Optimized Communication For Mobile Multimedia Collaboration Applications

Optimized Communication For Mobile Multimedia

Collaboration Applications

Sangyoon OhCommunity Grids Laboratory

Indiana [email protected]

CTS`05 St. Louis May 6th 2005

2

Contents

Introduction Related Works Handheld Flexible Representation Examples and Experiments Conclusion

Introduction

4

Why Interesting?

Prospective of popularity• Recent prominent data sharing: mobile

computing and other distributed system.

• SOAP Interoperability Connects disparate and distributed resources.

• Open Standard Community (W3C), Industry (Nokia, Sun, etc)• Binary Interchange of XML Infoset Workshop (Sep.

2003).

5

Problems

Possible performance overheads in Web services

• XML needs considerable resources for transmitting and parsing.

• Information storing in textual format

• XML’s descriptive tags and structure (increasing size)

Add parsing and transmission overheads.

Mobile environment

• Battery-constraint, limited computation

• High-latency, intermittent communication Compression of XML (GZip XML) would increase a

processing time and size of small message

6

Proposal of Flexible Representation

Purpose of Research:To design and develop an optimized communication framework preserving SOAP semantics for mobile computing.

Characteristics of research• Separate data presentation format and data content

• Loss of self description

• Saving parsing computation and data binding >> Latency Saving

High latency of cellular network

Related Works

8

Classification of SOAP Alternatives Some data don’t fit in XML serialization

: MTOM/XOP• Media data

• Standard format with compression

• JPEG, GIF, MP3

• Data that include digital signature• Binary integrity would not be preserved after serializing into

textual format Some application domains use a binary representation to

avoid verbose XML encoding. Fast Web Services/Fast Infoset, Extreme! Lab• Send pre-parse data over binary communication

9

Summary of projects

Extreme! Lab MTOM/XOPFast Web Services

Properties

Negotiation,

Binary Application Protocols

Support binary contents

GZip for XML

Target Scientific Data

Media File, Data that

includes digital signature

Java Application

(No changes on Application level)

Lack of mobile issues

QoS

Performance,

Optimized message

scheme for

in-memory representation

Fast Infoset is not interoperable,

QoS

Handheld Flexible Representation

11

Flexible Representation in general Using optimized data representation to improve

communication performances preserving SOAP semantics• Binary format stream• Negotiation• Quality of Service (reliability and security)

Imposing XML problems • Hard to address on individual message, but appears to be possible to

combine SOAP structure and binary format in stream processing. Work best for a stream

• Designed for high-frequency small messages.• Sharing message structure and WSDL information.• SOAP headers are largely unchanged.

12

Example of Filtering Data Representation

<wb:wireline>

<wb:points>

<wb:x>0</wb:x>

<wb:y>0</wb:y>

</wb:points>

.....

<wb:points>

<wb:x>100</wb:x>

<wb:y>100</wb:y>

</wb:points>

</wb:wireline>

<xs:complexType name="Wireline">

<xs:annotation>

<xs:appinfo>

<representation repType="binary“

byteOrder="bigEndian"/>

</xs:appinfo>

</xs:annotation>

<xs:sequence minOccurs="number of points"

maxOccurs="number of points">

<xs:element name="x" type="dfdl:binaryInt"/>

<xs:element name="y" type="dfdl:binaryInt"/>

</xs:sequence>

</xs:complexType>

(XML Representation) (DFDL Description)

13

Simple Scenario with negotiation1. Mobile device which is capable

of Flexible Representation initiates a negotiation with the mobile gateway.

2. SOAP message for negotiation is sent over the conventional SOAP.

3. mobile gateway responds to the negotiation request with its capability in the SOAP message.

4. response with message template/XML schema and quality of service issues.

5. agreed message format (Flexible Representation of SOAP Infoset) throughout the session.

Web Services Interface(NaradaBrokering)

HHMSGateway

MediaServer

SessionServer

SOAP over NB

RTP over NB

HHFR

Mobile Device(Camera Application)

14

Software architecture ContextHandler

• Schema Parser - Data Structure generator • Stream Reader/Writer• Context server

• Stores SOAP header of initial message (negotiation request message)

• Message schema • URI of Flexible Representation Specification(<xmlna:hhfr=“http://grids.ucs.indiana.edu/hhms/FlexRep”>)

• Each ContextBlock has a pointer to URI to Context server.

Currently, Ad-hoc scheme to store context WS-Context or any community-specific.

15

Relationship among different forms of SOAP messages and their defining context

Context Mapping

Optimized Communication

Context Generation onFirst Message : Data Structure (Schema) SOAP Header Stream(Session) Info

Preferred View on Mobile Application(In Memory version of HHFR)

XML/SOAPfor

Interoperability Optional

HHFR

ContextHandle

Context Server

16

HHFR in GlobalMMCS

1. Up-streaming the captured Image• Periodically captured images are converted

into stream using JMF library.

2. Down-streaming Video Session• Porting the conventional GlobalMMCS client

on mobile.

• Filtering the frame rate and image size.

MMAPI (JRS 135) in J2ME MIDP 2.0

17

Snap Shots

Conclusion and Future Works

19

Conclusion and future works Conclusion

• Negotiation and byte stream which is preserving SOAP infoset help to overcome possible performance overhead of mobile web services

• Help the integration of mobile device and collaboration systems in web services.

Future works• QoS Handler

• Reliable Messaging – WS-WRM• Security – Light weight security model

• Up-stream client porting on mobile

Appendix

21

Current status of 3G in the US

Cingular GPRS Cingular EDGE Cingular UMTS Verizon EV-DO

Rate56kbps (max.)30~40 kbps

120kbps (aver.)

Download:384kbps (max.)290kbps (aver.)

Upload:56kbps

Download:300~500kbps

Upload:90kbps

Coverage Nation-wide

Nation-wide (except

Montana, Dakotas and

Virginia)

Only six cities32 cities

(expensive plans)

Voice and data

-- -- Simultaneous

usage--

22

Wireless Tech. Comparison

Bandwidth Comparison of IR, WLAN and Bluetooth

Serial Infrared 115.2kbps

Bluetooth 1.1 723.1 kbps

Bluetooth 2.0 2.1 Mbps

802.11b 11Mbps

802.11g 54 Mbps

23

Handheld Messaging Service General mobile

communication framework by CGL

Provides a core pub/sub API for mobile application.• Lightweight user library

• Server-side gateway

• TCP and HTTP transport HHFR is a part

of HHMS

101

102

103

104

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

Payload (byte)

Ro

un

d T

rip

Tim

e (s

ec)

HHMSRPC

100

101

102

0

50

100

150

200

250

300

350

400

450

Number of Clients

Ro

un

d T

rip

Tim

e (m

sec

)

Pub/SubRPC

24

GlobalMMCS architecture

NaradaBrokeringXGSPClients

MediaServer

SessionServer

NB Link

RTP Link

XGSPGateways

(H.323, SIP,Streaming,

HHMS)

H.323, SIP,Streaming,

MobileClients

AccessGridVenues

WebServer

Client - GatewayCommunication