Optimized%20Communication%20For%20Mobile%20Multimedia%20Collaboration%20Applications

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Optimized Communication For Mobile Multimedia
Collaboration Applications
CTS05 St. Louis May 6th 2005

• Sangyoon Oh
• Community Grids Laboratory
• Indiana University
• ohsangy_at_cs.indiana.edu

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Contents

• Introduction
• Related Works
• Handheld Flexible Representation
• Examples and Experiments
• Conclusion

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Introduction
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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).

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Problems

• Possible performance overheads in Web services
• XML needs considerable resources for transmitting
  and parsing.
• Information storing in textual format
• XMLs 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

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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 gtgt
  Latency Saving
• High latency of cellular network

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Related Works
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Classification of SOAP Alternatives

• Some data dont 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

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Summary of projects
Extreme! Lab MTOM/XOP Fast 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
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Handheld Flexible Representation
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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.

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Example of Filtering Data Representation
ltwbwirelinegt ltwbpointsgt ltwbxgt0lt/wbxgt ltwbygt0lt/wbygt lt/wbpointsgt ..... ltwbpointsgt ltwbxgt100lt/wbxgt ltwbygt100lt/wbygt lt/wbpointsgt lt/wbwirelinegt ltxscomplexType name"Wireline"gt ltxsannotationgt ltxsappinfogt ltrepresentation repType"binary byteOrder"bigEndian"/gt lt/xsappinfogt lt/xsannotationgt ltxssequence minOccurs"number of points" maxOccurs"number of points"gt ltxselement name"x" type"dfdlbinaryInt"/gt ltxselement name"y" type"dfdlbinaryInt"/gt lt/xssequencegt lt/xscomplexTypegt
(XML Representation) (DFDL Description)
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Simple Scenario with negotiation

1. 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.

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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
• (ltxmlnahhfrhttp//grids.ucs.indiana.edu/hhms/Fl
  exRepgt)
• Each ContextBlock has a pointer to URI to Context
  server.
• Currently, Ad-hoc scheme to store context
• ? WS-Context or any community-specific.

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Relationship among different forms of SOAP
messages and their defining context
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HHFR in GlobalMMCS

• Up-streaming the captured Image
• Periodically captured images are converted into
  stream using JMF library.
• 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

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Snap Shots
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Conclusion and Future Works
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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

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Appendix
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Current status of 3G in the US
Cingular GPRS Cingular EDGE Cingular UMTS Verizon EV-DO
Rate 56kbps (max.) 3040 kbps 120kbps (aver.) Download 384kbps (max.) 290kbps (aver.) Upload 56kbps Download 300500kbps Upload 90kbps
Coverage Nation-wide Nation-wide (except Montana, Dakotas and Virginia) Only six cities 32 cities (expensive plans)
Voice and data -- -- Simultaneous usage --
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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
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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

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GlobalMMCS architecture