Arduino Cell phone repeater / signal booster

I would like to build my own cell phone repeater or signal booster and I was wondering if any one had tried this. I have no idea where to start or if this is even possible.

Any help would be great

edwardhensel:
I have no idea where to start

Google would be a good starting point.

edwardhensel:
or if this is even possible.

Given that you apparently don't want to simply buy one, you'd need to understand how they work and then design and build one. This seems to be mainly an RF project rather than an Arduino one. Given the "no idea where to start" I guess you don't know how cell phones work in which case it's probably not a realistic project for you. In any case, I don't see this as an Arduino project.

Any signal booster or repeater would have to operate on frequencies owned by your cellphone provider (or the company they lease from), so you would need permission to use them.

edwardhensel:
I have no idea where to start or if this is even possible.

Unless you live in an extremely remote area, or in a country with no law, the best place to start would probably be with the government communications regulator. The conversation is likely to be quite short.

Main problem with this project idea is you would need formal 'type acceptance' (at least that's what it is called in the US) from the government's RF spectrum manager (again, in the US that's the FCC). You are talking about transmitting in regulate spectrum.

If the FCC takes notice of your transmitter, they can and usually do issue stiff fines (a Notice of Forfeiture) in the $10,000 range.

The other RF devices you see used with Arduinos or by hobbists in general are in specifically-allocated spectrum for general unlicensed operation.

Boy I just love it when your looking for help on here all you find is assholes. I apologize for us nerds that have a lack of social and communication skills. I spent half my time in school keeping them from getting beat up..and still nothing in return
First thing would be to figure out what frequency your phone is running/transmitting and receiving. this can be done with a google search of your carrier. second is to do as I am doing and figure out how to build an amplifier for that general frq.(I need 1900mhz) Hope this helps you some...best I could do for now...still learning what all can be done with this amazing little board.

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DeBoe75:
Boy I just love it when your looking for help on here all you find is assholes. I apologize for us nerds that have a lack of social and communication skills. I spent half my time in school keeping them from getting beat up..and still nothing in return
First thing would be to figure out what frequency your phone is running/transmitting and receiving. this can be done with a google search of your carrier. second is to do as I am doing and figure out how to build an amplifier for that general frq.(I need 1900mhz) Hope this helps you some...best I could do for now...still learning what all can be done with this amazing little board.

Not sure if that was directed at me, but it really IS a serious matter to be aware of and steer clear of. The FCC is rather mercenary and heartless when it comes to infringing on their spectrum allocations.

DeBoe75: mind your language.
I have deleted your first outburst.

What you want to do is

  1. beyond the capabilities of an arduino (unless you really did want 1900mHz)
  2. illegal in most jurisdictions
  3. beyond your capabilities.

AWOL:
What you want to do is
...
2) illegal in most jurisdictions
...

More specifically, entirely illegal in all areas where there are jurisdictions. :smiley:

Why would you tell someone they can't do something because of lack of knowledge? We all come here to learn something. We all start out knowing nothing.
It is not illegal to make a signal repeater in the US. Every carrier has agreed that you can use their spectrum to boost your cell service. All you have to do is tell them you did it!
All you have to do is call and have your account marked that you have a booster.
Not illegal.

Now for those of you kind enough to share some wisdom, what is the best way to build your own signal booster? ~$500 to buy something pre-made is ridiculous. Especially for $30 in parts (at least it appears to be very inexpensive parts).

Thanks!

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It is not illegal to make a signal repeater in the US.

It may not be illegal to make, but it would be illegal to operate.

(Would it be too much to ask why you necroed a three year old thread?)

~$500 to buy something pre-made is ridiculous. Especially for $30 in parts

The physical parts maybe (though unlikely).

What about the software?
Have you budgeted for software?
Have you budgeted for FCC certification?

(Your ISP is also a wireless provider - ask them about certification and type approval)

jadericdawson:
Why would you tell someone they can't do something because of lack of knowledge? We all come here to learn something. We all start out knowing nothing.

OK, let's put it this way. From "I have no idea how to do this" to "I know what to do" is about a three year full time University degree course. By which time you will discover that you do not have the test equipment to make such a thing, and buying it would cost north of $10,000. What is more after the three years you would know that you could not do this legally without another $40,000.

It is way beyond what you could learn from forum replies. This is why we say this can not be done due to lack of knowledge. From your answer it would seem you lack this knowledge as well.

Using a cheap Software Defined Radio you can learn everything needed to build a cell phone repeater in less than 3 months. Much of what you learn in a 3 year degree course will be irrelevant - so why waste your time?

Google 'Arduino Cell Phone 4G LTE Signal Booster / Repeater / Femtocell' for current projects.

As far as legality is concerned, if your transmitter only reaches a distance of, say, 5 metres, who is going to care what you do?

Using an expensive SDR such as the LimeSDR + an Arduino it's almost plug and play. Currently, development in this field is fairly rapid so do search again in a month's time.

As far as legality is concerned, if your transmitter only reaches a distance of, say, 5 metres, who is going to care what you do?

So someone who's definition of legal revolves round the probability of being caught. At what probability rate does murder become legal.

Much of what you learn in a 3 year degree course will be irrelevant - so why waste your time?

Because you do not know what is relevant and what is not.

Why dig up this thread from over a year ago to make such stupid comments?

The point is that a low power transmitter at 800mhz i.e. 0.5 watts will do no harm. The whole LTE telecoms industry is starting to open up since about 2 years ago with 'democratisation' of the airwaves. I know this as I talk to some of the head honchos in BT, EE, Facebook, LimeMicrosystems etc. These people certainly do not consider me to be stupid or anything akin to a murderer !

As for the degree education . If someone is considering a particular course they should research it very carefully as electronics degrees may well only have a couple of days RF tuition in the whole 3years and you'll never get to use a spectrum analyser / signal generator etc. It's also likely to be horrendously out of date. I know this as I talked to a recent EE graduate. Instead you'll be bombarded by a huge amount of math and course work which will take up all your spare time and actually prevent individual research into RF etc.

One of the leading figures in the field at the moment is Michael Ossman ...... check out his work eg HackRF and YouTube videos. Very inspirational and no 'qualifications' in EE.

These people certainly do not consider me to be stupid or anything akin to a murderer !

Maybe not, but that is how you come across here.

The whole LTE telecoms industry is starting to open up since about 2 years ago with 'democratisation' of the airwaves.

They have been saying that for the last 30 years. The regulation concerning RF emission hasn't changed in that time.

As for the degree education ........

I know, in the UK this is crap. Successive governments have created a baby minding service, that is why I got out of higher education in 1998 after 21 years lecturing in Physics and Instrumentation.

But you seem to be great at missing the point. This thread started in 2013, it is dead, and you have nothing sensible to say.

Well, Grumpy, I'm glad we agree on something! I actually ditched my engineering degree after the second year because it was such rubbish. It seemed utterly pointless unless I was going to go into middle management.

I am a very religious person and believe strongly in the principle of Resurrection and the google algorithms seem to agree with me!. The original post says:

'I would like to build my own cell phone repeater or signal booster and I was wondering if any one had tried this. I have no idea where to start or if this is even possible.'

To answer the question: yes I've tried it and succeeded and if you want to try it yourself all the necessary info is documented here:

All open source.
I'm also using a limeSDR to do the same thing which is still work in progress and documented here:

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