On Device Applications aka Smart or Fat Clients

On Device Applications aka Smart or Fat Clients INF 245 H 2007 Ola Bø Høgskolen i Molde Build upon Martyn Mallick (2003) Molde University College INF 245 Fall 2007 OBø

Smart clients – an outline l l Smart clients may be used when not on line They may give access to data also when not on line l l May be solved by having a local data store Smart clients permit a better user interface than thin clients Molde University College INF 245 Fall 2007 OBø

Smart client development challenges and goals l Challenges l l l Limited UI and low device capacity Integration with other business systems Connectivity Application roll out and administration Technology in development – Goals l l Insight into challenges and solutions Cover possible technologies Molde University College INF 245 Fall 2007 OBø

On device application platforms l No clear leader – several possibilities l l Windows CE Symbian Palm OS Linux Molde University College INF 245 Fall 2007 OBø

Windows CE l l A bad start (1996) (unstable and cumbersome) Major progress l l l Pocket Word, Excel, IE, Outlook, Multimedia, Reader Simplified Win 32 API Support for Visual Studio. NET Communications using BT, WLAN, GPRS, IPv 6, 3 G Improved performance CE. NET Pocket PC Windows Mobile CE. NET as Core operating system l l CE is used in the operating system for several device types Pocket PC uses a version of CE. NET adapted to PDA Molde University College INF 245 Fall 2007 OBø Windows Automotive CE. NET

Windows CE development CE. NET 2004 5. 0 ARM, MIPS SH, x 86 2 G-3 G Vo. IP Molde University College INF 245 Fall 2007 OBø

Windows CE Architecture Molde University College INF 245 Fall 2007 Kilde Microsoft http: //msdn. microsoft. com/library/default. asp? url=/library/en-us/wceintro 5/html/wce 50 ori. Welcome. To. Windows. CE. asp OBø

Windows mobile l l l Started 2000 Supports several types of device Now in version 6. 0 l l l l connectivity persistent storage Office-support Multimedia Hard-disk storage Multimedia hard drive Kilde: Microsoft Molde University College INF 245 Fall 2007 OBø

Molde University College INF 245 Fall 2007 OBø

Palm OS l Early success l l 75 % of the market in early 2000 many applications now fading New Palm devices are using windows as operating system Molde University College INF 245 Fall 2007 OBø

Symbian l l Initially called EPOC an operationg system for the PSION device with 640*240 screen and pen based input Symbian v 6. 0 2000 l l l Better support for communications Applications using C++, Java and WAP Symbian V 7. 0 2002 l l l pen based UIQ series 60 for mobile phones Includes apps for personal information, web and messaging. l Strong in Europe l Owners l l Ericsson (15. 6%), Nokia (47. 9%), Panasonic (10. 5%), Samsung (4. 5%), Siemens (8. 4%) and Sony Ericsson (13. 1%) Installed base (per october 2007) l For advanced mobile phones Synchronizing OTA using Sync. ML Security Different UIs l l l Symbian operating system is used on an increasing number of mobile phones Over 145 million devices sold Symbian smartphone OS share for Q 2 2007 is 72%, Embracing (source computerworld. no http: //www. computerworld. no/index. cfm/fuseac tion/artikkel/id/47754) Molde University College INF 245 Fall 2007 OBø

Symbian ver 9, 5 Core OS Security, Privacy and Content Protection • Application capability management • Application data caging • Cryptographic algorithms – DES, 3 DES, RC 2, RC 4, RC 5 and AES • Cryptographic token framework • DRM framework and reference implementation • IPSec and VPN client support plus SSL and TLS • User permissions prompting Open Environments • Standard C environment • Standard libraries including partial POSIX support (P. I. P. S) Location-Based Services • GPS, A-GPS (terminal-assisted / terminal- based) and network-based positioning • Mobile originated and mobile terminated requests (including emergency requests) Telephony • Multimode Etel (2. 5 G / 3 G) • GSM Phase 2+ • HSCSD • GPRS, classes A, B and C (R 97/98) • EDGE (CSD and GPRS) • WCDMA (3 GPP R 4 and R 5 IMS support) • HSDPA, HSUPA • SMS (3 GPP TS 23. 040 V 6. 5. 0) Molde University College INF 245 Fall 2007 • EMS (3 GPP TS 23. 040 V 4. 5) OBø • SIM Application Toolkit • SIM and USIM support

Linux l l l The most well known device is Sharp Zaurus Nokia launched 770 ”Internet Tablet” spring 2005 See http: //www. linuxdevices. com/articles/AT 942308 4269. html Molde University College INF 245 Fall 2007 OBø

Java Optional JSR packages Optional JSR Packages MIDP Molde University College INF 245 Fall 2007 OBø

Molde University College INF 245 Fall 2007 OBø

Native vs. Java l Java applications l l l run in a J 2 ME environment isolated from the devices OS Cross platform Java augments productivity and reduces errors Java has good communications support J 2 ME standard is developped in cooperation JCP Native applications work directly with the device OS l Performance? l Can use more device functionality l Can also be developed using modern languages l ”de. Facto” standard developed by one company can move faster Molde University College INF 245 Fall 2007 OBø

l Server l Client and Server l Client l l Stale data risk l l Storage on the device reduces need for connectivity and improves performance and battery life l l Client must communicate with server and store data Ready made synchronization solutions are available Invisible for end user Responsability: l Data synchronization l Data storage l Message exchange Synchronization l l Several possibilities Several possible formats § § l l Databases and/or ERP-systems – In most cases only a limited amount of the data may be stored on device l What data should be on device? § § § l l Roll your own possibly using XML Sync. ML Only some tables? Only data for a certain geographic area Only data for certain customers? Building a custom solution or using COTS Often a good solution to use COTS Message based solutions may transfer data and events asynchroneously No need for connection while computing Molde University College INF 245 Fall 2007 OBø

Integration with other systems in the enterprise l l Different integration solutions: database, system, XMLdata, or integration using flat file. Complexity also varies l l Basic: using standard synchronization using communications over IP-networks with RDBs. -> develop custom solution or buy a cots solution Complicated: Support for heterogeneous terminals, simultaneous synchronization for several users and communications with systems having complicated interfaces. Complex data models, substantial amounts of data and transactions. Conflict handling -> Buy a COTS solution if possible Molde University College INF 245 Fall 2007 OBø

Advanced user interfaces l What can be improved? l Simplified navigation – l Few selections to get to the right place l The most used functionality should be most accessible l Must be developed while testing in practice l Pre filled field where possible Choose devices giving the right trade-off between screen size and mobility l Molde University College INF 245 Fall 2007 OBø

User interfaces l l l l Typically 80 % of code and cost Must work in use Screen size a problem Input must be adapted to the real users Early experimenting using prototypes is a good idea Experience and studies show that actual use is different from what was planned by developers User interface should be tested with real users in an early phase. Molde University College INF 245 Fall 2007 OBø

Local storage Molde University College INF 245 Fall 2007 OBø

Ways to store data – an outline l Flat Files – sequential access, difficult to insert and change data – easy to store in sequence. l Relational databases – logical structure built upon tables with rows and columns. Current standard for data storage. Improved with stored procedures and transactions l Object databases – A challenger for RDBs but with small success. Stores objects rather than tables. Can be appropriate for som niches but relatively infrequently used. XML-databases may be appropriate if all communications use XML, but is inefficient and slow if not. Infrequently used. l Molde University College INF 245 Fall 2007 OBø

Why persistent storage on device? l Client with no storage is an alternative but the storage is most ofte appropriate because of: l l l Network coverage problems Speed problems Static data Battery capacity Hybrid solutions is also possible l l Persistent storage for static data On-line update for data that must be up-to-date Molde University College INF 245 Fall 2007 OBø

Alternatives for on device persistent storage l l The proprietary storage mechanism for the device operating system J 2 ME record storage Custom built data base Commersial relational databases Molde University College INF 245 Fall 2007 OBø

Proprietary device storage solution l l Windows CE – object store API = database using flat files. Supports inserts, search and sorting. Present in RAM. Symbian OS – Relational data base supporting SQL and transactions are a part of the operating system (A C++ API for the database is also present) J 2 ME MIDP includes the RMS (Record Management System) that implements a standardized interface to the device data storage. RMS is covered in the J 2 ME programming part of this course. Common properties: All the built-in solutions are appropriate for simple applications with limited amounts of data. They may then be used to provide a cheap and quick solution, but all of them demands the development of your own code to synchronize with the enterprise data base and that may be difficult for complex applications Molde University College INF 245 Fall 2007 OBø

Commercial relational databases l l Many data base engine manufacturers also makes versions adapted to mobile devices and corresponding synchronization solutions Substantial differences between vendors Molde University College INF 245 Fall 2007 OBø

Vendor Product OS supported footprint synchronization encryption Sybase/ i. Anywhere SQL Anywhere Studio CE, Palm, Symbian, Linux, Java 3 MB on CE Ultralite 300 k Two ways to all ODBC. adaption using rules. Good comms solutions Storage and comms Market leader 68% ? Both Java og C++ IBM DB 2 Everyplace CE, Palm, Symb, Linux, Java 150 k. B Sync. ML two ways via Sync server DB 2 DB From DB 2 to ODBC ? SQL, but no transactions. Both VB, C, C++, Java, QBE Oracle 9 i Lite CE, Palm, Symb 5 MB on CE + DB Down to 1 MB på andre Proprietary solution synchs with Oracle databaser yes Powerful administration tools Microsoft SQL Server Compact CE 1 -3 MB Via HTTP over MIIS to Microsoft SQL Server SSL Development using Visual Studio. NET Point. Base embedded edition and ME Java EE->J 2 SE ME>+J 2 ME 45 kb -> Flexible synchonisation using Uni. Sync server and JDBC ? 100 % Java Molde University College INF 245 Fall 2007 OBø

Integration with enterprise systems Molde University College INF 245 Fall 2007 OBø

Integration using synchronization l Synchronization l l l Means all data on the mobile device is updated in one operation Continuous connection is not necessary Advantages: reduced traffic, costs and bandwidth, quick access and better control Synchronization is a two ways update Synchronization can be tethered or wireless Molde University College INF 245 Fall 2007 OBø

Types of Synchronization l PIM-synkronization: e-mail, addressbook and calendar l l l Microsoft Outlook og Lotus Notes on desktop File synchronization Data synchronization Molde University College INF 245 Fall 2007 OBø

Architecture for synchronization Molde University College INF 245 Fall 2007 OBø

Publish/Subscribe Model The server publishes data for different purposes The mobile device subscribes to data fitting the needs of the user Molde University College INF 245 Fall 2007 OBø

Techniques for synchronization l Snapshot l l l Delete the whole table at the receiving end and replace with an updated table Suitable if RO data, small datasets, high bandwidth, infrequent updates Net changes l l l Only changed data are sent Usually the most efficient solution saves time when frequent updates and large tables Molde University College INF 245 Fall 2007 OBø

Solutions for transferrign data for synchronization l l l Important for application efficiency Should happen without involving the user (difficult) Two solutions l l Session based l Direct connection between mobile and central databases updateing both databases simultaneously l Firewalls can be an obstacle Message based l Updates are sent as messages l Store and forward l Can support a considerable number of remote users Molde University College INF 245 Fall 2007 OBø

Important properties for synchronisation solutions l Support for splitting up data l l l Data compression l l l l A challenge with intermittent connections When two user wants to update the same row with different data l WWAN, WLAN, Via PC using BT. . . Enterprise integration Conflict detection l Handling of lost connection At least HTTP over TCP/IP Transport mechanisms l l Rules based – last wins Support for networing protocols Transaction integrity (ACID) l l floating point to integers fixed length to variable length Conflict resolution l Less data to transmit but overhead Data transformation l l Subsetting of the database Partitioning of data l Column partitioning l Row partitioning – reduces update conflict l Synchronization server should be able to communicate with all datasources l using JDB/ODBC with all data base engines l using adapters with ERP and CRM solutions Security l Authentication, Authorisation, Encryption Molde University College INF 245 Fall 2007 OBø

Synchronization using different transport mechanisms Molde University College INF 245 Fall 2007 OBø

Choices when developing synchronization solutions l l Depends upon solution for persistence Alternatives l l Solutions from the database vendor Custom built Buy one Synch solutions embedded in the device l Usually not made for database synchronization Molde University College INF 245 Fall 2007 OBø

Synchronization solutions embedded in the device OS OS synchsolution Connection Built in functionality Note Windows Cradle, Transfer files CE WLAN, and apps Active. Sync Ir. DA, BT Synchroni- C/S architecture Active Sync service providers can be bought or made. Two zation of e. COM modules must be mail, contacts, developed Palm OS Hot. Sync Symbian OS Connect calendar, Cradle plans, notes with MS Ir. DA over nett Outlook. Browse the internett, File BT, handling, kabel, Backup, Ir. DA Restore avh av Conduit plug-ins can be developed using VC++, VB or Java with Palm CDK Converter API permits development of custom solutions terminal Molde University College INF 245 Fall 2007 OBø

Data synchronization using mobile device OS synchronization support l l Solution has important functionality Users already employ this synchronization method l l An advantage to extend the solution already in place Several commercial synchronization solutions are extensions of the OS device synchronization. Molde University College INF 245 Fall 2007 OBø

Custom built synchronization solutions l l Build using C/C++ or Java Must solve l l l l l Database problems Device support Networking protocol Conflict resolution Safety Supoprt for Sync. ML? Integration with OS synch solution Maintenance Conclusion: Difficult/expensive Molde University College INF 245 Fall 2007 OBø

Commercial synch solutions l Delivered by database vendors l l Varying flexibility l l More or less tied to their own data base products Platform for mobil server and device Amounts of data Conflict handling May be sensible to let the choice of synch solution guide the choice of persistence solution Molde University College INF 245 Fall 2007 OBø

Commercial synch solutions Vendor Product OS supported Synchronization Sybase/ i. Anywhere Mobi. Link CE, Palm, Symbian, Linux, Java Two ways to all ODBC. Adapted using rules. Rich communications Publish/Subscribe, Synchronization and conflict solution in the data base Supports simultaneous connection to several databases. Both Java and. NET Only Sybase Message based solution SQL Remote IBM DB 2 Everyplace Sync Server CE, Palm, Symb, . . . Sync. ML two ways via Sync server DB 2 DB Thence to ODBC publish/subscribe Oracle 9 i Lite CE, Palm, Symb Proprietary solution conncting to Oracle databases Mobile server og mobile sync client. Microsoft SQL Server CE CE 1. RDA merge Publish/Subscribe Weak conflict handling, but may be programmed IBM (june 2007) Point. Base embedded edition and ME Java 2. Flexible synchronization Publish/Subscribe Uni. Sync server using JDBC net for PB and Oracle snapshot for other dbengines University College INF 245 Fall 2007 Molde OBø

Open source synch solutions l Funambol http: //www. funambol. com/ Molde University College INF 245 Fall 2007 OBø

Open Mobile Alliance Data Synchronization and Device Management aka Sync. ML l l l Heterogeneous synchronization solutions an obstacle to integration Sync. ML industry standard(? ) synchronization protocol Low impact so far l Already competing solutions on the market l Except PIM Several major companies such as Motorola, Nokia, Sony Ericsson, IBM and Siemens AG already support Sync. ML in their products (source Wikipedia) l l Sync. ML a data synchronization protocol l XML based l Supports a number of transport protocols TCP/IP, HTTP , WSP, OBEX, SMTP, POP 3, IMAP. . . l Can transfer all kinds of data l Makes allowances for limited resources on mobile devices l Should work on all mobile devices 245 Fall 2007 Molde University College INF using all kinds of data sources OBø

Sync. ML l l Packages containing messages containing commands Message format defined in Sync. ML representation prototcol Sync. ML Sync Protocol defines interaction between client and server as message sequences Sync. ML Transport Binding define transport protocol usage: HTTP, WSP og OBEX Molde University College INF 245 Fall 2007 OBø