LTE Cat 4 Cell Modem Card

However, this of course assumes similar order amounts per patch which we were having!

Out of curiosity: Are the parts that expensive? I found a reseller of the EG95-module for 58,61ā‚¬/pc. excl. VAT.
Or were they hard to work with due to a lack of documentation on the suppliers part, leading to a massive amount of testing material and effort costs?
Your comment about the missing resistor lets me assume itā€™s the latter ā€¦

Thereā€™s a lot more that goes into the price than that, all the other parts, loading fees, PCB board manufacturing, etc. It all adds up. If you want a cheaper place to buy that module, try sourcing it here. Or try contacting Quectel directly.

Nope, the documentation is good. Iā€™m just inexperienced in board design :wink:

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I just assumed, after researching this module, it to be the biggest cost factor. As there are whole brandnew LTE Smartphones available for as little as 43ā‚¬ (Zte Blade L9 1Gb 32Gb 5" Dual Sim Grau 6902176061769 6902176061769 | eBay), I was quite surprised to see the LTE-module for this one already being that priceyā€¦

Thanks for the link to the cheaper supplier. For now, I have other projects lined up, but I might come back to this one later, once Iā€™m done with those.

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Phones have been cheaper than equivalent standalone modems for quite a while now.

I am not 100% sure why but it probably has something to do with volume, integration and demand.

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It looks like the site is down now. Does anyone have a mirror of the repository? Iā€™m looking into fabricating a board for myself.

You mean jacob.eva/opencom-lte - opencom-lte - Git - Liberated Embedded Systems?
Itā€™s up for me.

-ah, it seems the site is inaccessible with Cloudflare WARP enabled. Sorry about that. Working on my regular home network. Thanks!

Personal Iā€™d rather stick with 4G. Depending on the type of 5G it has issues penetrating buildings. especially the mmwave variant. Itā€™s also a power hog. Consistently I turn it off on my phone because I get hours more with it disabled.

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Cell signals are in 3 main layers (this applies to both 4G and 5G but is more extreme with 5G):

Low-Band: Amazing range, ok speeds. Great for rural areas.

Mid-Band: Good balance between speed and coverage. Great for cities.

High-Band: Insanely fast speeds, insanely horrible coverage and struggles to go through solid objects. Great for areas where people are super densely packed like stadiums.

5G Low-Band is around 20% faster than 4G with the same range and building penetration. 20% isnā€™t nothing.

5G Mid-Band is often around 7.5x the speed of 4G Mid-Band. The signals that 5G Mid-Band uses tend to have slightly worse range/building penetration than Mid-Band 4G when using equivalent equipment, however 5G brings much better support for beam-forming equipment on Mid-Band (concentrating the signal in the directions that users are located to boost range and penetration). In practice 5G Mid-Band sometimes has better range than 4G Mid-Band.

5G High-Band (aka mmWave 5G) is the absurdly fast type of 5G that absolutely dwarfs even High-Band 4G. But the range is terrible. Only a handful of carriers have bothered with this so far and only one carrier (Verizon in the US) has actually tried to do extensive outdoors deployments of it. Most deployments are in stadiums or other crowded buildings.

People talk about 5G High-Band for having horrible range and 5G Low-Band for having speeds barely faster than 4G, however really it is 5G Mid-Band that matters a lot as it makes a huge difference.

5G is only a power hog on devices that implement it poorly.

5G supports a feature called dual connectivity (also referred to as NSA mode). Dual connectivity means that a device is connected to both 4G and 5G simultaneously to get the performance of both combined. But dual connectivity also gets the power consumption of both combined so devices are supposed to only connect to dual connectivity when doing something that will benefit from having the speeds of both combined. Unfortunately some devices latch onto dual connectivity and stay connected, leading to poor battery life. But I encourage you not to blame 5G for the failings of your phone manufacturer.

For a long time Apple had an amusing bug where iPhones would outright refuse to use dual connectivity normally on certain carriers but when someone turned on Low Power Mode it would connect to dual connectivity and drain the battery more.

Dual connectivity has gotten a bit of a bad reputation due to how most carriers used it when first rolling out 5G (and many still use it for this today). When first rolling out 5G many carriers didnā€™t support all the critical features of cellular networks on 5G, most didnā€™t support calls and many didnā€™t support uploading data over 5G (only downloads), so the carriers would roll out 5G but set it to require dual connectivity in order for devices to connect to 5G. That way anything that the carrier didnā€™t support on 5G they could route over 4G.

The problem is that it is complicated to support dual connectivity between 4G Low-Band and 5G Low-Band, so carriers with 5G Low-Band had dual connectivity setup with 4G Mid-Band. This meant that dual connectivity could not be used if outside of range of 4G Mid-Band. So if someone was within range of 5G Low-Band but had no 4G Mid-Band signal and the carrier required dual connectivity to use 5G then the user would be unable to connect to 5G despite having a 5G Low-Band signal. So as carriers began to roll out 5G that could operate on itā€™s own (aka Standalone) without 4G dual connectivity that resulted in a lot of articles talking about how 5G that canā€™t function on its own is a bad thing, leading a lot of people to assume that dual connectivity (5G that isnā€™t (big difference from canā€™t) functioning on itā€™s own) is also a bad thing, which isnā€™t the case (it can be good to bond 4G and 5G together to get faster speeds).

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Iā€™ve had two phone with 5G. Samsung Fold 4 and Pixel 6A both on T-Mobile and ATT which I just tested over the last few months. I wanted to be certain I was happy with performance going from T-Mobile to ATT. So I tested both phones in my area for the last couple months. In both cases 5G is not great when Iā€™ve been inside. 4G consistently has been solid across the board. Uncertain why we need to mess with 5G when there is these inconsistencies still. The information to provided was good. But honestly it supports my idea that we should go with 4G.

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Iā€™d like to order a modem for my framework laptop if youā€™re taking orders!

See here

Send me a DM and I can help you manufacture one.

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Iā€™ve now decided Iā€™m going to sell these with some BOM optimisations, and as I can get the EG95 module for under 35 USD, I should be able to sell these for 100 USD, maybe a bit more. If you are interested, send me an email at orders@i2claboratories.net or send me a PM here and we will work something out.

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How did you get it down to that level of cost? And how would the specs differentiate vs the original?

I have contacts directly to the manufacturer, and in Quectelā€™s words, ā€œdistributors like Digi-Key and Mouser tend to create their pricing for modulesā€. Iā€™m making the performance likely better due to bad PCB design practices, and using better cost-optimized parts so there is no negative difference in specs.

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Well, let me know when you start selling them.

Update:
PCB updates are all done, currently waiting on a final quote and lead time from Quectel and anyone who had emailed/PMed me should get a reply once Iā€™ve received that info. The 100USD total cost I mentioned earlier will be quite accurate, as my total costs ended up slightly cheaper than expected.

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Semi-serious question, why a LTE cat 4 card vs just tethering to your cell phone? Will a Cat 4 card have better antenna, and thus better chance of good reception?