WAP and WML

transcript

WAP and WML

DBI – Representation and Management of Data on the Internet

Millions

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

ProjectedcellularsubscribersMore handsets than PCs

connected to the Internet bythe end of 2003!

'putting the Internet in everyone's pocket'

Internet Connectivity Outlook

Projected PCsconnected tothe Internet(Dataquest 10/98)

Projected Webhandsets

• WAP = Wireless Application Protocol• A protocol and set of specifications to

connect wireless aplications to the Web

Needs for WAP

• Wireless networks and phones – have specific needs and requirements– not addressed by existing Internet technologies

• WAP enables any data transport – TCP/IP, UDP/IP, GUTS (IS-135/6), SMS, or USSD

• The WAP architecture – several modular entities– together form a fully compliant Internet entity– all WML content is accessed via HTTP 1.1 requests

Advantages of WAP

• WAP utilizes standard Internet markup language technology (XML)

• Optimizing the content and airlink protocols• The WML UI components map well onto existing

mobile phone user interfaces– no re-education of the end-users– leveraging market penetration of mobile devices

• WAP utilizes plain Web HTTP 1.1 servers– CGI, ASP, NSAPI, JAVA, Servlets, etc.

The Specification Includes

• WAP Architecture• Wireless Application Environment• Protocol Layers• Interoperability• Security

WAP Architecture

Web Server

Content

CGIScripts

WAP Gateway

WML Encoder

WMLScriptCompiler

Protocol Adapters

Client

WML-Script

HTTPWSP/WTP

Internet vs. WAPInternet

HTMLJavaScript

TLS - SSL

TCP/IPUDP/IP

SMS USSD CSD IS-136 CDMA CDPD PDC-P Etc..Bearers:

Wireless Application Protocol

Wireless ApplicationEnvironment (WAE)

Session Layer (WSP)

Security Layer (WTLS)

Transport Layer (WDP)

Transaction Layer (WTP)

Other Services andApplications

WAP Specifies• Wireless Application Environment

– WML Microbrowser– WMLScript Virtual Machine– WMLScript Standard Library– Wireless Telephony Application Interface– WAP Content Types

• Wireless Protocols– Wireless Session Protocol (WSP)– Wireless Transport Layer Security (WTLS)– Wireless Transaction Protocol (WTP)– Wireless Datagram Protocol (WDP)– Wireless network interface definitions

Big Pipe - Small Pipe SyndromeWireless network

<HTML><HEAD><TITLE>NNN Interactive</TITLE><META HTTP-EQUIV="Refresh" CONTENT="1800, URL=/index.html"></HEAD><BODY BGCOLOR="#FFFFFF" BACKGROUND="/images/9607/bgbar5.gif" LINK="#0A3990" ALINK="#FF0000" VLINK="#FF0000" TEXT="000000" ONLOAD="if(parent.frames.length!=0)top.location='http://nnn.com';"> <A NAME="#top"></A><TABLE WIDTH=599 BORDER="0"><TR ALIGN=LEFT><TD WIDTH=117 VALIGN=TOP ALIGN=LEFT>

<HTML><HEAD><TITLE>NNN Interactive</TITLE><META HTTP-EQUIV="Refresh" CONTENT="1800, URL=/index.html">

Internet<WML><CARD><DO TYPE="ACCEPT"><GO URL="/submit?Name=$N"/></DO>Enter name:<INPUT TYPE="TEXT" KEY="N"/></CARD></WML>

010011010011110110010011011011011101010010011010

Content encoding

HTTP/HTML WAP

WAP Application Environment Goals

• Network- neutral application environment• For narrowband wireless devices• With an Internet/WWW programming

model• And a high degree of interoperability

Device-Side Problems

• Device Independent• Network Independent• Different vendors – requires interfaces• Initial focus on phones

– Slow reactions– Small memory– Limited CPU– Small screen– Limited input model

Wireless Markup Language

• Tag-based browsing language:– Screen management (text, images)– Data input (text, selection lists, etc.)– Hyperlinks & navigation support

• W3C XML-based language• Inherits technology from HDML (Handheld

Device Markup Language) and HTML

WML (cont.)• Card metaphor

– User interactions are split into cards– Navigation occurs between cards– Cards are put in to decks

• Explicit inter-card navigation model– Hyperlinks– User interface Event handling– History

• State management and variables– Reduce network traffic– Results in better caching

All Decs Must Contain…

• Document prologue– XML & document type declaration

• <WML> element– Must contain one or more cards

<?xml version="1.0"?><!DOCTYPE WML PUBLIC "-//WAPFORUM//DTD WML 1.0//EN"

"http://www.wapforum.org/DTD/wml.xml">

Hello World Example<?xml version="1.0"?> <!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml">

<p>  Hello World </p> </card> </wml>

<wml> </wml> - It defines the beginning and the ending of the page, like <html> </html>

<card> </card> - It defines the beginning and the ending of a card

== The DBI Course ==Hello World

__________________________________________ Back

The Result On a Different Device

Detecting a Click<?xml version="1.0"?> <!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML

1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml"> <wml> <card id=“Card1” title=“The DBI Course”>

</do> <p> Select Next to go to Card 2. </p>

</card> <card id=“Card2” title=“The DBI Course”>

== The DBI Course ==Select Next to go toCard 2.

__________________________________________Next Back

== The DBI Course ==I am Card 2.

__________________________________________Next Back

<?xml version="1.0"?> <!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML

1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml"> <wml> <card id="Intro" ontimer="#Main" title=“DBI Course"> <timer value="150"/> <p> Welcome to the dbi site!! We will bring you to our main page after 15 seconds. </p> </card> <card id="Main" title="Menu"> <p> This is our main page. Under construction. </p> </card> </wml>

After 15 seconds

== DBI Course ==Welcome to the dbi site!! We will bring you to our main page after 15 seconds.

___________________________ Back

=== Menu ===This is our main page. Under construction.

___________________________ Back

<?xml version="1.0"?> <!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN"

"http://www.wapforum.org/DTD/wml_1.1.xml"> <wml> <card id="main" title=“DBI Example"> <do type="accept" label="Next"> <go href="#wel"/> </do> <p> Please enter your name: <input type="text" name="name"/> </p>

</card> <card id="wel" title="Welcome"> <do type="prev" label="Back"> <prev/>

</do> <p> Your name is $(name). Click Back to go to previous page. </p> </card> </wml>

Entering a name Choosing the “Options”

Choosing the “Next”

Sending Data to the Server

<?xml version="1.0"?> <!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN"

"http://www.wapforum.org/DTD/wml_1.1.xml"> <wml> <card id="main" title=“DBI Example"> <do type="accept" label=“Send"> <go method="post" href="www.cs.huji.ac.il/register.cgi"> <postfield name="firstname" value="$(first)"/> <postfield name=“course" value=“dbi"/> </go> </do> <p> Please enter your first name: <input type="text" name="first"/> </p> </card> </wml>

InputElements

WML Example

CardNavigation

Variables

<WML> <CARD> <DO TYPE=“ACCEPT”> <GO URL=“#eCard”/> </DO Welcome! </CARD> <CARD NAME=“eCard”> <DO TYPE=“ACCEPT”> <GO URL=“/submit?N=$(N)&S=$(S)”/> </DO> Enter name: <INPUT KEY=“N”/> Choose speed: <SELECT KEY=“S”> <OPTION VALUE=“0”>Fast</OPTION> <OPTION VALUE=“1”>Slow</OPTION> <SELECT> </CARD></WML>

<WML> <CARD> <DO TYPE="ACCEPT" LABEL="Next"> <GO URL="#card2"/> </DO> DBI Portal.<BR/>Directory </CARD>

<CARD NAME="card2"> <DO TYPE="ACCEPT"> <GO URL="?send=$type"/> </DO> Services <SELECT KEY="type"> <OPTION VALUE="em">Email</OPTION> <OPTION VALUE="ph">Phone</OPTION> <OPTION VALUE="fx">Fax</OPTION> </SELECT> </CARD></WML>

A Deck of Cards

DBI Portal.Directory_____________Next

Services1>Email2 Phone____________OK

Defining the Navigation Path

<CARD> <DO TYPE="ACCEPT" LABEL="Next"> <GO URL="#card2"/> </DO> First name: <INPUT KEY="fname"/></CARD>

The DO Element• Binds a task to a user action

– Action type: ACCEPT, OPTIONS, HELP PREV, DELETE, RESET

– Label: Text string or image (optional)– Task: GO

PREV, REFRESH, NOOP– Destination: URL– Post data: if METHOD=POST

Anchored Links• Bind a task to the ACCEPT action,

when cursor points to a link– TITLE= sets the label string (default = “Link”)– Links are not allowed in select list options

<CARD> Please visit our <A TITLE="Visit"> <GO URL="home.wml"/>home page</A> for details.</CARD>

Please visit our homepage for____________Visit

Task Binding Rules• User actions are scoped at three levels

• Deck • Card • Anchored links & select list options (ACCEPT)– When tasks are bound to an action at different levels,

the action with narrower scope takes precedence

• Default task bindingsUser Action TaskACCEPT, PREV PREV Others NOOP

<WML> <TEMPLATE> <DO TYPE="OPTIONS" LABEL="Main"> <GO URL="main_menu.wml"/> </DO> </TEMPLATE> <CARD NAME="msg1"> <DO TYPE="ACCEPT" LABEL="Next"> <GO URL="#msg2"/> </DO> First story </CARD> <CARD NAME="msg2"> Second story </CARD></WML>

The TEMPLATE Element• Defines actions & events for all cards in a deck

First story…

_____________Next Main

Second story...

_____________OK Main

Handling User Input

• Select lists– Choose from a list of options

• Input fields– Enter a string of text or numbers

• KEY variables– Set by SELECT and INPUT elements– How user input is passed to other cards and the

application server

<CARD> <DO TYPE="ACCEPT" LABEL="View"> <GO URL="getcity.cgi?location=$city"/> </DO> Forecast <SELECT KEY="city"> <OPTION VALUE=“jer">Jerusalem</OPTION> <OPTION VALUE=“TA">Tel-Aviv</OPTION> <OPTION TITLE="Find" ONCLICK="find.cgi">New City</OPTION> </SELECT></CARD>

Forecast1 Jerusalem2 Tel-Aviv3>New City____________Find

The SELECT Element• Display a list of options

– Each option may set the KEY variable and/or bind a task to the ACCEPT key

– TITLE= dynamically sets the label string

A Long Select List MULTIPLE and DEFAULT Attributes

<CARD> <DO TYPE="ACCEPT"> <GO URL="get_addr.cgi?id=$recid"/> </DO> Addr [1..9] <SELECT KEY="recid" MULTIPLE="TRUE" DEFAULT="1;3;5"> <OPTION VALUE="1">Bart</OPTION> <OPTION VALUE="2">Lisa</OPTION> <OPTION VALUE="3">Homer</OPTION> <OPTION VALUE="4">Marge</OPTION> <OPTION VALUE="5">Milhouse</OPTION> <OPTION VALUE="6">Nelson</OPTION> <OPTION VALUE="7">Smithers</OPTION> <OPTION VALUE="8">Maggie</OPTION> <OPTION VALUE="9">Burns</OPTION> <OPTION ONCLICK="#card2">More...</OPTION> </SELECT></CARD>

<CARD> <DO TYPE="ACCEPT"> <GO URL="?get=person" METHOD="POST" POSTDATA="userid=$ssn"/> </DO> Soc Security: <INPUT KEY="ssn" FORMAT="NNN\-NN\-NNNN"/></CARD>

Soc. Security:

287-33- _____________ NUM

Soc. Security:

287-33- 7629____________OK

The INPUT Element• Prompts user to enter a string of text

– Use FORMAT= to constrain input• UP.Browser reserves soft key for

text entry mode, if necessary

Other INPUT Attributes• DEFAULT=key_value

– Default KEY variable (displayed to user)• FORMAT=format_specifier

– If omitted, free-form entry is allowed• EMPTYOK="TRUE"

– Browser will accept null input, even with format• TYPE="PASSWORD"

– Special entry mode handled by the browser• MAXLENGTH=number

– Maximum number of allowed characters

FORMAT Control Characters– N Numeric character– A, a Alphabetic character– X, x Numeric or alphabetic character– M, m Any character

• Leading backslash specifies forced characters• Forced characters included in KEY variable value

• Leading * specifies 0 or more characters• Password: FORMAT=“mmmm*m”

• Leading number specifies 0..N characters• Zipcode: FORMAT=“NNNNN\-4N”

<CARD> <DO TYPE="ACCEPT"> <GO URL="#c2"/> </DO> Continue <IMG LOCALSRC="righthand" ALT="forward..."/></CARD>

<CARD NAME="c2"> <IMG SRC="../images/logo.bmp" ALT="Unwired Planet"/> <BR/>Welcome!</CARD>

Displaying Images• Insert app images or local icons within display

text– 1-bit BMP format

• Images are ignored by non-bitmapped devices

Image Attributes• alt=“..”

– ‘Names’ the image – If the image is not displayed by the browser

the label is displayed instead• src="..

– Image source - where the image is located• width=".. • height="..

– Sets the dimensions of the image. – For example, the screen sizes of the devices is

Nokia 7110 (48 x 96 pixels)

• Wap supports WBMP (Wireless Bitmap Picture) 2 bit images

• It is possible to convert existing images to wbmp

• The MIME type of the images is declered with the following header: Content-type: image/vnd.wap.wbmp

<?xml version="1.0"?> <!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml"> <wml> <card id="main" title="Where are you?"> <timer value="10"/>

Adding Images

Special WML Characters• Use character entities in display text

" "& &' '< <> > Blank space Soft hyphen (discretionary line break)

• Replace the “&” character in URL strings URL="query.cgi?first=$fname&last=$lname"

• Use “$$” to display a single “$” character

Doing more with WML• Setting card styles to create forms

• Using variables to cache user data

• Using card intrinsic events to trigger transparent tasks

• Using timers

• Securing WML decks

• Bookmarking decks

WMLScript• Scripting language:

– Procedural logic, loops, conditionals, etc.– Optimized for small-memory, small-cpu devices

• Derived from JavaScript™• Integrated with WML

– Reduces overall network traffic• Bytecode-based virtual machine

– Stack-oriented design– ROM-able

WMLScript Standard Libraries

• Lang - VM constants, general-purpose math functionality, etc.

• String - string processing functions• URL - URL processing• Browser - WML browser interface• Dialog - simple user interface• Float - floating point functions

WMLScript Example Uses

• Reduce network round-trips and enhance functionality

• Field validation– Check for formatting, input ranges, etc.

• Device extensions– Access device or vendor-specific API

• Conditional logic– Download intelligence into the device

Functions

WMLScript Example

ProgrammingConstructs

Variables

function currencyConvertor(currency, exchRate) { return currency*exchRate; }

function myDay(sunShines) { var myDay; if (sunShines) { myDay = “Good”; } else { myDay = “Not so good”; }; return myDay;}

Wireless Telephony Applications

• Tools for building telephony applications• Designed primarily for:

– Network Operators / Carriers– Equipment Vendors

• Network security and reliability a major consideration

WTA (cont.)• WTA Browser

– Extensions added to standard WML/WMLScript browser

– Exposes additional API (WTAI)• WTAI includes:

– Call control– Network text messaging– Phone book interface– Indicator control– Event processing

WTA (cont.)

• Network model for client/server interaction– Event signaling– Client requests to server

• Security model: segregation– Separate WTA browser– Separate WTA port

• WTAI available in WML & WMLScript

Placing an outgoing call with WTAI:

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>

WTA Example

Placing an outgoing call with WTAI:

WTA Example

WTAI Call

function checkNumber(N) { if (Lang.isInt(N)) WTAI.makeCall(N); else Dialog.alert(“Bad phone number”);}

Content Formats

• Common interchange formats• Promoting interoperability• Formats:

– Business cards: IMC vCard standard– Calendar: IMC vCalendar standard– Images: WBMP (Wireless BitMaP)– Compiled WML, WMLScript

Content Format Example

Image Element

<WML><CARD> Hello World!<BR/> <IMG SRC=“/world.wbmp” ALT=“[Globe]” /></CARD></WML>

Example Use of an Image:

Push• Push is under development• Network- push of content

– Alerts or service indications– Pre-caching of data

• Goals:– Extensibility and simplicity– Build upon WAP 1.0– End-to-end solution– Security– User friendly

User Agent Profiles (UAProf)

• UAProf is under development• Goal: content personalization, based upon:

– Device characteristics, user preferences– Other profile information

• Working with W3C on CC/PP– RDF-based content format– Describes “capability and profile” info

• Efficient transport over wireless links, caching, etc.

Wireless Transaction Service Access Point

Wireless Datagram Protocol

BearerService

CBearerService

Transport Service Access Point (TSAP)

BearerService

Physical Layer Air Link Technology

Wireless Transaction Protocol

Wireless Session Protocol

Wireless Session Service Access Point

WAP Protocol Layers

BearerService

Wireless Session Protocol Overview

• Provides shared state between client and server used to optimize content transfer

• Provides semantics and mechanisms based on HTTP 1.1

• Enhancements for WAE, wireless networks and “low-end” devices– Compact encoding– Push– Efficient negotiation

Capabilities

• Capabilities are defined for:– Message Size, client and server– Protocol Options: Confirmed Push Facility,

Push Facility, Session Suspend Facility, Acknowledgement headers

– Maximum Outstanding Requests– Extended Methods– Header Code Pages

Suspend and Resume• Server knows when client can accept a push

• Multi-bearer devices

• Dynamic addressing

• Allows the release of underlying bearer resources

Connection And Connectionless Modes

• Connection-mode– Long-lived communication– Benefits of the session state– Reliability

• Connectionless– Stateless applications– No session creation overhead– No reliability overhead

Wireless Transaction Protocol Overview

• Purpose:– Provide efficient request/reply based transport

mechanism suitable for devices with limited resources over networks with low to medium bandwidth.

• Advantages:– Operator Perspective - Load more subscribers on the

same network due to reduced bandwidth utilization.– Individual User - Performance is improved and cost is

reduced.

WTP Services and Protocols• WAP provides reliable data transfer based on request/reply

paradigm• no explicit connection setup or tear down• data carried in first packet of protocol exchange• seeks to reduce 3-way handshake on initial request• supports

– retransmission of lost packets– selective-retransmission– segmentation / re-assembly– port number addressing (UDP ports numbers)– flow control

• message oriented (not stream)• supports an Abort function for outstanding requests• supports concatenation of PDUs

Bearers• Bearers currently supported by WAP

– GSM SMS, USSD, C-S Data, GPRS– IS-136 R-Data, C-S Data, Packet– CDMA SMS, C-S Data– PDC C-S Data, Packet – PHS C-S Data– CDPD– iDEN SMS, C-S Data, Packet– FLEX and ReFLEX– DataTAC

Wireless Transport Layer Security• Specifies a framework for secure connections, using

protocol elements from common Internet security protocols like SSL and TLS.

• Provides security facilities for encryption, strong authentication, integrity, and key management

• Compliance with regulations on the use of cryptographic algorithms and key lengths in different countries

• Provides end-to-end security between protocol end points

Record Protocol

Handshake Protocol

Alert Protocol

Application Protocol

Change Cipher Spec Protocol

Transaction Protocol (WTP)

Datagram Protocol (WDP/UDP)

Bearer networks

Record protocol

WTLS Internal Architecture

Goals and Requirements for WTLS

• Interoperable protocols• Scalability to allow large scale application

deployment• First class security level • Support for public-key certificates• Support for WAP transport protocols

WTLS Services and Characteristics

– Provides connection security for two communicating applications

• privacy (encryption)• data integrity (MACs)• authentication (public-key and symmetric)

– Lightweight and efficient protocol with respect to bandwidth, memory and processing power

– Employs special adapted mechanisms for wireless usage• Long lived secure sessions• Optimised handshake procedures• Provides simple data reliability for operation over datagram

bearers

References• WAP Forum. “Wireless Application Protocol Architecture

Specification.” PDF File. April 30, 1998. http://www.wapforum.org/what/technical.html

• WAP Forum. “Wireless Application Environment Overview.” PDF File. June 16, 1999. http://www.wapforum.org/what/technical.html

• WAP Forum. “Wireless Transaction Protocol Specification.” PDF File. June 11, 1999. http://www.wapforum.org/what/technical.html

• Unwired Planet, Inc. “Wireless Internet Today.” PDF File. February 1999. http://www.phone.com/industry/wap.html

• Nokia Wireless Data Forum. “ Wireless Application Protocol.” Web Page. http://www.forum.nokia.com/developers/wap/wap.html

• Motorola “Wireless Application Development” PDF File http://www.mot.com/MIMS/MSPG/spin/library_files/wad.pdf

WAP and WML

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