media translation based on qos requirements of devices and services jun’ichi yura faculty of...
TRANSCRIPT
Media Translation Based onQoS Requirements of Devices and Servi
ces
Jun’ichi YuraFaculty of Environmental Information, Keio Univ.
8/12/99 RT-Mach Workshop
Background
• Various kinds of services are available.– WWW, Database, news ...
• Various kinds of hosts are available.– PC/WS, PDA, WC(Wearable Computer) …
web
database
news
PC/WS
PDA
Phone
8/12/99 RT-Mach Workshop
What’s Service Transparency?
• Absorb difference of services(e.g. protocol, format of data, UI).
PDA
web
database
news
http+{text,image...}
???+{text,image...}
nntp+{text}
8/12/99 RT-Mach Workshop
What’s Device Transparency?
• Absorb difference of hosts(e.g. I/O devices, CPU, Memory).
PC/WS
PDA
Phoneweb
8/12/99 RT-Mach Workshop
Objectives
• Media translation based on QoS requirements of devices and services. – Achieve service transparency
• Protocol translation
• UI construction
– Achieve device transparency• Data translation
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Scenario : Service Transparency
Home
Network
Internet
HGWHGW
WWW
I want toaccess web.
I want toread e-mail.
8/12/99 RT-Mach Workshop
Scenario : Device Transparency
Internet
WWWPDA, WC
I wantthe data.I want
the data.
8/12/99 RT-Mach Workshop
System Design
• tranService System– Uses QoS Profile
– Proxy Server Model
Service
tranServiceClient Appl.
Proxy Server
ExistingClient Appl.
8/12/99 RT-Mach Workshop
QoS Profile
• Information about data quality required by users.– Defined on the device.
– Description in XML.
• QoS profile types– Device QoS Profile
– Data QoS Profile
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QoS Profile Example<DATA><IN TYPE=“image/*”></IN><OUT TYPE=“image/tbmp”><VALUE NAME=“COLOR”>1</VA
LUE><VALUE NAME=“DEPTH”>0x02<
/VALUE></OUT></DATA><DATA><IN TYPE=“text/*”></IN><OUT TYPE=“text/*”><VALUE TYPE=“CHARSET”>Shi
ft-JIS</VALUE></OUT></DATA></QOS>
<?xml version=“1.0”?><!DOCTYPE tranService SYS
TEM “http://www.ht.sfc.keio.ac.jp/tranService/qos.dtd”>
<QOS><DEVICE><SPEC TYPE=“image”><VALUE NAME=“COLOR”>1</VA
LUE><VALUE NAME=“DEPTH”>0x02<
/VALUE><VALUE NAME=“WIDHT”>180</
VALUE><VALUE NAME=“HEIGHT”>180<
/VALUE></SPEC></DEVICE>
8/12/99 RT-Mach Workshop
Proxy Server Architecture
• Consists of 3 modules
– Service Module
• communicate with services.
– Interface Module
• communicate with devices.
– Translation Module
• translate data.
Proxy Server
ServiceModule
TranslationModule
InterfaceModule
8/12/99 RT-Mach Workshop
Protocol Translation
• Exchange protocols between client and proxy, between proxy and service
Proxy Server
ServiceModule
TranslationModule
InterfaceModule
Serviceclient
nntp+data
datadata
http+data
http+req nntp+req
reqreq
8/12/99 RT-Mach Workshop
UI Construction
• Select the UI which is suitable for the service.
Proxy Server
ServiceModule
TranslationModule
InterfaceModule
Serviceclient
UIUI
http+UI
http+req
reqreq
UI
8/12/99 RT-Mach Workshop
Data Translation
• Translate data based on QoS Profile.• Media, Type, Quality translation
Proxy Server
ServiceModule
TranslationModule
InterfaceModule
Serviceclient
http+data
datadata
http+data
http+QoS,req http+req
reqQoS,req
QoS
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Implementation
• Proxy Server– Java 2.
• Platform independent.
• Easy for network programming.
• Client Application– Palm III.
• An case of PDA.
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Conclusion
What’s tranService System?• Definition of QoS Profile.• System to provide service transparency
– Protocol Translation– UI Construction
• System to provide device transparency– Data Translation
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Fin.