performance analysis of peer-to-peer communication on 3g

Blekinge Institute of Technology

School of Engineering

Department of Electrical Engineering

Supervisor: Muhammad Imran Iqbal

Examiner: Prof. Hans-Jürgen Zepernick

Munigala Ranjeet

Katikar Praveen

Performance Analysis of Peer-to-Peer

Communication on 3G Cellular Networks

This thesis is presented as part of Degree of Master of Science in Electrical

Engineering


November 2011

Performance Analysis of Peer-to-Peer communications on 3G Cellular Networks

i

Contact Information:

Author(s):

Ranjeet Munigala

E-mail: [email protected]

Praveen Katikar

E-mail: [email protected]

University advisor: Muhammad Imran Iqbal,

School of Computing,

Blekinge Institute of Technology,

371 79, Karlskrona, Sweden

Mobil: 0455-385586

Email: [email protected]

University Examiner: Hans-Jürgen Zepernick,

School of Computing,

Blekinge Institute of Technology,

371 79, Karlskrona, Sweden

Mobil: 455-385718

Email: [email protected]

School of Engineering


SE – 371 79 Karlskrona

Sweden

Internet : www.bth.se/ing

Phone : +46 455 38 50 00

Fax : +46 455 38 50 57

This thesis is submitted to the School of Engineering at Blekinge Institute of Technology in

partial fulfillment of the requirements for the degree of Master of Science in Electrical

Engineering. The thesis is equivalent to 20 weeks of full time studies.

mailto:[email protected]

mailto:[email protected]


Abstract ii

ABSTRACT

Many technologies are emerging in the field of

telecommunications enabling higher data rate

services through mobile and portable modems on

3G networks. To support rich data services,

operators are looking beyond their 2G/2.5G

networks for long-term and cost-effective proven

solutions. Peer-to-Peer (P2P) communication

services play major role in third and upcoming

generations of cellular systems. P2P is gaining

significance because of growing popularity of

mobile web environment.

In this thesis, the authors investigate the

performance of Transmission Control Protocol

(TCP) and User Datagram Protocol (UDP) for P2P

communication services on 3G UMTS network.

This thesis examines how different parameters

such as network load, chunk size, data size, and

signal strength influence performance metrics on a

real time network. The performance metrics chosen

for this purpose are Normalized Average Delay

(NAD), throughput and data loss. From the

experimental results, it was observed that as chunk

size increases throughput increases and NAD

decreases. It was also noticed that better results for

non-peak hours and strong signal strengths when

compared to peak hours and weak signal strengths.

Finally, data loss was observed only for UDP.

Keywords: P2P, TCP, UDP, 3G, UMTS Network,

NAD, throughput, and data loss.


Acknowledgement iii

ACKNOWLEDGEMENT

I would like to take this opportunity to thank our thesis supervisor Muhammad

Imran Iqbal for consistently providing us with the required guidance which helped

us in the timely and successful completion of our thesis. In spite of his extremely

busy schedules in the department, he was always available to share with us his deep

insights, wide knowledge and extensive experience.

I would like to express my gratitude from heart to my mother Sayamma Katikar,

father Narsimha Katikar and my elder brother Raju Katikar. They rendered me

enormous support during the whole tenure of my stay in Sweden.

Finally, I would like to thank all those who have directly and indirectly contributed

to the success of my thesis.

Praveen Katikar

Karlskrona, November 2011

I would like to express my sincere gratitude to our thesis supervisor Muhammad

Imran Iqbal, who supported us with his valuable ideas, guidance, constant

encouragement and friendliness throughout this work which made this experience

productive and exciting. I would also like to thank our thesis examiner prof. Hans-

Jürgen Zepernick.

I would like to express my heartfelt gratitude to my parents (Ram Kumar Munigala

and Kalpana Munigala) and family for their love, patience, support and prayers that

helped me to overcome the difficulties during this journey in Sweden.

Finally, special thanks to my friends who motivated, encouraged and supported me

financially during hard times.

Ranjeet Munigala

Karlskrona, November 2011


Table of contents iv

TABLE OF CONTENTS

Contents

PERFORMANCE ANALYSIS OF PEER-TO-PEER COMMUNICATION ON

3G CELLULAR NETWORKS .................................................................................. I

ABSTRACT ............................................................................................................... II

ACKNOWLEDGEMENT ...................................................................................... III

TABLE OF CONTENTS ......................................................................................... IV

LIST OF FIGURES ................................................................................................. VI

LIST OF TABLES ................................................................................................. VII

LIST OF ABBREVIATIONS ............................................................................... VIII

1. INTRODUCTION .............................................................................................. 1

1.1 RELATED WORK AND MOTIVATION ...................................................................... 1

1.2 THESIS OBJECTIVE ............................................................................................... 2

1.3 RESEARCH METHODOLOGY ................................................................................. 3

2. PEER-TO-PEER COMMUNICATIONS ......................................................... 4

2.1 SIGNIFICANCE AND EMERGENCE .......................................................................... 4

2.2 OVERLAY NETWORKS .......................................................................................... 5

2.3 P2P NETWORKS ................................................................................................... 5

2.4 KEY CHARACTERISTICS OF P2P NETWORKS ......................................................... 7

2.4.1 Resource sharing .......................................................................................... 7

2.4.2 Symmetry ..................................................................................................... 7

2.4.3 Autonomy .................................................................................................... 7

2.4.4 Self-Organization ......................................................................................... 7

2.4.5 Scalability .................................................................................................... 7

2.4.6 Stability ........................................................................................................ 7

2.4.7 Decentralization ........................................................................................... 8

2.5 CLASSIFICATION OF P2P NETWORKS ................................................................... 8

2.5.1 Classification based on appeared time and purpose .................................... 8

2.5.2 Classification based on degree of centralization ........................................ 11

2.5.3 Classification based on network topology ................................................. 13

2.6 MOBILE P2P ...................................................................................................... 18

3. OVERVIEW OF CELLULAR NETWORKS ............................................... 20

3.1 INTRODUCTION .................................................................................................. 20

3.2 FIRST GENERATION RADIO SYSTEMS .................................................................. 21

3.3 SECOND GENERATION RADIO SYSTEMS .............................................................. 21

3.3.1 Code division multiple access (CDMA) .................................................... 21

3.3.2 Global system for mobile communications (GSM) ................................... 22

3.3.3 General Packet Radio Service (GPRS) ...................................................... 22

3.3.4 Enhanced Data Rate for GSM Evolution (EDGE) .................................... 23

3.4 THIRD GENERATION RADIO SYSTEMS ................................................................. 23

3.4.1 CDMA 2000 .............................................................................................. 24


Table of contents v

3.4.2 Universal Mobile Telecommunications System (UMTS) ......................... 25

4. EXPERIMENTAL SETUP .............................................................................. 28

4.1 THE BASIC APPROACH ....................................................................................... 28

4.2 THE ARCHITECTURE AND DEVELOPMENT OF HYBRID P2P MODEL ...................... 30

4.2.1 Socket Communication/ programming ...................................................... 30

4.2.2 Basic architecture and development of connection-oriented sockets ........ 31

4.2.3 Basic architecture and development connectionless- sockets .................... 32

4.3 CONNECTION ESTABLISHMENT BETWEEN PEERS AND DATA TRANSMISSION ....... 33

4.4 EXPERIMENT CONFIGURATION AND ANALYSIS PROCEDURE ............................... 33

4.4.1 Experimental configuration ....................................................................... 33

4.4.2 Analysis procedure .................................................................................... 35

5. RESULTS .......................................................................................................... 37

5.1 CASE 1 ............................................................................................................. 37

5.2 CASE 2 ............................................................................................................. 38

5.3 CASE 3 ............................................................................................................. 40

5.4 CASE 4 ............................................................................................................. 41

5.5 CASE 5 ............................................................................................................. 43

5.5.1 Effect of chunk size on data loss ............................................................... 43

5.5.2 Effect of data size on data loss ................................................................... 44

5.5.3 Effect of network load on data loss ........................................................... 44

5.5.4 Effect of signal strength on data loss ......................................................... 45

5.6 VALIDITY THREATS ............................................................................................ 46

6. CONCLUSIONS ............................................................................................... 47

7. FUTURE WORK .............................................................................................. 48

BIBLIOGRAPHY .................................................................................................... 50

APPENDICES .......................................................................................................... 53

APPENDIX A ............................................................................................................ 53

STEP BY STEP PROCEDURE OF CONNECTING PEERS FOR TCP APPLICATION .............. 53

APPENDIX B ............................................................................................................ 56

FOR UDP APPLICATION: ......................................................................................... 56

APPENDIX C ............................................................................................................ 56

COMPLETE RESULTS FOR DIFFERENT SCENARIO FOR TCP ........................................ 56

APPENDIX D ............................................................................................................ 62

COMPLETE RESULTS FOR DIFFERENT SCENARIO FOR UDP ....................................... 62


List of Figures vi

LIST OF FIGURES

FIGURE 1: OVERLAY NETWORK ............................................................................................................... 5 FIGURE 2: SAMPLE P2P NETWORK ......................................................................................................... 6 FIGURE 3: CENTRALIZED NETWORK........................................................................................................ 9 FIGURE 4: DECENTRALIZED NETWORK ................................................................................................. 10 FIGURE 5: PURE P2P ............................................................................................................................. 11 FIGURE 6: HYBRID P2P .......................................................................................................................... 12 FIGURE 7: MIXED P2P ........................................................................................................................... 13 FIGURE 8: CENTRALIZED TOPOLOGY .................................................................................................... 14 FIGURE 9: RING TOPOLOGY .................................................................................................................. 14 FIGURE 10: HIERARCHICAL TOPOLOGY................................................................................................. 15 FIGURE 11: DECENTRALIZED TOPOLOGY .............................................................................................. 16 FIGURE 12: CENTRALIZED AND RING TOPOLOGY ................................................................................. 17 FIGURE 13: CENTRALIZED AND CENTRALIZED TOPOLOGY ................................................................... 17 FIGURE 14: CENTRALIZED AND DECENTRALIZED TOPOLOGY ............................................................... 18 FIGURE 15: PROTOCOL ARCHITECTURE OF IS-95 (CDMA ONE) STANDARD [26]. ................................. 22 FIGURE 16: EVOLUTION OF 2G TO 3G CELLULAR NETWORKS [28]. ..................................................... 24 FIGURE 17: NETWORK ARCHITECTURE [26]. ........................................................................................ 26 FIGURE 18: AIR INTERFACE PROTOCOL STRUCTURE OF WCDMA (UMTS) [26]. ................................... 27 FIGURE 19: BASIC P2P MODEL .............................................................................................................. 28 FIGURE 20: HYBRID P2P MODEL ........................................................................................................... 29 FIGURE 21: OSI MODEL FOR SOCKET API’S ........................................................................................... 30 FIGURE 22: SCHEMATIC DIAGRAM SHOWING COMMUNICATION BETWEEN TWO PROCESSES ......... 31 FIGURE 23: BASIC ARCHITECTURE OF TCP STREAM SOCKET SESSION.................................................. 32 FIGURE 24: BASIC ARCHITECTURE OF UDP DATAGRAM SOCKET SESSION ........................................... 32 FIGURE 25: EFFECT OF CHUNK SIZE ON THROUGHPUT FOR TCP AND UDP ......................................... 37 FIGURE 26: EFFECT OF CHUNK SIZE ON NAD FOR TCP AND UDP ......................................................... 38 FIGURE 27: EFFECT OF DATA SIZE ON THROUGHPUT FOR BOTH TCP AND UDP .................................. 39 FIGURE 28: EFFECT OF DATA SIZE ON NAD FOR BOTH TCP AND UDP .................................................. 39 FIGURE 29: EFFECT OF NETWORK LOAD ON THROUGHPUT FOR BOTH TCP AND UDP ........................ 40 FIGURE 30: EFFECT OF NETWORK LOAD ON NAD FOR BOTH TCP AND UDP........................................ 41 FIGURE 31: EFFECT OF SIGNAL STRENGTH ON THROUGHPUT FOR BOTH TCP AND UDP .................... 42 FIGURE 32: EFFECT OF SIGNAL STRENGTH ON NAD FOR BOTH TCP AND UDP .................................... 42 FIGURE 33: EFFECT OF CHUNK SIZE ON DATA LOSS ............................................................................. 43 FIGURE 34: EFFECT OF DATA SIZE ON DATA LOSS ................................................................................ 44 FIGURE 35: EFFECT OF NETWORK LOAD ON DATA LOSS ...................................................................... 45 FIGURE 36: EFFECT OF SIGNAL STRENGTH ON DATA LOSS .................................................................. 46 FIGURE 37: COMMAND WINDOW OF SERVER WAITING FOR PEERS ................................................... 53 FIGURE 38: COMMAND WINDOW OF PEER A ...................................................................................... 54 FIGURE 39: COMMAND WINDOW OF SERVER AFTER CONNECTING PEER A ....................................... 54 FIGURE 40: COMMAND WINDOW OF PEER B ...................................................................................... 55 FIGURE 41: COMMAND WINDOW OF SERVER AFTER CONNECTING PEER A AND PEER B ................... 55


List of tables vii

LIST OF TABLES TABLE 1: SHOWS THE LIBRARY FUNCTIONS OF SOCKET ....................................................................... 31

TABLE 2: RESULTS OBTAINED FOR CONDITIONS STRONG SIGNAL, CHUNK SIZE OF 1024 BYTES AND NONPEAK NETWORK LOAD ......................................................................................................... 56

TABLE 3: RESULTS OBTAINED FOR CONDITIONS STRONG SIGNAL, CHUNK SIZE OF 1024 BYTES AND PEAK NETWORK LOAD ................................................................................................................. 57

TABLE 4: RESULTS OBTAINED FOR CONDITIONS WEAK SIGNAL, CHUNK SIZE OF 1024 BYTES AND NONPEAK NETWORK LOAD ......................................................................................................... 57

TABLE 5: RESULTS OBTAINED FOR CONDITIONS WEAK SIGNAL, CHUNK SIZE OF 1024 BYTES AND PEAK NETWORK LOAD .......................................................................................................................... 58












TABLE 17: RESULTS OBTAINED FOR CONDITIONS WEAK SIGNAL, CHUNK SIZE OF 1024 BYTES AND PEAK NETWORK LOAD ................................................................................................................. 64










List of Abbreviations viii

LIST OF ABBREVIATIONS

1G/2G/3G/4G First Generation/Second Generation/Third

Generation/Fourth Generation

3GPP2 Third Generation Partnership Project 2

API Application Programming Interface

AMPS Advanced Mobile Phone System

ARIB Alliance of Radio Industries and Business

ANSI American National Standards Institute

AMTS Advanced Mobile Telephone System

CA Certification Authorities

CPU Central Processing Unit

CN Core Network

CSD Circuit Switched Data

CWTS China Wireless Telecommunication Standard group

CDMA Code Division Multiple Access

DNS Domain Name System

DHT Distributed Hash Table

ETSI European Telecommunications Standards and Institute

EDGE Enhanced Data Rate for GSM Evolution


List of Abbreviations ix

EGPRS Enhanced General Packet Radio Service

ECSD Enhanced Circuit Switched Data

FDMA Frequency Division Multiple Access

FIFO First In First Out

GSM Global Systems for Mobile Communications

GPRS General Packet Radio Service

GPS Global Positioning System

HTML Hyper Text Markup Language

HSCSD High Speed Circuit Switched Data

IP Internet Protocol

ITU International Telecommunication Union

IMTS Improved Mobile Telephone Service

IMS IP Multimedia Subsystem

LTE Long Term Evolution

LAN Local Area Network

MANET Mobile Ad-hoc Network

MMS Multimedia Messaging Services

NAD Normalized Average Delay

NMT Nordic Mobile Telephone

NTT Nippon Telegraph and Telephone

P2P Peer to Peer


List of Abbreviations x

PTT Push to Talk

PDA Personal Device Assistant

PDC Personal Digital Cellular

PHS Personal Handy Phone System

RSSI Received Signal Quality Indicator

SMS Short Message Service

SIP Session Initiation Protocol

TCP Transmission Control Protocol

TDMA Time Division Multiple Access

TIA Telecommunications Industry Association

TACS Total Access Communication System

TTC Telecommunication Technology Committee

TIA Telecommunications Industry Association

TTA Telecommunications Technology Association

UMTS Universal Mobile Telecommunications System

UE User Equipment

UDP User Datagram Protocol

UWB Ultra-Wideband

UTRAN Universal Terrestrial Radio Access Network

VoIP Voice Over IP

VAS Value-added Service


List of Abbreviations xi

WIMAX Worldwide Interoperability for Microwave Access

WCDMA Wideband Code Division Multiple Access

WAP Wireless Application Protocol


Introduction 1

1. INTRODUCTION

Peer-to-Peer (P2P) communication services play major role in third and upcoming

generations of cellular systems. In P2P networking, all peers share equivalent

responsibility for processing data. Peers that participate in P2P communication

usually have equivalent capabilities and responsibilities unlike a traditional

client/server model in which some computers are specially dedicated for serving

others [1].

With the continuous development of network technologies, the traditional network

models based on client/server are gradually decreasing. More and more networks are

using P2P communication because it is difficult to meet user‟s requirements in

traditional client/server networks. The main advantages of P2P over client-server are

greater storage, more computer cycles, and greater bandwidth.

The number of mobile broadband users is growing day by day. Further, these users

have high expectations on mobile broadband comparable to those in fixed networks.

The services that can be delivered on mobile networks depend on the data rate these

networks may offer. Therefore, the services and features differ from one generation

to others. With new technological advancements the present networks are able to

deliver data at good speeds and are capable of handling multimedia services [2].

The need for higher bandwidth is increasing to support the advanced applications

such as video streaming, multimedia, mobile television. Other bandwidth intensive

applications have accelerated the adoption of third generation cellular systems. The

2/2.5G mobile networks are not appropriate for P2P multimedia applications (audio,

image and video) because of their higher data rate and ubiquitous communication

service demands. In order to fulfil these demands, Third Generation (3G) networks

have been introduced. 3G cellular services are now partially active all around the

world.

1.1 Related work and motivation

In the following, we will discuss some of the recent studies related to the topic of this

thesis. In [31], the authors investigated the performance of an eDonkey-based mobile

P2P file-sharing system by means of time-dynamic simulation. They investigated the

factors that impact the performance of their P2P file-sharing systems by considering

some factors like temporal pattern of the mobile subscribers or the access type, the

file size of mobile specific content, the churn behavior of mobile user and special

infrastructure entities. The authors investigated the performance of P2P file-sharing

system by means of extensive simulations and based on the results they concluded

that the factors which they choose impact the performance of their P2P file-sharing

system.

In [32], the authors propose architecture for implementing P2P as a Session Initiation

Protocol (SIP)-based service in the mobile cellular networks, in particular in IP


Introduction 2

Multimedia Subsystem (IMS) in 3G mobile networks. The performance of the

architecture is analyzed mathematically and then simulated by using programming.

Authors propose that there are some benefits of using SIP for mobile P2P like the

operators can have control on security and group management, and chargeability is

possible.

In [33], the authors propose a peer selection algorithm named Cell First for Load

Balancing (CFLB) for mobile P2P systems in 3G networks. This algorithm is useful

in selecting a peer with the highest available uplink bandwidth from a cell with the

lowest traffic load until the maximum number of peers is reached. And from the

simulation results, authors concluded that this algorithm can achieve excellent load

balance on the cells in 3G networks while ensuring favorable peer performance.

In [34], based on analysis and adaptation of comparable studies of the present

architecture of P2P authors proposed a new P2P file-sharing system model for 3G

networks. Extensive experimental evaluation is conducted on the P2P model. The

authors conclude that this P2P model brings new development of space and

application prospects for 3G network‟s settlement and application as well as mobile

value-added business in China.

In [35], the author investigated the impact of payload size and data rate on one-way

delay and packet loss in operational 3G mobile networks through network level

measurements on three different commercial mobile operators in Sweden. From the

experimental results the author concluded that the combination of maximum payload

size and data rate resulted in minimum one-way delay, with the big payload size the

percentage of packet loss is less as compared to the smaller payload sizes.

In most of the previous research works, the authors focused on proposing a P2P

model which was generally based on SIP for cellular networks and then they

evaluated the performance of P2P model by considering some performance metrics.

Evaluation of performance in most of the previous research works was mostly based

on simulation studies and at the same time the work did not concentrated on P2P

communications.

So, in this thesis work we are investigating the performance of P2P services using

both transport protocols (TCP and UDP) over real time 3G/UMTS networks. Based

on experimental results, we examined how parameters such as network load, signal

strength and chunk size affect the performance of P2P communication services.

This kind of work on real-time networks will help the P2P application developers to

improve the efficiency of application, to meet the ever increasing user demands for

quality applications.

1.2 Thesis Objective

In this thesis, the authors investigate the performance of TCP and UDP for P2P

services on 3G networks by examining the Normalized Average Delay (NAD),

Throughput and data loss. The evaluation is done in terms of NAD, throughput and

data loss by varying different parameters including network load, chunk size, data


Introduction 3

size and signal strength under different scenarios. Finally, we analyze how each of

these parameters influences the performance of P2P communication.

1.3 Research Methodology

In this thesis the authors will follow quantitative research methodology. An

experimental step up will be created for examining the performance of P2P

communications on 3G networks. Various experiments will be conducted by varying

different parameters including signal strength, network load, data size and chunk

size. Finally, the performance of TCP and UDP will be examined for P2P services.

This evaluation will be done in terms of three performance metrics including

throughput, NAD and data loss.


Peer-to-peer communications 4

2. PEER-TO-PEER COMMUNICATIONS

Peer-to-peer is a communications in which each peer has the same capabilities and either

peer can initiate a communication session. One peer have responsibility for "serving" data

and other peer “consume” data or otherwise act as client of those server.

2.1 Significance and Emergence Several important communication services have emerged in recent years that use

decentralized architecture to concurrently connect millions of users worldwide. In

order to exchange digital audio, video, emails and other types of files.

These applications can be classified as P2P because there are no central servers to

mediate between and can be called as overlay networks because they form a

virtualized network over the existing physical network. P2P is gaining significance

because of ever growing popularity of mobile web environment.

Future P2P communication services should constantly enable new important

applications to incorporate with continuously changing technology trends.

The following are some of the changes in technology trends

Continuous improvement of smart phones and other broadband-enabled

mobile devices.

Continuous improvements of the consumer quality of experience and quality

of service.

The wide deployment of broadband wireless networks Worldwide

Interoperability for Microwave Access (WiMax), Wi-Fi (802.11n), Ultra-

wideband (UWB), Long Term Evolution (LTE)

Continuous growth of real time applications using multimedia systems such

as VOIP and videoconferencing.

The increasing use of personal area networks, body area networks, and

vehicle networks, to connect both real-time sensors and embedded

computing devices [3].

Due to the continuous changes or improvements in above mentioned trends, there is

always a scope to enable new applications in the future that use P2P technology.

The growth of P2P services over traditional client-server communication can be

mainly constituted to some of the P2P properties.

The first property is decentralization, in a centralized structure the whole system

could be ruined by a single point failure which is not the case in decentralized

system. The second property is Self-organizing, because of the fact that P2P



networks can manage all their work without the help of any centralized server. The

third property is cost, to maintain and run a traditional client-server model is far too

expensive than a P2P systems and there are some other properties too but these are

the most important properties for rapid growth of P2P systems [4].

Hence due to above mentioned properties and ever increasing demand for enabling

new applications for increasing consumer demands, P2P networks are becoming an

important component of the future vision and research topics [3].

2.2 Overlay Networks An overlay network is a virtual computer network built on top of one or more

existing networks. Mostly overlay networks are built on top of existing Internet

protocol (IP) Networks.

The nodes that participate in these networks can be thought of as being connected by

virtual or logical links and each of these links corresponds to a path with many

physical links in the underlying network. P2P networks, cloud computing and client-

server networks are some the examples of overlay networks.

Overlay networks are generally distributed systems in nature without any centralized

structure or control and hierarchical organization. The participating nodes or peers

form self-organizing overlay networks on the top of existing IP networks. Peers look

for some resources or data for sharing and once the resource is found, a session is

established between the holder of the resource and the requester [5] [6].

Figure 1: Overlay Network [7]

2.3 P2P Networks P2P networks are distributed systems that divide the work between the peers that are

connected in the network and each peer in the network has equal capabilities,

responsibilities and share equal privileges. P2P systems do not have central control

http://en.wikipedia.org/wiki/Computer_network

http://en.wikipedia.org/wiki/Cloud_computing

http://en.wikipedia.org/wiki/Client-server

http://en.wikipedia.org/wiki/Client-server



or hierarchical architecture. A peer makes a portion of their resource for instance

content and processing power available on the network and shares them directly with

other peers without any need of centralized server for controlling or monitoring.

In P2P systems, peers act as both clients and servers depending upon the situation,

and it is very difficult to distinguish between a server and client in P2P systems,

because they might have server and client relationship with other peers at the same

time. For example, in a file sharing system like bit torrent, a peer acts as a client by

getting some files from other peers and on the other hand it will also act as a server

because it shares that file with the other neighbouring peer at the same time [7]. The

Figure 2 shows a sample pure P2P network.

Figure 2: Sample P2P Network [7]

The research on P2P networks mainly focuses on making the P2P systems

independent of any centralized elements and also which are scalable, efficient in

bandwidth usage and load balancing. The latest research in P2P is to study the

possibilities and to optimize the usage of P2P techniques in mobile devices as much

as possible because in recent times it has been noticed that there is lot of increase in

mobile usage. Hence there is a need to utilize this change efficiently and to introduce

different and new features in P2P applications for the mobile environments than the

traditional applications which runs on desktop and laptop environments [5].

The traditional applications have been considered too heavy for mobile usage, high

bandwidth for working effectively. There are lot of P2P applications already

available for wireless or mobile devices but still there is a need for applications

which are very light and utilizes very less bandwidth and perform effectively in the

mobile telephone networks, hence, there is lot of research going on in P2P [5].



2.4 Key characteristics of P2P networks

Following are the key characteristics of P2P networks

2.4.1 Resource sharing

Each peer provides a part of its resource available on the network and shares it

directly with other connected peers without any centralized support. Due to this P2P

systems are gaining popularity rapidly.

2.4.2 Symmetry

All peers are interconnected with each other to form a P2P network and each peer in

this network has equal capabilities, responsibilities and share equal roles for

successful operation of the network. In recent times, this characteristic is relaxed by

using some special peer which has some greater responsibilities like super peer or

relay peer.

2.4.3 Autonomy

Participation of the peers in the P2P network is determined locally, and there is no

single administrative context for the P2P network. Peers can join or leave the

network any time.

2.4.4 Self-Organization

P2P systems are self-organizing because all the nodes recognize and create relatively

stable connections with other nodes. They manage all their work without the help of

any centralized server.

2.4.5 Scalability

Scalability is another important characteristic of P2P network because these

networks typically consist of large number of heterogeneous, distributed and

dynamic nodes. These kind of large scale networks present many challenges, for

instance it is very difficult to know when exactly a peer joins or leave the network

continuously. Sophisticated mechanisms are needed to perform effective queries and

stabilizations, which uphold the integrity of these networks [3].

2.4.6 Stability

There is always chance of network failures in P2P networks because the peers joins

and leaves the network continuously therefore P2P network must be stable and

maintain its connectivity in all times.



2.4.7 Decentralization

Most of the P2P networks are decentralized in nature because they do not have any

centralized control and all the participating peers have equal capabilities,

responsibilities and share equal privileges [3].

2.5 Classification of P2P Networks

The first ever server based P2P application developed was Napster and after the

inception of Napster, the internet underwent nothing short of revolution [7]. After

many years of research and development, the P2P networks have evolved to the

current form as it exists today to meet the purposes, needs of various users and

organizations.

At present P2P networks are very large in number and each of them has different

properties that make it difficult to classify these networks using a unique criterion. In

order to understand the existing P2P networks well, we can classify them based on

some criterion, i.e. appeared time and purpose, degree of centralization and topology

[7] [9] [10].

2.5.1 Classification based on appeared time and purpose

From the time file sharing concept has been invented till today, P2P networks have

underwent many changes to meet the purposes, needs of various users and

organizations.

We can classify the existing P2P networks into three generations according to

appeared time and purpose [10].

1) First generation P2P

2) Second generation P2P

3) Third generation P2P

2.5.1.1 First Generation P2P networks

The first generation P2P networks were client-servers. There is a centralized server

which is the provider of content and services, and the clients request for content or

services from the server.

The first generation P2P systems are again divided in to two types centralized and

decentralized.



In centralized networks, servers provide the necessary content or services and clients

requests for the required content or service. A centralized server stores the index

resource of all the required data and if any clients (peers) send search request to the

server for the desired data than the server responds to the client by sending the

address location of the data. Finally clients directly connect to the peer which holds

the desired data. Generally centralized systems are too simple, but have bad

scalability and low query efficiency. Napster is the typical example for this kind of

systems [10] [7]. Figure 3 is an example of centralized network.

Figure 3: Centralized Network [7]

Decentralized networks are those that do not have any central server to control or

manage peers. All peers have equal responsibilities and capabilities. Communication

between the peers is symmetric as there is no central index server where the metadata

of data is stored. This metadata is stored locally among all peers. In contrast to a

client-server network, it is difficult to distinguish between a content requestor (client)

and a content provider (server), because a peer acts as both client and server at the

same time. Figure 4 is a typical example of decentralized network.

In this type of systems, search of desired data is done by broadcasting mechanism. A

peer sends a request to the neighboring peer for some data item and when neighbor

peer receives the request, it tries to search for that item locally. If the requested data

item is not present then the request is forwarded to another peer. The report of failure

or success of desired data is sent back to the requested peer on the same path of

incoming request. Such kinds of systems have many advantages because there is no

longer a single point of failure. These networks have better scalability, anonymity

Peer

Peer

Peer

Peer

Peer

Peer

Peer

Central serverPeer



and better fault tolerance. Gnutella 0.4 and Freenet are typical examples of such kind

of systems [10] [7] [11].

Figure 4: Decentralized Network [7]

2.5.1.2 Second generation P2P networks

The second generation P2P networks have no central index server and try to solve

the non-determinism problem of resource location. The idea is that if there is any

specific resource available on the network, then it should be found and to achieve it,

these networks should start following some tightly controlled structured node

groupings like Mesh, Ring, d-dimension Torus, K-ary tree, SkipList. Nodes are

arranged in a structured fashion, following tree or ring formations. Content or

resources are placed not at random nodes but at a specified node location. The

objective of storing content at some particular specified node location is to help a

node which is looking for a resource, at that particular time. This node must be

redirected to the node which is supposed to hold it.

These kind of networks usually have better scalability and query efficiency, and

provide load balancing and deterministic search guarantees because they utilize the

distributed hash table (DHT) technique. On the other hand, they are not so fault-

tolerant and resilient.

The main challenges of second generation networks are, Distribution of

responsibilities evenly among the existing peers to avoid bottlenecks in particular

nodes and quickly adapting to nodes joining or leaving [11] [7] [9].



2.5.1.3 Third generation P2P networks

Third generation P2P utilized hybrid network architecture to provide networks with

high resilience and search capabilities. The first generation centralized P2P networks

had many problems including bad scalability and low query efficiency. These

problems were solved by the second generation P2P systems with decentralized

architecture. As there is no central server in second generation systems which

always introduced new issues for instance traffic generated in the network due to the

lookup process which is done in a broadcast manner.

The third generation P2P networks have solved these issues in an admirable manner

by using super peers that have more functionalities than the ordinary peer same as

the server functionalities in the centralized P2P network. The super peer acts as a

gateway to the P2P network for group of peers connected to that super peer [5] [7].

2.5.2 Classification based on degree of centralization

P2P networks can be broadly classified in to the following three types based on the

degree of centralization are

Pure P2P

Hybrid P2P

Mixed P2P

2.5.2.1 Pure P2P

In a pure P2P network, the notion of clients or servers does not exist because each

peer has similar responsibilities, capabilities and share equal priority and

simultaneously they function as both "clients" and "servers". Sometimes the

nodes/peers of these networks are referred as “Servents”, because of their

(server+client) capabilities. Figure 5 shows an example of pure P2P network.

Peer 4Peer 3

Peer 5

Peer 1

Peer 2

Figure 5: Pure P2P [12]

http://en.wikipedia.org/wiki/Client_(computing)



2.5.2.2 Hybrid P2P

These networks are also known as hybrid decentralized networks. Hybrid P2P

networks have a single central server, but not as the general purpose servers as used

in the case of client-server model. In these networks, servers keep track of the entire

information in the network. Peers make use of the servers for searching and

identifying the nodes/peers that hold some data or resource.

Servers stores the entire resource index of all the required data and if any peer send

search request of the desired data than the server responds to the client by sending

the address location of the data. Thereby, the peer establishes direct interaction with

another peer which holds the data. Figure 6 shows an example of hybrid P2P

network.

Peer 2

Peer 1

Peer 5

Peer 3

Peer 4

Central server

Figure 6: Hybrid P2P [12]

2.5.2.3 Mixed P2P

Mixed P2P network stands between pure P2P and hybrid networks which can be

clearly seen from the Figure 7. These are also known as partially centralized

networks. Some nodes or peers in this kind of networks are given super powers by

assigning some responsibilities like maintaining central index of resource files and

helping and managing peers. The peers with some super powers can be referred as

super nodes or super peers [12] [13].



Peer 1

Super Peer

Peer 6

Peer 2

Peer 3

Peer 4

Peer 5

Figure 7: Mixed P2P [12]

2.5.3 Classification based on network topology

No matter how many different topologies exists or how peers connect with each

other, all the P2P file sharing systems have one common feature that is all file

transfers between peers are always done directly between the peers. In terms of

network topology, P2P can be broadly classified in to following five classes

Centralized Topology

Ring Topology

Hierarchical Topology

Decentralized Topology

Hybrid Topology

2.5.3.1 Centralized Topology

A sample network of centralized topology is illustrated in Figure 8. In this type of

networks, a centralized server always exists which is much identical to server of

client-server model and it is mainly used for managing and controlling multiple

peers. A peer connects to the server and shares all the information which they are

willing to share [14].



Peer 1

Peer 3

Peer 2

Peer 7

Peer 5

Peer 4

Peer 6

Figure 8: Centralized topology [14]

2.5.3.2 Ring Topology

A sample network of centralized topology is illustrated in Figure 9. In this type of

networks, a centralized server always exists which is much identical to server of

client-server model and it is mainly used for managing and controlling multiple

peers. A peer connects to the server and shares all the information which they are

willing to share [14].

Peer 1

Peer 3Peer 2

Peer 5

Peer 4 Peer 6

Figure 9: Ring Topology [14]



2.5.3.3 Hierarchical Topology

Some of the best known examples for hierarchical model are Domain Name System

(DNS) and Certification Authorities (CAs). This topology is appropriate for systems

that require some governance or control and it can also be implemented in the

systems that require higher scalability. The Figure 10 illustrates an example of

hierarchical topology [14].

Peer 8

Peer 1

Peer 3 Peer 7Peer 5 Peer 6Peer 4

Peer 2

Figure 10: Hierarchical Topology [14]

2.5.3.4 Decentralized Topology

This topology follows a pure P2P architecture without any central server. All peers

share the responsibilities among each other and have equal capabilities. Peers acts as

both clients and servers at the same time. Figure 11 shows an example of

decentralized topology



Peer

Peer

Peer

Peer

Peer

Peer

Peer

Peer

Peer Peer

Peer

Figure 11: Decentralized topology [14]

2.5.3.5 Hybrid Topology

There were some problems with the centralized and decentralized network

topologies, to overcome those problems hybrid along with hierarchical topologies are

evolved and recently have been used by many popular P2P applications for better

scalability performance.

There are several topologies in which hybrid technologies can be divided but some

basic topologies of hybrid topologies are

Centralized and Ring Topology

The best example of hybrid topologies are web server applications which are heavily

loaded and to balance the load on the web servers they are arranged in the form of

ring structure and then the clients are connected to the ring of servers [14]. Figure 12

shows the example of centralized and ring topology



Peer Peer

Peer

Peer Peer

Peer

Peer

Peer

Peer Peer Peer

Figure 12: Centralized and ring topology [14]

Centralized and Centralized Topology

An example of centralized and centralized topology is shown in Figure 13, where the

server itself acts as a client for some bigger network. A simple example that can

illustrate this point is, when a web browser contacts a web server. Then that server

might contact other servers (database servers) to obtain necessary information to

process and show the results in HTML format [14].

Peer

Peer

Peer Peer

Peer Peer Peer

Figure 13: Centralized and centralized topology [14]



Centralized and Decentralized Topology

There are some peers which acts as a super node. The super node acts as a

centralized server for subset of peers which are connected to it. And the super node

itself is connected to another super node in a decentralized manner. The best

examples for such kind of topologies are Kazaa and FastTrack [14]. Figure 14 shows

a sample of centralized and decentralized Topology.

Peer

Peer

Peer

Peer Peer

Peer

Peer

Figure 14: Centralized and decentralized topology [14]

2.6 Mobile P2P

The mobile P2P networks are generally formed by mobile devices such as mobile

phones, laptop‟s and PDA‟s which are capable of ad-hoc communications. With the

integration of wireless communication technologies like Bluetooth, IEEE 802.11b

Wi-Fi into such mobile devices made the current mobile P2P networks feasible. At

present the number of mobile users. With such kind of technologies represent a small

percentage but in near future as the capabilities and network bandwidth increases the

population of users of such devices will increase [3] [15].

The four important challenges for the mobile devices which affect their interaction

with the P2P networks when compared with the conventional desktop computers are

roaming, energy limitations, node heterogeneity and multi-homed interfaces. If these

challenges are handled effectively, mobile P2P networks become more feasible and

usage of such kind of devices will rapidly increase [3]. As the demands for mobile

devices with ad-hoc communication capabilities are increasing constantly, it has

made mobile ad hoc networks (MANET‟s) a hot topic for research.



MANET‟s consist of mobile nodes communicating with each other through multi-

hop wireless radio links. P2P and MANET networks share some fundamental

features such as decentralized architectures, self-organization and dynamic

topologies. The nodes in both networks can serve multiple purposes, for instance

they can act as both routers and hosts. P2P file sharing over MANET‟s and P2P

information sharing on MANET‟s has gained momentum in the research of recent

years due to the tremendous popularity of both P2P and MANET‟s. [16]


Overview of Cellular Networks 20

3. OVERVIEW OF CELLULAR NETWORKS

3.1 Introduction

Mobile networks are differentiated from each other by the word generation such as

first-generation (1G), second-generation (2G), third-generation (3G), fourth-

generation (4G) and Future-generation. This is quite suitable because there is a big

generation gap between the technologies.

The 1G mobile communication systems were analog systems, which came in the

early 80‟s. These networks are also known as the Nordic Mobile Telephone (NMT).

These systems supported only speech and related services. The main drawback of

these systems was the limited services offered and incompatibility with

contemporary systems of other countries.

Different standards were used in different countries. These standards include NMT

used in Nordic countries (Sweden, Iceland, Denmark, Norway and Finland), Total

Access Communication System (TACS) used in United Kingdom and Advanced

Mobile Phone System (AMPS) used in the United States. There was radio telephone

system even before this [21].

The increasing demands for mobile communication systems need more

compatibility, resulted in the birth of the second generation mobile systems. But

again none of the standards in the 2G were able to fulfill the globalization dream of

the standardization bodies. This would be fulfilled by the third-generation mobile

systems. It is expected that these 3G systems will be mainly oriented towards data

traffic, compared the 2G networks that were carrying mainly voice traffic.

4G is an extension of the 3G technology that provides a completely packet switched

network with all digital network elements and high available bandwidth. For the

most part, it is believed that 4G will get true multimedia capabilities such as high

quality audio/video streaming over end-to-end Internet Protocol. 4G is the future

technology that is mostly in their maturity period (Research period) [22].

International Telecommunication Union (ITU), Alliance of radio Industries and

Business (ARIB), European Telecommunications standards and institute (ETSI),

Third Generation Partnership Project (3GPP) and American National Standards

Institute (ANSI) are the standard bodies that have been playing an important role in

defining the specifications for the mobile systems.

http://www.freewimaxinfo.com/3g-technology.html



The different generations are discussed in the following sections

3.2 First generation radio systems 1G refers to the wireless telecommunication technology first generation, more

commonly known as cell phones. In 1980's a set of wireless standards were

developed to replace the 0G technology by 1G which in turn changed the impression

of two way mobile communication. Technologies such as Improved Mobile

Telephone Service (IMTS), Advanced Mobile Telephone System (AMTS), Mobile

Telephone System (MTS), and Push to Talk (PTT).

Unlike its successor 2G, that use digital signals, 1G uses analog radio signals in

network. Through 1G, the voice calls get modulated up to 150MHz and above as it is

transmitted between radio towers. . This is done by using so-called frequency

division multiple access (FDMA).

1G is not favorable to its successors in terms of connection quality. It has poor voice

link, no reliability in handoff, low capacity and no security. 1G have some

advantages over 2G, digital signals of 2G are very dependent on location when

compared with analog signal of 1G. When call made from 1G handset generally

quality is poor when compared to 2G handset but 1G covers longer distance than 2G.

While call made from a 2G handset would terminates in the middle or completely

drops before reaching the destination [21] [22] [23].

3.3 Second generation radio systems

Few significant changes made the shift from 1G to 2G. First, unlike 1G cellular

network which was used for analog communication, the 2G networks were used for

digital communication in both radio and between network entities. Second, 1G

standards were supported with-in national boundaries whereas 2G standards are

supported by global roaming services in large regions beyond national boundaries.

The 2G mobile communication systems were digital system that came in the early

90s. The wireless systems including Global Systems for Mobile Communications

(GSM), Time Division Multiple Access (TDMA, TDMA IS-136), Code Division

Multiple Access (CDMA, CDMA IS-95), Personal Digital Cellular (PDC) and

Personal Handy Phone System (PHS) can be considered as 2G systems [21] [24]

[22].

3.3.1 Code division multiple access (CDMA)

CDMA is a form of multiplexing not a modulation scheme. It was developed by

Qualcomm originally known as interim standard (IS-95) of the Telecommunications

Industry Association (TIA). CDMA offers several advantages such as improved

security system, improved quality, increase in capacity (around 10 times that of the

AMPS), improved coverage and anti-jamming capabilities. IS-95B was the

enhancement of IS-95. The advantage of IS-95B includes frequency diversity, which



is the signal has less effect of frequency dependent transmission and increased

privacy [21] [25]. The Protocol architecture of IS-95 is shown in Figure 15.

Figure 15: Protocol architecture of IS-95 (CDMA One) Standard [26]

3.3.2 Global system for mobile communications (GSM)

GSM standard was first commercially launched on 2G cellular networks by

Radiolinja in 1991 (Finland). Due to features such as prepaid calling and

international roaming. GSM is widely implemented and is popular cellular system

with around two billion users by 2005. Apart from just making calls GSM also

provided the services such as short message service (SMS), call waiting, call

forwarding which enhanced the popularity of this system. This led to the

development of new handsets with more features like smaller, thinner and lighter

handsets.

The GSM systems have been an advantage to both consumers and network operators

as they provide better voice quality compared to 1G systems and low cost of text

messaging alternatives of calls. Network operators have ability to choose equipment

from different vendors. GSM cellular networks operate on different frequencies

depending on the system used by service provider. In US and Canada, 850MHz and

/or 1900MHz and in Europe 900 MHz and 1800 MHz [21].

3.3.3 General Packet Radio Service (GPRS)

GPRS is a (data) service added to the GSM networks. GPRS is a cellular service that

supports Wireless Application Protocol (WAP), SMS text messaging, Multimedia

Messaging Services (MMS), and other data communications. It is also called as



2.5G. GPRS increases the communication speed up to 115 kbps a vast improvement

over the 2G standard speed of 9.6 kbps. GPRS was integrated into GSM standards

from 97.

Before introducing GPRS, the available radio capacity was used for both voice traffic

and data traffic within the GSM network in a rather inefficient way. For data

transmission the entire channel was reserved. In Circuit Switched Data (CSD), a data

connection establishes a circuit and occupies the full bandwidth of that circuit during

the lifetime of the connection. GPRS is quite different from the CSD connection

included in the GMS standards. GPRS data traffic uses packet switching while voice

traffic uses circuit switching. GPRS works on packet switched which means same

transmission channel can be shared by multiple users. GPRS enables the resources to

be used only when the user actually sending and receiving the data. The amount of

data transfer depends on the number of active users [21].

3.3.4 Enhanced Data Rate for GSM Evolution (EDGE)

EDGE technology is an extension of two existing services named High Speed Circuit

Switched Data (HSCSD) and GPRS. It works in TDMA and GSM networks. EDGE

is preferred for GSM networks due to its circuit and packet–switched services.

Enhanced Genera Packet Radio Service (EGPRS) is packet–oriented and Enhanced

Circuit Switched data (ECSD) is circuit–oriented. EDGE was introduced to the ESTI

for the first time in 1997 for the evolution of GSM. EDGE reaches very high raw bit

rates of up to 69kbps per physical channel by applying modified modulation and

coding schemes. The theoretical maximum raw bit rate rises to 554kbs, if a user

utilizes all 8 time slots in parallel. The maximum bearer bit rate achievable rises to

about 384kbs. The architecture of the GSM for EDGE is same only modification was

at the air interface to support higher data rates. 8-Phase-Shifit-Keying (8-PSK) is

modulation technique to support higher data rates, which in turn supports bandwidth

extensive data applications [21] [27].

3.4 Third generation radio systems 3G is the third generation mobile network technology and it was developed with the

plan of offering high speed data and multimedia connectivity to subscribers. It is

based on the International Telecommunication Union (ITU) under the initiative of

International Mobile Telecommunications (IMT). Evolution of 2G to 3G cellular

networks is shown in Figure 16.



Figure 16: Evolution of 2G to 3G cellular networks [28]

3.4.1 CDMA 2000

CDMA 2000 is compatible with IS-95 systems and it has many variants such as 1x,

1xEV-DO, 3x and 1xEV-DV. Among these 1xEV specification was developed by

the Third Generation Partnership Project 2 (3GPP2). Alliance of Radio Industries

and Business (ARIB) and Telecommunication Technology Committee (TTC) in Japan,

china Wireless Telecommunication Standard group (CWTS) in China and

Telecommunications Technology Association (TTA) in Korea and Telecommunications

Industry Association (TIA) in North America are five telecommunications

standardization bodies in 3GPP2.

CDMA 2000 provides many advantages such as higher voice quality, improved

security, spectrum efficiency, differentiated value-added service (VAS), high

throughput and flexibility in architecture. By using selectable mode vocoders and

various antenna diversity schemes, this technology offers voice capacity that is

almost three times that of CDMA (IS-95). At 64kbps to 144kbps, CDMA2000

delivers low data rate services. For all environments 144bps would be possible while

indoors environment, 2Mbps would be possible. CDMA2000 EV-DV (CDMA2000

evolution data/voice) is able to carry data rates up to 3.1Mbps on the forwarded link

and 1.8mbps on the reverse link. DV is preferred by operators because it does not

require an overlay. CDMA2000 has less support when compared with 3GPPP

scheme but it will be an important technology where IS-95 networks are used. 3G



network in the United States uses 2G spectrum in many cases and thus CDMA2000

is an attractive technology choice as it can coexist with IS-95 systems [30] [29] [21].

3.4.2 Universal Mobile Telecommunications System (UMTS) The UMTS is one of the 3G technologies and it uses Wideband Code Division

Multiple Access (WCDMA) as the Access scheme. Nippon Telegraph and Telephone

(NTT) DocoMo developed WCDMA as air interface for their 3G network FOMA.

Later, the specification was submitted to the ITU as a member for the international

3G standard as IMT-2000. Finally, ITU accepted WCDMA as part of IMT2000

family of 3G network. It is used as air interface for UMTS. The bandwidth of a

WCDMA system is 5MHz or more and this 5 MHz is also the nominal bandwidth of

all 3G WCDMA proposals.

WCDMA air interface can be made into two groups such as network asynchronous

and network synchronous. All base stations in synchronous network are time

synchronized to each other. More expensive hardware is required in base station of

synchronous network but it provides more efficient air interface. For example, it

could be possible to achieve synchronization with the use of Global Positioning

System (GPS) receivers but it may fail in high-block city centers or indoors.

WCDMA contains fast power control in both downlink and uplink. Further using

variable spreading, it provides the ability to vary bit rate and service parameter on a

frame-by-frame basis [29] [21].

3.4.2.1 UMTS Network Architecture

The UMTS network architecture consists of User Equipment (UE), Universal

Terrestrial Radio Access Network (UTRAN) and Core Network (CN) as depicted in

Figure17.



Figure 17: Network Architecture [26]

UE is the name given to a mobile terminal within a UMTS network. This enables

subscriber to access UMTS services through the radio interface „Uu‟.

UTRAN connects the UE to CN and enables cell level motilities and it has many

radio network subsystems (RNS), call handover control, call handover control and

radio resource management are some of the main functions perform by RNS.

There are two modes of operation of Universal Terrestrial Radio Access (UTRA)

systems UTRA-FDD and UTRA-TDD which are compatible with UTRA system.

FDD mode of the UTRA technology makes use of WCDMA, up/down links using

separate frequencies. Approximately 250 channels are provided by FDD mode for

handling different user‟s traffic. Direct sequence spread spectrum (DSSS) coding is

used achieving a maximum data rate of 2Mbits/sec.

TDMA/CDMA is used for UTRA-TDD and both up and down links use same

frequency. Approximately 120 channels can be provided by TDD mode for handling

different user‟s traffic. DSSS coding is used and maximum data rate of 2Mbits/sec

can be achieved. UTRA-TDD uses QPSK modulation scheme.

The CN is central part of telecommunication network which manages the services

such as establishment, termination and modification of UE authentication

interconnection with external world for each UMTS subscriber [30].



Air interface protocol structure of WCDMA (UMTS) is shown in Figure 18.

Figure 18: Air interface protocol structure of WCDMA (UMTS) [26]


Experimental setup 28

4. EXPERIMENTAL SETUP

The objective of this thesis is to investigate the characteristics of data transmission

for P2P communication services on 3G networks considering performance metrics

such as normalized average delay, throughput and data loss. To achieve this, it is

necessary to develop a P2P model using which various experiments could be

conducted under different scenarios.

This chapter is divided into three sections; first section discusses the basic approach

of experimental setup. The next section discusses architecture and development of

P2P model and the final section discusses experimental configuration and analysis

procedure.

4.1 The Basic Approach

The main goal of this thesis work is to evaluate performance of P2P communications

on 3G networks and in order to achieve this, a P2P model should be developed which

supports data transmission between two peers.

Peer A Peer B

Internet

Figure 19: Basic P2P model

Figure 19 shows a basic P2P model in which two peers connect and communicate

with each other via Internet. This was the basic model which was initially thought

but our P2P model should exhibit some important prerequisites which are discussed

below



The main prerequisites for our P2P model are:

Two peers should be capable of transmitting data, for example in Figure 19, if

“peer A” sends the data then “peer B” should receive it successfully and vice

versa. In this type of communication peers act as “servents” (both server and

clients simultaneously [17].

The peers should be able to communicate and transmit data regardless of

network they use to connect to Internet. As we are analysing the performance

of data services on 3G networks, the P2P application should have the

capabilities of transferring data on 3G network.

In order to meet the above requirements, we followed hybrid P2P model for the

experiments. It consists of two peers and one linking server. The main reason for

using hybrid P2P model is to avoid private IP problems.P2P communication is not

possible through Internet if both peers have private IP‟s.

Two way communication

Central Server

Internet

Modem

Peer A Peer B

Figure 20: Hybrid P2P model

Figure 20 illustrates the hybrid P2P model used for our experiments. It consists of

two peers and one linking server. In this model, the linking server acts as a mediator

for helping peers to connect with each other without requiring the public IP addresses

for peers. Initially „peer A‟ connects to server via internet and provides necessary

information about itself and then the other „peer B‟ connects to the server via

3G/UMTS internet services provided by the mobile operator through the modem.

Once the connection is established between the peers, they can exchange any type of



data between each other. The modem used for our experimental purpose is “Telit

GT846-3G terminal”.

4.2 The architecture and development of hybrid P2P model The P2P model discussed in section 4.1 has been developed using windows sockets

programming.

4.2.1 Socket Communication/ programming

Socket programming is an application (higher level) layer programming and it is

generally implemented by using socket application programming interfaces (API‟s).

Sockets API acts like an interface between application layer and transport layer.

Alternatively, socket Apps act as a door between application layer and transport layer

which can be accessed by using only specific IP address and port number. Figure 21

shows OSI model for Socket API‟s

Application Layer

Socket API

Transport Layer

Network Layer

Data link Layer

Physical Layer

Figure 21: OSI model for Socket API‟s [20]

Socket is a kind of data structure provided by operating system, it provides access

between the processes for sending and receiving messages in the absence of

correlation between them. Sockets allow communication between two different

processes on the same or different devices as can be seen in Figure 22. Generally a

socket can be treated as an endpoint in a network communication just as a fax

machine is the endpoint for a fax communication [18] [19] [20].

In pure UNIX terms, a socket is just like a file descriptor. In UNIX, any kind of I/O

operation is done by reading or writing to a file descriptor. A file descriptor is simply

an integer associated with an open file and that file can be a network connection, a

first in first out (FIFO), a pipe or a terminal. Additionally the communication



between two different processes over the Internet it is also done by using file

descriptor [18] [19] [20]. The file descriptor for network communication can be

simply used by calling system routine “socket ()”, it returns a socket descriptor

through which communication over network is possible by using some of the

specialized functions. Some of these library functions are given in the Table 1.

There are mainly two types of Internet sockets for communication namely

connection-oriented socket and connectionless-socket [19] [20].

Process A

Ports (Sockets)

Network

Process B

Figure 22: Schematic diagram showing communication between two processes [20]

Table 1: Shows the library functions of socket

Function Name Description

Socket () Creates a socket

Bind () Binds the socket to the local address and it is optional for initiator

Listen () Alerts the TCP/IP machines with the incoming client connection

requests and specifies the maximum number of connection requests

that can be pending

Connect () connects socket to a foreign host

Accept () Establish the connection with a specific client

Send (), recv () Write and read data on sockets until all data has been exchanged Close () Closes the socket and releases kernel data structure

4.2.2 Basic architecture and development of connection-oriented

sockets

Connection-oriented sockets generally uses TCP protocol and in this type of service

a connection should be established between the two peers before the actual data

exchange starts and the connection will be released once the data transmission is

complete. Connection-oriented data transmission takes place in the following three

steps. (1) establishment of connection (2) data transmission (3) releasing the

connection [18] [19]. Figure 23 illustrates architecture of basic TCP stream socket

session.



Socket ()

Bind ()Optional

Listen ()

Send () and recv ()

Accept ()

Close ()

Socket ()

Bind ()

Connect ()

Close ()

Send () and recv ()

TCP ServerTCP Client

Figure 23: Basic architecture of TCP stream socket session [20]

4.2.3 Basic architecture and development connectionless- sockets

Connectionless-sockets generally use UDP protocol, and there is no need to establish

connection in advance between the two peers. In this type of service the UDP

protocol simply delivers the datagram and it does not guarantee reliable transmission

of data hence there is always possibility of missing, duplicating and disordering the

data. This service can generally be used if the data has no relation with the order of

arriving at the other end. Connectionless sockets provide faster data transmission

compared to connection oriented sockets [19] [20]. Figure 24 illustrates a general

UDP datagram socket session.

Socket ()

Bind ()Optional

Send () and recv ()

Close ()

Socket ()

Bind ()

Close ()

Send () and recv ()

UDP ServerUDP Client

Figure 24: Basic architecture of UDP datagram socket session [20]



In connectionless service, some of the socket function calls such as accept (), listen ()

and connect () are not used because it does not require any advance connection

establishment between the peers.

The above mentioned basic architectures of connection-oriented and connectionless

services have been implemented using socket programming to develop P2P model

for both type of services for our experiments.

4.3 Connection establishment between peers and data

transmission

We developed separate applications for peers and the linking server according to our

experimental need. The establishment of connection between the peers is done as

fallows. First, run the server application on the linking server. At least one of the

peers has to know ID of another to make a connection. Run the peer (peer A)

application from one system to connect the server. When peer connects to the server

and waits for another peer to connect. Server stores the peer ID (peer name) in its

database to wait for another peer. Repeat the same for the other peer (peer B) from

different system with another peer name. When server receives the connection

request form second peer it establishes the connection between these two peers. Once

the connection is established both peers are ready to exchange the data between

them. Refer to appendix A and appendix B for further details.

4.4 Experiment configuration and analysis procedure

In the following we will discuss the experimental configurations and parameters

signal strength, network load and chunk size.

4.4.1 Experimental configuration

In the following we will discussed the experimental setup used in our work which is

also shown in Figure 20. The entire experimentation is done in Blekinge Institute of

Technology (BTH, one peer) Karlskrona campus network and as the complete

analysis is done over 3G networks(other peer), a modem (GT846-3G terminal) with

Telenor mobile operator has been used.

To analyze the performance of P2P communication over 3G networks, ten different

data sizes are transferred from „peer A‟ to „peer B‟ under different conditions. The

data sizes used for the experiment are 512 bytes, 1 kilo byte (KB), 50 KB, 100KB,

300KB, 600KB, 800KB, 1 megabyte (MB), 5MBand 10 MB. Each of this data size is

transferred for 20 times and finally, average of them is taken for analysis and the

different parameters while transferring data of one of these sizes are signal strength,

network load and chunk size.



Signal strengths:

Signal strength is one of the important parameters and we are categorized it into as

strong and weak signal for our experiments. The signal strength of modem is

represented by received signal quality indicator (RSSI) whose range is from 0 to 31.

Each RSSI value is associated with a value in dBm for example, RSSI=0 means the

modem has signal strength of -113 dBm or less which is lowest signal level. We

categorized weak signal for RSSI value between 0-6 and strong signal for RSSI≥ 23.

Network load:

To analyze the effect of network load on performance, we categorized network load

as peaks hours and non-peak hours. Peak hours mean the day time between 14:00 to

18:00 hours with high traffic load on network and non-peak hours mean that the

experimentation should be conducted during night time between 2:00 to 6:00 hours

when low traffic is expected on network.

Chunk size: Chunk size is the amount of data transferred from „peer A‟ to „peer B‟ each time

during transmission. For example, if „1mb‟ data is transferred from „peer A‟ to „peer

B‟ and the selected chunk size is 1024 bytes, this means that 1MB data will be

transferred in chunks of the size1024 bytes each time from „peer A‟ to „peer B‟. To

examine the effect of different chunk sizes, three different chunk sizes have been

used for the experiments and they are 512, 768 and 1024.

System/Hardware specifications:

The specifications of device used for experimentation are

System properties (peer1):

Brand: Dell

Processor: Intel Core duo, CPU @2.10GHz

RAM: 4 GB

System properties (linking server):

Brand: Acer

Processor: AMD Turion (tm) X2 Dual - Core

Mobile RM - 74, CPU @2.20GHz

RAM: 4 GB

System properties (peer2):

Brand: Dell

Processor: Intel Core duo CPU @2.10GHz

RAM: 4 GB

Modem:

Brand: Telit GT-864 terminal

Specifications: downlink = 7.2Mbps, uplink=384kbps, Sensitivity =

- 107dbm,

Supported features: HSDPA, UMTS, GPRS, EDGE and AT commands on

both UART and USB.



4.4.2 Analysis procedure

To analyze the performance of P2P communications on 3G networks and to

investigate how different parameters such as signal strength, network load and chunk

size effect the performance. Different scenarios have been created with different

combination of all the examined parameters. Data sizes are transferred from peer A

to peer B as shown in Figure 20 under different conditions.

Data is transferred between the peers using different data sizes. In the following, the

scenarios used for signal strength and network load for all chunk sizes are given.

using strong signal during non-peak hours

using strong signal during peak hours

using weak signal during non-peak hours

using weak signal during peak hours

In order to keep the track of transmission time, logs (timestamps) are collected for all

cases and then average of all these results are taken for analyzing the performance.

4.4.2.1 Performance metrics calculation

Whenever a data is transmitted from peer A to peer B, the time when a chunk was

sent (Ts) and received time (Tr) for each chunk is recorded and once the entire data

size is transferred logs are generated with all these time stamps. The timestamps

contain all the sent and received times for complete data. Using the timestamps, the

following performance metrics are calculated for analysis.

Throughput:

Throughput is the amount of useful data (payload) that is transmitted through a

channel in fixed amount of time. Throughput can be estimated by dividing the

transmitted data size (Dt) with the total transmission time (Tt).

Throughput𝐷𝑡×8

𝑇𝑡

Normalized Average Delay (𝒅𝑵𝑨):

NAD is the normalized average end-to-end delay.

In order to estimate NAD, first it is necessary to know the total transmitted time for

each data size. Once total transmission time is known, and then NAD can be

calculated by dividing total transmission time by the transmitted data size.

dNA =

𝑇𝑡

𝐷𝑡



Data loss (L):

Since there was no loss of data for TCP case, it is only estimated in the case of UDP.

Percentage data loss L can be computed as. Where Dr is Received Data size

L% 𝐷𝑡 −𝐷𝑟

𝐷𝑡 ×100


Results 37

5. RESULTS

In this chapter, we present the detailed results obtained from the experiments

conducted to evaluate the performance of P2P communication of 3G/ UMTS

networks in terms of NAD, throughput and percentage data loss.

The performance is analysed for both TCP and UDP. To analyse the performance

metrics effectively, different parameters such as signal strength, network load and

chunk size have been selected for experiments and the results have been collected

under different conditions. There are some potential threats that might limit the

validity of study such as, clock synchronization, Wi-Fi problem, devices

specifications and mobile network operator. To evaluate how these parameters affect

the P2P performance, we considered different conditions for these parameters. Such

as for parameter signal strength we considered strong and weak signal, for parameter

network load we consider peak and non-peak load and for parameter chunk size we

consider 1024, 768 and 512 bytes of chunk. The results have been divided in to five

cases where each case presents. Refer to appendix C for further details.

5.1 CASE 1

Effect of chunk size:

To analyze the effect of chunk size on the performance for both TCP and UDP under

the following scenario

Signal strength: Strong

Network Load: Non-peak

Data Size: 1MB

Protocols: TCP and UDP

Chunk size: (512, 768, 1024 bytes)

Figure 25: Effect of chunk size on throughput for TCP and UDP


Results 38

Figure 25 and 26 show the effects of chunk size on throughput and NAD

respectively.

Figure 26: Effect of chunk size on NAD for TCP and UDP

From Figures 25 and 26, it is clear that chunk size affects both the performance

metrics. The throughput increases as chunk size increases while NAD decreases. The

reason for this trend is that when we configure peers with larger chunk size, it sends

less number of packets (chunks) when compared with smaller chunk size, which

results in decrease of transmission time, hence throughputs are more for larger chunk

size. And as the data rates increases delays tend to decrease which results in

decrease of NAD‟s for larger chunk size models. And one more reason for this

behavior is that peers with smaller chunk size has large overhead compared to large

chunk size, due to which peers configured with larger chunk size perform better than

the smaller chunk size (i.e.) they have better throughputs. It can also been noticed

that UDP has better performance compared to TCP in terms of both throughput and

NAD.

5.2 CASE 2

Effect of data size:

The conditions selected to analyze the impact of data size on performance of P2P

communications are



Chunk size: 1024 bytes



Results 39

Data size: (512bytes, 1KB, 50 KB, 100 KB, 300 KB, 600 KB, 800 KB, 1 MB, 5

MB and 10 MB)

Figure 27 is the graphical representation of effect of data size on throughput. From

the Figure, it can be noticed that for the smaller data sizes such as from 512 bytes to

100 kb throughput is less when compared to larger data sizes. It is observed that

throughput for larger data (300KB to 10MB) is almost same with very small

variations.

Figure 27: Effect of data size on throughput for both TCP and UDP

Figure 28: Effect of data size on NAD for both TCP and UDP

Figure 28 shows the graphical representation of effect of data size on NAD. From

the Figure, it can be seen that for the smaller data sizes such as from 512 bytes to 100

kb NAD is higher compared to NAD for the larger data and NAD for 512 data is

highest among all. It is also observed that for larger data sizes (300KB to 10MB)

there is small difference in NAD. In this case, also UDP has better performance

when compared to TCP.


Results 40

5.3 CASE 3

Effect of network load:

Following scenario was used in order to examine the impact of network load on

performance P2P communication.


Data size: 300KB, 1MB and 10MB



Network Load: Non-peak (low network load) and peak (high network load)

Figure 29: Effect of network load on throughput for both TCP and UDP

Figure 29 shows the effect of network load on throughput for the examined scenario.

It is clear from the Figure that network load has impact on throughput and it can also

be noticed that during non-peak hours throughput is comparatively high than the

peak hours. And upon comparing transport protocols, UDP has better throughputs

than TCP.

From Figure 30, it can be noticed that network load has more impact during peak

hours due to which NAD‟s are relatively higher in case of peak hours than the non-

peak hours. And upon comparing both protocols, UDP has better performance.


Results 41

Figure 30: Effect of network load on NAD for both TCP and UDP

5.4 CASE 4

Effect of signal strength:

Following scenario was considered to see the effect of signal strength on P2P

communication.

Network load: Non-peak




Signal strength: Strong signal and weak signal

Figure 31 shows the graphical representation of effect of signal strength on

throughput. From the Figure, it can be seen that throughput for strong signal is very

high compared to the throughput for weak signal. Upon comparing transport

protocols, UDP has better throughput than TCP.


Results 42

Figure 31: Effect of signal strength on throughput for both TCP and UDP

Figure 32 shows the graphical representation of effect of signal strength on NAD.

From the Figure, it can be noticed that NAD for weak signal is very high when

compared to the NAD for strong signal.

The reason for showing less throughputs and high NAD‟s for the weak signals is, the

time taken for transmission of data for weak signal strengths are high compared with

time taken for transmission of data for strong signals. This can be because during

weak signal strength while the data is transmitted it encounters lot of errors and

connectivity problems. For example, TCP retransmits that data again and again

unless it is reached successfully to the receiver end and hence due to which data

transmission times increases which results in increase of NAD and decrease of

throughputs for weaker signal.

Figure 32: Effect of signal strength on NAD for both TCP and UDP


Results 43

5.5 CASE 5

Data loss:

In order to examine the effect of different parameters on the amount of data loss

following sub cases are considered. In all the cases no loss has been observed for

TCP. The conditions selected for each of the sub case to analyze the impact on data

loss are

5.5.1 Effect of chunk size on data loss



Data size: 300KB

Protocol: UDP

Chunk size: (512, 768, 1024 bytes)

Figure 33 shows the graphical representation of the effect of chunk size on the data

loss. From Figure, it can be clearly observed that when chunk size increases data loss

decreases. The reason for this trend is, when we configure the peer with 512 chunk

size it takes more time to transfer a data of any size compare to chunk sizes of 768

and 1024. 512 chunk size faces more number of signal fluctuations as it consumes

more time for transmission of data. Data loss is more for 512 chunk size than 768

and 1024 due to the signal variations.

Figure 33: Effect of chunk size on data loss


Results 44

5.5.2 Effect of data size on data loss




Protocols: UDP

Performance metrics: Data loss

Data size: (512bytes, 1KB, 50 KB, 100 KB, 300 KB, 600 KB, 800 KB, 1 MB, 5

MB and 10 MB)

Figure 34 shows the graphical representation of the effect of data size on the data loss.

For very small data sizes (512 bytes and 1KB) there is no data loss and this trend has

been noticed for all the cases under different conditions.

For other data sizes, in general it was observed that as data size increases data loss

decreases.

Figure 34: Effect of data size on data loss

5.5.3 Effect of network load on data loss




Protocols: UDP

Network Load: Non-peak and peak

Figure 35 shows the effect of network load on the data loss. We can notice from the

Figure that when network load is high (peak), percentage of data loss is more and

when load is less (non-peak) data loss is also less.


Results 45

Figure 35: Effect of network load on data loss

5.5.4 Effect of signal strength on data loss

Network load: Non-peak



Protocols: UDP

Signal strength: Strong signal and weak signal

Figure 36 shows the effect of signal strength on data loss for 300MB data. From the

graph it can be observed that for weak signal data loss is more compare to strong

signal. This is because while transferring the data form one peer to another peer there

were connection failures between two peers due to weak signal. When Connection

failure occurs during transmission of data all the data is dropped and UDP does not

retransmit the data.

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

300KB

%D

ata

loss

Data size

non peak

peak


Results 46

.

Figure 36: Effect of signal strength on data loss

5.6 Validity threats

There are some potential threats that might limit the validity of this study. In the

following we will discuss the validity threats.

Clock synchronization: Standardized time synchronization techniques such as “GPS

synchronization” were not employed during this experimentation and all the devices

(peers) were synchronized manually. Even then, there are chances that devices are

not perfectly synchronized due to which some delays might be introduced affecting

the performance and in turn the validity of this study.

Wi-Fi problems: One of the peers in our experiments was connected to Internet

through Wi-Fi. Proper care was taken that peer always received signal and tried to

maintain it good signal levels throughout the experiments. However, there might be

some errors or problems of signal strengths during experiments process which might

add some additional delays or reduce throughput.

Device specifications: The results are valid for the devices such as, pc‟s and modem

we used in the experiments. The results may vary if we use for example a modem

that supports even high speed.

Mobile network operator: We used “Telenor” mobile service which is one of the

major mobile network operators in Sweden. The results may vary depending on

different network setting that might have been using.


Results 47

6. CONCLUSIONS

In this thesis work, experiments were conducted to analyses the performance of P2P

communication over 3G /UMTS networks. Two transport protocols TCP and UDP

were examined under different scenarios. The following conclusions can be drawn

from the experiments conducted in the course of this study. The performance

matrices used are throughput, normalized average delay and data loss.

Network load has an obvious effect on the performance for both TCP and UDP.

Throughput is higher during non-peak hours compared to peak hours and NAD is

higher during peak hours when compared with non-peak hours. Chunk size also

impacts the performance. As the chunk size is increases NAD decreases while

throughput increases. This means that in order to keep higher throughput it is better

to send data in bigger chunks.

The transmitted data sizes show considerable effect on NAD and throughput for

both protocols. From the collected results, it was observed that, NAD and throughput

had lot of fluctuations for smaller data size when compared to the larger data sizes.

Although for larger data sizes, it was observed that throughput and NAD does not

change much.

Signal strength has also a considerable impact on the performance for both protocols.

From the results, it was clear that when signal is strong, NAD is lower and

throughput is higher when compared to when the signal is weak.

Data loss was encountered only in case of UDP. It was observed that data loss is high

when signal is weak under peak hours with chunk size 512 bytes compare to other

conditions.

Upon comparing and analyzing all the results under different scenarios some

conclusions were drawn. It was observed that for strong signal strength under non-

peak hours with 1024 chunk size data of size 800KB and 1MB provides better

performance out of all the scenarios.


Future work 48

7. FUTURE WORK

For future work, we suggest that these same experiments be conducted on network

layer by considering exact packet sizes or even the same experiments can be carried

out following different set of configurations following standardized clock

synchronization techniques.

Another interesting future work of this thesis is to carry out same experiments on

future networks (4G) on both application layer and network layer.


Bibliography 50

BIBLIOGRAPHY

[1] S. C. Kim, M. G. Kim, and B. H. Rhee, "Seamless Connection for Mobile P2P

and Conventional Wireless Network," in The 9th International Conference on

Advanced Communication Technology, South Korea, 2007, vol. 3, pp. 1602-1605.

[2] P. Arlos and M. Fiedler, "Influence of the Packet Size on the One-way Delay on

the Down-link in 3G Networks," in 2010 5th International Symposium on Wireless

Pervasive Computing (ISWPC), Italy, 2010, pp. 573-578.

[3] X. Shen, H. Yu, J. Buford, and M. Akon Handbook of Peer-to-Peer Networking, 1st

ed., Springer, New York, 2009. pp. 1403.

[4] J. Yang, “Project Report: Measuring the Performance and Reliability of Routing

in Peer to Peer Systems,” M.S. thesis, Dept. Comp. Science, Victoria Univ. of

Wellington, Wellington, New Zealand, 2005.

[5] S. Simo, “Simulating a Mobile Peer-to-Peer Network”, M.S. thesis, Dept. of

Communication and networking, Helsinki Univ. of Tech., Helsinki, Finland, 2009.

[6] [Online]. Available: http://en.wikipedia.org/wiki/Overlay_network [Accessed:

June 25, 2011]

[7] S. Shimul and A. K. M. M. Rahman, “A Decentralized Key Database for Overlay

Identification” M.S. thesis, Dept. of Computing. Blekinge Institute of Tech.,

Karlskrona, Sweden, 2010.

[8] S. A-Theotokis and D. Spinellis, "A Survey of Peer-to-Peer Content Distribution

Technologies", ACM Computing Surveys, Vol. 36, No. 4, pp. 335–371, Dec. 2004.

[9] C. Wang and B. Li, “Peer-to-Peer Overlay Networks: A Survey,” Dept. of Comp.

Science, The Hong Kong Univ. of Science and Technology, Hongkong, 2003.

[10] J. Eberspächer and R. Schollmeier, “First and Second Generation of Peer-to-

Peer systems,” Munich Univ. of Tech., München, 2005.

[11] [Online]. Available: http://ants.etse.urv.es/wiki/P2p [Accessed: June 25, 2011]

[12] B. Prêtre, “Attacks on Peer-to-Peer Networks,” thesis, Dept. of Comp. Science,

Swiss Federal Institute of Tech., Zurich, Switzerland, 2005.

[13] M. D. Reddy, “A Study on Anonymous P2P Networks and their

Vulnerabilities,” M. S. thesis, Dept. of Applied Physics and Elec., Umeå Univ.,

Umeå, Sweden, 2007.

[14] H. D. Choon, N. Sarana, and B. Rajkumar, “Peer-to-Peer Networks for Content

Sharing”, Grid Computing and Distributed Systems Laboratory, Department of

http://en.wikipedia.org/wiki/Overlay_network

http://ants.etse.urv.es/wiki/P2p


Bibliography 51

Computer Science and Software Engineering, The University of Melbourne,

Australia.

[15] Z. Qu, Y. Ge, K. Jiang, T. Lu, and Z. Wang, “A Study on the Model of Mobile

P2P File-Sharing System in 3G Network,” in third conf. of Semantics, Knowledge

and Grid, 2007, pp. 306-309.

[16] B. Tang, Z. Zhou, A. Kashyap, and T. Chiueh, “An Integrated Approach for P2P

File Sharing on Multi-hop Wireless Networks,” in IEEE International Conf. on

Wireless and Mobile Computing, Networking and Communications, 2005, vol. 3, pp.

268- 274.

[17] M. Iguchi, M. Terada and K. Fujimura, “Managing Resource and Servent

Reputation in P2P Networks,” in Proc. of the 37th Annual Hawaii International

Conf. on System Sciences, 2004, pp. 9.

[18] M. Xue and C. Zhu, "The Socket Programming and Software Design for

Communication Based on Client/Server," in conf. of Pacific-Asia on Circuits,

Communications and Systems, 2009, pp. 775-777.

[19] B. Hall, Network Programming using Internet Sockets, 3rd

ed., Jorgensen

Publishing, 2009, pp. 1-97.

[20] W. R. Stevens, UNIX Network Programming, vol. 1, 2nd

ed., Prentice Hall, NJ,

1998, pp. 1-1009

[21] A. Mishra, “Cellular Networks,” in Advanced cellular network planning and

optimisation: 2G/2.5G/3G - evolution, West Sussex, England: Wiley, 2007, pp. 1–12.

[22] B. M. Ratana and B. A. Vardhan, “Generations of Mobile Wireless

Technology: A Survey,” International Journal of Computer Applications, Vol. 5,

Aug. 2010.

[23] J. Nubarron, Evolution Of Mobile Technology: A Brief History of 1G, 2G, 3G

and 4G Mobile Phones [Online; accessed on January 11, 2011] Available :

http://www.brighthub.com/mobile/emerging-platforms/articles/30965.aspx

[24] C. Smith and D. Collins, “Second Generation,” in 3G Wireless Networks, New

York: McGraw Hill, 2002, pp. 45–68.

[25] _, Code Division Multiple Access [Online] Available:

http://www.experiencefestival.com/a/Code_division_multiple_access/id/1942000

[26] V. J. Arokiamary, “Second Generation and Third Generation Wireless

Networks and Standards,” in Cellular & Mobile Communications, 1st ed. pune, India:

Technical Publications, 2009, pp. 46–76.

[27] P. Stuckmann, “Edge and Evolution to GERAN,” in The GSM evolution, West

Sussex, England: Wiley, 2003, pp. 97.

http://www.brighthub.com/mobile/emerging-platforms/articles/30965.aspx

http://www.experiencefestival.com/a/Code_division_multiple_access/id/1942000


Bibliography 52

[28] Z. Han and K. J. R. Liu, “Wireless Networks,” in Resource Allocation for

Wireless Networks, New York: Cambridge University Press, 2008, pp. 18.

[29] J. Korhonen, “History of Mobile Cellular Systems,” in Introduction to 3G

Mobile Communications, 2nd

ed. Norwood: ARTech House, Inc, 2003, pp. 1–16.

[30] J. Sanchez and M. Thioune, “Network Evolution from GSM to UMTS,” in

Umts, London, United Kingdom: ISTE, 2004, pp. 27–28.

[31] T. Hopfeld, K. Tutschku, F. -U. Andersen, H. d. Meer and J. O. Oberender,

"Simulative Performance Evaluation of a Mobile Peer-to-peer File-sharing

System," in Conf. Next Generation Internet Networks, 2005, pp. 281 - 287.

[32] L. Shuping, J. Weirong, and L. Jinpei, "Architecture and Performance

Evaluation for P2P Application in 3G Mobile Cellular Systems," in Int. Conf. of

WiCom on Wireless Communications, Networking and Mobile Computing, 2007, pp.

914-917.

[33] Y. Zhang, X. Zhou, F. Bai, and Song Junping, "Peer Selection for Load

Balancing in 3G Cellular Networks," in 2nd

Int. Conf. on Information Science and

Engineering (ICISE), 2010, pp. 2227-2230.

[34] Q. Zhiyi, G. Yuanting, J. Kaiyuan, L. Tiangang, and W. Zhong, "A Study on the

Model of Mobile P2P File-Sharing System in 3G Network," in 3rd

Int. Conf. on

Semantics, Knowledge and Grid, 2007, pp. 306-309.

[35] K. Ravichandra, “Performance of 3G Data Services Over Mobile Network in

Sweden” M.S. thesis, Dept. of Computing, Blekinge Institute of Technology,

Karlskrona, Sweden, 2010.


Appendices 53

APPENDICES

Appendix A

Step by step procedure of connecting peers for TCP

application

Run the TCP server application by double clicking it. A window will appear

as shown in Figure 37.

Figure 37: command window of server waiting for peers

Run the “peer A” TCP application from one system, to do so first open the

command window and change the path to the folder in which TCP Peer „.exe‟

file exits.

Using the following command peer A can be connected to linking Server

Command Syntax: Peer Name.exe[space] IP address [space] Port Number

[space] Peer A Name

In the above command, “Peer Name.exe” is the name you have given to your

peer application, In the place of “IP address” type the IP address of the

linking server application is running, in place of “Port number” just type 5150

and in place of “peer A name” type name

If you type the above command in command windows and hit enter, a

window will appears as shown in Figure 38.

For Example: “Clienm1024.exe 192.168.1.10 5150 sai”


Appendices 54

Figure 38: command window of peer A

The server window should display text indicating that peer A has connected as can

be seen in Figure 39.

Figure 39: command window of server after connecting peer A

Connect peer B TCP application from another system.

Command Syntax: Peer Name.exe[space] IP address [space] Port Number

[space] Peer B Name [space] peer A Name

Peer Name.exe, IP address, Port number are same as given for peer A.


Appendices 55

In the place of “peer B name” type any new name other than previously used

name for connecting the peer A. In place of “Peer A name” type the name

that is given to peer A.

If you type the above command in command windows and hit enter, a

window should appear as shown in the Figure 40.

For Example: “Clientm1024.exe 192.168.1.10 5150 jeet sai”

Figure 40: command window of peer B

Server application should indicate the connection of peer B as shown in

Figure 41.

Figure 41: command window of server after connecting peer A and peer B


Appendices 56

In this case both peers are interconnected via the linking server. once both

Peers are connected data can be transferred by entering following command”

“file: filename. Extension”, for ex: file: report.docx (before transferring data

just make sure that files are located in the same folder in which peer

application exits exists)

Once the data is transferred, a log file containing sent and received times can

be generated by typing “printlog” in the receiver peer window.

Appendix B

For UDP Application: Follow the same steps as in the case of TCP for connecting UDP peer to

the UDP server.

When both peers are connected to other via linking server, then for

transferring data type the following command:

“send: filename. Extension”, for ex: send: report.docx (before transferring

data just make sure that files are located in the same folder in which peer

application exists)

Once the data is transferred, a log file containing sent and received times

can be generated by typing “printlog” in the receiver peer window.

Appendix C

Complete results for different scenario for TCP

Table 2: Results obtained for conditions strong signal, chunk size of 1024 bytes and

nonpeak network load

TCP/1024/strong signal/non-peak load

Data Size

NAD ( µs) Throughput (kbps)

512 bytes 28.6132 279.590

1 kb 20.4101 391.961

50 kb 20.2050 395.940

100 kb 19.7138 405.806

300 kb 18.1321 441.205

600 kb 17.4625 458.123

800 kb 18.1403 441.005

1mb 17.4683 457.972

5mb 17.8474 448.245

10mb 17.9755 445.050


Appendices 57


peak network load

Table 4: Results obtained for conditions weak signal, chunk size of 1024 bytes and


TCP/1024/strong signal/peak load

Data Size


512 bytes 30.3710 263.408

1 kb 23.7792 336.427

50 kb 23.1572 345.465

100 kb 21.7265 368.213

300 kb 19.5657 408.511

600 kb 19.2791 414.956

800 kb 18.7544 426.565

1mb 18.7679 426.259

5mb 18.4928 432.6

10mb 18.7866 425.835

TCP/1024/weak signal/non-peak load

Data Size


512 bytes 104.785 76.347

1 kb 202.539 39.499

50 kb 32.1875 248.544

100 kb 23.7622 336.669

300 kb 22.8608 349.943

600 kb 24.3594 382.415

800 kb 28.7940 277.836

1mb 27.7760 288.017

5mb 21.4745 372.533

10mb 22.6579 353.077


Appendices 58


peak network load



TCP/1024/weak signal/peak load

Data Size


512 bytes 198.076 40.389

1 kb 215.869 37.059

50 kb 35.9199 222.718

100 kb 32.3266 247.474

300 kb 30.3606 263.499

600 kb 34.9013 229.217

800 kb 31.6210 252.996

1mb 32.6701 244.872

5mb 25.9544 308.232

10mb 24.7709 322.959


Data Size


512 bytes 63.1835 126.615

1 kb 137.792 58.058

50 kb 21.5791 370.729

100 kb 20.9472 381.911

300 kb 19.3891 412.625

600 kb 19.3024 414.470

800 kb 18.9884 421.182

1mb 19.3645 405.129

5mb 20.4127 391.911

10mb 20.4136 391.894


Appendices 59


peak network load



TCP/768/strong signal/peak load

Data Size


512 bytes 94.2558 85.33

1 kb 169.482 47.203

50 kb 24.6513 324.525

100 kb 23.5600 339.557

300 kb 20.6347 387.695

600 kb 20.5331 389.631

800 kb 24.8892 321.424

1mb 20.7006 386.464

5mb 23.6062 338.933

10mb 20.9913 381.109


Data Size


512 bytes 162.792 49.142

1 kb 222.900 35.890

50 kb 48.5375 165.162

100 kb 28.7841 277.695

300 kb 24.1175 332.108

600 kb 24.5381 326.028

800 kb 30.3333 263.726

1mb 28.8022 277.760

5mb 25.3253 315.883

10mb 23.0612 346.902


Appendices 60


peak network load




Data Size


512 bytes 306.25 26.122

1 kb 478.417 16.722

50 kb 69.5380 115.044

100 kb 38.2529 208.980

300 kb 33.7537 237.011

600 kb 36.7355 217.776

800 kb 33.1171 241.581

1mb 40.5183 197.444

5mb 30.1051 265.735

10mb 26.2007 305.331


Data Size


512 bytes 135.742 58.935

1 kb 200.781 39.844

50 kb 23.6435 338.359

100 kb 21.5825 370.670

300 kb 20.2412 395.233

600 kb 21.4757 372.513

800 kb 23.3284 342.929

1mb 23.4883 340.599

5mb 30.2971 264.058

10mb 30.4173 263.008


Appendices 61


peak network load



TCP/512/ strong signal/for peak load

Data Size


512 bytes 153.515 52.111

1 kb 268.847 29.757

50 kb 30.1035 265.750

100 kb 25.5410 313.222

300 kb 30.2674 264.543

600 kb 30.0721 265.974

800 kb 31.1955 256.447

1mb 30.0981 265.797

5mb 31.2271 256.218

10mb 31.2249 256.205


Data Size


512 bytes 517.480 15.754

1 kb 300.439 26.628

50 kb 49.5136 161.572

100 kb 40.1093 199.455

300 kb 37.9651 210.720

600 kb 37.4132 213.828

800 kb 39.7492 201.262

1mb 37.0822 215.737

5mb 33.3892 239.598

10mb 31.2979 255.608


Appendices 62


peak network load

Appendix D

Complete results for different scenario for UDP




Data Size


512 bytes 529.589 15.106

1 kb 536.376 14.915

50 kb 76.5468 104.511

100 kb 49.8076 160.618

300 kb 46.5724 171.775

600 kb 42.4356 188.521

800 kb 54.3740 147.129

1mb 46.7029 171.296

5mb 36.4178 219.673

10mb 34.4597 232.155

UDP/1024/strong signal/non-peak load

Data Size

NAD ( µs) Throughput (kbps) Drop%

512 bytes 22.94921 348 0

1 kb 17.33398 461.521 0

50 kb 9.58496 802.92 3.80

100 kb 11.54882 672.622 2.90

300 kb 10.86979 700.412 4.90

600 kb 13.86767 556.738 3.49

800 kb 9.9114 778.043 3.60

1mb 12.74476 619.525 1.30

5mb 14.39865 547.854 1.40

10mb 15.31407 520.597 0.34


Appendices 63


peak network load



.

UDP/1024/strong signal/peak load

Data Size


512 bytes 24.51171 326 0

1 kb 20.80078 384.6 0

50 kb 14.27246 535.296 4.50

100 kb 11.69824 643.515 5.90

300 kb 12.20605 598.282 8.72

600 kb 11.59008 646.932 6.28

800 kb 12.15075 619.261 5.94

1mb 14.60594 531.301 3.00

5mb 13.54276 578.589 2.05

10mb 15.32696 518.752 0.61

UD/1024/weak signal/non-peak load

Data Size


512 bytes 125.7812 63.602 0

1 kb 97.0117 82.464 0

50 kb 19.7083 364.927 10.10

100 kb 11.4013 518.183 26.15

300 kb 12.9657 538.372 12.75

600 kb 21.4372 338.071 9.41

800 kb 15.9819 357.808 28.52

1mb 9.9892 550.865 31.22

5mb 5.6349 821.225 42.16

10mb 6.1072 981.226 38.07


Appendices 64


peak network load



UDP/1024/weak signal/peak load

Data Size


512 bytes 173.12572 46.209 0

1 kb 132.17773 60.524 0

50 kb 14.86621 368.621 31.50

100 kb 20.42431 225.613 42.45

300 kb 17.88704 318.368 28.82

600 kb 7.20312 743.658 33.04

800 kb 15.9819 935.399 47.75

1mb 8.11476 570.285 42.15

5mb 5.42106 855.199 47.32

10mb 6.10724 703.518 46.29

UDP/768 /strong signal/non-peak load

Data Size


512 bytes 13.7695 580.992 0

1 kb 12.8906 620.606 0

50 kb 15.8242 505.554 5

100 kb 19.2548 415.479 1.70

300 kb 14.2612 560.961 2.59

600 kb 15.9161 502.633 2.30

800 kb 17.8983 446.969 1.01

1mb 15.67397 510.395 1.70

5mb 19.1767 417.173 0.60

10mb 19.6018 408.125 0.414


Appendices 65


peak network load




Data Size


512 bytes 16.6015 345.645 0

1 kb 16.2109 493.493 0

50 kb 17.3486 461.131 8.80

100 kb 18.1816 440.004 8.65

300 kb 17.6461 453.356 6.04

600 kb 19.0613 419.3697 4.62

800 kb 19.2931 414.654 3.38

1mb 19.4494 392.096 4.01

5mb 20.1459 397.103 0.91

10mb 20.2523 395.672 0.59

UDP/768/weak signal/non-peak load

Data size


512 bytes 43.9453 182.044 0

1 kb 16.1621 494.984 0

50 kb 19.2851 262.170 36.80

100 kb 10.9716 349.388 42.65

300 kb 5.5055 751.001 48.30

600 kb 6.3513 753.324 40.19

800 kb 18.3415 260.061 40.25

1mb 10.8263 526.382 28.76

5mb 7.7623 521.246 49.42

10mb 8.3658 592.536 38.04


Appendices 66

Table 21: Results obtained for conditions weak signal, chunk size of 768 bytes and peak

network load



UDP/768/weak signal strength/peak load

Data Size


512 bytes 56.5429 141.485 0

1 kb 24.7070 323.794 0

50 kb 20.5419 222.373 42.90

100 kb 15.0561 227.415 57.20

300 kb 11.4347 365.203 47.80

600 kb 5.7137 690.620 57.68

800 kb 9.4734 413.682 51.01

1mb 14.7290 256.402 52.79

5mb 5.0950 630.343 59.85

10mb 4.3865 675.282 62.97

UDP/512/strong signal/non-peak load

Data Size


512 bytes 35.0585 228.189 0

1 kb 36.6210 219.306 0

50 kb 16.3476 487.409 0.4

100 kb 20.3007 382.251 3

300 kb 16.7985 470.597 1.1833

600 kb 16.9133 459.006 2.958

800 kb 20.7120 381.998 1.1

1mb 21.0591 372.426 1.9628

5mb 29.3477 271.227 0.5009

10mb 29.1486 271.726 0.9941


Appendices 67


peak network load




Data size


512 bytes 41.2109 194.123 0

1 kb 47.2656 169.256 0

50 kb 27.3300 242.370 17.2

100 kb 29.5854 261.074 3.45

300 kb 28.7270 271.799 2.4

600 kb 29.2355 267.824 2.125

800 kb 29.9907 261.780 1.8625

1mb 26.5285 293.787 2.578125

5mb 30.4816 260.994 0.55

10mb 30.1718 260.935 1.5888

UDP/512/ weak signal strength for/ non-peak load

Data Size


512 bytes 43.9453 182.044 0

1 kb 25.9277 30.854 0

50 kb 32.5818 200.848 18.2

100 kb 13.8950 366.174 36.4

300 kb 11.3780 412.722 41.3

600 kb 7.89518 593.610 41.416

800 kb 22.0145 306.661 15.6

1mb 12.31431 487.332 22.055

5mb 8.67733 543.180 41.083

10mb 5.15860 704.610 54.3


Appendices 68


peak network load

UDP/512/weak signal/peak load

Data Size


512 bytes 56.5429 141.485 0

1 kb 29.5410 327.025 0

50 kb 20.5419 222.373 42.9

100 kb 16.7827 307.220 35.55

300 kb 11.9899 360.636 45.95

600 kb 8.35660 557.642 41.75

800 kb 20.0717 304.158 23.687

1mb 16.7021 368.309 23.105

5mb 6.81894 592.742 49.48

10mb 5.54459 649.724 54.968

performance analysis of peer-to-peer communication on 3g

Documents