1. A Modular WAP Reference Stack Protocol Implementation
Johan Blom
WAP Program
Ericsson Radio AB

2. Content WAP Intro Background Standard Ericsson WAP Gateway Products
WAP Reference System Erlang Implementation
Usage
Design ideas

3. WAP (Wireless Application Protocol)
Purpose: Connect wireless data and internet
Open standard:
Specs available from
General industry acceptance
Based on existing (W3C, IETF) Internet standards
Features:
Saves bandwith, by encode messages and store static information
Applications can be made bearer independent
Possible to integrate telephone applications

4. More than 100 million users by the end of 2000 ?
WAP Advantages
Users
Synergy of “mobile” and “internet” applications
Manufactures
Optimised for hand-held devices with limited capabilities
Browser works on all networks
Operators
Visual interface to existing and new features
Generates traffic in the network...
Developers
Possible to create applications using telephony events and push
More than 100 million users by the end of 2000 ?

5. WAP Content Format
The WAP Markup Language (WML) maps well onto existing mobile phone user interfaces
Encoding compress content to approximately 75% of the original size
Characteristics of WML:
Card metaphor
Variables with application scope
<WML>
<CARD>
<DO TYPE=“ACCEPT”>
<GO URL=“#eCard”/>
</DO
Welcome!
</CARD>
<CARD NAME=“eCard”>
<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>
</WML>

6. The Ericsson WAP Gateway/Proxy Brings advanced services to mobile users
WTA Server
WWW Server
WWW Server
WIRELESS NW
INTERNET
INTRANET
Proxy Firewall
WAP Gateway/ Proxy

7. Typical Internet Configuration
Client
Server
HTML/JavaScript
browser
HTML/JavaScript
application
HTTP
TCP
HTTP
TCP IP

8. Typical WAP Configuration
Client
WAP Gateway/Proxy
Application Server
Application
WML/WMLScript
browser
WML/WMLScript
application
WAE
WSP
WTP
WDP
WSP
WTP
WDP
HTTP
TCP
HTTP
TCP
IP/SMS/USSD/Mobitex... IP

9. WAP Standard still growing…
WTA
Framework for telephony applications
handling of events originating in the mobile net
WAP Encoding/Decoding
WML, WTA etc. content compressing
Graphics encoded to 2 bits Bitmap (WBMP)
WIM
Typically the SIM card in the GSM world
Storing of cryptographic parameters
Provisioning
Bootstrapping, locking mechanisms
Client side
Provisioning
WIM
WTA
WAP Content Decoding
WSP
WTP
WTLS
WDP
Adaptation

10. WAP Standard still growing…
WSP Session layer
Corresponds to HTTP
WTP Transport layer
WTLS Security layer
Data encryption, similar to TLS (formerly known as SSL)
WDP Datagram layer
Bearer Adaptations
PUSH
For pre-caching of data and to send Alerts
UAPROF
Profiling content to specific devices
WCMP
Error reporting, similar to ICMP
Server side
WAP Content Encoding
Push
UAPROF
WSP
WTP
WTLS
WDP
WCMP
Adaptation

11. Security aspects Application level security
Encrypt only specifc content
WMLScript Crypto API
Transport level security
Encrypt all content over a session
WTLS
Application Server owned by Bank
WAP Gateway owned by Operator

12. Features for WAP Gateway/Proxy 1.0
WAP 1.1 compliant
UDP/IP (CSD) Bearer Service
SMS Bearer Service direct on MAP
Connectionless & connection oriented mode
WML encoding/decoding
WML Script Compiling
Subscriber Authentication
HTTP 1.1 Caching
Internet Security using SSL
Storage of Subscriber Data
Operation & Maintenance
Process Supervision
Fault Handling

13. Ericsson WAP Gateway/Proxy Products
NT WAP Gateway
NT only
European market
Jambala Gateway
TelORB only
North and South American market
Non-product: WAP Reference System
Any Erlang supported platform

14. WAP Reference System - Usage
Various Demo/Prototyping projects
WTA and WML/WMLScript applications
Internal testing of products
Both Ericsson client and server products
Jambala
Today communicating over CORBA in trials
WapIDE
WAP terminal emulator and application development tool
Written in Erlang and Tcl/Tk

15. WapIDE - WAP Integrated Development Environment
Components in the WAP Service Development Kit
Browser – View WML decks and cards using a “standard” WAP device
Device Designer – Simulate the “look and feel” of a device of your choice
Application Designer – Create WML decks and cards in a WYSIWYG mode
Server Toolset – Add dynamic WML content with server-side applications
WAP Reference client stacks integrated part of WapIDE
Downloadable free of charge:

16. WAP Reference System - Implementation status
Client and Server WAP stacks
WSP Connection-less and Connection oriented versions (Complete WAP 1.1)
WTP Message oriented transaction layer (Complete WAP 1.1 except SAR)
WDP Only UDP/IP supported
Management and operation
Logging
WAP Gateway/Proxy application features
WML encoding
Character encoding
HTTP client
CORBA interface

17. WAP Reference System - Design issues
WAP standard architecture consists of several modular entities
WAP is still evolving rapidly
Implementation should support this !!
Possible valid WAP stacks in current WAP standard
WSP
WSP
WSP
WSP
WTP
WTP
WTLS
WTLS
WDP
WDP
WDP
WDP

18. WAP Reference System - Design
Observations
C++ based WAP product design focused on performance issues
Monolithic, much harder to add new components without redesign
Regarded as successful project
Erlang based WAP Reference system design focused on close relation to standard
Reusable WAP components
Well-defined WAP component interfaces
Conclusions
To make components reusable it is much more important to have a modular design than a modular (object-oriented) language
Low-level language => low-level design