wireless transaction protocol (wtp)
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
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
Other ServicesAnd
Applications
Transport Layer (WDP)
Security Layer (WTLS)
Transaction Layer (WTP)
Session Layer (WSP)
Application Layer (WAE)
SMS USSD CSD IS-136 CDMA CDPD PDC-P Etc
WAP Architecture
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
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)
TR-Invoke/Request
Operation of Class 0
Initiator Responder
TR-Invoke/ Indication
Invoke PDU(TID=N, TG, C=0,…)
TR-Invoke/Confirm
TR-Invoke/Request
Basic Operation of Class 1
Initiator Responder
TR-Invoke/ Indication
Invoke PDU(TID=N, TG, C=1,…)
Ack PDU(TID=N*)
TR-Invoke/Request
TR-Invoke/Confirm
Class 1 – with ‘User’ Acknowledgement
Initiator Responder
TR-Invoke/ Indication
Invoke PDU(TID=N, TG, C=1,…)
Ack PDU(TID=N*) TR-Invoke/
Response
Basic Operation of Class 2
Initiator Responder
TR-Invoke/Request
TR-Invoke/ Indication
Invoke PDU(TID=N, TG, C=2,…)
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 Responder
TR-Invoke/Request
TR-Invoke/ Indication
Invoke PDU(TID=N, TG, C=2,…)
TR-Invoke/Confirm
TR-Result/Indication
TR-Result/Response
Ack PDU
TR-Result/Confirm
TR-Invoke/Request
Result PDU
Ack PDU
Class 2 - with ‘User’ Acknowledgement
Initiator Responder
TR-Invoke/Request
TR-Invoke/ Indication
Invoke PDU(TID=N, TG, C=2,…)
TR-Invoke/Confirm
TR-Result/Indication
TR-Result/Response
Ack PDU
TR-Result/Confirm
TR-Invoke/Request
Result PDU
Ack PDU TR-Invoke/Response
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