Mobile Application Support

Transcription

1 Mobile Application Support 1

2 Problems and Requirements Problem fields: dynamic system and network configuration dynamic change of Quality-of-Service-properties decoupling/re-connection transparency of resource access security aspects Requirements: connection monitoring and selection treatment of decoupling and migration; emulation of services configuration update localization of mobile servers and clients advanced security and transaction services 2

3 Message Queuing: MQ Series example dynamic coupling between applications and local Queues via logon/logoff; therefore suited for mobile scenarios Basis: Messages, Queues with Queue Manager use of Queues for transmission or receiving; also mixed use is possible coupling of distributed Queue Managers via Message Channels Internet Gateway, C++- and Java-Support support of essential operating system platforms 3

4 Example scenario Computer A Computer B MQGET Queue Manager Queue Manager MQPUT Application 1 MQPUT Queue Manager Message Channel Queue Manager MQGET Application 2 decoupling of application by Queue Manager: Message forwarding is possible even if application is not running 4

5 N:M - communication Access to Server via multiple Clients Load balancing (selective delivery) or Parallel processing (replicated delivery) C A D B Queue, with optional support of message priorities E 5

6 Message Queuing: Assessment Advantages + simple manageability + robust message delivery + flexible application fields (for instance load balancing, parallelization, batch-transmission of branch data etc.) + relevant for loose coupling of programs, for instance via Internet, or for Mobile Computing Disadvantages limited communication semantics interaction model is different than with procedures/method invocations limited accessibility of higher services mainly proprietary solutions up to now, only step-by-step standardization 6

7 Mobile Application Architectures Ethernet Ethernet Distributed Database DB Firm E-Fax-Order E-Fax-Order Branch office xdsl Application Resource GSM Cache Management Management DB-Access DB-Access Ethernet Mobile Station Communication path Distributed Database Client X 7

8 Domain-concept 8

9 Main functionality: Domain and Station Manager Domain Manager: management of all global objects (users, global available resources, stations, network topology) Station Manager: management of all local objects of a station (network access, current applications etc.) 9

10 Architecture of Station Manager Application Subsystem (Application Programming Interface) Subsystem (System Calls) Location Service Registry Service Active Database Resource Broker Bandwidth and Cost Management Service Application Data Mobilizer and Manager Authentication and Encryption Service Disconnected Operation Handling Service 10

11 Mobile Multimedia message User Agent transfer protocol Subsystem Queuing Service protocol Queuing Service protocol Proxy Message Store message transfer Mobile Enhanced Message Handling System 11

12 Mobile Multimedia selection of quality parameters 12

13 Mobile end-devices / players / products receiving of s via mobile phones and PDAs account maintenance synchronization with desktop office applications approaches: mobile - software on the mobile phones and PDAs Mail Services (Mail access via proxies) handwritten s on the PDAs multiple end-devices and providers of mobile Palm One (USA) PDA with Palm OS (handhelds) / different Clients (Snapper Mail, Versa Mail, Eudora etc.) Nokia (Finland) Nokia One / Nokia Access Mobilizer / Mobile Business Devices Nextel (USA) mobile BlackBerry PDAs / Client T-Mobile mobile with various kinds of configuration software 13

14 Mobile phone, configured for mobile mobile phone must be equipped with an Client: Client controls data exchange of the mobile phone with an server features: en-route fetching of important s use of account on the mobile phone configuration software supports for different models of mobile phones for different providers (WEB.de, GMX.de, yahoo.com ) device- and provider-specific personalization 14

15 PDAs: end-devices for mobile and office applications Palm: Handhelds Palm, Zire, Tungsten Smartphones Treo BlackBerry: Nextel: Handhelds BlackBerry 15

16 PDA-Functionality PDA combines the convenience of constant access to , a cell phone, and a personal organizer consists of wireless capabilities data-enabled phone modem Office applications, available via PDA: Calendar Address Book Memo Pad Task List Calculator USB-Interface: simple loading of desktop software under Windows onto a PC and vice versa synchronization with a PC via the following programs: MS Outlook ASCII Text File Importer/Exporter MS Schedule IBM Lotus Notes IBM Notes Organizer etc. PDA market leaders in areas such as m-business, -healthcare, - education and -government PalmOne BlackBerry Nokia 16

17 PDA-products for Mobile consist of: PDA , e.g. for palm computing platform PDA Web Browser PDA Mail Conduit (synchronization software for desktop applications) features: support of POP3, APOP, SMTP-AUTH, SSL, HTML rendering with URLs and Phone Number Linking PDA and PDA Web Browser support SSL (Secure Socket Layer) and TLS (Transport Layer Security): end-to-end security synchronization of Bookmarks/ Addresses between PC Web Browser and PDA Web Browser via PDA Web Conduit synchronization with PC- applications multiple accounts are possible (IMAP) below: some examples of products (for instance, Snapper Mail, VersaMail, Eudora etc.) with screen dumps 17

18 Mobile SnapperMail popular solution for smartphone/pda supports POP3, APOP, SMTP- AUTH, SSL, HTML rendering with URL and phone number linking unlimited accounts and message size, automatic mail fetching with alerts attachment support via full memory card file browsers handling applications (ZIP, JPEG) for attachments handwritten note-taking software 18

19 Mobile VersaMail based on MultiMailPro (by Palm Inc.) supports POP3, APOP, IMAP4, SMTP-AUTH filters and attachments possible synchronization with Windows or Mac desktops automatic mail fetching with alerts HTML rendering access to SSL mail servers under Palm OS 19

20 Mobile Eudora attachment support integration with a browser Conduit Software for synchronization of with desktop core POP3 client supports SSL, HTML rendering filtering capabilities synchronisation 20

21 Handwritten Mail Messages Viewing and writing of handwritten and typed [via keyboard] messages on PDA Products: BugMe Messenger: relaying of handwritten, text or graphic notes to desktop and web-based mail applications Rit vector based writing engine aided sketching, automatic shaping for handwritten character/ geometrical symbols relaying of handwritten messages to desktop 21

22 PDA: mobile VPN-Clients PDA can also communicate via secure VPN-tunnel secure connection to a private network via different protocols vendors of VPN-software for PDAs: Certicom, SafeNet, Mergic Requirements to PDAs: Palm OS available memory: approx KByte used protocols PPTP: Point-to-Point Tunneling Protocol (MS proprietary, Windows) L2TP: Layer 2 Tunneling Protocol powered with IPSec IPSec: Secure Internet Protocol Products: major players: 3Com, Alcatel, Cisco Intel, Lucent, NortelNetworks FreeBSD, Linux, Windows 22

23 Mobile Agents Agent is an independent program; it consists of data, code and execution state, and works in the interest and on the order of a third party (e.g. user, application). An agent-system consists of the agents themselves and an execution engine that offers basic services to the agents. place 5 place 4 Place 1 Operating System Hardware Network Place 3 Operating system Hardware OS Hardware 23

24 Agent model Client create Agent code, data, state migration Serverinterface Client result Agent code, data, state Serverinterface migration: transfer of code, data, state local interactions with server transfer of the result 24

25 Properties of mobile agents Advantages: + reduction of network load + autonomy and asynchronity + dynamic adaptation according to environment + heterogeneity + robustness and fault tolerance + scalability + personalization and individualization + dynamic code installation + encapsulation of protocols Disadvantages: special execution engine required (Middleware) high security requirements transfer of code, data, state Decision: migration vs. remote communication 25

26 Application Areas and Systems Mobile computing E-commerce (e.g. search for appropriate offers) Database requests and Web search Office applications/workflow; load balancing Traffic telematics However, in general not suited towards security-critical business transactions, but rather for read-only queries Platforms and standards (examples): JADE (Java Agent Development Framework) open source platform FIPA (Foundation for Intelligent Physical Agents) 26