What do you need to build an Iridium 9704 product?
Series Building with the Iridium 9704 Part 1 of 10
In short
Three parts: the device, IMT CloudConnect delivery and your own server.
SBD messages can be delivered to email, so getting a first message through is easy. The Iridium® Certus® 9704 uses Iridium Messaging Transport® (IMT®), which works differently: messages arrive as JSON in Amazon SQS queues inside the customer's own AWS account, organised by Topic. A 9704 product therefore needs three parts working:
| Part | What it involves | Where teams get stuck |
|---|---|---|
| Device | The 9704 module, a host processor, antenna and power; firmware for the JSON serial protocol, sending, receiving, storage, retries and power saving | A 100 KB message does not fit in a small memory; current peaks during transmission; the product must be certified |
| IMT CloudConnect | Queues and cross-account permissions in AWS for each Topic, so Iridium can deliver messages and collect the ones you send to devices | Topics must be requested from a provider first; queue and permission setup; message format and checksums |
| Your server | Collect messages from devices (MO), send messages to devices (MT), track delivery, keep the data | What to do when a device is asleep; when to ring again after a failure; managing many devices |
Debugging is the hard part when all three are new
When none of the three is stable yet and a message does not arrive, it is hard to tell whether the firmware, the queue setup or the server is at fault. Small teams often lose the most time here.
Develop in stages
- Firmware first: use IMT CC as the back end, send and receive from the web console or an API tool, and focus on making the device solid.
- Then the server: once the firmware is stable, have your server call the same API. Nothing changes on the device.
- Then the product: freeze the hardware, certify it and go to production (see why 9704 products need certification).
Sources
- IMT message size (1–100,000 bytes), JSON delivery to Amazon SQS in the customer's AWS, Topic-based queues, cross-account authentication: Iridium, "Iridium Messaging Transport (IMT)".
Do I need all three parts just to build a prototype?
With IMT CC, N3D runs the cloud delivery, and during development the web console can stand in for your server.
Do I need my own AWS account?
Yes if you connect to Iridium CloudConnect yourself; no with IMT CC, where N3D runs the cloud queues.
Can I reuse my SBD back end?
No. SBD and IMT are delivered differently: SBD devices use SBD CC, the 9704 uses IMT CC.
All parts in this series
From developer kit to certified product: what an Iridium 9704 product needs, the limits of the developer kit, why certification matters, how to choose hardware, where it fits, and measured timing and power. Ten parts, in order, each readable on its own.
- What do you need to build an Iridium 9704 product?
- What problems does IMT CC actually solve?
- What are the limits of the Iridium 9704 Launch Pad?
- Why do 9704 products need certification, and what does it cover?
- Who is the RockBLOCK 9704 for?
- Launch Pad, N-9704, RockBLOCK 9704 or your own design: which should you choose?
- Where can the IMT 9704 be used? Mountain rescue, maritime and monitoring
- How should power be designed for the 9704?
- Why can an IMT message take several minutes?
- How does the Iridium 9704 compare with Starlink and OneWeb?
Related notes
Related hardware
Related services
Updated 2026-10-27
N3D supplies satellite communication for alpine and industrial use. See services