1. Design and Implementation of Mobile Peer-to-Peer Application
S Thesis Seminar on Networking Technology
Design and Implementation of Mobile Peer-to-Peer Application
Juuso Lehtinen
Thesis written at Networking Laboratory,
Department of Electrical and Communications Engineering,
Helsinki University of Technology
Author: Juuso Lehtinen
Supervisor: Prof. Raimo Kantola
Instructor: Nicklas Beijar, Lic.Tech.

2. S-38.3310 Thesis Seminar on Networking Technology
Agenda
Introduction
The Problem
Objectives
Research Questions
Methodology
Background
Client-Server Architecture
Peer-to-Peer Architectures
Mobile Peer-to-Peer Application
Requirements for Mobile Peer-to-Peer
Design and Implementation
Measurements
Conclusions
Further Research Possibilities
September 21, 2018
S Thesis Seminar on Networking Technology

3. S-38.3310 Thesis Seminar on Networking Technology
Introduction
Today, 60-80% of all Internet traffic is peer-to-peer
Services seen traditionally only in the fixed networks are becoming available in the mobile networks too as the mobile terminals get more powerful
Users want to be able to share content on their mobile phones regardless place or time
September 21, 2018
S Thesis Seminar on Networking Technology

4. The Problem – User Perspective
No convenient way to share information between phones
The content must be uploaded to be available, even though there is no knowledge if anyone will ever download it
Search for the content must be done manually if the location of the content is not known in advance
September 21, 2018
S Thesis Seminar on Networking Technology

5. The Problem – Operator Perspective
Operator has to maintain a centralized server which holds the content
The storage server costs money, is a single point of failure, and has hard time dealing with the flash crowd phenomenon
Possible revenues are lost because the operator is not able to provide users effective way to share content
September 21, 2018
S Thesis Seminar on Networking Technology

6. S-38.3310 Thesis Seminar on Networking Technology
Objectives (1/2)
The objective of the thesis is to find out how to efficiently realize a peer-to-peer file sharing application for mobile phone networks and effectively allow users to share and acquire content which is saved in their and their friends’ mobile phones
The software has to be efficient on resource usage, both on those of the handset and the network, and use the already existing (and upcoming) network infrastructure as much as possible to allow easy development and deployment
September 21, 2018
S Thesis Seminar on Networking Technology

7. S-38.3310 Thesis Seminar on Networking Technology
Objectives (2/2)
The Session Initiation Protocol (SIP) is used as the underlying signaling protocol
Use of SIP allows easy integration with the future IMS networks
Charging and billing for the application can be easily implemented in the SIP-aware core network
September 21, 2018
S Thesis Seminar on Networking Technology

8. S-38.3310 Thesis Seminar on Networking Technology
Research Questions
Does a modern mobile phone have enough resources to run the peer-to-peer application?
Is SIP a suitable protocol for peer-to-peer signaling?
Is the software performance satisfying in user perspective?
September 21, 2018
S Thesis Seminar on Networking Technology

9. S-38.3310 Thesis Seminar on Networking Technology
Methodology
Literature study
Comparison of different peer-to-peer architectures
Special needs for peer-to-peer imposed by mobile environment
Design and Implementation of mobile peer-to-peer application
Performance measurements
September 21, 2018
S Thesis Seminar on Networking Technology

10. S-38.3310 Thesis Seminar on Networking Technology
Agenda
Introduction
The Problem
Objectives
Research Questions
Methodology
Background
Client-Server Architecture
Peer-to-Peer Architectures
Mobile Peer-to-Peer Application
Requirements for Mobile Peer-to-Peer
Design and Implementation
Measurements
Conclusions
Further Research Possibilities
September 21, 2018
S Thesis Seminar on Networking Technology

11. Client-Server Architecture
One high-performance server holds all the content in the network
Owner of the server has full control on the shared content
Multiple clients share content via the centralized server
September 21, 2018
S Thesis Seminar on Networking Technology

12. Peer-to-Peer Architectures
Unstructured peer-to-peer architectures
Centralized architecture
Decentralized architecture
Hybrid architecture
Structured peer-to-peer architectures
Based on DHT-algorithm
Wildcard searches are not possible
Exact name or hash for the searched content must be known
September 21, 2018
S Thesis Seminar on Networking Technology

13. Centralized Peer-to-Peer Architecture
A centralized server, or a cluster of servers holds information about the files available on the clients
Owner of the server has high control on content
The clients transfer content directly without the server involvement
The server is used only for content searches
September 21, 2018
S Thesis Seminar on Networking Technology

14. Decentralized Peer-to-Peer Architecture
All nodes are equal in the network – There is no centralization
No single node has control over the content shared by the other users
Searches are done by flooding search requests in the network
Downloads are executed in peer-to-peer fashion
September 21, 2018
S Thesis Seminar on Networking Technology

15. Hybrid Peer-to-Peer Architecture
Ordinary clients are connected to super-peers as in centralized peer-to-peer architecture
A super-peer has high control on content shared by ordinary nodes connected to it
Super-peers are connected to each other in decentralized manner
Super-peers do not have control on content announced by the other super-peers
Downloads are executed in peer-to-peer fashion
September 21, 2018
S Thesis Seminar on Networking Technology

16. S-38.3310 Thesis Seminar on Networking Technology
Agenda
Introduction
The Problem
Objectives
Research Questions
Methodology
Background
Client-Server Architecture
Peer-to-Peer Architectures
Mobile Peer-to-Peer Application
Requirements for Mobile Peer-to-Peer
Design and Implementation
Measurements
Conclusions
Further Research Possibilities
September 21, 2018
S Thesis Seminar on Networking Technology

17. Requirements for Mobile Peer-to-Peer (1/2)
Technical Constraints
Memory size
CPU performance
Screen and keyboard size
Battery capacity
Access Network Parameters
Limited bandwidth shared between multiple users in the same cell
September 21, 2018
S Thesis Seminar on Networking Technology

18. Requirements for Mobile Peer-to-Peer (2/2)
Special Needs of Mobile Environment
Support for various access networks
Operator control
Feasible bandwidth pricing
User Requirements
Quick response times
Rapid downloads
Group management features for sharing private content
Lot of content is probably self-created, like pictures/videos taken with camera-phone
September 21, 2018
S Thesis Seminar on Networking Technology

19. S-38.3310 Thesis Seminar on Networking Technology
Optimal Architecture
Hybrid architecture optimal for mobile use
Minimizes signaling load on the air interface
Allows operator to have control on content by controlling the super-peer
Multiple operators can network super-peers in peer-to-peer fashion still retaining quite high autonomy
Super-peer can be also operated by private entity, e.g. family or sports club
September 21, 2018
S Thesis Seminar on Networking Technology

20. Design and Implementation of MP2P
Hybrid peer-to-peer architecture was chosen for implementation
Software was implemented in C++ on Nokia Series 60 Platform
SIP functionality is provided by phone’s built-in SIP-stack
September 21, 2018
S Thesis Seminar on Networking Technology

21. S-38.3310 Thesis Seminar on Networking Technology
Implementation
Software is designed to be modular so it can be easily enhanced
Client consists of four modules: Finder, Register, Transfer, and Graphical User Interface
Chatting and streaming modules are to be implemented in near future
September 21, 2018
S Thesis Seminar on Networking Technology

22. SIP Requests Used for Peer-to-Peer Signaling
INVITE – Content search and download session establishment
MESSAGE – File-list updates to super-peers
Search and file-list update messages have all content information encoded in XML to enable easy parsing and extension of the format in the future
September 21, 2018
S Thesis Seminar on Networking Technology

23. Use Case – Search and Download
September 21, 2018
S Thesis Seminar on Networking Technology

24. S-38.3310 Thesis Seminar on Networking Technology
Measurements
Both signaling delays, and file transfer bandwidth were measured
All measurements were conducted in 3G/WCDMA network
Search delays were measured to be under 700ms in most of the cases
Signaling delays for download session set-ups were measured to be under 1.5s
File transfer speeds were around 11kB/s
This is restricted by the available upstream bandwidth in the mobile network (upstream 128kbit/s, downstream: 384kbit/s)
September 21, 2018
S Thesis Seminar on Networking Technology

25. S-38.3310 Thesis Seminar on Networking Technology
Agenda
Introduction
The Problem
Objectives
Research Questions
Methodology
Background
Client-Server Architecture
Peer-to-Peer Architectures
Mobile Peer-to-Peer Application
Requirements for Mobile Peer-to-Peer
Design and Implementation
Measurements
Conclusions
Further Research Possibilities
September 21, 2018
S Thesis Seminar on Networking Technology

26. S-38.3310 Thesis Seminar on Networking Technology
Conclusions
The working prototype application proves that peer-to-peer file sharing can be implemented on mobile platform
The user perceived performance of the application is close to the performance seen in applications in fixed networks
The SIP signaling is suitable for mobile peer-to-peer use. The protocol overhead is not a problem in the modern cellular networks.
September 21, 2018
S Thesis Seminar on Networking Technology

27. Further Research Possibilities
Grouping / clustering mechanisms for peer-to-peer content sharing
Caching of popular files into the fixed network to reduce load on the air interface
Trust, reputation, accountability, security, and interoperability issues in the mobile peer-to-peer context
September 21, 2018
S Thesis Seminar on Networking Technology

28. S-38.3310 Thesis Seminar on Networking Technology
Thanks for patience!
Questions?
Contact:
References:
M. Matuszewski, N. Beijar, J. Lehtinen and T. Hyyryläinen, Mobile Peer-to-Peer Content Sharing Application, in IEEE Consumer Communications and Networking Conference, CCNC2006, 2006, Las Vegas, Nevada, USA
N. Beijar, M. Matuszewski, J. Lehtinen and T. Hyyryläinen, Mobile Peer-to-Peer Content Sharing Services in IMS, in The International Conference on Telecommunication Systems, Modeling and Analysis 2005, ICTSM2005, 2005, Dallas, Texas, USA
September 21, 2018
S Thesis Seminar on Networking Technology