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

mail

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

8/12/99 RT-Mach Workshop

Fin.