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Communications Characteristics

Satellite IoT links behave very differently from terrestrial networks.
Understanding these characteristics is essential when planning integrations with Viasat, Inmarsat, and Orbcomm services.

Latency​

  • GEO satellites typically add ~600–1200 ms round-trip time (sometimes higher).
  • Applications must be tolerant of delayed acknowledgements and use longer timeouts.

Bandwidth​

  • Optimised for compact IoT messages rather than bulk transfer.
  • IoT Nano (OGx): supports payloads up to ~1 MB.
  • IDP (IsatData Pro): payloads typically tens of kilobytes.

Reliability & Delivery Model​

  • Store-and-forward: messages may queue at terminals or ground stations.
  • Acknowledgements may arrive significantly after submission.
  • Retries & duplicate detection are normal parts of operation.

Cost Considerations​

  • Billing is generally tied to bytes and message counts.
  • Retransmissions or chatty polling add cost.
  • Filtering, batching, and deduplication reduce spend.

Modem-Side Characteristics​

When MAPS connects directly to IoT Nano (OGx) or IDP modems, it handles:

  • Polling for incoming messages — periodically checking the modem for new mobile-terminated traffic.
  • Monitoring satellite visibility state — tracking when a satellite is available before attempting transmission.
  • GPS location and spamming state — reading GNSS fixes and managing back-off rules to avoid excessive retries or “spamming.”
  • Configurable time window for packaging outbound data — batching messages together before uplink to reduce overhead and costs.

REST-Side Characteristics​

When MAPS connects at the REST API layer (Orbcomm / Inmarsat cloud services):

  • Handles fleets from hundreds to tens of thousands of devices by polling REST endpoints for new messages.
  • Polling and retry cycles are similar to modem-side handling but scaled to API endpoints rather than individual terminals.
  • Session and delivery tracking — MAPS tracks message IDs, dedupes across poll cycles, and manages acknowledgements.
  • Outbound Messages - Manages events bound for remote servers and batches them for delivery managed by the time window configured

Summary​

  • Modem-side integration — for remote/off-grid endpoints where the device talks directly via an IoT Nano (OGx) or IDP modem (e.g., ships, vehicles, isolated stations). Operates without terrestrial IP; MAPS handles polling, satellite-visibility windows, GNSS, batching, and back-off locally.

  • REST-side integration — for connected backhaul where MAPS communicates with Orbcomm/Inmarsat cloud APIs over the internet. Suited to centrally managing large fleets; no live GNSS/visibility unless included in payload; scales from hundreds to tens of thousands of devices.