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The Wavix Stasia 906
Satellite Groundstation

Overview

The Wavix Satellite Groundstation, Stasia 906, used in conjunction with Wavix Satellite Services, provides satellite based real-enough time communications for transmitting e-mail or data streams. The system is completely autonomous to the user, requiring no knowledge of satellite communication protocols or special software. The groundstation includes an embedded computer so there is no software to install on the user's computer and minimal configuration to prepare the user's computer for use with the groundstation. The satellite groundstation interfaces to the user's computer via an RS-232 serial port; the user operates the groundstation through the user's own e-mail software and web browser. The system includes an omni-directional dual band satellite antenna, GPS for automatic time and position information, and a custom satellite radio that performs automatic tracking and communication with Wavix satellites. The groundstation is battery operated and can be recharged using the supplied universal AC to DC transformer or with appropriate user-supplied DC power (i.e., solar charging system, car battery, or DC generator).

Hardware Description

The standard Stasia 906 Satellite Groundstation consists of the following ten subcomponents:
  1. Waterproof, rugged container w/hinged lid
  2. Electronics Assembly
  3. Fuses - box of 5
  4. Serial cable (DB-9m to DB-9f, straight through)
  5. Power transformer & cable
  6. Quick setup check list (in lid)
  7. Satellite Antenna
  8. Satellite Antenna Cable - 15m
  9. GPS antenna and cable - 5m
  10. Instruction Manual
Enclosure

  • Custom rugged container w/hinged lid
  • Outside dimensions: approx. 13" x 12" x 6" deep
  • Customized with an inside bezel for mounting electronics housing
  • Weight: approximately 19 pounds (including electronics)
  • Sealed against the elements (no fans) with lid closed
  • Waterproof, dustproof, and crush resistant when closed
Face Plate

  • 9-pin D-connector for computer cable
  • Connector for power input from supplied transformer or other 16.0 volt DC supply
  • TNC connector for supplied satellite antenna cable
  • SMA connector for supplied GPS antenna cable
  • Power on/off toggle switch
  • Fuse holder (shipped with fuse removed)
  • Six LED indicators:
    • Charger On
    • Power On
    • Satellite Activity
    • Email Arrived
    • Attention
    • Battery Low
Electronics Housing

Designed to be enclosed in a customized case (or optionally mounted in a customized electronics rack). Provides RF shielding to minimize spurious emissions.

Computer System

  • Embedded computer
  • Built-in e-mail handling - POP3/SMTP
  • User-configurable mailbox names and passwords
  • Automatic low-power sleep mode to conserve battery energy
  • Interface to client-computer via serial port operates in PPP or bare-serial modes
Computer Control of Radio

  • Automatic tracking of satellites
  • Turns on radio only when satellites are in view
  • Satellite tracking data updated without user intervention
  • Automatic switching between designated satellites
  • Automatic Doppler frequency shift compensation
Satellite Radio

  • Custom, full-duplex digital radio
  • Operates at Little-LEO frequencies licensed to VITA
  • Data Rate: fixed at 9600 bps on uplink and downlink
GPS System

  • Updates location and time once per day or when unit is first turned on
  • Automatically updates satellite tracking program with current location
  • Automatically updates computer clock for accurate pass predictions
Power System

  • Runs on internal battery (Note: unit cannot run solely on external power sources. A minimum level of internal battery charge is required to allow for effective satellite communication.)
    • 12 Amp-hour rechargeable 12V battery
    • 16.5 Volt optimum input voltage to maximize time between charges and overall battery life.
    • 13.5 to18 VDC input (internally current limited to 1 Amp DC) for recharging batteries
    • 86-240VAC wall outlet transformer included
    • Supports alternate DC power sources for recharging, e.g., solar or car battery
  • Power conservation features
    • Radio electronics only turn on when satellite comes into view
    • Turns on at pre-determined satellite elevation for each satellite
    • High-power amplifier only on during transmit bursts
    • Computer goes to sleep when not in use
    • User can manually shut down system for long-term storage (by removing fuse)
  • Power requirements
    • Estimated at 1.4 Ah per day calculated at 13 volts:

      ModeAmpsHoursAmp-Hours
      Standby0.09642.20.212
      Receive0.47621.90.905
      Transmit7.44990.030.223
      GPS0.20620.050.010
      Sleep0.004319.820.085
      Total 241.435

    • The supplied 12 Ah battery will operate for at least 8 days (12Ah/1.435Ah/day) in the above scenario before needing to be recharged
Environmental Specifications

  • Operational temperature range: 0°C to +40°C
  • Storage temperature range: -40°C to +80°C
Antennas

  • Dual-band Uplink (Transmit)/Downlink (Receive) Antenna
    • Environmental: waterproof, dustproof, shock resistant
    • Size: 36" high x 8" diameter
    • Weight: TBD
    • Mounting: pipe threaded flange
    • Connector: TNC female to connect to supplied satellite antenna cable
  • Antenna Cable
    • Type: low loss
    • Connectors: TNC male both ends.
    • Length: 15 meters
  • GPS antenna/cable assembly
    • Mounting: magnetic
    • Environmental: waterproof
    • Connector: SMA
    • Cable length: 5m (permanently attached)
Operations Overview

Summary

Since the groundstation operates autonomously, the client computer functions solely as a user interface, data or e-mail source, and recipient of commands or e-mail. When the satellite groundstation is used as part of a remote e-mail station, it acts just like a modem connected to an Internet service provider. It is configured to operate in a TCP/IP-over-serial-line mode (PPP), and uses TCP/IP protocols to communicate with the client computer. In particular, the client computer will run one of the many available e-mail programs, which will communicate with the groundstation via SMTP (sending mail) and POP3 (receiving mail) protocols.

When the groundstation is used as a data & command transceiver, for example in a remote data-gathering platform, the client computer will typically be the platform's data system, and the serial port will be used directly: the data system will feed a stream of data to the groundstation which is then relayed to a subscriber in the format they were received by the groundstation. Also, the data system can receive from the groundstation commands that have been sent by the subscriber, in the form they were sent.

The Client Computer

When the Stasia 906 is configured as an e-mail groundstation, the user must provide a client laptop, desktop, or even palmtop computer. Older, slower computers can work just as well as newer, faster computers for this purpose, especially if the computer is dedicated to this task. The client computer can be any available computer that meets these requirements:
  • An operating system that supports use of Point-to-Point (PPP) protocols
  • An available serial interface
  • A user-supplied e-mail program (such as Microsoft Outlook, Eudora, Pegasus, etc.) that supports POP3 and SMTP protocols
  • A user-supplied Web browser that can support forms, tables, and HTTP1.1 (virtually any of recent vintage, such as Netscape Navigator, Internet Explorer, etc.)
Physical Interface

  • The Serial Interface is the standard interface to the Satellite Groundstation
  • Uses a straight-through RS-232 cable, DB-9f to DB-9m, to mate with a DB-9 female connector on the Satellite Groundstation
  • The connection and subsequent configuration of the Satellite Groundstation is handled by the Client Computer's operating system
E-mail Interface

  • All interaction between the User and the Satellite Groundstation takes place transparently through the User's E-Mail program and Web browser running on the Client Computer
  • The User composes messages, and sends and receives mail using the familiar interface of the Client-Computer programs
  • The E-Mail Client uses the SMTP protocol to pass outgoing e-mail to the Satellite Groundstation for delivery
  • The E-Mail Client uses the POP3 protocol to retrieve incoming e-mail from the Satellite Groundstation
  • All information (e.g., server address, user name, and password) necessary to configure the E-Mail Client for using POP3/SMTP will be supplied
  • The Client Web browser is used to access online Help files, monitor system operation, and perform system configuration tasks (e.g, create new user mailboxes)
Field Configuration & System Administration

  • The Satellite Groundstation is delivered in a fully configured, ready-to-use state
  • Satellite Groundstations used in a LAN or other multi-user system can be easily managed by a non-expert for performing tasks such as adding a new e-mail users or deleting unused user IDs
  • For standard Field Configuration tasks, the User will interact with the Satellite Groundstation through a web browser on the Client Computer that will provide limited access to the Groundstation's file system and configuration
  • Configuration tasks will be performed through the Web-browser interface, and step-by-step instructions for configuration tasks will be provided
  • Access to the Satellite Groundstation for Field Configuration or System Administration is restricted by password protection, and different passwords are used for the different levels of access
E-mail Addressing Scheme

  • E-mail addresses used for (and by) the User will all be the familiar Internet-standard style of address, as understood by the User's E-Mail Client programs
  • Mail addressed by the User to a person at an Internet location will simply use that person's Internet address, e.g., user@organization.dom.
  • Each Satellite Groundstation will be given an Internet node name in an appropriate domain such as gs.wavix.net, gs.vitasat.net, or gs.healthnet.org (where gs uniquely identifies each Satellite Groundstation)
  • E-mail to the User will simply be addressed as user@gs.organization.net (where the actual names for user, gs, and organization will vary)
System Status Reporting

  • The Groundstation maintains web pages to allow the user to monitor such things as upcoming satellite passes, confirmation of message transfers, and status of battery power
  • The web pages are accessible to the User with standard web browser software over the same serial link used for e-mail access
  • Wavix receives and maintains copies of Satellite Groundstation Status Reports in order to evaluate system performance and proper operation of the Satellite Groundstations
Copyright (c) 2001
by Wavix, Incorporated.