Cheapest module

What is the cheapest module you know of that has PTCRB certification compatible with Hologram?

What technology? 2g? 3g? LTE/M1? Do you have an idea on which carriers you want to do end device certification with? I ask because Verizon does not require PTCRB but does require GCF, where I think T-mobile and AT&T require PTCRB.

A word of caution from someone who learned the hard way chasing cheap module cost. Go with what is easiest to certify / integrate, not with what is the cheapest per unit cost.

Depending on your end device design FCC testing can be $2-10k, PTCRB end device certification (thats right, the module alone isnt sufficient, you will need to perform additional testing on your end device) can be ~$10-20k, and if the carriers require additional certification those can be $5-50k depending.

You will need to check all those boxes to be 100% compliant with all regulations for just the US. Add CE / IC if you want to do Europe and/or Canada as well.

That being said, look at Verizon Approved Modules and ATT Module Catalog (excel download). For a list of modules that should be easy to get approved by those US carriers.

I originally went with an old 2G SIMCom module (SIM800H) but realized scope of end device certifications and then went with U-Blox SARA-R4 series modules which have much better documentation, support, and fine print in their certifications. Of course they are 4-6x more expensive than the SIMCom 2G but we will easily make that back in reduced certification costs.

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Im interested in M1 , because it seems the most cost effective.

Im debating goiing with a module and getting ptcrb verification or going with an “end device” that already has ptcrb certification.

Im trying to find a cost effective “end device” like:

Essentially the skywire is really just a breakout for the underlying module, but they paid for ptcrb certification so they get to rip you off.


Yea that all depends on volume, that Skywire module is based on the Quectel BG96-NA which is ~$35-17/ea depending on volume (~25-1000 units between those two prices). The Skywire is about $79.00 ea qty 1. So you are paying $~45/ea premium. If using the skywire eliminates $45,000 in compliance testing and your initial volume is < 1,000 then they are actually cheaper.

Also think about cashflow for your company. Even overpaying to use the skywire in the long run may be ok if it means you dont need a “huge” initial investment up front. Its easier to build a rev 2 of your product after you’ve sold say 2,000 units, demonstrated the marketability of your product, fixed any bugs and then drop $80k in certification costs to use a module for the next 10,000 units. If your market is small or grows slowly, then you may be glad you didn’t drop $50k+ up front and just spend it slowly in Skywire markups. Does that make sense?

Also since the Skywire is basically the Quectel module inside, most of your firmware / board design / analysis / etc will apply if you just drop a Quectel chip directly on your PCB in place of this modem in the future.

If you have your heart set on going with a module, I would go with Quectel or U-Blox. They have the best documentation and will be easiest to go through end device certifications.

What do you think about the IMS2 from WNC for at&t fro $10 a piece?

I looked at those and found them difficult to procure, although “cheap” the only way I found to buy them is to fill out AT&T’s online form which just goes into the void. I filled it out, got no response. I am guessing their pricing has some pretty large minimum order quantities as well.

Verizon has a similar program where they heavily discount modules (SARA-R4 for like $9.50) but require volumes of 5-10k+.

My advice still stands, go with what is easiest to get started with and get certified with. I would get your R&D done and get your product to market and then cost optimize. Pricing will always go down with volume so even if your product is barely profitable or even loses some money on the first X number of units, you can easily fix that down the road.

If on the other hand your product is only viable with a $8-12 module and no certification costs, then it might not work out.

for the IMS2 you will still have to do FCC, PTCRB (end device) and maybe additional AT&T testing for antenna efficiency. So the IMS2 saves you money on module costs but not on certification costs. I would sit down and put together an exhaustive list of the costs you need to go to market. I think you are only looking at one small slice.

You make a good point, but I did the math and it makes more sense for me like this, unless there something in the $20-$30 range.
The IMS2 is readily available from Avnet. They also have a development kit which I tried.
I have been able to get decent support through Avnet/WNC.
My goal is to make a device like the skywire:

get the certification, and then use it in different devices.
I studied the PTCRB documents. What they call the PPMD document. Basically a device that meets the criteria of they call an “end product” can be reused in different products without further certification,
I have a quote for PTCRB testing at $5,250.
FCC I personally dont need as I meet the exclusion in
15.103 Exempted devices:
(a) A digital device utilized exclusively in any transportation vehicle including motor vehicles and aircraft.

The truth is I dont really get why the manufactures themselves dont make the modules like the skywire and thus help the small businesses avoid the whole PTCRB…


Interesting. I don’t remember seeing them on AVNet when I looked, but i guess that was about 6 months ago.
I’d be very interested what you think of those modules. Im glad to hear your getting decent support from them too. I struggled getting support from SIMCom.

Certification can definitely be a rabbits hole and I am definitely no expert, but I don’t see how Skywire (or similar devices) can really call themselves PTCRB certified without specifying an antenna or list of antennas. (I know the skywire spec specificallly says “all certified antenna doesnt matter” but I look at and say they have radiated power and sensitivity requirements as part of the PTCRB testing. To get TRP / TIS you need an antenna (well to pass them you do).

I agree, I don’t know why the manufacturers don’t supply their own version of the Skywire with at least as much certification and hand-holding is feasible or at least give a good reference design for an end-device so users can go in to testing with confidence they wont fail. I guess some would say their dev-kits fill this role, but no one would put a $140 3x4" PCB in their end device.

I think it would be great too if Hologram could write some white papers or blog posts about details of the certification process they went through for their Dash / Nova and give some highlights / lessons learned / common misconceptions / etc. I bet certification is one of the biggest hurdles to their customers, atleast those that will have moderate volume. I know its the biggest pain for us.

@Maiky do you guys have something like this already I am just not aware of?

Anyway, best of luck!

Hey @AndrewGifft Andrew, thanks for the valuable information here. Loving this thread.

Cellular certification’s different standards and levels varying by country and carrier can certainly be confusing. Even within the industry, there are discussions to clarify PTCRB module certification vs. PTCRB testing with a device that includes a pre-certified module through a different certification title. We’ve found the best way when building a cellular IoT product is to find a good test house provider who can walk you through the nuances to make sure your product and organization are covered. If you’re looking for an introduction to the facility we used for the Hologram Nova products we’d be happy to connect you.

I’ll see what I can do about getting information on our personal certification process for the Dash and Nova.


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