By Zhongyin J. Daye Han-Chung Lee Beyond WAP By Zhongyin J. Daye Han-Chung Lee

Agenda Introduction Application Layer Transport Layer Conclusion 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

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 Transport Layer Conclusion iMode Java (Accessory Application Support) Mobile Markup Language (MML) WAP 2.0 Transport Layer Conclusion

iMode Current Service Comparison: NTT DoCoMo & Java Alliance - enhanced security - game downloads - vector-driven client-generated graphics Source: Eurotechnology Japan K. K., NTT DoCoMo, & Beyond WAP Group

Java Java™ 2 Platform, Micro Edition (J2ME) K virtual Machine (KVM) - 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 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) 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 Source: MOBIDY, J-Phone, & Beyond WAP Group

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 Conclusion 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 Transport 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.