Wireless Joint

Hello everyone. New user here.
Looking for advice on a budget 4g router setup that I can upgrade as I go.

Initially I was considering buying one of the branded 4g router modem units with multiple external antenna connections, but maybe there is a better path. Teltonika was on my radar until I found out they are affiliated with Mofi (is this correct?), which has been said to have poor customer service. I also have considered products from Cudy.

My details
Service:
- have had T-mo tablet data plan for a few years
- location is a fairly dense large-ish city (planning to move rural soon)
- also have vzw service
- local towers from both have become increasingly congested, making connection speed drop to almost nothing (sub 200kbps most days)
- no landline service available to my location, except DSL, which is worse than the mobile service

Goal:
- setup a 4g router utilizing my t-mo data line
- would also like to be able to tether (either wifi or usb) my vzw phone to the router as well periodically for failover or cross carrier aggregation for better speeds
- eventually install external antennas to connect to a tower further away to get out of the congested area
- band lock, tower lock, device id options

Recently I found out that it is possible to build a cellular router from a Rpi. I have 2 Rpi4 hanging around doing nothing, so this seems like a good option.
Where I am seeking advice is would this be a more economical option after purchasing an m.2 or mPCIe adapter + 4g network card + antenna adapters + basic antenna... over going with a pre-built unit from Cudy or Teltonika which includes everything up front.

I am leaning towards the Rpi setup, as that would allow to run any software you choose, without restrictions of a particular brand's flavor of UI and user options.
Also the ability to upgrade the hardware componets as you go seems very friendly.
I could buy a decent budget 4g m.2 card now, then upgrade to a better card, or even 5g, later.

What budget 4g cards would you recommend to start with?
I would like carrier aggregation and band 66 support at least.
I've seen several complaints of Quectel having issues with T-mo recently, so maybe it would be wise to stay away from them for now? Are Sierra Wireless cards a better option?

Also does anyone have recommendations for cheap m.2 or mPCIe adapters for Rpi, and antenna + adapters.
Ideally I would like to keep the budget to under $150 total to get me started. External high gain antenna can be a future upgrade.

Thanks all!

There are a lot of options out there. I started with a WG1608 and hated it and moved on to an x86 router built from an $80 HP 260 G2 and a $40 DW5821e, which is a Quectel. With cabling and antenna I'm at double your entry, but that's the cost of cabling+antenna if you need runs that are lengthy.

The RPi build idea was nice but finding one was hard when I looked and the LTE hat was pricier than I was willing to pay. So many SBCs out there were going to do the trick but I ended up building on this HP 260 because it was laying around from ebay a few years ago. It's a vm host running proxmox with home assistant vm and a few variants of OpenWRT if I feel like flipping back and forth.

I guess my summary on this would be if you want the most expandable future build on SFF x86 and have some fun with a hypervisor. If you are worried about a brand's reputation for customer service you'll probably find that anyone selling in your price range has uhh mixed reviews. I'm not certain why mobile internet devices seem to have such an inflated value but that seems to be the case if you are looking at a Nighthawk or Orbi or anything from a brand with high marks for service.

Thank you for the advice.

eskaryo wrote: ↑Tue Jan 24, 2023 12:24 am The RPi build idea was nice but finding one was hard when I looked and the LTE hat was pricier than I was willing to pay. So many SBCs out there were going to do the trick but I ended up building on this HP 260 because it was laying around from ebay a few years ago.

I have considered an X86 box, but size and power consumption is an issue. I really would like to have a small battery powered mobile setup that can be carried around like a hotspot device. The Rpi seems ideal for that. And I already have a few of them not being used currently.
I do have a few older laptops that could be used temporarily as the X86 base. They are really old though, so not exactly the best option for a permanent setup.

As for the Rpi hat, there are the hats with integrated LTE modem. I'm not interested in those. I would like a hat with a m.2 slot for future proofing. Another issue I've found is that most of the hats out there use USB 2.0, which is too low bandwidth for higher CAT class cards I think. I know the USB m.2 adapters won't support 5g cards. That's probably due to the higher power consumption of those cards, that 2.0 simply does not have the capacity for. The 5g cards can also run at 12v I think, instead of being limited to 5v. I don't see why it would not be possible to rig up 12v supply to a card in a 2.0 adapter, though the limited bandwidth may still be an issue.

So my options right now are a Rpi hat that has 3.0, or a USB 3.0 m.2 sled.
I like the nicer integration of a pi hat, but a USB sled would be more universal. Hmmmm


I have a question pertaining to the use of USB sleds and sim cards.

If you use a basic m.2 USB adapter that does not have a sim card slot, can a separate adapter for a sim card be used via USB or another interface?
Or is it a reqirement for the sim to be integrated into the adapter with the modem card.
Also do any USB-C m.2 adapters with sim card slot exist? That would likely be the most ideal.

Yeah my power draw is larger than I'd like, though I am running on a 15w CPU while there are 6w available... I'm stationary and don't worry all that much about the power draw, except during a power outage since I have a small battery backup behind it. This is an old USFF system running a 6th gen i3.
Your rpi will be a great alternative. USB2 and USB3 enclosures both exist and work well for SSIC-based modems. Be careful of MHI/PCIE modems such as the T99W175 if you are USB. They will not work.

I have used the SIM in other slots than the 'primary' sim location. It always seems to be detected.

As for devices and enclosures - the answer is yes but there are a ton out there and I don't really have a catalog to give you

Ok. So I've been checking out that T77W968/DW5821e. That is a lot of card for the price. I can see why you chose that model.
Minor gripe, no band 71 support. I really would like to have 71, but that is not a complete deal breaker. The fact that you get a cat16 class card with 5x CA is nothing to scoff at. I was prepared to spend nearly as much, if not more, on a paltry cat6 card.
I know you said it was a Quectel card, but over all the reading I have done I don't recall seeing mention of that. Not that I am doubting, just an observation.

Although it may be a Quectel, it is really hard to pass up the value. I only hope I am not going to run into issues getting it to work on Tmobile.
There also seems to be a bit of legwork required to use this modem, as it was an OEM card designed for limited machines from Dell, Lenovo, and a few others. How much of a battle is it going to be to get this card unlocked, "rooted", update firmware, and operational on a Rpi? I see ROOter and Windows support mentioned. Hope that this will work mostly painlessly on the Rpi with ROOter. I do not have any experience with that software so it is going to be a climb regardless. I am not averse to doing a bit of work to get it going, but I also have a ton of stuff on my plate at the moment, and do not really have the capacity to take on another month long project.


I do wonder why these are so cheap. I understand part of it is corporate machines being recycled, liquidated, upgraded and the parts being sold off.
But I'm curious if there are other issues with these that have driven the price down. Such as firmware bugs, compatibility issues, erratic behavior, or overheating. Anything noteworthy I should watch out for?

Again, I really appreciate the advice you've offered.


Moving on to the USB adapter choices.. for USB 3.0 m.2 adapters, there seems to be only a handful of models out there, with multiple variants or revisions of each. Searching around the bay I found one of the smaller formfactor adapters that claims to support 5g cards with "Industrial DC-DC, 3.5A High Current design". Whatever that is supposed to mean.
I will post the link for reference, as I do not know the actual model of this sled. https://www.ebay.com/itm/383433177996
They claim to use an LDO to down convert the 5v to 3.7v, then go on the say the operational range of (m.2) is 3.3-4.2v.
Even if you supplied 2A @ 5v via USB 3.0, that's only 10w chief. Not sure which crack calculator they used to get 3.5A @ 3.7v.

BUT! I did find a USB-C sled variant!! https://www.ebay.com/itm/225094645357?
As far as I have found, that's the only USB-C m.2 modem adapter I have seen so far that actually transmits the data over the USB-C. The others appear to only use the port for power injection, and USB-A 3.0 for the data.

I did not explain before why I am looking for this option.
From what I understand, mounting the adapter with 4g/5g card remotely and running a USB extension cable becomes unstable after 12ft.
That is likely due to the resistance and low voltage of USB-A.
USB-C can push PD up to 20v (actually 48v currently, but equipment with that capability is still scarce in the market).
Theoretically, you could run a PD negotiating IC to get a higher voltage to the adapter location, break out the USB-C connection before the adapter itself, step voltage down to 5v with higher current, and it should allow for a stable connection over longer extensions.
I am saying this because I assume that USB-C adapter I linked to will not support higher voltages or even PD at all.
Hard to tell as all of the ICs on the board appear to be hidden under that large EM shield. No mention of anything about voltages or PD in the product description, so I very much doubt it will have that support. They would be sure to advertise if it did.

Anyways I am curious if anyone has tested that adapter yet and had feedback. Maybe I should post a separate thread specifically for the product as it will get lost in the noise that is this non-sense kitchen sink thread I've created.