1. Wireless Application Protocol (WAP)

2. Definition of WAP
Wireless application protocol (WAP) is an application environment and set of communication protocols for wireless devices designed to enable access to the Internet
and advanced telephony services to the wireless community.
Develop By WAP Forum, Summer 1997
WAP 1.0 Standard, 1998
Open Standard
Industry-Wide Specification
WAP 2.0 Standard, 2002

3. What is WAP WAP – The Wireless Application Protocol
Makes it possible to access the Internet via wireless devices such as mobile phones, PDAs etc.
Set of rules governing transmission/reception of data by wireless devices (e.g. mobile phones)
WAP is a set of specifications that addresses the Wireless network characteristics by adapting existing network technologies (and introducing new ones where appropriate) to the special requirements of handheld wireless devices. Therefore, WAP intends to standardize the way wireless devices (mobile phones, PDAs, and so forth) access Internet data and services. WAP's reuse of existing Internet protocols will ease the development of WAP services for Java and other Web developers.
How is WAP different from Internet?
WAP is a standardized technology for cross-platform, distributed computing, very similar to Internet’s combination of HTTP and HTML except that it includes one vital feature…
Optimization for low-display capability, low-memory and low bandwidth devices such as PDA, mobile phones etc.
It introduces a new way of looking at the wireless phenomenon – letting the application follow their customers and provide them with innovative services.
As a matter of fact WAP is not one single protocol but a collection of protocols and specifications that cover everything from how the WAP device and the user agent should work to how the transport protocols interact within the bearers themselves.
So how is it any different from Internet ??
WAP is a standardized technology for cross-platform, distributed computing, very similar to Internet’s combo of HTTP and HTML, except that it includes one vital feature : optimization of low-display capability , low memory etc.

4. Limitations of Internet for Wireless Applications
Traditional Internet applications cannot run on mobile devices because of the following limitations:
Low bandwidth network
High Latency network
Limited connection stability
Small display size
Limited input facility
Limited memory
Limited processing power
There are lots of problems that need to be addressed before Internet and mobile devices can be brought together.
How is WAP different from Internet?
WAP is a standardized technology for cross-platform, distributed computing, very similar to Internet’s combination of HTTP and HTML except that it includes one vital feature…
Optimization for low-display capability, low-memory and low bandwidth devices such as PDA, mobile phones etc.

5. Limitations of Internet for Wireless Applications
Low bandwidth
Size of an HTML page, including graphics … 20 KB
Download time (56Kbps modem) … 3 s
Bandwidth of wireless network … 9.6Kbps
Download time for data on one page … 17 s
High latency
At the expiry of retransmission timer value, the TCP layer resends the packet of data
An average latency in a wireless network is around ½ s but can be as high as 10s
This can cause a lot of retransmission causing severe congestion
Internet as it is now, is not well suited to mobile phone.
Is complex.
Takes up too much bandwidth
Latency – Round trip delay between something being sent on the network and acknowledgement obtained that whatever was sent was received OK
The information coming from the Internet and going to mobile phones has to go thro’ various elements in the mobile network. Each one introducing a little delay.
Also, the air interface used to transmit data to mobile telephones has a very limited bandwidth (9.6Kbps compared to 56kbps on a wired network) Thus Internet protocols, which send many large messages result in large latency.

6. Limitations of Internet for Wireless Applications
Limited connection stability
Small display size
Limited input facility
Limited memory
Limited processing power
The Internet protocols (TCP/IP & HTTP) are far from being suitable for use with mobile phone communications. They introduce far too many overheads, requiring many messages bet. Clients and server just to set up a connection. These overheads call for a high processing power on the client device.

7. What can be done with WAP?
Information services
Similar to web browsing
Small downloadable programs
WAP script language is based on JavaScript™
Telephony functionality combined with browser
Call the airline when your flight is delayed
Push
Server initiated content push
These are the basic application types.
I will explain them all in more detail during a few next slides.

8. What is defined in WAP? Layered telecommunication stack including
Datagrams and Transactions
Security
Session
Micro browser
Concept that is similar to the Internet browsing
XML based markup language ( WML )
Scripting ( WMLS )
WTA / WTAI
Access to telephone functionality
Content formats e.g.
Service Indication
Wireless Bitmap ( WBMP )

9. WAP Architecture Web Server WAP Gateway Client HTTP WSP/WTP
Content
CGI
Scripts
etc.
with WML-Script
WML Decks
WAP Gateway
WML Encoder
WMLScript
Compiler
Protocol Adapters
Client
WML
WML-Script
WTAI
Etc.
HTTP
WSP/WTP

10. How It Works User enter the URL with his cellular phone.
Static file or CGI
Output WML 7 1
Request
Encrypted URL 2
HTTP Request
xxx wml 3 4
Client
WML
WML-Script
WTAI
Etc.
Web Server
Content
CGI
Scripts
etc.
with WML-Script
WML Decks
WAP Gateway
Encoder,Decoder
WMLScript
Compiler
Protocol Adapters
HTTP Response
xxx wml 5
Response
Encrypted WML
Content 6
User enter the URL with his cellular phone.
URL is encrypted in WAP browser
2. Cellular phone utilizes WAP to send a request (Binary WML) to WAP gateway
Gateway decodes binary WML to WML
3. WAP gateway utilizes HTTP to send a request to Web server
4. Web server executes the request
Generate response content for request
5. Web server sends back a response with HTTP headers to WAP gateway
6. Gateway encodes WML to binary WML
WAP gateway verifies HTTP header and transforms received data into binary format
Send the binary content to the cellular phone.
7. User can browse the information with micro-browser.
HTTP
WAP

11. Internet and WAP architecture
Wireless Application Protocol
HTML
JavaScript™
Wireless Application Environment (WAE)
Other Services and
Applications
Wireless Session Layer (WSP)
HTTP
Wireless Transaction Protocol (WTP)
TLS - SSL
Wireless Transport Layer Security (WTLS)
WAP architecture consists of several layers
WEB model
Different layers can be used independently
Layered model is extensible
Allows also other applications
Allows various bearers
TCP/IP
UDP/IP
Wireless Datagram Protocol (WDP)
Bearers:
SMS
USSD
CSD
R-Data
Packet
UDP
PDC-P
Etc...

12. WAP & Standards
Submit specifications for adoption by appropriate industry and standards bodies
Good relationships with standards bodies
Several Liaisons with ETSI
ETSI / WAP compliance profile for GSM and UMTS.
CTIA official Liaison Officer to the WAP Forum
WAP is actively working with the W3C and IETF

13. WAP Protocol Stack Wireless Protocols Group (WPG)
Wireless Transaction Service Access Point
Wireless Datagram Protocol
Bearer
Service D C B
Transport Service Access Point (TSAP) A
Physical 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.

14. WAP Protocols Recall the ISO OSI model:
WAE (Wireless Application Environment): WML, WML Script
WSP (Wireless Session Protocol) and WTP (Wireless
Transaction Protocol): together provide session layer services
connection oriented sessions or connectionless sessions. Reliable
sessions can be resumed.
WTLS (Wireless Transport Layer Security) (Optional)

15. WAP Protocol Stack - WSP
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
Enhancements beyond HTTP
Binary header encoding
Confirmed and non-confirmed data push
Capability negotiation
Suspend and resume
Connectionless service

16. 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 network
Capabilities
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

17. WAP Protocol Stack - WSP
Connection & Connectionless service
Connection-mode
Long-lived communication
Benefits of the session state
Reliability
Connectionless
Stateless applications
No session creation overhead
No reliability overhead

18. 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)

19. WAP Protocol Stack - WTLS
Specifies a framework for secure connections, using protocol elements from common Internet security protocols like SSL and TLS.
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

20. WAP Protocol Stack - WDP
WDP provides a connection-less, unreliable datagram service
WDP 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 everywhere
Replaced by UDP when used over an IP network layer.
WDP over IP is UDP/IP
Uses the Service Primitive
T-UnitData.req .ind

21. WAP Protocol Stack - Bearer support
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

22. WAP: Applications Location-based services Enterprise solutions
Real-time traffic reporting, Event/restaurant recommendation
Enterprise solutions
access, Database access, “global” intranet access
Information updates “pushed” to WAP devices
Financial services
Banking, Bill-paying, Stock trading, Funds transfers
Travel services
Schedules and rescheduling, Reservations
Gaming and Entertainment
Online, real-time, multi-player games
Downloadable horoscopes, cartoons, quotes, advice
M-Commerce
Shopping on the go
Instant comparison shopping
Location-based special offers and sales

23. FUTURE OF WAP
Will WAP comply with Third Generation wireless standards?
Yes, WAP has been designed to be as independent as possible from the underlying network technology.
Is WAP necessary with higher bandwidth 3G networks?
Even as bandwidths increase, the cost of that bandwidth does not fall to zero. These costs result from higher power usage in the terminals, higher costs in the radio sections, greater use of RF spectrum, and increased network loading. In addition, the original constraints WAP was designed for -- intermittent coverage, small screens, low power consumption, wide scalability over bearers and devices, and one-handed operation -- are still valid in 3G networks. Finally, we can expect the bandwidth required by application users to steadily increase. Therefore, there is still a need to optimize the device and network resources for wireless environments. We can expect WAP to optimize support for multimedia applications that continue to be relevant.

24. FUTURE OF WAP The reasons to migrate to WAP technology
If WAP is very successful in mass-markets on 2.5G networks, 3G networks may be needed purely for capacity relief.
The reasons to migrate to WAP technology
Network operators are behind WAP
With minimal risk and investment, WAP enables operators to decrease churn, cut costs, and increase revenues by improving existing, value-added services and offering exciting new informational services.
Why are equipment manufacturers interested in WAP?
Being a global open specification suite, WAP has generated the critical mass for manufacturers. This has opened up new product and marketing opportunities in the wireless industry and provides new revenue to participating companies.

25. ADVANTAGES open standard, vendor independent
network-standard independent
transport mechanism–optimized for wireless data bearers
application downloaded from the server, enabling fast service creation and introduction, as opposed to embedded software

26. DISADVANTAGES of WAP
Small screens: For web phones, there's an incredibly small viewing area; palmtops are barely better.
Speed of access: All devices have slow access.
Limited or fragmented availability: Wireless web access is sporadic in many areas and entirely unavailable in other areas.
Price: Many technology limitations are being addressed by higher-end devices and services. But the entry price for a good wireless web palmtop with decent display, keyboard, and speed is easily $700 to $900, not including monthly access.
Lack of user habit: It takes some patience and overcoming the learning curve to get the hang of it -- connecting, putting in an address, typing. Users just aren't used to the idea and protocol yet.