Transcript Document 7933074

Wireless Transaction Protocol
(WTP)
By Pathfinders
WHAT IS WAP?

Wireless Application Protocol

Standard created by wireless and Internet companies

Enables internet access from a cellular phone
Enables applications to scale across variety of
transport options and device types

Protocol Stack for WAP
Application Layer (WAE)
Other Services
And
Applications
Session Layer (WSP)
Transaction Layer (WTP)
Security Layer (WTLS)
Transport Layer (WDP)
SMS
USSD
CSD
IS-136
CDMA
CDPD PDC-P
Etc
WAP Architecture
Web Server
WAP Gateway
WML
WML Encoder
WMLScript
WSP/WTP
WMLScript
Compiler
HTTP
CGI
Scripts
etc.
WTAI
Protocol Adapters
Etc.
Content
WML Decks
with WML-Script
Client
WHAT IS WTP?

Light weight transaction oriented protocol

Runs on top of datagram service

Chops data packets into lower level datagram's

Concatenates received datagram's into useful data
Operates above WDP to provide simple protocol
suitable for low bandwidth mobile station

How it is designed for Wireless
Environment

no explicit connection setup or tear down
optimized
setup (data carried in first packet of
protocol exchange)
seeks to reduce 3-way handshake on initial
request

supports User acknowledgement or Stack
acknowledgement option [acks may be forced
from the WTP user (upper layer) default is
stack ack]

WTP Transaction Services
WTP offers 3 classes of transactions
services:
•Unreliable
one-way request (Class 0)
•Reliable
one-way request (Class 1)
•Reliable
two-way request/response (Class 2)
Operation of Class 0
Initiator
TR-Invoke/
Request
Responder
Invoke PDU
(TID=N, TG, C=0,…)
TR-Invoke/
Indication
Basic Operation of Class 1
Initiator
TR-Invoke/
Request
Responder
Invoke PDU
(TID=N, TG, C=1,…)
TR-Invoke/
Indication
Ack PDU
(TID=N*)
TR-Invoke/
Confirm
Class 1 – with ‘User’ Acknowledgement
Initiator
TR-Invoke/
Request
Responder
Invoke PDU
(TID=N, TG, C=1,…)
TR-Invoke/
Indication
Ack PDU
(TID=N*)
TR-Invoke/
Confirm
TR-Invoke/
Response
Basic Operation of Class 2
Initiator
TR-Invoke/
Request
Responder
Invoke PDU
(TID=N, TG, C=2,…)
TR-Invoke/
Indication
Result PDU
TR-Invoke/
Confirm
TR-Invoke/
Request
TR-Result/
Indication
TR-Result/
Response
Ack PDU
TR-Result/
Confirm
Class 2 - with ‘Hold On’ Acknowledgement
Initiator
TR-Invoke/
Request
Responder
Invoke PDU
(TID=N, TG, C=2,…)
TR-Invoke/
Indication
Ack PDU
TR-Invoke/
Confirm
Result PDU
TR-Result/
Indication
TR-Result/
Response
TR-Invoke/
Request
Ack PDU
TR-Result/
Confirm
Class 2 - with ‘User’ Acknowledgement
Initiator
TR-Invoke/
Request
Responder
Invoke PDU
(TID=N, TG, C=2,…)
TR-Invoke/
Indication
Ack PDU
TR-Invoke/
Response
Result PDU
TR-Invoke/
Request
TR-Invoke/
Confirm
TR-Result/
Indication
TR-Result/
Response
Ack PDU
TR-Result/
Confirm
WTP Management Entity
Interface between WTP layer and environment of
device



Monitors the state of mobile environment
Deals with all the issues related to
 Initialization
 Configuration
 Resources
as they pertain to WTP layer
WTP Features
Provides reliable, efficient data transfer based on
request/reply paradigm


Supports selective re-transmission

Message oriented (not stream)

Supports Abort function

Supports concatenation of PDUs
Mobile WWW
References and Resources

Books
- Understanding WAP

Official Website (specifications)
-
www.wapforum.org
Thank You