Post on 03-Jan-2016
Media Translation Based onQoS Requirements of Devices and Servi
ces
Jun’ichi YuraFaculty of Environmental Information, Keio Univ.
yurayura@ht.sfc.keio.ac.jp
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
8/12/99 RT-Mach Workshop
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
8/12/99 RT-Mach Workshop
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
8/12/99 RT-Mach Workshop
Implementation
• Proxy Server– Java 2.
• Platform independent.
• Easy for network programming.
• Client Application– Palm III.
• An case of PDA.
8/12/99 RT-Mach Workshop
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