1. Wireless Application Protocol (WAP)
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김형민

2. Why Choose WAP Wireless handheld devices
Restricted user interface (small displays and keypads)
Less powerful CPU
Reduced memory capacity
Wireless Network
Limited bandwidth
Longer latency
Lower degree of reliability
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3. The WAP Model
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4. The WAP Model
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5. WAP Gateway
The WAP Gateway utilizes Web proxy technology to provide efficient wireless access to the Internet
Implementation of WAP protocol stack layers
Access Control
Protocol conversion: WSP <-> HTTP
Domain Name resolution
HTML to WML conversion
Encording of WML content
WMLScript compilation
Security
Provide caching for frequently accessed content
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6. WAP Protocol Stack
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7. WAP Protocols WDP (Wireless Datagram Protocol)
End-To-End 전송을 위해 port 어드레싱을 제공
인터넷의 UDP와 같은 전송 기능을 담당
WTLS (Wireless Transport Layer Security)
인터넷의 TLS (Transport Layer Security)를 근간으로 작성된 보안 프로토콜
인증(Authentication), 부인봉쇄(Non-Repudiation), 무결성(Constraint), 기밀성(Security) 등의 보안 서비스를 제공
WTP (Wireless Transaction Protocol)
트랜잭션 형태의 데이터 전송 기능을 제공
신뢰성 및 비신뢰성 전송 기능을 제공하고 오류복구를 위해 재전송 기능도 담당
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8. WAP Protocols WSP (Wireless Session Protocol) HTTP/1.1에 상응하는 기능을 정의
장시간 활용의 세션을 정의하고, 세션 관리를 위해 suspend/resume 기능도 제공
프로토콜 기능에 대한 협상도 가능하게 함
WAE(Wireless Application Environment)
일반적, 다목적 응용을 개발하기 위한 응용 환경에 대한 규격을 정의
WML(Wireless Markup Language), WMLScript 등을 정의하여 휴대 단말기에 적용될 수 있는 소규모 브라우저를 개발할 수 있도록 함
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9. WAP 1.2 & 2.0
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10. WAP UAProf and Caching WAP proxy may provide a variety of functions
Protocol Gateway
The protocol gateway translates requests from a wireless protocol stack to the WWW protocols
The gateway also performs DNS lookups of the servers named by the client in the request URLs
Content Encoders and Decoders
The content encoders can be used to translate WAP content into a compact format that allows for better utilisation of the underlying link due to its reduced size
User Agent Profile Management
User agent profiles describing client capabilities and personal preferences [UAProf] are composed and presented to the applications
Caching Proxy
A caching proxy can improve perceived performance and network utilisation by maintaining a cache of frequently accessed resources
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11. Wireless Bearers for WAP
The WAP protocol stack is built on top of wireless bearer services
IP-based bearer
GPRS
UDP
Non-IP-based bearer
GSM SMS
GSM USSD
ReFlex
IS-637SMS
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12. WAP SDK Simulator
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13. Mobile Station Application Execution Environment
단말기 응용 프로그램 실행환경
서비스 능력을 협상하여 MS에서 표준화된 실행환경을 제공
MExE classmark 1
WAP environment
MExE classmark 2
Personal Java environment
Future classmark
Java-packages
APIs
음성인식
On-line (de)compression을 가진 video-I/O
초고속 로컬 통신
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