Wireless Service Engineering
Resources
What to adapt?
Communication
packet sizes
chatty protocol?
Operation
Why and when adapt
Adaptation is needed when service can be used with different devices
Adaptation can be taken into account either on server side or on client side
Different approaches exist for capabillity informing
Client tells it all (CC/PP and UAProf)
Server fetches the client device name and erver fetches the capabilite from database(wurfl)
Your own approach combining these two somehow
CC/PP
Composite capabilities and preference profile
Motivation
Provides the rules of how to construct a vocabulary that describes capabilities and preferences
Based on RDF (Resource Description Framework)
CC/PP exhange profile
CC/PP is very verbose
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UAPROF
User agent profile
User agent = the application that interacts with information source e.g. microbrowser
User agent profiles defines the capabilities of user agent and the platform it is run on
Specific vocabulary for user agents based on CC/PP
Hardware platform e.g. vendor, model, screen size, input and output methods.
Software platform e.g. operating system, java support, audio and video encoder.
Network characteristics e.g. security support, bearer support (latency, reliability)…
Browser user agent, e.g. browser name, supported
HTML and XML versions…
WAP characteristics e.g. supported WAP and WML version, WML script libraries WAP deck size…
Push characteristics e.g. accepted type of content, maximum message size content types of a push message, maximum size of a push message.
The final profile arriving to server is combination of characteristics on the transmission path
Similarly to CC/PP in UAProf the client states the default profile (hardware, software, browser capabilities)
The network may add or override networking characteristics in the profile during the transmission
When the profile reaches a WAP proxy, the profile may be updated with WAP characteristics.
With UAProf information the service can be adapted for the user device and network capabilities
UAProf is also extensible
Example profiles
WURFL
Open source XML based repository for device capabilities
Targeted for WAP page developers
API's for several languages exist
Several tools are provided that use wurfl information to adapt content e.g. picture size
Wurfl example