A DISTRIBUTED DATABASE ARCHITECTURE FOR GLOBAL ROAMING IN NEXT-GENERATION MOBILE NETWORKS

The next-generation mobile network will support terminal mobility, personal mobility, and service provider portability, making global roaming seamless. A location-independent personal telecommunication number (PTN) scheme is conducive to implementing such a global mobile system. However, the nongeographic PTNs coupled with the anticipated large number of mobile users in future mobile networks may introduce very large centralized databases. This necessitates research into the design and performance of high-throughput database technologies used in mobile systems to ensure that future systems will be able to carry efficiently the anticipated loads. This paper proposes a scalable, robust, efficient location database architecture based on the location-independent PTNs. The proposed multitree database architecture consists of a number of database subsystems, each of which is a three-level tree structure and is connected to the others only through its root. By exploiting the localized nature of calling and mobility patterns, the proposed architecture effectively reduces the database loads as well as the signaling traffic incurred by the location registration and call delivery procedures. In addition, two memory-resident database indices, memory-resident direct file and T-tree, are proposed for the location databases to further improve their throughput. Analysis model and numerical results are presented to evaluate the efficiency of the proposed database architecture. Results have revealed that the proposed database architecture for location management can effectively support the anticipated high user density in the future mobile networks

CHAPTER ONE:

INTRODUCTION

  

1.1   Background to the study

 The first generation mobile phones which used analog technology were heavy and their coverage was patchy. Technical innovations in terms of hardware, software and protocols have contributed to the success of the mobile phones and have added them new capabilities. The handsets have become smaller and lighter, the battery life has increased and the reception has improved due to the improvements in digital technology and better use of the finite spectrum. The current generation of mobile phones is built using digital technology and they connect to the internet via the new generation of wireless communications. Therefore, they provide higher information transfer capability than the earlier generations (Yesim and Kivanc, 2007).

 

Due to the advancement of mobile phones and wireless technologies, data functionalities (such as the text or multimedia messages, email and streaming video) are now possible at a variety of broadband speeds, making the popularity of these media soar. The mobile terminals are developing, getting new features and enhanced hardware at a fast pace. The new mobile phones are called smart phones, because their features can be added and modified. Most of these smart mobile phones are programmable and can run any conceivable application. They readily support General Packet Radio Service (GPRS), Bluetooth, Multimedia Messaging Service (MMS), inbuilt or attachable camera, as well as other sophisticated applications. The smart phones have high-resolution color display (176x208 pixels with 4096 colors) and several megabytes of internal memory, which can be supplemented with memory cards. They are small, light, but powerful mobile terminals (Tsalgatidou et al., 2005).

 

Mass production has substantially lowered the cost of smart phones on the cellular phone market making them more affordable to the average consumer. It is estimated that currently over one half of the world‟s population own a mobile phone (Winters et al., 2008). The convergence of multiple technologies including GPS, GIS, mobile information systems, internet, wireless communications, location identification and mobile devices has given rise to exciting new types of information utilities called Location Based Services (LBS). They provide the capability to find the  geographical location of the mobile device and then offer services based on information of this location (Steiniger et al.,2006).

 

Location Based Services (LBS) are especially used in special circumstances such as driving or walking; thus the user is not piled with large amounts of information that may distract his/her attention. A mobile environment imposes strong constraints on the implementation of LBS because mobile devices have limited memory, low computational power and small screen size with low resolution, short battery life and uncomfortable input tools that usually do not allow a user to operate quickly. Besides, mobile networks are characterized with limited bandwidth, high latency, low connection stability and low predictable availability (Yesim and Kivanc, 2007). By taking all these constraints into consideration along with user‟s high performance and good service demands that conflict with them, an optimal security application for java-enabled mobile phones has been designed and implemented in this research.

Location awareness plays a major role in security enhancement and several applications have been proposed that rely on knowing or predicting the location of the user. Several key issues should be addressed when designing location-aware software applications that require real-time traveler information using GPS-enabled mobile phones. First, the user experience is severely constrained due to the limited user interface. To provide an effective user experience, every effort must be made to design intelligent applications which require user input only when  necessary (Maharj et al., 2009). Therefore, a predictive mechanism is desired that will passively monitor traveler‟s transit behavior.

 

Another consideration for designing traveler security systems is the underlying circumstances. In case the user is attacked in a kidnap, which in many cases the attackers force the user to deviate from his usual route to unusual destinations, he/she may not be in a position to call the care-givers for help. Therefore, a system that is automated to immediately inform the care-givers of any deviations from the route is required.In recent research, route prediction is being extensively examined for use in the context of mobile and wireless computing, towards more efficient network and resource management schemes. If the network can predict where the user is, then considerable bandwidth can be saved and resources optimizedfor mobility management (Akoush et al.,2006).

 

In this work, a GPS-enabled phone has been programmed to periodically obtain and send its location data to a database server. This allows one to get real-time information logs about the user‟s movements. The application focusses on monitoring the user while on transit and detects any possible deviation from thepre-destined route or speed range. An alert is send to the required personnel if any of these two aspects is transgressed.

 

1.2   Problem statement and justification

 

We are living in an insecure society where people are in danger from criminal attacks like kidnaps to internet predators. Systems that can detect situations where the care-givers attention is required exist in form of domestic fire and burglar alarms. In the area of security and health care, industry and academia have actively conducted research using various external sensors such as visual monitors, motion detectors and proximity sensors. However, these sensors may not always be available in outdoor activities. An easily portable and a versatile device like a mobile phone then become handy for enhancing personal security. The expectation that mobile phone users are able to answer phone calls most of the time enables one to determine the well-being of another by simply calling them. However in case of an accident or emergency situation, conditions may not be favorable for any phone call. This raises a question of how to increase awareness of our dependents‟ situations in order to provide help when needed.

 

Mobile phones equipped with GPS receivers can enable the tracking of one‟s location. This functionality can be used by individuals to identify where they are on a map. However, there are a few problems with the existing GPS security systems. First, the interface for monitoring position requires a lot of user input and is based on plotting a dot on an electronic map. A moving dot on a map only shows information about where the user is located but doesn‟t give detailed information about the type of situation in which he/shemaybe. Secondly,current GPS systems do not detect any deviations. Guardians are constantly required to focus their attention on the map and assess the situations themselves. In this work, the above issues are addressed by developing a system which can store the user‟s regular routes, monitor him/her while on transit and alert required personnel if there is deviation from the expected route or speed range.

 

1.3   Objectives of the study

 

1.3.1    Main objective

 

To develop and implement an optimal mobile phone-based security system, with the ability to locate the user‟s current location, monitor his/her movements and notify the required personnel in the event of deviations from the required route and speed range.

 

1.3.2    Specific objectives

 

1. To develop the client-side application using Java 2 Micro Edition (J2ME), for the phone to submit its position data periodically to a database server.
2. To develop the server-side application, which has a database with tables to receive and update the phones position data, then store all the users possible route data and speed limits.
3. To develop an optimal method for detecting deviations from the pre- determined route and speed range.
4. To develop a mechanism for sending an alert to the required personnel in case of any deviation.

 

1.4   Rationale of the research

 

Currently, security all over the world has become a serious issue, raising a lot of concern among the affected parties. This study increases awareness of the dependents‟ situations and be able to provide help remotely. Therefore, it is deemed that this study is necessary due to the following reasons;

1. It will enable the dissemination of mobile terminal‟s position data to third party security service providers ensuring that in case of any criminal attack, necessary measures are taken quickly andeffectively.
2. It will enable care-givers have peace of mind because they are aware of their dependents‟movements.
3. The system can also be extended to applications like vehicle tracking, asset monitoring and management, monitoring of criminals and location based emergency warnings for publicsafety.