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					                                S          P         A   C       E
                           Structures, Propulsion, And Control Engineering
                                              Center




       Faculty Advisors:                                        Student Assistants:

       Dr. Helen Boussalis     - Director                       Sergio Beltran
                                                                Alexander Alegre
       Dr. Charles Liu         -Assistant Director              Jorge Estrada
                                                                Aleksander Milshteyn




Computer Team Progress Report




                                                                            NASA Grant URC NCC NNX08BA44A
                                                                            August 20, 2009
   Distributed tuple space system
     Utilizes the capabilities of different serving computers at
      various processing levels

   Screen-scraping utility
     “Computer-friendly” tagging system


   Development of video conferencing software
Server Hierarchy
   Objectives
   Current Tuple Architecture
   Ubiquitous Aerospace Server
   Screen Scraping
   Ubiquitous Video Conferencing
   Conclusion
   Supports One Server

   Multiple Clients

   Multiple Workers

   One Database

   Not Platform Independent
   Supports Multiple
    Server

   Supports Multiple
    Clients

   Transparent to the
    Client

   Fault tolerant Capability
   Listing of information which provides details
    about an object. For our case Semantic Web
    Objects.

   Example
     Phone Book
     Domain Controller
   A specialized database that stores typed and
    ordered information about objects

   Directories allow users or applications to find
    resources that have the characteristics
    needed for a particular task.
   Will hold information pertaining to objects in
    the Database

   For Example
     Files
     Objects ( images, text excerpts, …)
     Semantic Tagged objects
     Location of data
Semantic Web
   Text editing Capability

   Scrape data from Web Browser

   Image scrapping or cut and paste

   Capability to upload and Download from a Server

   Ability to modify an create new Tags

   Written in Java (Platform Independent)
Ubiquitous Video
 Conferencing
            Ubiquitous Computing Video
             Conferencing Ubiquitous
                    Computing
    Ubicomp - Human-computer interaction that goes
    beyond desktop environment and is used in

    everyday life

    Video Conferencing – Visual collaboration between
    two or more locations. Transmits audio and video
    information cohesively in a real time, over the
    specified network.
                Objectives

   Server Configuration
   Video Encoding Selection
   Bandwidth
   Security
   UDP
 Ring Configuration
 Peer-to-Peer Configuration
 Hybrid Configuration
(globally decentralized, locally centralized)
•Node connects EXACTLY to two other nodes
• Data travels from node to node
• Single failure in any node will disrupt the whole network, making it unreliable
   Distributed Network Architecture
   Formed by Ad-hoc, addition of nodes
   Not ideal for ubiquitous videoconferencing (E.G. Multiple connections)
   Globally decentralized, locally centralized
   Model without handshaking

-   dropping packets preferable of
    delayed packets

-   error checking is not necessary

-   widely used in multicasting
                                      http://en.wikipedia.org/wiki/User_Datagram_Protocol
-   Use datagram sockets to establish host to host
    communication

-   Sockets bind the application to service ports, that
    function as the endpoints of data transmission

- Ports from 30,000 through 65,535 - used as
  temporary ports by clients connecting to servers
 RP: 30000
              Server            RP: 60000

                    RP: 50000




C1
                                    C4
TP: [40000]   C2                    RP: [40000]
              RP: [40000]
    Proposed Hybrid Setup

Infinite amount of nodes (cameras) on a distributed
video server
    Proposed Hybrid Setup

Infinite amount of nodes (cameras) on a distributed
video server
     Previous Setup

Three nodes connected
to the one centralized
Internet server
   Intra-Group Connection

Four nodes connected to one centralized SPACE Center Video
server, including one user from a different network.
   Motion JPEG                          MPEG-4
- Encodes similarly to MPEG-1, MPEG-2   - Encodes mixed media-data (video/audio)
- Maximum compression rate – 1:20
                                        - Real world compression – 1:50
- Low computational complexity
- Low group delay                       -Transforms into other types of signals
                                        - Scalable to deliver content at any data rate
   Proposed Settings:
    - 50 text-only users
    - 5 to 16 video users
(determined by bandwidth/memory calculations and real-time testing)
   Existing programs
    - Skype: 50 text-only users, 5 video users
    - MegaMeeting: text-only users, 16 video users
   Channel delivers at a lower rate than its
    nominal transmission rate



             CL = Capacity of channel          HL = Total layer-2 overhead
             PL = Packet size                  CL2 = New capacity




Example: For a 10BaseT Ethernet, C L = 10Mps, HL = 18bytes and a 100-byte
           packets the capacity is 7.24Mbps
   Calculating server bandwidth(BWs):
    BWs = (P × N) × S
    P = number of senders
    N = number of receivers
    S = average stream bit-rate of encoded A/V
    content
   Calculating client bandwidth needs (BWc):
    BWc = P × S
    P = number of senders
    S = average stream bit rate of encoded A/V
    content
   Reserve about 20% of Client’s bandwidth for other
    simultaneous applications during videoconferencing
    - email, internet browser, other downloading



   Upload speed varies from download speed on
    different networks
  User Adjustments:
1) Lower Resolution
2) Video Window Resizing
3) Close video portion. Keep audio/text intact


  Automatic Adjustment:
1) Change compression algorithms based on the need
 E.G. MPEG-4  Motion JPEG
Intra-group: requires each member of the group to
have user name and valid password
Inter-group: Administrators of two or more groups
 established connection with each other, allow their
 members to see every client involved
User who has a simultaneous access to more than
one group will NOT be able to distribute the
video/audio/text data between members of
different groups
   Set-up and integrate server communication
    with real-time video transmission

   Integrate security protocols (SSL)

   Development of screen-scraping and
    hierarchical protocol structures
                                                                2009                                                                        2010
               MAR        APR       MAY        JUN        JUL        AUG            SEP           OCT      NOV        DEC       JAN           FEB        MAR

                                                       Development of
                                                     hirearchical object-
                                                     oriented structure                                                                     Screen
Alex Alegre Research on screen scraping utilities                                         Development of Screen Scrapper Tool              Scrapper
                                                                                                                                          Integration
                                                    Development of Screen
                                                                                                                                                          D
                                                        Scrapping GUI
                                                                                                                                                          O
                                                                                                                                                          C
                                                                                                                                          Integration     U
                                                       Development of
  Sergio                                                                           Development of Ubiquitous Tuple Space Server         and Debugging     M
               Research on Ubiquitous Server        Ubiquitous Tuple Space
  Beltran                                                                                          Achitecture                           of Ubiquitous    E
                                                       Server Protocol
                                                                                                                                            Server        N
                                                                                                                                                          T
              Research of video                                                              Thread/Processor task                                        A
   Jorge        conferencing        Implementation of Audio/Video              Security         assigning for AV       Integration of client-server       T
  Estrada       mediums and                  protocols                      Implementation      protocols (Host)        algorithms and debugging          I
                  protocols                                                                                                                               O
                                                                                                                                                          N

              Research of video   Implementation
                                                                            User Bandwidth Thread/Processor task
 Aleks          conferencing       of Audio/Video    Establishing                                                      Integration of client-server
                                                                              Refinement      assigning for AV
Milshteyn       mediums and           protocols   Server Protocols                                                      algorithms and debugging
                                                                                              protocols (Host)
                  protocols

				
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