LTE Cat 4 Cell Modem Card

LTE doesn’t have nearly as much capacity as the 5G networks they’re currently building out. You will almost never see 300 Mbps on LTE due to overcrowding, but it would be a regular occurrence on 5G on a good band like N41 on T-Mobile or C-band on the other guys.

OP, I would love to see T-Mobile band support!

Hey this sounds like an interesting fun challenge. I’d love to help. I’m a Embedded Systems Engineer and I’ve personally developed a PCB for the SARA-N3 (NB-IoT). This included design and final assembly of the development board. I might also be able to get access to equipment for verification such as a VNA.

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Well count me in when you start taking orders! This was my one hang-up on moving from my current workhorse (Dell Latitude 5490) to the Framework. I just ordered my Framework so for now I’ll hotspot using my phone, but I much prefer the laptop to have the LTE directly on it. Thanks for designing this @Tim_Taylor !! Can’t wait to see the results!

@Luke_Oliver You could use this to easily retrofit a usb-c connector: Neat And Tidy USB-C Conversions For Legacy Devices | Hackaday (especially the simpler board with just the four usb2 breakout pads could possibly be directly soldered in place of the USB-A connector).

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I’m planning on restarting this project using the LARA L6, but cannot find any documentation on design, do you have any access to this?

You are going to need to request further documentation using this form from them. They will quite easily provide the reference manual and you will almost certainly be referred to the local reseller in your area. This reseller might also provide some support on getting it working. At least that was my experience while working for a company. This reseller is also the place to get your supply of modules. While working with the SARA-N3 we got easy access to 2 of those modules.

I’m still interested in doing something with this so if you are interested feel free to reach out.

Lost my framework 2 days ago… Got it back yesterday phew

I was an emotional rollercoaster. Bought 4 airtags today but can’t think of where I can hide it… The internals are very efficiently tessellated and the expansion ports are just too small.

I’ll report back once I settle on a solution. IMHO the airtag network is just about the best method of finding something there is.

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Hi. I am not an expert but somebody mentioned that existing LTE cards can be mounted instad of wifi module. Mabye this would be a solution with wifi expansion card (that i guess is easier to design)?

The issue being the antennas.

antenas for wifi, or for lte?

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Both. A Wifi antenna inside an expansion card is possible, but might not have good signal quality. There’s no buildin LTE antenna inside the Framework laptop, so you’d need to DIY something. (There’s also the problem with having a SIM slot)

Regarding AirTag trackers, as far as I know they are only compatible with iPhones but Tile trackers work with iPhones and Android phones (via bluetooth). A number of laptop makers (Lenovo, HP, ASUS, INTEL, etc.). are embedding Tile trackers in their laptops. That way you don’t have to figure out a way to attach a tracker and nobody could easily separate the tracker from the laptop. Might be a nice thing for Framework laptops. They need to be powered 24/7 so plugged in as an expansion card module might not be practical.

@Josh_Cook Sorry for the late reply but i was made an engineering manager at my day job and kinda dropped this project. I can provide you all of my altium and solidworks files if you want, just contact me at tim+framework @ 42-e.com.

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Could a link to the module and a 3d printer file for the module be provided? In that case I could assemble it myself.

For anyone interested in exploring LTE at low data rates, there are some new CAT1.bis modules getting released that are quite small and can operate using a single antenna: LTE EG800Q-EU | Quectel

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The EG800Q-EU is an LTE Cat 1 module optimized specially for M2M and IoT applications. Designed in a compact and unified form factor and based on 3GPP Rel-14 LTE technology, it delivers maximum data rates of up to 10Mbps downlink and 5Mbps uplink.

Now those are some quite harsh limits, 1MB/s in an ideal setup would only allow for emergency or remote-text sessions. (Or even sending small data frequently to a remote server)

Thanks for the link, even though it doesn’t fit my requirements. :slight_smile:

I think these might be of interest
https://m.aliexpress.us/item/2261799925220921.html

I feel like both of these could be combined to make an expansion card (though it will definitely stick out

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@Neal_shah

I had already thought of this, based on another board as it only has the 4 standard USB pins. It would be quite simple to replace that plug with a usb c type, but fiddly. I made a mock up of what it would look like. I decided not to proceed because I didn’t like the external antennas. You would have to remove the serial component on the bottom of the board, otherwise it would be too deep.

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what is wrong with external antennae? Old school is not necessarily bad

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