Submitted by
Mr. Sagar Byali

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ABSTRACT
A distributed database system is built on standalone mobile databases found on mobile devices. At the heart of the architecture are elected devices that take on the role of data directories which collect the schema of the databases and become the contact points for all nodes that wish to submit queries against the distributed database. The system is implemented on pocket PCs that run the Microsoft WinCE operating system and communicate using Bluetooth.
The most interesting and promising form of such environments is the mobile ad hoc network (MANET) in which a mobile host can act as a source of information, destination, or a router that transfers data toward its destination. The system consists of moving nodes that can take one of three possible roles: requesting nodes (Rns), database nodes (DBNs) and a database directory (DD). A DBN node has its own mobile database. DD stores the schemas of the DBNs in the network. RN can be a node that sends its request (query) to the DD for processing.
Keywords: Data availability, Mobile databases, Distributed database, Mobile computing, Bluetooth
CHAPTER-1
INTRODUCTION
Now a day’s mobile applications have become more popular and a demand for database data in mobile settings has increased. The most promising form of such environments is the mobile adhoc network (MANET). In MANET a mobile host can act as a source of information, destination, or a router that transfers data towards its destination. Mobile hosts are generally small computing devices with relatively limited resources that can join or leave the network unexpectedly at any time. In addition more sophisticated mobile database management systems are being developed to offer capabilities that parallel those of enterprise level database systems.
The ultimate goal of this design and implementation is to provide a system through which mobile devices share data in disconnected settings. That is, our work targets environments in which mobile hosts collaborate in answering each other’s queries. More specifically, we develop a distributed database system on top of isolated mobile databases that exist on mobile devices that happen to be in close proximity with each other. The protocol used communication is Bluetooth which is prevalent on mobile devices due to its low cost and efficient utilization of battery power. The implementation of the system involved several issues relating to locating the data sources for the particular query among the participating mobile devices and joining the individual results by some mobile device before returning them to the client application.
CHAPTER-2
LITERATURE SURVEY
The developed application described tackles three main areas namely, connectivity using Bluetooth communication protocol, collaboration between mobile devices and distributed databases in MANETs.
A study of recent research trends and experimental guidelines in MANETs, which was presented by Dow et al, surveyed more than 1300 MANET related papers from 1998 to 2003. It was found that topics like routing and power management attracted most of the attention, while issues such as IP addressing, fault tolerance and collaboration were also popular among MANETs. The framework of distributed mobile database addressed here is collaborative in the sense that nodes cooperate by providing service to each other in order to answer a mobile node query. The subject provides an actual implementation of Pocket PCs that communicate using Bluetooth (BT) through the formation of piconet, where one master device can connect within up to seven active slave devices. Of concern to our work is the fact that current implementation of Bluetooth communication on mobile computing devices like Pocket PCs do not support master slave role switching and therefore scatternets. Similarly, previous works that involved BT communication were limited to piconets. For example, Altundag and Gokturk (2006) developed a scatternet formation protocol and implemented a chat room application that utilized this protocol using J2ME.
This work involves query processing and result coalescing. Several approaches have appeared that discuss processing queries in distributed environments. The scheme presented in Kottkamp and Zukunft (1998) is one of such approaches. It aims to optimize location aware queries for mobile database systems and develop a mobility-aware cost model. The work in Kossmann (2000) presents a “textbook” architecture for query processing and discusses a series of specific techniques for distributed based database systems. It describes several methods for shipping data from one site to others, implementing joins and selection of sites for executing the elements of queries. The query processor receives an SQL query, translates and optimizes this query in several phases into executable query plan and and executes the plan in order to obtain the results.
CHAPTER-3
DESIGN OF DISTRIBUTED MOBILE DATABASE
2.1 System Architecture
This system provides a cooperative framework that builds a distributed database out of possibly heterogeneous databases running on mobile devices that may be roaming in the wireless network in close proximity (within transmission range) to each other.