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 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
Java Java™ 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 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.
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.