1. 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
Copyright: A. Umar

2. Mobility Issues at Various Levels
M-Business and
Mobile Applications
Platforms for Mobile Applications
-Middleware Platforms (WAP, I-Mode, J2ME)
- Mobile Platform Services (Mobile OS, Utilities)
Wireless
Infrastructure
Types of outsourcing
non-IT
e.g., delivery services (e.g., FEDEX) IT
Traditionally
desktop
network services
network management
software development
New “ASP”
web hosting
application software
computing services
Wireless Networks
Copyright: A. Umar

3. Mobile Computing Platforms
Copyright: A. Umar

4. 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
Copyright: A. Umar

5. 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)
Copyright: A. Umar

6. 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.
Copyright: A. Umar

7. 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
Copyright: A. Umar

8. Mobile Application Servers
Copyright: A. Umar

9. 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.”
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
Copyright: A. Umar

10. New Versus Old WAP
Copyright: A. Umar

11. 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
Copyright: A. Umar

12. Wireless Markup Language (WML) Example
<CARD>
<DO TYPE="ACCEPT" LABEL="Next">
<GO URL="#card2"/>
</DO>
Acme Inc.<BR/>Directory
</CARD>
<CARD NAME="card2">
<DO TYPE="ACCEPT">
<GO URL="?send=$type"/>
Services
<SELECT KEY="type">
<OPTION VALUE="em"> </OPTION>
<OPTION VALUE="ph">Phone</OPTION>
<OPTION VALUE="fx">Fax</OPTION>
</SELECT>
</WML>
Acme Inc.
Directory
_____________
Next
Services
1>
2 Phone
____________ OK
Slide adapted from WAP web site
Copyright: A. Umar

13. WMLScript Scripting language derived from JavaScriptTM
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
Copyright: A. Umar

14. 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
Copyright: A. Umar

15. 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
Copyright: A. Umar

16. WTA Example: Placing a call
Slides from WAP web site
Input Element
WTAI Call
<WML>
<CARD>
<DO TYPE=“ACCEPT”>
<GO URL=“wtai:cc/mc;$(N)”/>
</DO>
Enter phone number:
<INPUT TYPE=“TEXT” KEY=“N”/>
</CARD>
</WML>
function checkNumber(N) {
if (Lang.isInt(N))
WTAI.makeCall(N);
else
Dialog.alert(“Bad phone number”); }
Copyright: A. Umar

17. 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)
Copyright: A. Umar

18. 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
Copyright: A. Umar

19. 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)
Copyright: A. Umar

20. 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
Copyright: A. Umar

21. 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
Copyright: A. Umar

22. 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
Copyright: A. Umar

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

24. 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?
Copyright: A. Umar

25. 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
Copyright: A. Umar

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

27. 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.
Copyright: A. Umar

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

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

30. Voice XML for V-Commerce
Voice XML Forum (
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
<?xml version=“1.0”>
<vxml version=“1.0”>
<form>
<field name=“drink”>
<prompt> would you like coffee, milk, or tea?</prompt>
<grammar src=“drink.gram” type=“application/x-jsgf”/>
</field>
<block>
<submit next = “
</block>
</form>
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; |
Copyright: A. Umar

31. VoiceXML gateway Voice XML Gateway Text Voice Browser
Web
Server
VXML
Doc
Automated
Speech
Recognition
Text to
Speech
Text
Speech
Voice
Browser
Text
Speech
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
Copyright: A. Umar