Beyond WAP

By Zhongyin J. Daye

Han-Chung Lee

Agenda

• Introduction– WAP Protocol Stack

– Future Wireless Environment

– Problem Facing WAP

• Application Layer

• Transport Layer

• Conclusion

WAP Protocol Stack

• WAP has layer-to-layer communication.

• Wireless Datagram Protocol (WDP) runs on top of different network bearer.

• Wireless Transaction Protocol operates on top of WDP.

Future Wireless Environment

Source: Merill Lynch, WAP Forum, & Beyond WAP Group

Platform NetworkingSystem

Cost per BaseStation

Cost perOperator

Maximum DataTransmissionRate

CDPD TDMA Circuit Switched $500-1000 $3-6 million 32kbpsHSCSD GSM Circuit Switched $4000 $20-30 million 57.6kbpsGPRS GSM Packet Switched $20,000 $50-120 million 115kbpsEDGE GSM Packet Switched $70,000 $300-600

million384kbps

IS-136+ TDMA Circuit/PacketSwitched

$20,000 $50-120 million 64kbps

IS-95B CDMA Packet Switched $20,000 $50-120 million 64kbps1XRTT CDMA Packet Switched $70,000 $300-600

million144kbps

W-CDMA GSM/PDC

Packet Switched N/A N/A 2Mbps

IS-136HS/UWC-136

TMDA Packet Switched $70,000 $300-600million

384kbps

CDMA2000 CDMA Packet Switched N/A N/A 144kbps

Generation Attributes ApplicationsFirst Analog Basic VoiceSecond Digital, 9.6kbps Advanced Voice, SMS2.5 Digital, 57.6-384kbps SMS, InternetThird Digital, 384kbps-2Mbps Video, Internet, Multimedia

Problems Facing WAP

• WAP only support simple graphic and text in one specific format and is not compatible with the Internet.

• 3G wireless applications will be dominate by streaming multimedia, which WAP does not support.

Agenda

• Introduction

• Application Layer– iMode

– Java (Accessory Application Support)

– Mobile Markup Language (MML)

– WAP 2.0

• Transport Layer

• Conclusion

iMode

Imode WAPcHTML WMLPacket switched Circuit switchedColored gifs Wireless (uncolored) bmpApplication and appletdownloads

Server-centricapplication

Current Service Comparison:

Source: Eurotechnology Japan K. K., NTT DoCoMo, & Beyond WAP Group

NTT DoCoMo & Java Alliance

- enhanced security

- game downloads

- vector-driven client-generated graphics

JavaJava™ 2 Platform, Micro Edition (J2ME)

- allows dynamic download of new applications over wireless networks

- vector-driven client-generated graphics ensures viability of real-time games such as Tetric and 3D Maze

K virtual Machine (KVM)

- provides highly optimized runtime environment for small hand-held devices

- offers multithreading and garbage collection

- compatible with Java 2 Platform, Standard Edition (J2SE) & Java 2 Platform, Enterprise Edition (J2EE)

Mobile Information Device (MID) profile offers APIs facilitating user interface, persistent storage, security and messaging on wireless devices.

Source: Sun Microsystems, Inc.

Java (Continued)

JavaPhone provides direct telephony control, datagram messaging, address book and calendar information, user profile access, power monitoring, and application installation.

Source: Sun Microsystems, Inc.

Mobile Markup Language(MML)

Subset Principle: uses different application environment package for different devices

S-MML M-MML Full MML12 letters by 4lines display

¼ VGA display PC display

No Images Images support Images supportTables notindicated

Tables not indicated Tablesindicated

Source: MOBIDY & Beyond WAP Group

MML (Continued)

MML is built chiefly upon the SMS system, but is also applicable to both the packet and circuit switch platform

Source: MOBIDY & Beyond WAP Group

MML (Continued)

Source: MOBIDY, J-Phone, & Beyond WAP Group

MML’s Advantage over WAP

A. Support of HTML 4.0: guarantees HTML convergence later on.

B. Subset Concept: Allows device differentiation while maintaining same language support

WAP 2.0

•WAP envisions the convergence of WAP and XHTML.

•XHTML is the next generation HTML that seeks to separate content from transmission.

Source: Phone.com, Lehman Brothers, & Beyond WAP group

Agenda

• Introduction

• Application Layer

• Transport Layer– WAP Transport Layer

– Alternative Transport Protocols

– ESRO, VMTP, and MNCP

– TCP

– Suggestion on Transport Layer

• Conclusion

WAP Transport Layer

• WDP is replaced by UDP when the underlying network bearer is IP.

• WTP is built on top of a datagram service.

• WTP is transactional based.

• WTP has no congestion control.

Alternative Transport Protocols

ESRO, VMTP, and MNCP

• Both ESRO and VMTP are transaction-based protocol built for RPC.

• WDP used ESRO and T/TCP as its design model.

• MNCP is another proxy service similar to WAP.

TCP

• TCP has too much overhead for wireless links.

• TCP assumes all packet loss is due to congestion.

• TCP does not provide layer to layer communication.

Suggestion on Transport Layer

• Use TCP for streaming applications and keep WTP for transactional applications.

• Improve TCP overhead by using Delayed Dupack and SACK.

• Implement layer-to-layer communication in TCP as an option.

• Adjust TCP window size to fit high latency, high bandwidth wireless links.

Conclusion

• Application Layer– WAP, iMode, & MML will coexist– WAP will dominate within the next few years

due to its multi-bearer support– iMode will dominate afterwards with its

unmatchable function supports

• Transport Layer– Transport Layer converges to TCP.