Is it difficult to make a cell phone ( 4G ) ?

[ejeffrey]

If you want to make a candy bar sized device with a high performance SoC, multiple state of the art radios, full size screen, and all day battery life that's impossible.  You won't get the chips, the documentation, or the licenses.  Even if you did the development effort, production NRE, and FCC approval are well beyond a hobby project.  If you actually have the team and the budget to actually do this in large volume it won't be hard to get contacts from the chip manufacturers.

If you just want to make a device that speaks to the cell network, that is possible.  There are LTE chips and modules targeting the IoT related fields.  You may still need an NDA and seem legit to get the documentation, but its a whole different ballgame than state of the art cell phone SoCs.  It won't have the performance, integration, cost, or efficiency of what is in even a low end phone, but it can get your device talking to the network.

The best bet is to get a complete module.  In particular that will take care of a lot of the FCC licensing concerns since it will contain the whole radio stack (baseband processor, radio, filters, amplifiers, etc) and have its configuration fixed for a specific market.  Here are some hits you could have found with a quick google search:

https://www.u-blox.com/en/cellular-modules
https://www.lairdconnect.com/wireless-modules/cellular-solutions
https://store.particle.io/products/e-series-lte-module
https://www.mouser.com/ProductDetail/Quectel/EC21JFA-512-STD

None of those are going to make you a modern cell phone, but if you are actually serious about making a project that works on the LTE network, there are a lot of options.

[Bud]

@OP

Why ?

[DrG]

Kit:

https://www.makershed.com/products/ringo-diy-mobilephone

Already built:

https://www.target.com/p/skip-hop-zoo-unicorn-baby-cell-phone-toy/-/A-76474741

[SiliconWizard]

If you want to design a cell phone as an individual or a very small company, your best bet would be to use a ready-to-use LTE module.
For instance: https://www.u-blox.com/en/product/toby-l2-series?utm_source=en%2Fwireless-modules%2Flte%2Ftoby-l2-lte-module-series.html

Note that for personal use, that should be OK... maybe... but if you're planning on selling products based on this, this is another story. Complying with current regulations is a pain, and using such a module would not exempt you from doing all the testing and paperwork on your final product.

[Jan Audio]

If you want to make a candy bar sized device with a high performance SoC, multiple state of the art radios, full size screen, and all day battery life that's impossible.  You won't get the chips, the documentation, or the licenses.
...
If you just want to make a device that speaks to the cell network, that is possible.

I want a phone that you can call with, and text, nothing else, i dont mind it being big as a 80s cell phone, i would like it with handle-bar and antenna i dont mind.

no facebook
no google
the list goes on.

utopia.

[Monkeh]

If you want to make a candy bar sized device with a high performance SoC, multiple state of the art radios, full size screen, and all day battery life that's impossible.  You won't get the chips, the documentation, or the licenses.
...
If you just want to make a device that speaks to the cell network, that is possible.

I want a phone that you can call with, and text, nothing else, i dont mind it being big as a 80s cell phone, i would like it with handle-bar and antenna i dont mind.

no facebook
no google
the list goes on.

utopia.

https://www.nokia.com/phones/en_gb/nokia-225-4g

Done.

[YurkshireLad]

If you want to make a candy bar sized device with a high performance SoC, multiple state of the art radios, full size screen, and all day battery life that's impossible.  You won't get the chips, the documentation, or the licenses.
...
If you just want to make a device that speaks to the cell network, that is possible.

I want a phone that you can call with, and text, nothing else, i dont mind it being big as a 80s cell phone, i would like it with handle-bar and antenna i dont mind.

no facebook
no google
the list goes on.

utopia.

https://www.nokia.com/phones/en_gb/nokia-225-4g

Done.

From the website:

"You’ve even got essentials like Facebook..."

[Monkeh]

If you want to make a candy bar sized device with a high performance SoC, multiple state of the art radios, full size screen, and all day battery life that's impossible.  You won't get the chips, the documentation, or the licenses.
...
If you just want to make a device that speaks to the cell network, that is possible.

I want a phone that you can call with, and text, nothing else, i dont mind it being big as a 80s cell phone, i would like it with handle-bar and antenna i dont mind.

no facebook
no google
the list goes on.

utopia.

https://www.nokia.com/phones/en_gb/nokia-225-4g

Done.

From the website:

"You’ve even got essentials like Facebook..."

And it's totally impractical and you don't have to use it. Much like on any other phone, actually. There are even dumber phones, but he wanted 4G, presumably out of awareness that awful legacy standards have to die sooner or later.

[tszaboo]

And it's totally impractical and you don't have to use it. Much like on any other phone, actually. There are even dumber phones, but he wanted 4G, presumably out of awareness that awful legacy standards have to die sooner or later.

Getting replaced by equally awful standards.
I still dont get it, how could they define the LTE CAT M frequency bands like a swiss cheese from 800 MHz to 3.something GHz.

[amyk]

This question goes into the "if you have to ask..." territory.

That said, the protocol specs are available at the 3GPP site; what's not so easy is understanding them.

You can also find a lot of leaked stuff including source code if you search the right way, mostly from Mediatek and shared amongst various Chinese forums.

[bson]

The Pine64 uses a Quectel EG-25G module.  I'm pretty sure the AAEON-UP is the same: https://www.mouser.com/ProductDetail/AAEON-UP/RE-UPLTEG25GSIM/?qs=Zz7%252BYVVL6bFvuIPew%252BvNpw%3D%3D

[ejeffrey]

If you want to make a candy bar sized device with a high performance SoC, multiple state of the art radios, full size screen, and all day battery life that's impossible.  You won't get the chips, the documentation, or the licenses.
...
If you just want to make a device that speaks to the cell network, that is possible.

I want a phone that you can call with, and text, nothing else, i dont mind it being big as a 80s cell phone, i would like it with handle-bar and antenna i dont mind.

no facebook
no google
the list goes on.

utopia.

Take it one step further:

https://www.thenophone.com/

Or you could get a cheap phone and not use the features you don't want.

[DrG]

If one did want to know what goes into making a phone, I would still consider the kit posted in #27.

You can get the schematics and the code https://github.com/CircuitMess/CircuitMess-Ringo

It's been around for a while, can have 4G (SIM7600) chipset, ESP32, display and so on.  If one really wondered how difficult it is to make a cell phone, this would be a good place to start - or to put you off the idea

[Someone]

If you want to make a candy bar sized device with a high performance SoC, multiple state of the art radios, full size screen, and all day battery life that's impossible.  You won't get the chips, the documentation, or the licenses.
...
If you just want to make a device that speaks to the cell network, that is possible.

I want a phone that you can call with, and text, nothing else, i dont mind it being big as a 80s cell phone, i would like it with handle-bar and antenna i dont mind.

no facebook
no google
the list goes on.

utopia.

Take it one step further:

https://www.thenophone.com/

Or you could get a cheap phone and not use the features you don't want.

General rule: if there is a mass market consumer product that can do the job, you are unlikely to find any cheaper way of doing it, and you certainly won't be able to build or make a cheaper something that can do the job.

Dumb phones exist, they are marketed to specific users and are undesirable for the salespeople/networks as they don't drive recurring income. Australian examples below.

[james_s]

I want a phone that you can call with, and text, nothing else, i dont mind it being big as a 80s cell phone, i would like it with handle-bar and antenna i dont mind.

no facebook
no google
the list goes on.

utopia.

You know, you don't have to use features you don't want, even on a smartphone you don't have to install any apps and you can delete most of the stuff that comes on it.

You can also still buy basic phones, they're called "feature phones", they're getting harder to find because almost nobody wants them anymore but they are still available.

If you are seriously considering building one, I would suggest getting evaluated by a professional psychiatrist. Aren't you the guy who was complaining that hobbyists can't even work with surface mount components? Mobile phone chipsets are some of the tiniest most dense components available.

[gnuarm]

@Jan Audio. You're just trolling.

I think everyone in this thread is Trolling including you and I.

[Jan Audio]

Yes the network will block my working nokia dumb phone at 1 juni this year.
Those nokia telephones available now all have a camera, google assistent, facebook, all pre-installed.
I dont want those thing making use of my phone behind my back.

Did you know a regular used smartphone connects to 10.000 IP adresses within 1 hour ?
First of all i pay each month almost 7 euro, suppose that google or facebook becomes alive and uses the internet, i will be poor, they dont give a warning message if you need to pay above your normal payment,
they only send a message if i am to late with paying.

I dont believe you can remove facebook and google assistent from any phone, if it is possible show me please.
I always say : a smart-phone is for dumb-people.

Really who is using your phone the most ?, they want you to wear one at all times, because of GPS and the ban of cash money.
Some "....." people pay 200 per month, i laugh very hard.

If you are seriously considering building one, I would suggest getting evaluated by a professional psychiatrist. Aren't you the guy who was complaining that hobbyists can't even work with surface mount components? Mobile phone chipsets are some of the tiniest most dense components available.

I did not say i wanto build one (yet)
I just like to know if it can be done, i need a extra good reason to start with SMD.

[Gyro]

@Jan Audio. You're just trolling.

I think everyone in this thread is Trolling including you and I.

Yes, I think we would have all benefited from greater clarity in the OP. We would all have got off to a much better start then regarding expectations (difficult though when he talks about finding chips on aliexpress).

[cgroen]

.
I did not say i wanto build one (yet)
I just like to know if it can be done, i need a extra good reason to start with SMD.

 

[Monkeh]

I dont want those thing making use of my phone behind my back.

Good news: They don't.

suppose that google or facebook becomes alive and uses the internet, i will be poor, they dont give a warning message if you need to pay above your normal payment,
they only send a message if i am to late with paying.

Well, your provider is crap. Also, suppose your mattress becomes sentient and decides to eat you one night.

I dont believe you can remove facebook and google assistent from any phone, if it is possible show me please.

Well, there's no Facebook on my phone. No, I won't show you how to use Google.

I always say : a smart-phone is for dumb-people.

Thank you for insulting those of us who make use of tools instead of crying about them.

[Jan Audio]

Good news: They don't.

Did you not know a regular used smartphone connects to 10.000 unique IP adresses within 1 hour ?
Only you dont see, how do you know then ?, how can you be sure the telephone is not connecting to anything ?

If a telephone can only call then i am sure it wont connect to anything.

[DrG]

Good news: They don't.

Did you not know a regular used smartphone connects to 10.000 unique IP adresses within 1 hour ?
Only you dont see, how do you know then ?, how can you be sure the telephone is not connecting to anything ?

If a telephone can only call then i am sure it wont connect to anything.

How do you know it isn't 21,345 connections within an hour? If I have a slow phone will it connect to 10,000 addresses within 2 hours? If I get 5G can I connect to 20,000 within an hour?

If I store the phone in a lead box, cleverly disguised as a book, can I stop all those connections and farcebook using my camera when I turn my back? 
https://www.amazon.com/MONOJOY-Faraday-Keyless-Blocking-Shielding/dp/B07WG6F8DH/ref=sr_1_2?crid=3EJY4JWI80XRQ&dchild=1&keywords=lead+box+for+cell+phone&qid=1615651551&sprefix=lead+box%2Caps%2C150&sr=8-2

Does this have anything to do with NASA?


Yes, I am making light of your post and the thread because you have ignored all attempts at serious responses and it seems like you are either trolling or just are not interested in learning at all.

[Jan Audio]

I still wanna call, else i would buy the nophone.

[Monkeh]

Good news: They don't.

Did you not know a regular used smartphone connects to 10.000 unique IP adresses within 1 hour ?
Only you dont see, how do you know then ?, how can you be sure the telephone is not connecting to anything ?

If a telephone can only call then i am sure it wont connect to anything.

Well, unlike you, I do see, and my phone in the last 10 minutes has connected to exactly 9 IPs, two of which are within my network(s). It's got a lot of work to do to make it to 10,000.

[MK14]

Does this have anything to do with NASA?

No, you are getting suckered into the wrong/silly answer.

Obviously, it is actually the NSA, not NASA.
https://en.wikipedia.org/wiki/National_Security_Agency

On a more serious note, I'd suggest going to 1G, not 4G. Since 4G needs surface mount (ONLY) components, and too many unobtainium 320K 1% resistors.
Source:  https://www.eevblog.com/forum/chat/what-happend-to-320k-resistors/msg3472288/#msg3472288