Research Journal of Applied Sciences, Engineering and Technology 6(9): 1639-1648, 2013 ISSN: 2040-7459; e-ISSN: 2040-7467 © Maxwell Scientific Organization, 2013 Submitted: December 31, 2012 Accepted: February 08, 2013 Published: July 15, 2013 Corresponding Author: Haroon Shahzad, School of Computer Science and Technology, Harbin Engineering University, Harbin 150001, China 1639 Review of Data Replication Techniques for Mobile Computing Environment Haroon Shahzad, Xiang Li and Muhammad Irfan School of Computer Science and Technology, Harbin Engineering University, Harbin 150001, China Abstract: With the tremendous growth of the portable computing devices and wireless communication, the mobile computing has become extremely popular. The wireless enabled portable computing devices with massive storage capacity and high-end processing capabilities have started to make the extensive use of mobile databases already. The rising popularity in these computing paradigms demands that the mobile computing be reliable enough to ensure the continuous data availability and integrity. However mobility comes at the cost of bandwidth, limited power, security and interference. In modern mobile computing systems data replication has been adopted as an efficient means to ensure the data availability and integrity as well as an effective means to achieve the fault tolerance. Data replication not only ensure the availability of the data but also reduce the communication cost, increase data sharing and increase the safety of the critical data. Furthermore, it also determine when and where (location) to place the replica of data, controlling the number of data replicas over a network for efficient utilization of the network resources. In this study we survey the research work in data replication for mobile computing. We reviewed some of the existing data replication techniques proposed by the research community for mobile computing environment for efficient management of data replicas. Keywords: Computing algorithm, data replication, data availability, fault tolerance, mobile computing, reliability, reliability engineering INTRODUCTION The field of wireless and mobile computing is a conjunction of the personal computing, distributed computing, wireless networks and Internet applications. This integration is supported by a large number of devices and wireless networks, which is based on a continuously and increasing interaction between communication and computing. Mobile computing system is a type of distributed system (Biswas and Neogy, 2010). The success of mobile data communication lies in the expectation to provide different services to users anytime and anywhere. In simple terms mobile computing can be defined as the computing on the go. Mobile computing is a new software paradigm that is of tremendous interest in the Information Technology research community. Today, mobile computing technology is used to link portable computing equipment to corporate distributed computing and other sources of information. Many researchers and scientists from both academia and industry are undertaking efforts to explore new technology for mobile computing and wireless communication, in a heterogeneous wireless and wired network environment, with mobile computing applications (Boukerche, 2006). We begin by considering the requirement for mobility and its cost. Mobility and portability are important aspects in mobile computing. With its popularity, it is very important that these systems be dependable and fail safe. To address the question of data availability various data replication protocols and techniques have been proposed and developed in the mobile computing systems. Data replication increases data availability and reduces data access latency may be at the cost of data storage. The main goal of mobile computing was to support the anytime, any-form and anywhere computing with the tremendous growth in the mobile technologies. To provide the data to the users with portable computers and mobile phones, the many a more techniques have been proposed for the improvement of QoS. All these requirements made mobile data management, transaction processing and query processing and data dissemination hot topics for research. Pitoura and Chrysanthis (2007) listed three challenges for the research in mobile computing: Mobility: Hampers the capability of processing at the network layer. The nodes being highly moveable pose greater challenge and a number of complexities. Limited resources: Limited battery, limited processing capabilities and memory of mobile devices also contributes toward the challenges for mobile computing to be a dependable computing environment. Intermittent connectivity: The absence of a permanent communication link caused frequent disconnection due to signal strength.