ABSTRACT
With growing demand for higher bandwidth multimedia services in a network domain over
the past few years, Asynchronous Transfer Mode (ATM) has emerged as a fine solution.
ATM provides mobility support for mobile users as they move among base stations. One of
the key issues to support user mobility is the handoff. Efficient usage of network resources is
also required. Most handover scheme like Mobile Motion Prediction (MMP) Algorithm and
Hierarchical Position Prediction Algorithm reviewed considered the traffic history of their
users only without considering change in the user’s mobility. This proposed resource
reservation scheme statistically reserves the resources in separate ways according to the
classes of the possible inter-switch handoff calls. This thesis therefore, focuses on the
development of an effective handover resource reservation scheme of ATM network. ATM
handover resource reservation system was modelled using flowchart and simulated using
MATLAB. The performance of the system was analysed and conclusion drawn. And this
ATM handover resource reservation schemes consider the traffic history of the users at a time
intervals to ensure maximum utilization of the reserved resources thereby taking care of
redundancy in the system. The system changes size of the reserved resources after every one
hundred arrivals and a new reserved resources is calculated using the traffic history of the
network.
TABLE OF CONTENTS
Title Page ……………………………………………………………………………………………………… i
Approval Page ………………………………………………………………………………………………. ii
Certification …………………………………………………………………………………………………. iii
Declaration …………………………………………………………………………………………………… iv
Dedication ……………………………………………………………………………………………………. v
Acknowledgement ………………………………………………………………………………………… vi
Table of Contents …………………………………………………………………………………………. vii
Abstract ………………………………………………………………………………………………………. xi
List of Figures ……………………………………………………………………………………………… xii
List of Tables ………………………………………………………………………………………………. xiii
List of Abbreviations ……………………………………………………………………………………. xiv
CHAPTER ONE: INTRODUCTION
1.1 Background…………………………………………………………………………………………….. 1
1.2 Problem Statement …………………………………………………………………………………… 2
1.3 Objective of the work……………………………………………………………………………….. 2
1.4 Significance of the study …………………………………………………………………………… 2
1.5 Scope of the work…………………………………………………………………………………….. 2
1.6 Limitation of the study ……………………………………………………………………………… 2
1.7 Organization of the Work………………………………………………………………………….. 3
CHAPTER TWO: LITERATURE REVIEW
2.0 ATM Network ……………………………………………………………………………………. 4
2.1 ATM cell …………………………………………………………………………………………… 4
2.1.1 ATM cell structure …………………………………………………………………… 4
2.1.2 ATM cell component……………………………………………………………….. 6
2.2 ATM Cell protocol model ……………………………………………………………………. 6
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2.2.1 The physical layers …………………………………………………………………… 7
2.2.2 ATM layers ……………………………………………………………………………… 8
2.2.3 ATM adaptation layers ……………………………………………………………… 8
2.2.4 Management planes………………………………………………………………….. 10
2.2.4.1 Layer management ……………………………………………………………. 10
2.2.4.2 Plane management ……………………………………………………………. 10
2.3 ATM connection………………………………………………………………………………….. 10
2.3.1 ATM Services …………………………………………………………………………… 11
2.3.2 ATM nodes/interfaces ………………………………………………………………… 12
2.3.2.1 ATM user-to-network interface (UNI) …………………………………. 12
2.3.2.2 ATM network-to-node interface………………………………………….. 13
2.4 ATM component …………………………………………………………………………………. 13
2.4.1 ATM end points …………………………………………………………………………. 13
2.4.2 ATM switch……………………………………………………………………………….. 13
2.5 ATM switch architecture…………………………………………………………………….. 14
2.5.1 Classification of ATM switch architecture…………………………………….. 16
2.5.2 Shared medium approach…………………………………………………………….. 21
2.6 Wireless ATM…………………………………………………………………………………….. 28
2.7 Handover system …………………………………………………………………………………. 29
2.7.1 Handoff protocol …………………………………………………………………………. 30
2.7.2 Handoff management …………………………………………………………………… 31
2.7.3 Handoff Schemes ………………………………………………………………………… 32
2.7.4 Handover classes …………………………………………………………………………. 33
2.7.5 Performance Metrics of Handoff Schemes ……………………………………… 34
2.8 Resource reservation protocol……………………………………………………………….. 34
2.8.1 Reservation styles …………………………………………………………………………. 35
2.8.2 The flow spec……………………………………………………………………………….. 36
2.8.3 The filter spec ………………………………………………………………………………. 36
2.8.4 Massage formats and massage processing ………………………………………..37
2.8.5 RSVP in ATM network ……………………………………………………………….. 40
2.8.6 Related work ………………………………………………………………………………. 42
2.9 Conclusion to Literature ……………………………………………………………………… 44
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CHAPTER THREE: METHODOLOGY
3.0 Introduction ……………………………………………………………………………………… 45
3.1 Model ……………………………………………………………………………………………… 45
3.1.1 Start ………………………………………………………………………………………… 46
3.1.2 Initialization start ……………………………………………………………………… 46
3.1.3 Idle/wait stage……………………………………………………………………………. 47
3.1.4 Resource reservation/Allocation …………………………………………………. 47
CHAPTER FOUR: SIMULATION RESULTS AND ANALYSIS
4.1 Simulation………………………………………………………………………………………….. 50
4.1.1 Source …………………………………………………………………………………… 50
4.1.2 The resource Reservation/Generation……………………………………….. 52
4.1.3 The probe ………………………………………………………………………………. 54
4.2 Results……………………………………………………………………………………………….. 54
CHAPTER FIVE: CONCLUSION, RECOMMENDATION AND CONTRIBUTION
5.1 Conclusion …………………………………………………………………………………………. 59
5.2 Recommendation for Further Research………………………………………………….. 60
REFERENCES
CHAPTER ONE
INTRODUCTION
1.1 Background
Handover is a process to reroute the call to a new station that requires network resources. It
occurs when a mobile station moves beyond the radio range of one access point (AP) to
another AP. During the handoff, management frames are exchanged between the AP and the
stations. APs involved may exchange certain context information specific to the station.
Consequently, there is latency involved in the handoff process during which the station is
unable to send or receive traffic [1].
ATM Network handoff latency is solved using various techniques. These techniques find out
all the adjacent access points having better signal strength by selective scanning technique. In
this scanning technique, the mobile host will find all the active APs by using received signal
strength indicator. After the scanning process, the mobile station will start the authentication
and re-association process to register all the mobile station with the selected APs [2].
According to the B-ISDN standard, to scan the channels for APs, there are two methodspassive
and active. Passive scanning involves scanning which is performed manually and
active scanning involves active determination of each channel status. Once the best Access
Point is identified; the mobile station authenticates and re-associates with the new AP.
The MAC specification allows for two operating modes namely, the ad hoc and the
infrastructure mode. In the ad hoc mode, two or more wireless stations recognize each other
and establish a peer to peer communication, whereas in infra-structure mode there is a fixed
entity called an access point.
This report analysed various handover schemes in ATM and other networks and came up
with an optimized system.
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1.2 Problem statement
Modern telecommunication networks like ATM Networks are growing in complexity due to
increased Network versatility and connectivity. Losses associated with handover increases as
the mobility increases. User mobility in mobile wireless networks always suffers
fluctuation/unavailability of network resources due to congestion. This leads to inefficient or
low utilization of network resources. The need for a sophisticated resource reservation
scheme to handle this problem arises. The aim of this research is to develop a system that
employs the use of dynamic resource reservation with buffering technique for handoff calls to
address this problem.
1.3 Objective of the work
The aims of carrying out this study include:
· To develop an ATM resource reservation for handover.
· To allocate resources to minimize call drop.
· To guarantee user mobility.
1.4 Significance of the Study
The issue of appropriateness of the traffic models employed in a real-time network, as well as
their suitability in a dynamic scenario is imperative to the overall performance of an ATM
network. This research work will help to develop a good ATM resources reservation scheme to
provide the associated QoS on an ATM network.
1.5 Scope of the work
There are many causes of call drops in ATM Network like power failure, irregular user
behaviour, inadequate resource allocation, improper handoff and propagation condition. This
work handled call drops as a result of improper handoff and inadequate resource allocation.
The ATM resource in question is bandwidth. This work is limited to ATM network
bandwidth allocation and reservation for voice services. The analysis of the allocation system
is based on the computer simulation of the model.
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1.6 Methodology
The following steps were taken in order to realise this project.
1. literature review / review of related works
2. Model development
3. Model simulation in MATLAB Environment
4. Model Result Analysis
1.7 Organisation of the work
The remaining parts of this work was organized in chapters as follows: Chapter two presented
an overview of ATM network and a review of other people’s work on resource reservation.
Chapter three discussed the process modelling. Chapter four showed the results and findings.
In chapter five conclusions were drawn.
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