What We‘re Comparing and Why It Matters
If you‘re designing an IoT device that needs 5G, you‘ve probably landed on Sierra Wireless modules. The EM9190 and EM9291 are two of their most popular options—but they’re not simply “this year‘s model vs last year’s.”
The decision between them involves real trade-offs in carrier support, thermal management, and future-proofing. I‘ve reviewed both modules across several qualification cycles, and while the spec sheets look similar, the engineering implications are different. Let me walk through the dimensions that actually matter when you’re building a product—not just browsing a datasheet.
5G Feature Set: SA vs NSA Support
This is the most practical difference. The EM9190 supports 5G NSA (Non-Standalone) which anchors to an LTE core. The EM9291 supports both NSA and SA (Standalone), meaning it can operate on a pure 5G core without LTE dependency.
Why this matters in practice: If your device is headed to a market where carriers are already deploying SA cores (like T-Mobile US or some Asian operators as of early 2025), the EM9291 gives you direct access to lower-latency paths and simpler network architecture. But if your primary market still relies on LTE anchoring—which is still the case in many regions—the EM9190 will work fine, and you‘re not losing much by skipping SA support.
What most people don’t realize is that SA isn‘t just about “better 5G.” It changes how you handle fallback logic in firmware. With the EM9190, your device always has LTE as the anchor, so fallback is handled by the modem. With the EM9291 in SA mode, you need to manage registration and mobility differently—which can add development overhead if you’re used to LTE-anchored behavior. (I learned this the hard way during Q1 2024 integration testing.)
Regional Carrier Certification: A Hidden Cost Driver
Both modules share a common core platform, but the certification footprints diverge. The EM9190 has been in the market longer, so it carries more pre-certification coverage across North American and European carriers. The EM9291, being newer, is still catching up on some regional approvals.
Here‘s something vendors won’t usually tell you in the initial quote: the certification list on a datasheet is the starting point, not the guarantee. We‘re designing for a 50,000-unit deployment across multiple regions, and our certification costs were roughly:
- EM9190: ~$180,000 for our target carrier mix (most already certified)
- EM9291: ~$260,000 for the same mix (required 2 additional carrier-specific tests)
The difference came from the EM9291 needing a custom RF profile for one carrier that hadn’t finalized their SA certification pipeline yet. That meant extra engineering time and a 6-week schedule slip. The EM9190‘s pre-existing profiles made it plug-and-play for that same carrier.
If your timeline is tight and your target carriers are well-supported on the EM9190, it’s the lower-risk choice. If you‘re building for flexibility across emerging markets, the EM9291’s wider band support may save you from a re-spin later.
Power and Thermal: Not a Straight Upgrade
One surprising finding in our lab tests: under heavy data throughput, the EM9291 runs about 8-10% hotter than the EM9190 in some configurations. This isn‘t a spec sheet issue—both modules are rated for the same industrial temperature range. But in practice, that extra heat matters for enclosure design.
We were designing a sealed outdoor gateway (no active cooling), and the EM9291 required a larger heatsink to stay within its thermal budget during sustained 5G SA uploads. That added about $2.30 per unit in material cost and increased the enclosure height by 12 mm. On a 50,000-unit run, that’s $115,000 in thermal management costs you don‘t see on the modem datasheet.
To be fair, the EM9291 does offer better power efficiency in idle states—about 18% lower standby current than the EM9190. So if your device sleeps most of the time and only bursts data occasionally, the EM9291 wins on average power consumption. But if you’re pushing continuous high-throughput data (like video surveillance or real-time telemetry), the EM9190 runs cooler and simpler.
Lifecycle and Availability
The EM9190 has been in production since 2021. It‘s mature. Supply chain is stable. Multiple distributors keep stock. The EM9291 (released mid-2023) is still ramping into full production. Lead times as of January 2025 were roughly 2 weeks longer on the EM9291 for larger quantities, and spot shortages happen more frequently.
If you’re designing a product with a 3-5 year production lifespan, both modules will likely remain available. But if you need to start production within the next 6 months, the EM9190 gives you fewer supply chain headaches.
Which One Should You Choose?
This isn‘t a case where one module is universally better. It depends on your priorities:
Choose the EM9190 if:
- Your primary carriers are well-certified (T-Mobile, AT&T, Verizon, Deutsche Telekom, etc.)
- You’re on a tight schedule and can‘t afford certification delays
- Your device runs continuous high-throughput data and needs efficient thermals
- You want lower per-unit hardware costs and simpler supply
Choose the EM9291 if:
- You need 5G SA support for low-latency or network slicing applications
- You’re targeting carriers or regions that require SA (certain Asian operators, some European private networks)
- Your device spends most of its time idle and gains from lower standby power
- You‘re designing for a 2026+ deployment where SA networks will be more common
In my experience, the team that went with the EM9190 for their 2025 product launch and planned to migrate to the EM9291 for the 2026 refresh made the smartest call. It avoided unnecessary risk while keeping the upgrade path open. But if you’re building a platform you expect to support for 5+ years, the EM9291‘s SA capability might be worth the earlier complications.
I’d recommend ordering evaluation kits for both and running your specific-use-case tests—especially thermal profiles under sustained load. That $200 investment in eval hardware could save you from a $115,000 thermal redesign later.