Mobile Transaction Management in Mobisnap

Operations Research/Computer Science Interfaces Series, 2002

Mobile computing paradigm has emerged due to advances in wireless or cellular networking technology. This rapidly expanding technology poses many challenging research problems in the area of mobile database systems. The mobile users can access information independent of their physical location through wireless connections. However, accessing and manipulating information without restricting users to specific locations complicates data processing activities. There are computing constraints that make mobile database processing different from the wired distributed database computing. In this paper, we survey the fundamental research challenges particular to mobile database computing, review some of the proposed solutions and identify some of the upcoming research challenges. We discuss interesting research areas, which include mobile location data management, transaction processing and broadcast, cache management and replication and query processing. We highlight new upcoming research directions in mobile digital library, mobile data warehousing, mobile workflow and mobile web and e-commerce.

The need for information access and processing in mobile computing environments presents great challenges to database researchers. Apart from advances in wireless communications and device technology, new data management techniques are needed to provide a transparent interaction between fixed and mobile devices in global information systems. A key aspect is to provide a flexible and powerful transaction processing infrastructure that takes into account the peculiarities of mobile computing. Mobile transaction processing shall be able to transparently deal with frequent disconnections and occasional movements of mobile devices. This paper surveys the mobile transaction models proposed in academia and outlines the state-of-the-art of transaction processing in commercial mobile databases.

… in Parallel and Distributed Systems, 1993., …, 1993

Distributed systems are expected to support mobile computations ezecuted over a computer network of fixed and mobile hosts. This paper examines the re-quirements for structuring such mobile computations that access shared data in a database, argues that open-nesting ...

Lecture Notes in Computer Science, 2002

In this paper, we present a multi-version transaction model, which exploits versions to increase availability in a mobile database environment. Each transaction in our model is either in start, committed or terminated state. A transaction can start and commit at mobile host (MH) but terminates only at mobile service station (MSS). We first present a two-version model, where each data object can have two versions, one committed and the other is terminated. A read transaction is never blocked, as it is always made available either a committed or a terminated version. We have extended the model to handle multiversions.

Previous research in mobile data management has been focused on scenarios where mobile clients replace fixed ones. However, not all potential application fields of mobile computing fit into this scenario. There exist scenarios where mobile clients will not replace but accompany fixed ones. In this paper we introduce a real world application scenario requiring the capability to process a transaction from alternating, potentially mobile client hosts. With this scenario in mind we have developed three approaches supporting multiple clients in combination with a so called TXAgent, an object in the fixed network, which manages transactions on behalf of the client and the approach to realise the client as a migrating object. Finally we present a prototype implementation of the most promising approach.

International Journal of Intelligent Computing Research, 2011

In mobile computing environment, many mobile clients are concurrently accessing the database residing at the server, in the form of reads and writes. The broadcast-based data dissemination, in mobile computing systems, poses new challenging issues on data consistency of mobile transaction processing due to frequent disconnection from the network. Although data broadcast has been shown to be an efficient method for disseminating data items in mobile computing systems, the issue on how to ensure consistency and currency of data items provided to mobile transactions, which are generated by mobile clients, has not been examined adequately. In this paper, we model smart server (SSM) and we control the concurrency of mobile clients' reads and writes to provide consistent highly dynamic data to the mobile clients which are often disconnected from the network. We dynamic transmission disks (DTD) which are broadcasts to satisfy two types of users: frequently accessed data items user, rarely accessed data item users taking into consideration of frequency of accession and also frequency of updates which optimizes size of dynamic multiversion data transmission disks in order to meet consistency and currency. And also we prioritize the reads and writes of mobile clients to maintain consistency of the data provided to the mobile clients.

In recent years data management in mobile environments has generated a great interest. Several proposals concerning mobile transactions have been done, however, it is very di cult to have an overview of all these approaches. In this paper we analyze and compare some proposals, we focus on the e ect of mobile transactions on the ACID properties and on the execution model. In addition, we analyze approaches that deal particularly with the mobile nature of mobile hosts; in these proposals the ACID properties are not compromised because transactions are executed at multidatabase systems on the wired network. Based on our analysis, we introduce our ongoing research: the de nition, design and implementation of a Mobile Transaction Service.

Information Sciences, 2002

Mobile computing paradigm has emerged due to advances in wireless or cellular networking technology. This rapidly expanding technology poses many challenging research problems in the area of mobile database systems. The mobile users can access information independent of their physical location through wireless connections. However, accessing and manipulating information without restricting users to specific locations complicates data processing activities. There are computing constraints that make mobile database processing different from the wired distributed database computing. In this paper, we survey the fundamental research challenges particular to mobile database computing, review some of the proposed solutions and identify some of the upcoming research challenges. We discuss interesting research areas, which include mobile location data management, transaction processing and broadcast, cache management and replication and query processing. We highlight new upcoming research directions in mobile digital library, mobile data warehousing, mobile workflow and mobile web and e-commerce.

Journal of Computer Science, 2011

Problem statement: Improvement in mobile communication technology and increased capability of mobile devices has made transaction processing possible with mobile devices. Transactions access services provided by the data server connected to the packet data network. Direct data access may overload the network and server. Data items are cached to improve data availability. The cache should be managed and maintained effectively to support concurrent transaction execution in mobile wireless environment. This study proposes a cache management strategy that includes cache invalidation and replacement. Approach: The contents of the cache are invalidated based on the predicted life time of the data item and the cache contents are replaced based on the degree of sharing. The count of dependent transactions determines the degree of sharing of the data item. Results: The experimental results ensure reduced stale hit probability and restart probability of the proposed PLP based cache invalidation technique. The proposed cache replacement policy improves the cache hit ratio at least by 20% when compared to the existing replacement policies. Conclusion: The proposed cache invalidation strategy and replacement policy suit well for concurrent transaction execution environment where the degree of data sharing and the dynamism in data update need to be considered.