Thin Client Development and Thin Client Development and Wireless Wireless Markup Markup Languages Languages David Tipper Associate Professor Associate Professor Department of Information Science and Telecommunications University of Pittsburgh [email protected][email protected]http://www.sis.pitt.edu/~dtipper/2727.html Slides 11 Slides 11 Infsci 1073/Telcom 2727 2 Thin Client Development • Adopt architecture similar to wired Internet • Components – microbrowser (thin client), Web Server, content/data source, possibly a proxy gateway • Advantages – Rapid deployment, fresh data, easy to use, broad deployment WWAN Internet Base Station Web Server Wireless Microbrowser Clients Enterprise Data Sources Wireless Gateway
18
Embed
Thin Client Development and Wireless Markup …dtipper/2727/2727_Slides11.pdfThin Client Development and Wireless Markup Languages David Tipper Associate Professor Department of Information
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Thin Client Development and Thin Client Development and Wireless Wireless MarkupMarkup Languages Languages
David TipperAssociate ProfessorAssociate Professor
Department of Information Science and Telecommunications
• Note does not provide card/deck format of WML – If content exceeds display size must scroll down page– NTT DoCoMo maintains list of cHTML display limits
• cHTML websites can be viewed and developed using standard web tools
Infsci 1073/Telcom 27278
cHTML Example 2
• 1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD Compact HTML 1.0 Draft//EN"2 3 4 <!-- Introduction to hyperlinks -->5 6 <html>7 <head>8 <title>Wireless</title>9 </head>10 11 <body>12 <h1>Internet Search Engines</h1>13 14 <p><strong>Click on the Search Engine 15 address.</strong></p> 16 17 <!-- hyperlink format: <a href = "address"> -->18 <p><a href = http://www.google.comaccesskey=1>Google</a></p>19 20 <p><a href = http://www.askjeeves.com accesskey= 3>Ask Jeeves</a></p> 21 </body>22 </html>
Infsci 1073/Telcom 27279
cHTML
• cHTML/i-mode simulators available• cHTML also called i-mode compatible HTML• Seems to be going out of favor in countries that were
late to implement (Germany, Australia)
Infsci 1073/Telcom 272710
i-mode• Access to Internet services in Japan provided by NTT DoCoMo
– Services• Email, short messages, web, picture exchange, horoscope, ...
– Big success – more than 30 million users in Japan• Many use i-mode as PC replacement• Very simple to use, convenient – specific I-mode button
– Technology • Originally 2G Cellular Technology 28.8 kbit/s, packet oriented • Compact HTML plus proprietary tags, special transport layer (Stop/go, ARQ,
push, connection oriented)
Cellular Net
TLHTTP(S)
cHTML + tagsmobile terminal
CellularNet
TL
mobile network gatewaycontent provider
L1L2IP
TCP
L1L2IP
TCP
L1L2IP
TCP
L1L2IP
TCPHTTP(S)
cHTML + tags
Infsci 1073/Telcom 272711
i-mode business model
application
WSP
WTP
WDP
SMS
Example: Operator sends an SMS containing a push message if a new email has arrived. If the user wants to read the email, an HTTP get follows with the email as response.
Popular misconception:WAP was a failure, i-mode is different and a success – wrong from a technology point of view, right from a business point of view…
i-mode as a business model:• Free Development Software• Few access restrictions
DoMoCo‘s ``bill-on-behalf“ for 9%-independent of technology
(GSM/GPRS in Europe,PDC/UMTS in Japan)
Infsci 1073/Telcom 272712
i-mode based on WAP 2.0
user equipment gateway
i-mode can use WAP 2.0/Internet protocols (example: i-mode in Germany over GSM/GPRS)
server
cHTML
HTTP
WTCP
IP
L2
L1
SSL
WTCP
IP
L2
L1
TCP
IP
L2
L1
cHTML
HTTPSSL
TCP
IP
L2
L1
Infsci 1073/Telcom 272713
i-mode system requirements
3GPP standard system
MVoice termination notified and responded during i-mode communications
SMF basedMRinging melody downloadRinging tone download
Compatible i-mode JAVA
OJava application made availableJava
SSL (Version 2, 3), TLS 1
OEnd-End securitySecurity
HTTP 1.1MInternet e-mail and inter-terminal emailE-mail
i-mode compatible HTML (cHTML+tags)
MPortal Site / Internet AccessWEB Access
RequirementStatusDescriptionsFunctions
Infsci 1073/Telcom 272714
i-mode requirements
Hard or soft keyODedicated buttoni-mode button
HTTP 1.1MBrowser specifications to be notifiedUser Agent
To be defined by operators
MCharacter code set supported by browser and used to develop content
Character code set supported
To be defined by operators (e.g. 500 byte, 1K byte, 10K byte)
MNumber of characters (byte) per e-mailNumber of characters per e-mail
Specifications depend on each operator’s billing system
OPacket usage charges can be billed to third party
Reverse billing
Specifications depend on each operator’s billing system
MContent charge collection on behalf of Content Provider
Third party payment collection
RequirementStatusDescriptionsFunctions
Infsci 1073/Telcom 272715
i-mode examples
Infsci 1073/Telcom 272716
Wireless Markup Languages• Markup Languages: ML
describe how a document is rendered
• HDML: Handheld Device ML • WML : Wireless ML
– Attempt to get one markup language – part of WAP
• cHTML: compact HTML– Developed from i-mode
service in Asia• XHTML-MP: extensible HTML
mobile profile – Part of WAP 2.0
• Recent survey found that most content in cHTML and WML. WAP 2.0 browsers support WML and XHTML-MP.
Infsci 1073/Telcom 272717
XHTML-MP• XHTML-MP: eXtensible HTML Mobile Profile• The official mark-up language of WAP 2.0• Evolved from WML, HTML and cHTML• Meant to unify development and replace older
markup languages• Contains:
– Subset of XHTML (which is an XML version of HTML)– Some of WML 1.0 (WTIA)– Mobile Profile specific components
• Format more similar to HTML– easier for HTML developers to learn
• Also excludes many WML functions– No scripting– No Deck/card structure– No Timer– No Softkeys
Infsci 1073/Telcom 272719
XHTML-MP• Like XML support cascading style sheets (CSS)
– CSS allows one to establish a consistent design and format across a set of documents
• Excludes many XML functions– Frames– Image Maps– Scripting– Complex forms– Nested cascading style sheets
• Also excludes many WML functions– No scripting– No Deck/card structure– No Timer– No Softkeys
Infsci 1073/Telcom 272720
XHTML-MP
• Inherits the following from XHTML Basic– Structure– Text– Hypertext– List– Basic forms– Basic tables– Images (GIF,JPEG, PNG)– Meta-information– Subset of XHTML forms and presentation modules– Style Sheets
Infsci 1073/Telcom 272721
XHTML-MP Format• Document prologue:
– Document type and XML Version– Prepares parsing engine to interpret deck
according to Document Type Definition (DTD)<?xml version="1.0" charset="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//WAPFORUM//DTD XHTML Mobile
Plain text<br/> <em>Lots of emphasis</em><br/> <i>Some italics</i><br/> <b>This should be bold</b><br/> <strong>This one bold too</strong><br/> <b><i>Bold and italic</i></b><br/><q>Just a quote</q><br/> <kbd>mono-spaced</kbd>
</p> </body>
Infsci 1073/Telcom 272727
XHTML –MP Example 4
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//WAPFORUM//DTD XHTML Mobile 1.0//EN"