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Copyright: A. Umar SESSION : Pltaforms for Mobile Applications  Mobile computing platforms  Middleware to support mobile commerce  Wireless Application.

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Presentation on theme: "Copyright: A. Umar SESSION : Pltaforms for Mobile Applications  Mobile computing platforms  Middleware to support mobile commerce  Wireless Application."— Presentation transcript:

1 Copyright: A. Umar SESSION : Pltaforms for Mobile Applications  Mobile computing platforms  Middleware to support mobile commerce  Wireless Application Protocol (WAP)  I-mode and Wireless Java Voice Markup Language Amjad Umar

2 Copyright: A. Umar Mobility Issues at Various Levels M-Business and Mobile Applications Wireless Networks Wireless Infrastructure Platforms for Mobile Applications -Middleware Platforms (WAP, I-Mode, J2ME) - Mobile Platform Services (Mobile OS, Utilities)

3 Copyright: A. Umar Mobile Computing Platforms

4 Copyright: A. Umar Mobile Computing Platforms Mobile operating systems - Palm OS -Windows CE - Symbian OS Mobile database managers Mobile transaction managers Utilities for mobile devices Wireless Middleware Wireless Gateways Mobile Application Servers

5 Copyright: A. Umar Support Needed for Mobile Apps Depends on how extensively the applications use the underlying network. Applications in mobile computing fall into the following three broad categories: –Stand-alone applications run entirely on mobile computers in disconnect (detached) mode. –Simple C/S applications (e.g., DB query). the connection time for C/S interactions is short. –Advanced mobile applications (groupware and distributed multimedia) - information exchanged is time critical (i.e., real time)

6 Copyright: A. Umar The Role of Wireless Middleware Hide the underlying wireless/wired issues Transformation: Convert between two contents (HTML to WML) Detection and adjustment: Wireless middleware products can detect different devices and can optimize the wireless data output according to device attributes. Compression. Middleware products can use various data- compression algorithms to minimize the amount of data being sent over the wireless link. Security: Wireless middleware should ensure end-to-end security from handheld devices to application servers. Message delivery: Middleware can perform message storage and forwarding should the user get disconnected from the network. Operation support: Middleware should offer utilities and tools to allow MIS personnel to manage and troubleshoot wireless devices.

7 Copyright: A. Umar Middleware for Mobile Computing Applications Two approaches: "information hiding” wireless middleware –attempts to smooth over the mobile computing issues –the same applications can run on wired as well as wireless networks. –This goal is met through specialized APIs –Example: WAP "information providing" wireless middleware – provides as much information about the underlying environment to the application as possible. –exploits the network quality of service, cost, and location information for optimum performance –Many specialized middleware systems

8 Copyright: A. Umar Mobile Application Servers

9 Copyright: A. Umar WAP(Wireless Application Protocol) Intended for data entry/display on cellular phones “An open, global specification that empowers mobile users with wireless devices to easily access and interact with information and services instantly.” www.wapforum.org Complete protocol stack similar to Internet protocols but optimized for wireless information pull and push transport layer and above; across multiple wireless technologies Designed to work with all wireless networks such as GSM, CDMA, and TDMA

10 Copyright: A. Umar New Versus Old WAP

11 Copyright: A. Umar Wireless Markup Language (WML) Features Text and image support – formatting and layout commands Deck/card organizational metaphor – WML documents subdivided into cards, which specify one or more units of interaction Support for navigation among cards and decks – includes provisions for event handling; used for navigation or executing scripts

12 Copyright: A. Umar Wireless Markup Language (WML) Example Acme Inc. Directory Services Email Phone Fax Acme Inc. Directory _____________ Next Services 1>Email 2 Phone ____________ OK Slide adapted from WAP web site

13 Copyright: A. Umar WMLScript Scripting language derived from JavaScript TM –Optimized for use with small CPU, small-memory devices –Omits some functions –Integrates easily with WML Assumes a bytecode-based, stack-oriented VM Assume compiler is in network for reducing network bandwidth and terminal memory/CPU usage Libraries for URL processing, simple dialog (UI) processing, math and string processing, WML browser interface

14 Copyright: A. Umar WMLScript Example function currencyConvertor(currency,exchRate ) { return currency*exchangeRate; } function myDay(sunShines) { var myDay; if (sunShines) { myDay = “Good”; } else { myDay = “Not so good”; }; return myDay; } Functions Programming Constructs Variables

15 Copyright: A. Umar Wireless Telephony Application (WTA) Application framework for telephony services Adds to the WAP architecture a user-agent on client side and WTA server for mobile telephony Adds extensions to the WML/WMLScript browser Security by having a separate WTA browser and port Exposes additional API (WTAI) for: –Call control –Network text messaging –Phone book interface –Indicator control –Event processing

16 Copyright: A. Umar WTA Example: Placing a call Input Element WTAI Call Enter phone number: WTAI Call function checkNumber(N) { if (Lang.isInt(N)) WTAI.makeCall(N); else Dialog.alert(“Bad phone number”); } Slides from WAP web site

17 Copyright: A. Umar Wireless Application Environment (WAE) WAE specifies an application framework for wireless devices WAE elements: –WAE User agents – software that executes in the wireless device –Content generators – applications that produce standard content formats in response to requests from user agents in the mobile terminal –Standard content encoding – defined to allow a WAE user agent to navigate Web content –Wireless telephony applications (WTA) – collection of telephony- specific extensions for call and feature control mechanisms –Libraries common network specific (GSM)

18 Copyright: A. Umar Wireless Session Protocol (WSP) Transaction-oriented protocol based on the concept of a request and a reply (based on HTTP) Provides applications with interface for two session services: –Connection-oriented session service – operates above reliable transport protocol WTP –Connectionless session service – operates above unreliable transport protocol WDP PDUs contain WML, WMLscript, images and headers

19 Copyright: A. Umar Wireless Transaction Protocol (WTP) Lightweight protocol suitable for "thin" clients and over low-bandwidth wireless links (e-commerce transactions) WTP features –Three classes of transaction service –Optional user-to-user reliability: WTP user triggers confirmation of each received message –Optional out-of-band data on acknowledgments –PDU concatenation and delayed acknowledgment to reduce the number of messages sent –Asynchronous transactions WTP Transaction Classes Class 0: Unreliable invoke message with no result message (unreliable push) Class 1: Reliable invoke message with no result message (reliable push, get acknowledgement) Class 2: Unreliable invoke message with one reliable result message (supports a request-reply model with some data from server)

20 Copyright: A. Umar Wireless Transport Layer Security (WTLS) Data integrity – ensures that data sent between client and gateway are not modified, using message authentication Privacy – ensures that the data cannot be read by a third party, using encryption Authentication – establishes authentication of the two parties, using digital certificates Denial-of-service protection – detects and rejects messages that are replayed or not successfully verified WTLS Protocol Stack: two layers of protocols –WTLS Record Protocol – provides basic security services to various higher-layer protocols –Higher-layer protocols: The Handshake Protocol The Change Cipher Spec Protocol The Alert Protocol

21 Copyright: A. Umar Wireless Datagram Protocol (WDP) Used to adapt higher-layer WAP protocol to the communication mechanism used between mobile node and WAP gateway WDP hides details of the various bearer networks from the other layers of WAP Adaptation may include: –Partitioning data into segments of appropriate size for the bearer –Interfacing with the bearer network

22 Copyright: A. Umar Wireless Control Message Protocol (WCMP) Performs the same support function for WDP as ICMP does for IP (I.e., provide feedback on problems - not reaching destination, router buffer problems) Used in environments that don’t provide IP bearer and don’t lend themselves to the use of ICMP Used by wireless nodes and WAP gateways to report errors encountered in processing WDP datagrams Can also be used for informational and diagnostic purposes

23 Copyright: A. Umar Figure 2: WAP Prototype WAP Devices Web Browser WAP Gateway Web Server Servet Content (XML/HTML) eCommerce Module HTML/XML over HTTP WML over WAP HTML/XML over HTTP

24 Copyright: A. Umar WAP Summary WAP is becoming an important element of the wireless and mobile middleware space WAP penetration is greater in Europe and Far East than US and elsewhere -- but gaining ground rapidly Some questions: –How many content providers will generate WAP/WML content? How well will automatic HTML/WML translators work? –Will existing Internet technology mature fast enough to reduce impact of WAP? –Will sophisticated e-commerce services for mobile users (e.g. stock purchase, transactions etc.) really become a significant market?

25 Copyright: A. Umar I-Mode Very popular in Japan (around 20 Million users) Competitor to WAP Very heavy graphics oriented WAP and I-mode may combine NTT Docomo runs I-mode Always on service (use GPRS) 9.6 Kbps at present - 3G later Need a special I-mode phone, larger screens I-mode sites have pre-fabricated content

26 Copyright: A. Umar Wireless Java and J2ME Wireless Java = J2ME + other Java Technologies (e.g., Java Cards) Wireless Java

27 Copyright: A. Umar BREW QualComm created the BREW to address a specific problem –Nearly every cell phone sold today is expected to be thrown away. –Handset manufacturers must load each phone's applications onto the handset at the factory. –Each application must be custom-built for each individual handset. –How can the applications installed on your current phone be transferred to your new one quickly BREW is intended to simplify application development on CDMA handsets (from QualComm) End users can download new applications as binary code.

28 Copyright: A. Umar Voice Browsers WAP Browser HTML Browser Web Content in XML WML Stylesheet XSL Processor Dialog ML or Voice XML Stylesheet HTML Stylesheet Voice Browser Voice Browser Voice-Commerce is an area of considerable activity (voice portal) Voice communication is convenient but more complex VoiceXML is used for dialogs

29 Copyright: A. Umar VoiceXML Prototype WAP Gateway Web Server Servelet Content (XML/HTML) eCommerce Module HTML/XML WML VoiceXML Gateway VoiceXML

30 Copyright: A. Umar Voice XML for V-Commerce Voice XML Forum (www.voicexml.org) Extension of XML in cooperation with W3C Participation through IBM, AT&T, Lucent Goals Enable internet access via voice and phone (e.g Voice activated web browsing). Make setup of voice services, development of interactive speech-enabled applications easier and cheaper. Enable easy integration of voice and data services. Example would you like coffee, milk, or tea? C: would you like coffee, milk, or tea? U: Juice C: Sorry, try Again U: Tea Coffee | Black, Cream&sugar; Milk | Milk; Tea | ice, hot; |

31 Copyright: A. Umar VoiceXML gateway Text to Speech Automated Speech Recognition Text Voice XML Gateway Text Speech Voice Browser User calls a site Site sends VXML Voice browser handles VXML TTS translates to speech User answers Gateway invokes ASR to convert to VXML text Browser sends VXML to the server Web Server VXML Doc


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