Communications Theory

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Communications Theory
Sam Majid Solution Architect/Business Manager
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Concepts

• Communication Protocols in spatial applications
• Inter-Components Communication
• Web-Mapping Concepts and examples
• Spatial databases
• Practical
• Web Mapping Tender Submission

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Communication Protocols in spatial applications

• What
• Why
• How
• Future

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Communication Protocols in spatial applications-
What
What

• Using current communication protocols to deliver
  spatial information to your target audience.
• Intranet / Internet considerations
• OLEDB, COM, SQLNET, VPN
• Target audience considerations
• Business drivers

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Intranet
What

• Typically more demanding users
• More demands for data and functionalities
• Trained and knowledge workers
• Thick clients with simple communication path e.g.
  OLEDB, ODBC, COM

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Internet
What

• Typically are general users
• Simple requests and short burst of usage
• Untrained and would easily lose interest
• Thin clients with complex communication path e.g.
  thin bandwidth, Security considerations, platform
  considerations

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TCP/IP
What

• Cons
• Verbose

• Pro
• Reliable
• Very widely supported by hardware and software
  vendors
• Medium independent e.g. WAN, ISDN, Broadband

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Data DriversOLEDB/ODBC
What

• Allows for communication between a data store and
  application
• Provides the conduit to perform SQL against a
  known schema

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Data DriversOLEDB/ODBC
What

• ODBC standard way of communication to most
  databases.
• OLEDB use vendor specific drivers to perform
  SQL with greater speed and compatibility e.g.
  retrieve spatial objects

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Data DriversOLEDB/ODBC
What

• Typical steps to use OLEDB/ODBC
• Authenticates against data store using syntax
  containing
• Hostname
• Username
• Password
• Database / instance name

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Data DriversOLEDB/ODBC
What

• What if there is a Firewall in-between data store
  and application?
• Understand your OLEDB/ODBC Drivers
• Oracle uses TCP Port 1521 to flow both ways, on
  the same port or multi-ports
• Microsoft uses xxx

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COM Interface
What

• Component Object Model
• Uses Windows API and vendor specific functions to
  communicate between applications e.g.
• GIS application in a web browser delivers data to
  a Java application running on the same PC
• Requires an understanding of the popular
  programming environments for building API e.g. VB
  .NET, C, Java
• COM relies on data drivers to process the data

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COM Interface
What

• Examples of COM interface
• Virtual Machines e.g. JVM and .NET Framework

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Communication Protocols in spatial applications-
Why
Why

• Business Drivers
• Delivering backend spatial information to target
  users
• Pushing spatial application into the mainstream
• Pushing to be business critical applications such
  as Email and Web Access

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Communication Protocols in spatial applications-
How
How

• Have your data ready
• Decide on an application platform
• Have your application scoped and developed based
  on requirements
• Understand communication protocols, network and
  security constraints

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Typical Enterprise GIS Architecture
Work Planning
Determine Work Programme
Service Providers Package Work
Create Assign Work Orders
Produce Reports
Redline Mark ups
Download Work Orders
Completed Work
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Working with Customers Darebin City Council -
Victoria
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GT Web MobileField Mobile Computing- Asset
Inspection(FMC-AI) PowerCor and Ergon Energy
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Communication Protocols in spatial applications-
How
How

• Data performance
• Is too detail a disadvantage
• too many vertices, too many colours, complex
  datatypes
• Can your data format cope with multi-user
  environments

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Communication Protocols in spatial applications-
How
How

• Decide on an application platform
• Client-data
• ArcView - SHP, AutoCAD DWG, AutoMap to Oracle
• Client Server
• ArcGIS OLEDB - SDE
• VB Jet MS Access
• Web-GIS engine
• Firefox - MapGuide - OLEDB - Database / File data
• Netscape - ArcGIS - ODBC - SDE / File data
• Mobile devices
• Pocket IE - Mobile Server - Web-GIS Engine -
  OLEDB - Database

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Communication Protocols in spatial applications-
How
How

• Application interface and functions
• Do you know what the user requires?. Documents
• Business Requirement document
• Solution Architecture
• Technical /Design Requirements
• Data requirements
• Application interface and screen designs
• User manuals
• Are you prepared ?. Do you have the tools to
  build the application?
• Testing functional, regression, security etc

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Communication Protocols in spatial applications-
How
How

• Understand communication protocols, network and
  security constraints
• What does the IT Section really want you to do?
• Application security e.g. how does your clients
  connect to your application Internet / Intranet
• Network flows
• Know how and where data is routed between your
  application to your users
• Impediments
• Firewalls, encryption protocols (VPN, IPSEC),
  badly design network topology

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Communication Protocols in spatial applications-
How
How

• Understand communication protocols, network and
  security constraints
• Need to work with the IT Section by understanding
  their concerns and policies
• for smooth implementation and security validation

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Communication Protocols in spatial applications-
How
How

• Understand communication protocols,
• Firewalls
• deliver your app via the most standard manner
  possible e.g. HTTP via the standard TCP port 80
• If non-standard, perform packet sniffing by
  understanding how the application platform
  packages your data into packets
• Mobile devices understand the mobile
  requirements e.g. can it do HTTP request, must it
  do Encryption and provide rules to the IT Section
  for Firewall managements

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Communication Protocols in spatial applications-
Future
Future

• Mainstream application
• GT Spatial Smart Tag
• Using GIS within Microsoft Word / Excel
• Web Services
• Integration with COTS
• Commercial-Of-The-Shelf
• Microsoft MapPoint

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Communication Protocols in spatial applications-
Future
Future

• Using OGC standards to perform inter-vendor calls
  for data contents
• Cross Vendor communications via WMS
• ESRI software talking to MapInfo software
• Relational spatial databases
• Oracle 10g Spatial
• MySQL / Postgres