Design and Analysis of a Mobile
File Sharing
BY:
SADIQUE NAYEEM
(PONDICHERRY UNIVERSITY)
Outline
• Design and analyze a mobile file sharing system
over opportunistic networks using Bluetooth
technology.
• To ena...
Opportunistic networks
• Now a days many devices can support spontaneous
interaction among mobile users through wireless
l...
Basic
operational
phases in an
Oppnet.
File Sharing
File sharing scenario of the system can be described as follows:
• Mobile devices search for available device...
File Pulling & File Pushing
• File pulling is to download files from neighbors.
• File pushing is to distribute files(Ex- ...
• Puller is the one who requests for pulling service and
desires to download files from the service provider called
pullee...
File Sharing
Pusher(Responder)
Pullee (Responder)
Pushee (Requester)
Puller (Requester)
Download
Mobile File Sharing
System for Opportunistic Networks
The mobile file sharing system includes three
main components:
• Con...
System Overview
Connectivity mechanism
The connectivity mechanism is designed to
handle connection for a mobile device for its
diverse rol...
Connectivity mechanism - Device discovery
• Bluetooth technology for short range communication
which scans for available d...
Connectivity mechanism -Neighbor selection
• Once available neighbors are discovered
• The neighbor selection strategy is ...
Connectivity mechanism - Neighbor selection
• A file pusher also maintains a list locally which
records all the mobile dev...
Connectivity mechanism - Connection Establishment 1
The system involves two pairs of roles i.e (puller, pullee) and
(pushe...
Connectivity mechanism - Connection Establishment - 2
• For file pusher and pushee, the pushed file information is
used by...
ROLES AND FILE INFORMATION LISTS
Each mobile device is capable of serving up to 4 types of
roles whose connection processe...
Download Control
After the connection established, download control
handles file transferring process. The challenge of
do...
PRIORITIZED DOWNLOAD SEQUENCE
Piece Information
• The puller or pushee breaks all the prioritized files that are
about to be downloaded into certain siz...
Connection Break Handling
• Due to device mobility in opportunistic networks,
opportunistic contacts occur and disappear
f...
EVALUATION - I
The file transferring data rate – limiting the peer number to 4
will maximize the data rate
EVALUATION - II
The time taken to merge pieces into a file is minimal when the
file piece size is 100 KB.
EVALUATION - III
File compression is applied on the file provider to reduce file size,
thereby reducing the file transferr...
EVALUATION - IV
Finally the whole system efficiency is measured considering
the time taken not only for the file transferr...
EVALUATION - V
The time taken to transfer files and merge pieces into files are
directly related to the file size
CONCLUSION
• The mobile file sharing system proposed in this paper provides
an efficient solution for mobile devices in op...
Thank you!
Design and analysis of a mobile file sharing system for opportunistic networks
Design and analysis of a mobile file sharing system for opportunistic networks
Design and analysis of a mobile file sharing system for opportunistic networks
Design and analysis of a mobile file sharing system for opportunistic networks
Design and analysis of a mobile file sharing system for opportunistic networks
Design and analysis of a mobile file sharing system for opportunistic networks
Design and analysis of a mobile file sharing system for opportunistic networks
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Design and analysis of a mobile file sharing system for opportunistic networks

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Design and analysis of a mobile file sharing system for opportunistic networks

  1. 1. Design and Analysis of a Mobile File Sharing BY: SADIQUE NAYEEM (PONDICHERRY UNIVERSITY)
  2. 2. Outline • Design and analyze a mobile file sharing system over opportunistic networks using Bluetooth technology. • To enable a mobile device to download desired files from available devices in its neighborhood and also allow its files to be disseminated to the network with the facilitation of opportunistic contacts. • The key challenges to be address are system automation and file sharing efficiency.
  3. 3. Opportunistic networks • Now a days many devices can support spontaneous interaction among mobile users through wireless links, such as Bluetooth and Wi-Fi. The resulted network is often referred as an opportunistic network(Oppnet). In these networks, contacts among users are usually opportunistic and connections among devices are intermittent.
  4. 4. Basic operational phases in an Oppnet.
  5. 5. File Sharing File sharing scenario of the system can be described as follows: • Mobile devices search for available devices in their neighborhoods. • Request for file sharing services • Establish the connection • At the same time, these mobile devices serve as service providers and respond to requests sent from their neighbors • The Transaction can be • File Pulling • File Pushing
  6. 6. File Pulling & File Pushing • File pulling is to download files from neighbors. • File pushing is to distribute files(Ex- Conference) • There are two different pairs of roles in our file sharing system: • (puller, pullee) • (pusher, pushee)
  7. 7. • Puller is the one who requests for pulling service and desires to download files from the service provider called pullee. • Pusher is the one who requests for pushing services and wants to distribute its owned files to the service provider named pushee. ROLES RELATIONSHIP
  8. 8. File Sharing Pusher(Responder) Pullee (Responder) Pushee (Requester) Puller (Requester) Download
  9. 9. Mobile File Sharing System for Opportunistic Networks The mobile file sharing system includes three main components: • Connectivity mechanism • Download control and • Break handling.
  10. 10. System Overview
  11. 11. Connectivity mechanism The connectivity mechanism is designed to handle connection for a mobile device for its diverse roles. • Device discovery • Neighbor selection • Connection establishment.
  12. 12. Connectivity mechanism - Device discovery • Bluetooth technology for short range communication which scans for available devices in the neighborhood periodically. • Experimentally the device discover neighbors within 17 seconds if there exists at least one in the neighborhood.
  13. 13. Connectivity mechanism -Neighbor selection • Once available neighbors are discovered • The neighbor selection strategy is applied for file puller and pusher to choose a neighbor. • The file puller maintains a list locally which traces all the mobile devices that have unfinished file transferring in their last connections with the puller. • If such neighbor is found then file transferring completes successfully . • Else the file puller chooses the connection candidate from all available neighbors randomly.
  14. 14. Connectivity mechanism - Neighbor selection • A file pusher also maintains a list locally which records all the mobile devices which it has pushed its files. • If discovered neighbors exist in the list, the file pusher will avoid selecting them as connection candidate, since pusher does not want to push files to the same device repeatedly. • Then the file pusher chooses the connection candidate randomly from all the other available ones.
  15. 15. Connectivity mechanism - Connection Establishment 1 The system involves two pairs of roles i.e (puller, pullee) and (pusher, pushee) and connection only occurs between puller and pullee or pusher and pushee respectively. • For the pair of file puller and pullee, search criterion is used to announce its file requirement including file types it requests. ie. jpeg, .mp3 etc. • search criterion is send to file pullee • file pullee accepts the service request if at least one file in its possession meets the criterion and sends back acceptance notice with its provided files information. • After receiving the acceptance notice from file pullee,the connection b/w puller and pullee is established successfully.
  16. 16. Connectivity mechanism - Connection Establishment - 2 • For file pusher and pushee, the pushed file information is used by the pusher to announce files that it desires to distribute to the network. • The file pusher sends out pushing request along with the pushed file information. • A selected neighbor acting as file pushee accepts the service request and sends back an acceptance notice. • The connection is announced to be established successfully.
  17. 17. ROLES AND FILE INFORMATION LISTS Each mobile device is capable of serving up to 4 types of roles whose connection processes for file puller, pullee, pusher and pushee can be described by the following four Algorithm.
  18. 18. Download Control After the connection established, download control handles file transferring process. The challenge of download control is • To reduce file transferring duration • Improve file sharing efficiency As puller and pushee are the ones that download files from pullee and pusher, they can customize their download sequences with the help of prioritizing sequence of these files.
  19. 19. PRIORITIZED DOWNLOAD SEQUENCE
  20. 20. Piece Information • The puller or pushee breaks all the prioritized files that are about to be downloaded into certain size of pieces. • Piece information is recorded in a meta file. • Using file piece has two advantages. – Firstly, it allows a file to be downloaded from multiple devices as a device can request different pieces of a file from multiple devices simultaneously. – Secondly, it facilitates connection break handling. • Similar to connectivity mechanism, download control manages the downloads for the mobile device in different roles and the download control processes can be described by the following Algorithm.
  21. 21. Connection Break Handling • Due to device mobility in opportunistic networks, opportunistic contacts occur and disappear frequently. As a result the transfer of data is not completed successfully. Here the break handler works which store all existing pieces of unfinished files temporarily and request for the rest pieces when the connection is rebuilt.
  22. 22. EVALUATION - I The file transferring data rate – limiting the peer number to 4 will maximize the data rate
  23. 23. EVALUATION - II The time taken to merge pieces into a file is minimal when the file piece size is 100 KB.
  24. 24. EVALUATION - III File compression is applied on the file provider to reduce file size, thereby reducing the file transferring duration. The time taken to download files can be reduced significantly for some file types, such as .txt and .bmp.
  25. 25. EVALUATION - IV Finally the whole system efficiency is measured considering the time taken not only for the file transferring but also the preparation operations before the transferring and the merging afterwards. •Preparation operations includes •discovering neighbors •establishing connection with the selected neighbor •Initiation work in download control.
  26. 26. EVALUATION - V The time taken to transfer files and merge pieces into files are directly related to the file size
  27. 27. CONCLUSION • The mobile file sharing system proposed in this paper provides an efficient solution for mobile devices in opportunistic networks to acquire interested files from neighbors and also distribute files to the network. It is implemented on HP iPAQ 910 smart phones equipped with Bluetooth interfaces. It allows one mobile device to download or upload files from or to multiple neighbors and achieves up to 417 KB per second data rate for file transferring. It is indicated that limiting the peer number to 4 maximizes the data rate and enhances the system efficiency. The use of file piece enables connection break handling. It is clearly shown that file piece with 100 KB size can minimize the extra time cost according to our experiment results.
  28. 28. Thank you!

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