Transcript Mobile Device Connectivity Protocols

CPET 565 Mobile Computing Systems
Mobile Device Connectivity Protocols
Lecture 14
Hongli Luo
Indiana University-Purdue University Fort Wayne
Mobile Device Connectivity Protocols
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Wireless Protocols
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WAP (Wireless Application Protocol)
WML (Wireless Markup Language)
Bluetooth
OBEX (Object Exchange)
WBXML
Mobile Internet Protocols
Mobile Device Connectivity Protocols
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Limitations of Internet for wireless applications:
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Low bandwidth
High latency
Limited connection stability
Small display size
Limited input facility
Limited memory
Limited processing power
Mobile Device Connectivity Protocols
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Mobile software development considerations
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Size of display limited
Input device may be harder to manipulate
Sound may be limited
Storage/processing ability could be slower
Mobile Device Connectivity Protocols
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WAP (Wireless Application Protocol)
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HTTP/HTML ->WAP/WML
Allows accessing the web from a mobile phone or PDA
WAP Forum, http://www.wapforum.org/
WAP 2.0,
http://www.openmobilealliance.org/tech/affiliates/
wap/wapindex.html
• Integrates telephony services with browser technology,
interactive Internet access for mobile handsets
• Typical WAP applications
 Over-the-air e-commerce transactions, online banking,
information provisioning, and messaging
• WAP 2.0 Technical White paper,
www.wapforum.org/what/WAPWhite_Paper1.pdf
Mobile Device Connectivity Protocols
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WAP Infrastructure
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Mobile client
A public land mobile network (GMS, etc)
A public telephony network
A WAP gateway
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Protocol conversion
Content encoding
• An IP network
• A WAP application server
http://www.wiziq.com/tutorial/11611-wireless-markuplang-WAP-WML
Mobile Device Connectivity Protocols
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WAP Architecture (client)
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Application Layer (WAE)
Session Layer (WSP)
Transaction Layer (WTP)
Security Layer (WTLS)
Transport Layer (WDP)
Bearers (Lowest Transport mechanism)
Mobile Device Connectivity Protocols
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WAP Architecture (client): Bearers (Lowest
Transport mechanism)
• GSM (Global System for Mobile
Communications)
• CDMA
• IP
• UMTS (Universal Mobile Telecommunication
System)
Mobile Device Connectivity Protocols
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WAP Architecture (client): Transport Layer
(WDP)
• Wireless Datagram Protocol (WDP)
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Transport layer protocol that sends and receives
message via any available bearer network.
• Wireless Control Message Protocol (WCMP)
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WAP Architecture (client): Transport
Layer Security (WTLS)
• Optional security layer
• Provides the secure transport service required
by many applications, such as e-commerce
Mobile Device Connectivity Protocols
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WAP Architecture (client):
Transaction Layer (WTP)
• Provides transaction support, adding
reliability to the datagram service
provided by WDP
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Class 0 – unreliable one-way messages
without confirmation
Class 1 – reliable one-way message without
result messages (push Short Message
Services)
Class 2 – reliable two-way request-response
messages (confirmation, result of a query)
Mobile Device Connectivity Protocols
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WAP Architecture (client): Session Layer
(WSP)
• Provides a lightweight session layer to allow
efficient exchange of data between
applications
• Connection-Oriented services based on WTP
• Connectionless services above datagram
transport services
• Supports HTTP 1.1 functionality and semantics
in a binary-encoded format
Mobile Device Connectivity Protocols
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WAP Architecture (client): Application
Layer (WAE) environment
• Micro-browser
• Displaying WML pages
• Executing WML script
WAP and Internet
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Internet
• HTTP/HTML/JavaScript
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WAP
• WAP/WML/WML Script
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WML (wireless Markup language)
• A Light markup language, optimized for use in
handheld mobile terminals
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WML Script
• A lightweight scripting language, similar to
JavaScript
From WAP white paper
Mobile Device Connectivity Protocols
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WAP Gateway
• Protocol conversion
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translates requests from a wireless protocol stack to
WWW protocol (HTTP and TCP/IP)
• Content encoders and decoders
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translate WAP contents into a compact format
• User agent profile management
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describe client capabilities and personal preferences
• Caching proxy
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improve perceived performance and network
utilization
WAP 2.0 Features
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Protocol layers for networks
supporting IP
• Introduced in WAP 2.0
• Motivated by the high-speed wireless
network (e.g. 2.5G and 3G)
• Protocol layers
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Wireless Profiled HTTP (WP-HTTP)
Transport Layer Security (TLS)
Wireless Profiled TCP (WP-TCP)
Mobile Device Connectivity Protocols
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WAP 2.0
http://www.openmobilealliance.org/tech/affiliates/wap/wap
index.html
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Architecture
Client ID
Client Provisioning
External Functional Interface (EFI)
General Formats
Multimedia Messaging Services (MMS)
Persistence
Push
Mobile Device Connectivity Protocols
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WAP 2.0
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Synchronization
User Agent Profile
Wireless Application Environment
Wireless Protocols
Wireless Security
Wireless Telephony Application (WTA)
Mobile Device Connectivity Protocols
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WAP Profile
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Homepage: http://x.yy.xx.xyz/homepage.wml
Connection type
Connection security
Bearer
Dial-up number
IP address
Authentication type
Data call type
Data call speed
User name
Password
From WAP white paper
Proxy can optimize the communication and may offer
mobile service enhancements,
• such as location, privacy, and presence based services.
•It is necessary to offer Push functionality.