Wireless Application Protocol - 123seminarsonly.com Application Protocol Wireless Session Layer ... WDP Adaptation utilises SMPP, ... flow control

WAP• Wireless Application Protocol

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Why is Internet not enough? … or actually … "too much" ...

Big screen - small screen syndrome

What can be done with WAP?

Information servicesSimilar to web browsing

Small downloadable programsWAP script language is based on

JavaScript™Telephony functionality combined with browserCall the airline when your flight is delayed

PushServer initiated content push

What is defined in WAP?Layered telecommunication stack includingDatagrams and TransactionsSecuritySession

Micro browserConcept that is similar to the Internet

browsingXML based markup language ( WML )Scripting ( WMLS )

WTA / WTAIAccess to telephone functionality

Content formats e.g.Service IndicationWireless Bitmap ( WBMP )

WAP Architecture

Web Server

Content

CGIScripts

etc.

WM

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WAP Gateway

WML Encoder

WMLScriptCompiler

Protocol Adapters

Client

WML

WML-Script

WTAI

Etc.

HTTPWSP/WTP

Internet

HTMLJavaScript™

HTTP

TLS - SSL

TCP/IPUDP/IP

Internet and WAP architecture

Wireless ApplicationEnvironment (WAE)

SMS USSD CSD R-Data Packet UDP PDC-P Etc...

Bearers:

Wireless Application Protocol

Wireless Session Layer (WSP)

Wireless Transport Layer Security (WTLS)

Wireless Datagram Protocol (WDP)

Other Services andApplications

Wireless Transaction Protocol (WTP)

WAP Protocol Stack

Wireless Transaction Service Access Point

Wireless Datagram Protocol

BearerService

D

BearerService

CBearerService

B

Transport Service Access Point (TSAP)

BearerService

APhysical Layer Air Link Technology

Wireless Transaction Protocol

Wireless Session Protocol

Wireless Session Service Access Point

WCMP

Developed by Wireless Protocols

Group (WPG) A WAP technical

working group.

WAP Protocols

Wireless ApplicationEnvironment (WAE)

Session Layer (WSP)

Security Layer (WTLS)

Transport Layer (WDP)

Other Services andApplications

Transaction Layer (WTP)

SMS USSD GPRS CDPD Etc..Circuit SwitchedData Flex

Wireless Datagram Protocol

Provides a network and bearer independent interface to higher layersProvides port level addressingProvides segmentation and reassemblyFor link layers that support IP, UDP is used as the Wireless Datagram Protocol layer

Wireless Transaction Protocol

Provides efficient, reliable data transfer based on request/reply paradigmSupports selective-retransmissionSupports segmentation and re-assemblyMessage oriented (not stream)Supports an Abort functionSupports concatenation of PDUs

Wireless Session Protocol

Provides shared state between client and server used to optimize content transferProvides semantics and mechanisms based on HTTP 1.1Supports compact encoding of headersSupports push functionalitySupports capability negotiation

Standard Message Center Adaptation Protocol

Non-IP bearer (e.g. SMS)

WDP

WTLS

Non-IP bearer(e.g. SMS)

WDP Adaptation WDP Adaptation

MessageCenter

WAP Proxy/ServerMobile

TCP

WTP

WSP

WAE

WDP

WTLS

WTP

WSP

WAE

IP

TCP

IPWDP Adaptation utilises SMPP, industry standard for Message

Center access

WAP Protocol Stack - WSP

Provides shared state between client and server used to optimize content transferProvides semantics and mechanisms based on HTTP 1.1Enhancements for WAE, wireless networks and “low-end” devicesEnhancements beyond HTTP Binary header encoding Confirmed and non-confirmed data push Capability negotiation Suspend and resume Connectionless service

WAP Protocol Stack - WSP

Binary header encoding Compact binary encoding of headers, content type

identifiers and other well-known textual or structured values

Reduces the data actually sent over the networkCapabilities 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 & Resume Allows the release of underlying bearer resources

WAP Protocol Stack - WSP

Connection & Connectionless service Connection-mode

Long-lived communicationBenefits of the session stateReliability

ConnectionlessStateless applicationsNo session creation overheadNo reliability overhead

WAP Protocol Stack - WTP

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 abort function for outstanding requests concatenation of PDUs

Message oriented (not stream)

WAP Protocol Stack - WTP

WTP Protocol ExchangeClient Server

Invoke

Ack

Result

Ack

T-TRInvoke.req

T-TRResult.ind

T-TRInvoke.cnf

T-TRResult.res

(PDUs)

T-TRInvoke.ind

T-TRResult.req

T-TRInvoke.res

T-TRResult.cnf

WAP Protocol Stack - WDP

WDP provides a connection-less, unreliable datagram serviceWDP is adapted to each particular wireless network to provide the generic datagram transport.The basic datagram service is fundamental to all wireless networks and makes it possible to utilize WAP everywhereReplaced by UDP when used over an IP network layer. WDP over IP is UDP/IP

Uses the Service Primitive T-UnitData.req .ind

Wireless Application Environment ( WAE )

WAP Application framework Network-neutral application environment; Suitable for narrowband wireless devices; Follows the Internet/WWW programming

model; Ensures high degree of interoperability. Leverages Internet standard technology Device Independent Network Independent International Support

Developed by Wireless Applications Group (WAG); A WAP technical working group.

WAE "Components"

WML Display language

WMLScript Scripting language

WTA Telephony services API and architecture

Content Formats Data exchange

User Agent Profiling Content customized for device

Push Server-initiated content delivery

WAE - WAP Gateway

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

WAE - WAP Application Server

WAP Application Server

Content

ApplicationLogic

WM

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wit

h W

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WML Encoder

WMLScriptCompiler

Protocol Adapters

Client

WML

WML-Script

WTAI

Etc.

WSP/WTP

WAE - WML

Wireless Markup Language (WML) is a Tag-based browsing language: Screen management (text, images) Data input (text, selection lists, etc.) Hyperlinks & navigation support

W3C XML-based language

WAE - WML

Card metaphor User interactions are split into cards Navigation occurs between cards

Explicit inter-card navigation model Hyperlinks UI Event handling History

State management and variables Reduce network traffic Results in better caching

WAE - WML

InputElements

Deck

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>

WAE - WML Script

Scripting language: Procedural logic, loops, conditionals, etc. Optimized for small-memory, small-cpu

devicesDerived from JavaScript™Integrated with WML Powerful extension mechanism Reduces overall network traffic

Bytecode-based virtual machine Stack-oriented design Designed for simple, low-impact

implementationCompiler in network Better network bandwidth use Better use of terminal memory/cpu.

WAE - WML Script

Reduces network round-trips and enhance functionality.Example usages Field validation

Check for formatting, input ranges, etc. Device extensions

Access device or vendor-specific API Conditional logic

Download intelligence into the device

WAE - WML Script

Functions

WMLScript is very similar to JavaScript

ProgrammingConstructs

Variables

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

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

WAE - WTA

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

WTAI available in WML & WMLScript

WAE - WTA

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>

WAE - WTA

Placing an outgoing call with WTAI

WTAI Call

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

WAE - Content Formats

Common interchange formatsPromoting interoperabilityFormats: Business cards: IMC vCard standard Calendar: IMC vCalendar standard Images: WBMP (Wireless BitMaP) Compiled WML, WMLScript

WAE - Content Formats

Binary format for size reduction Bytecodes/tokens for common values and operators Compressed headers Data compression (e.g. images)

Example use of image

Image Element

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

WAE - Push

Server initiated content pushProvides end-to-end solutionEasy for developers XML based Push Access Protocol layered on

top of HTTP Helpful push specific content types

Service IndicationService Loading

Underlying wireless network complexity hidden

Push Specifications are currently on Proposed status

WAE - Push Framework

CLIENTPUSH PROXY

GATEWAYPUSH

INITIATOR

PUSH ACCESS

PROTOCOL

OVER-THE-AIR

PROTOCOL

PPG SERVICES

PUSH MESSAGE

WAE - User Agent Profile (UAPROF)

Assist in 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.UAProf specification is currently on Proposed status

Thank you!