability in vehicular networks |
| Author | Kapadia, Shyam N. |
| Author email | shyamkapadia@gmail.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Computer Science |
| School | Viterbi School of Engineering |
| Date defended/completed | 2006-12-11 |
| Date submitted | 2007 |
| Restricted until | Unrestricted |
| Date published | 2007-02-18 |
| Advisor (committee chair) | Krishnamachari, Bhaskar |
| Advisor (committee member) |
Psounis, Konstantinos Zimmerman, Roger |
| Abstract | On-demand delivery of audio and video clips in a vehicular network is a growing area of interest. A given repository of such data items, each with an associated popularity, may be available to the passengers of the vehicles. The vehicles themselves are equipped with a 'TiVO' like device that has several gigabytes of storage and a wireless interface allowing short range communication at 10s to 100s of Megabits per second. The goal is to minimize the latency between request issuance and the time till a copy of the requested item is encountered. This latency is termed the availability latency. This thesis explores two generic tools to alleviateavailability latency: (a) data replication (b) data delivery scheduling.; With the replication study, we propose a general optimization formulation that seeks to minimize average availability latency subject to a storage constraint per vehicle. We explore the effects of a family of popularity-based replication schemes on availability latency. When the vehicles follow a 2D random walk based mobility model, via analysis and extensive simulations, we determine the optimal replication scheme that minimizes latency across a wide parameter space with major dimensions being data item size and client trip duration.; Once an appropriate static replication scheme has allocated replicas, the vehicles themselves may be employed as data carriers to further improve availability latency. These data carriers aretermed zebroids. However, a zebroid's local storage may be completely exhausted. Hence, to accommodate this new data item, it may need to evict an existing one. Various replacement policies such as LFU, LRU, random etc. are examined and their relative performance is studied. Via analysis and extensive simulations we study the behavior of zebroids as a function of large parameter space comprising data item repository size, storage per vehicle, number of vehicles, popularity distribution of the data items, different replacement schemes for zebroids etc.; We validate the Markov model based observations with two independent validation phases employing (a) freeway tra±c information on a city map (b) real world traces from a small bus network. |
| Keyword | vehicular networks; availability latency; Markov mobility; data carriers; static replication; trace-based validation; linear; square-root; random replication; Markov chains |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Type | texts |
| Legacy record ID | usctheses-m278 |
| Rights | Kapadia, Shyam N. |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-Kapadia-20070218 |
| Archival file | uscthesesreloadpub_Volume40/etd-Kapadia-20070218.pdf |
Description
| Title | Page 1 |
| Full text | DATA REPLICATION AND SCHEDULING FOR CONTENT AVAILABILITY IN VEHICULAR NETWORKS by Shyam N Kapadia A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Ful¯llment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (COMPUTER SCIENCE) January 2007 Copyright 2007 Shyam N Kapadia |
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