SYNCHRONIZATION
- 1. G.VINOTHINI
- 2. Data synchronization in mobile computing systems Data synchronization is defined as the process of maintaining the availability of data generated from the source and maintaining consistency between the copies pushed from the source and local cached or ordered data at different computing systems without discrepanciesor conflicts among the distributed data A consistency copy of data is a copy which may not be identical to the present data record at the data generating source,but must satisfy all the required functions and domain dependent specific rules
- 3. Types of synchronization 1. Two-way synchronization of partial or full copies of data Between mobile-device and personalarea computer For example, whenever the list of contacts and personal information manager data is modified at any of them, it is made consistent after synchronization
- 4. 2. Server-alerted synchronization The server alerts the client the data modification or additions The client synchronizes the modified or new data by pull reques For example, alerting new e-mail and the device pulling that 3. One-way server-initiated synchronization Server initiates synchronization of any new modification since communication of last modification Sends modified data copies to the client When a new email arrives at a server, it initiates the synchronization as and when the device connects to the server and pushes the mail
- 5. 4. Client initiated refresh synchronization The client initiates synchronization with the server for refreshing its existing data copies For refreshing the configuration parameters saved at the server for it Client initiated refresh synchronization─ Example For example, a computer or mobile device initiates refreshing of the hoarded contacts and personal information data either at periodic intervals or as and when it connects
- 6. SYNCHRONIZATION Data disseminated and replicated at remote stations may occur in number of ways Data replication may done by copying the data from one place to another place or copying data from one place to many other other places or copying the data from many other places to many other places For examples music files are copied into ipods,iphones,and to several devices The replicated data may be full copy or a partial copy
- 7. Synchronization software for mobile devices Let us consider a pc is associated with mobile device and this computer connected to the internet which download applications and larger files Now consider the data at the computer is modified at some instant,the disseminated data at the server has changed at another instant-the changes are take place at one of the three ends at different instants there be a need to synchronize the data at three ends
- 8. Synchronization protocols By definition, mobile users are not always connected to a network and its stored data. Users retrieve data from the network and store it on the mobile device, where they access and manipulate the local copy of the data. Periodically, users reconnect with the network to send any local changes back to the networked data repository. Users also have the opportunity to learn about updates made to the networked data while the device was disconnected. Occasionally, they need to resolve conflicts among the updates made to the networked data. This reconciliation operation – where updates are exchanged and conflicts are resolved – is known as data synchronization. Data synchronization, then, is the process of making two sets of data look identical. For a mobile device, synchronization applies to the data that the mobile device stores locally. A data synchronization protocol defines the workflow for communication during a data synchronization session when the mobile device is connected to the network. The protocol must support naming and identification of records, common protocol commands to synchronize local and network data, and it can support identification and resolution of synchronization conflicts.
- 9. Mobile devices server and management
- 10. Mobile agent application server Application level logic that handles business functions involved in a particular organization (e.g. how to handle information requests from sales personnel in the field) and its integration with backend database or business application systems such as mainframe financial accounting systems, manufacturing systems, inventory, ERP (Enterprise Resource Planning) and emerging CRM (Customer Resource Management) systems Presentation services for the Mobile client device (handheld computers, notebook, PDA, etc) i.e. application server takes raw data from database applications/queries and transforms the data on a specific thin client (or a thick client like a PC) considering its presentation space characteristics and limitations. This is also called GUI (Graphical User Interface) in some cases though some handheld are more like older text terminals than PC. It includes breaking the messages into smaller chunks, filtering redundant information, and even logically compressing the data , etc. Transaction services, in some cases - including multi-threading for heavy volumes and persistency i.e. recovery across session failures Application programming level interfaces (APIs) with specialized communications protocols An application server may be considered as part of a multi-tier (mostly three tier) architecture. Conventional tiers are: First tier - A thin client based on handheld devices or a thick client on a PC - typically a browser-based interface in the Web context Middle tier consists of business applications on a set of servers - communications and business applications Third Tier - backend legacy data base systems and mission-critical ERP systems on a large server or mainframe
- 11. Gateway, portals, service discovery Gateway is a server or daemon typically installed onto physical or virtual appliance placed into DMZ. The Gateway's public interface is exposed to the Internet (or other untrusted network) and accepts TCP/IP connections from mobile applications. It operates on IPv4 and/or IPv6 networks. Incoming client connections typically use SSL/TLS to provide security for the network communication and a mutual trust of communicating peers. Communication protocol is typically based on HTTP A mobile portal is an Internet gateway that enables mobile devices to connect remotely with an enterprise intranet or extranet, typically via a Web browser interface. Consumer-oriented mobile portals provide access to mobile services and content using channels such as SMS, a microbrowser such as WAP, i-mode and voice. Consumer mobile portals aggregate content from many sources and may offer personalized services and content to mobile users — for example, unified messaging, news, search facilities, directories and m-commerce transactions. Service discovery is the automatic detection of devices and services offered by these devices on a computer network. ... Service discovery requires a common language to allow software agents to make use of one another's services without the need for continuous user intervention.
- 12. Device management MDM is typically a deployment of a combination of on-device applications and configurations, corporate policies and certificates, and backend infrastructure, for the purpose of simplifying and enhancing the IT management of end user devices. In modern corporate IT environments, the sheer number and diversity of managed devices (and user behavior) has motivated MDM solutions that allow the management of devices and users in a consistent and scalable way. The overall role of MDM is to increase device supportability, security, and corporate functionality while maintaining some user flexibility. Many organizations administer devices and applications using MDM products/services. MDM primarily deals with corporate data segregation, securing emails, securing corporate documents on devices, enforcing corporate policies, integrating and managing mobile devices including laptops and handhelds of various categories. MDM implementations may be either on-premises or cloud-based. Some of the core functions of MDM include: Ensuring that diverse user equipment is configured to a consistent standard / supported set of applications, functions, or corporate policies Updating equipment, applications, functions, or policies in a scalable manner Ensuring that users use applications in a consistent and supportable manner Ensuring that equipment performs consistently Monitoring and tracking equipment (e.g. location, status, ownership, activity) Being able to efficiently diagnose and troubleshoot equipment remotely
- 13. Mobile file system A file system for mobile computing Information systems. Information storage systems. Record storage systems. Software and its engineering. Software organization and properties. Contextual software domains. Operating systems. File systems management. ... Theory of computation. Design and analysis of algorithms. Data structures design and analysis. Sorting and searching.
- 14. security Mobile computing security can be implemented in various layers of mobile software, operating systems, and downloadable apps. In addition, end users can be sensitized to the dangers and educated as to best practices, greatly increasing their devices' security. Updates: Hackers and defensive software are engaged in running battles for superiority, so any delay in updating operating systems and/or security systems leaves mobile devices particularly vulnerable. Systems should be set to check automatically for updates, and users should get in the habit of performing manual updates at regular intervals. While it may seem like no data is safe in this technological age, users can greatly decrease the likelihood of a security breach on their devices by adhering to these mobile computing security guidelines.