wap and wml dbi – representation and management of data on the internet
TRANSCRIPT
WAP and WML
DBI – Representation and Management of Data on the Internet
Millions
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
1,400
1,200
1,000
800
600
400
200
0
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
• 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
etc.
WM
L D
ecks
wit
h W
ML
-Scr
ipt
WAP Gateway
WML Encoder
WMLScriptCompiler
Protocol Adapters
Client
WML
WML-Script
WTAI
Etc.
HTTPWSP/WTP
Internet vs. WAPInternet
HTMLJavaScript
HTTP
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
WML
Big Pipe - Small Pipe Syndrome
Wireless 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
WML
Wireless Markup Language
WML
• 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">
<WML> ... </WML>
<?xml version="1.0"?><!DOCTYPE WML PUBLIC "-//WAPFORUM//DTD WML 1.0//EN"
"http://www.wapforum.org/DTD/wml.xml">
<WML> ... </WML>
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">
<wml> <card id="Card1" title="The dbi Course">
<p> <!-- Hello World example --> 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 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 type=“accept” label=“Next”> <go href=“#Card2”/>
</do> <p> Select Next to go to Card 2. </p>
</card> <card id=“Card2” title=“The DBI Course”>
<p> I'm Card 2. </p> </card> </wml>
== The DBI Course ==Select Next to go toCard 2.
__________________________________________Next Back
== The DBI Course ==Select Next to go toCard 2.
__________________________________________Next Back
== The DBI Course ==I am Card 2.
__________________________________________Next Back
== The DBI Course ==I am Card 2.
__________________________________________Next Back
Timer
<?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
== 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
=== Menu ===This is our main page. Under construction.
___________________________ Back
Input
<?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>
Deck
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=$type"/> </DO> Services <SELECT KEY="type"> <OPTION VALUE="em">Email</OPTION> <OPTION VALUE="ph">Phone</OPTION> <OPTION VALUE="fx">Fax</OPTION> </SELECT> </CARD></WML>
A Deck of Cards
DBI Portal.Directory_____________Next
Services1>Email2 Phone____________OK
Defining the Navigation Path
<CARD> <DO TYPE="ACCEPT" LABEL="Next"> <GO URL="#card2"/> </DO> First name: <INPUT KEY="fname"/></CARD>
<CARD NAME="card2"> <DO TYPE="ACCEPT" LABEL="Done"> <GO URL="?get=person" METHOD="POST" POSTDATA="first=$fname&last=$lname"/> </DO> Last name: <INPUT KEY="lname"/></CARD>
<DO TYPE="ACCEPT" LABEL="Next"> <GO URL="http://www.mysite.com/myapp.wml"/></DO>
The DO Element• Binds a task to a user action
– Action type: ACCEPT, OPTIONS, HELP PREV, DELETE, RESET
– Label: Text string or image (optional)– Task: GO
PREV, REFRESH, NOOP– Destination: URL– Post data: if METHOD=POST
Anchored Links• Bind a task to the ACCEPT action,
when cursor points to a link– TITLE= sets the label string (default = “Link”)
– Links are not allowed in select list options
<CARD> Please visit our <A TITLE="Visit"> <GO URL="home.wml"/>home page</A> for details.</CARD>
Please visit our homepage for____________Visit
Task Binding Rules• User actions are scoped at three levels
• Deck • Card • Anchored links & select list options (ACCEPT)– When tasks are bound to an action at different levels,
the action with narrower scope takes precedence
• Default task bindingsUser Action TaskACCEPT, PREV PREV Others NOOP
<WML> <TEMPLATE> <DO TYPE="OPTIONS" LABEL="Main"> <GO URL="main_menu.wml"/> </DO> </TEMPLATE> <CARD NAME="msg1"> <DO TYPE="ACCEPT" LABEL="Next"> <GO URL="#msg2"/> </DO> First story </CARD> <CARD NAME="msg2"> Second story </CARD></WML>
The TEMPLATE Element• Defines actions & events for all cards in a deck
First story…
_____________Next Main
Second story...
_____________OK Main
Handling User Input
• Select lists– Choose from a list of options
• Input fields– Enter a string of text or numbers
• KEY variables– Set by SELECT and INPUT elements– How user input is passed to other cards and the
application server
<CARD> <DO TYPE="ACCEPT" LABEL="View"> <GO URL="getcity.cgi?location=$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 fortext 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)
WBMP
• 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"/>
<img src="snail2.wbmp" alt="A search snail"/>
</card>
<card id="look" title="I found you">
<img src="snail3.wbmp" alt="A looking snail"/>
</card>
</wml>
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
B
Transport Service Access Point (TSAP)
BearerService
A
Physical Layer Air Link Technology
Wireless Transaction Protocol
Wireless Session Protocol
Wireless Session Service Access Point
WCMP
WAP Protocol Layers
BearerService
D
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
WTLS
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