IRIDIUM® Airtime


The Circuit Switched Data (CSD) Service supports the transfer of relatively large data volumes (tens of kilobytes) using the Iridium dial-up capability. The Iridium Data Module (IDM) places a call to the Public Switched Telephone Network (PSTN) or to another IDM then exchanges the data through that open circuit at approximately 2400 bits per second.

When to use CSD:

CSD is best suited for the transmission of large data sets, for applications with a small number of deployed platforms.

  • Bi-directional continuous communication (dial-up)
  • Average transmission power: 8W
  • Effective data rate: 10 to 12 Kbytes / min
  • Data transferred by a data call from an Iridium modem (9522B or 9523), relayed through PSTN or to another Iridium modem
  • Service is billed according to the call duration
  • Requires a SIM card (to be activated)