OpenBTS - Create your own personal cellphone network

floyd

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Mar 9, 2008
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I been playing with OpenBTS for a while now and my website even features on the OpenBTS site. So I want to let you guys know how much fun it is.

via http://openbts.sourceforge.net/:

" The OpenBTS Project is an effort to construct an open-source Unix application that uses the Universal Software Radio Peripheral (USRP) to present a GSM air interface ("Um") to standard GSM handset and uses the Asterisk software PBX to connect calls. The combination of the ubiquitous GSM air interface with VoIP backhaul could form the basis of a new type of cellular network that could be deployed and operated at substantially lower cost than existing technologies in greenfields in the developing world.

In plain language, we are working on a new kind of cellular network that can be installed and operated at about 1/10 the cost of current technologies, but that will still be compatible with most of the handsets that are already in the market. "

Basicly I have a cellphone network in my office for about R15 000. Here is a vid: [ame="http://www.youtube.com/watch?v=0vSG7H38J4g"]http://www.youtube.com/watch?v=0vSG7H38J4g[/ame]

I hope to get funding to implement this for rural communities in SA many whom have never had a telecoms connection. Yes I'm an engineer I know what I'm doing. I don't have plans to make money with this as it is totally (hardware and software) opensource.

If anybody wants to know more don't hesitate to reply to this thread or just pm me.
 

warwickw

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Feb 8, 2008
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This is awesome, nice going. I enjoy dabbling with Asterisk and Linux maybe this will have to be my next little project.

Some questions :

I see you're using some old cell phones for testing, was that just for testing or was there a specific technical reason to use the old phones?

What about sim cards did you have to create your own to register them to your BTS ?

If you plan to roll out to rural SA, how do yo plan to get spectrum allocated, I somehow doubt if the networks will give up their spectrum too eagerly.
 

floyd

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Mar 9, 2008
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Thanks for asking:
Q1: The USRP's (software radio) clock isnt very accurate and it was difficult to register phones. To fix this I connected an external clock (signal generator) and now thats fixed as can be seen here: http://students.ee.sun.ac.za/~gshmaritz/?p=152. Now any phone (HTC, iPhone,Nokia,Samsung,LG,Sony Ericsson) can connect and register
But I will get a new small oscillator module to make it mobile (signal generator is about 4 times the size of the usrp)...

Q2: I use normal operator SIM's. Vodacom, Cell C, MTN, Virgin even a Madagascar SIM randomly connected.

Q3: There is still a lot of channels available in the GSM 900 Band and GSM 1800. and the GSM 850 band is not even used in SA for GSM, as far as I can tell it is for cordless phones... The problem is I doubt that rural areas will have quad-band phones which are the only phones in SA which can use the 850.
 

bdt

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It's amazing what results can be achieved with the open/free collaboration model, that's just fabulous! But at what stage are you with R&D - still only a GSM-esque network in the lab, or have you (CAN you?!) taken it outside for further range? I have to know more about this! (sorry, this is my old dormant interest in light/radio electronics getting excited - it's been awhile since I saw something this interesting)
 

floyd

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Mar 9, 2008
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bdt, it's lots of fun I have enjoyed working on it. Well I think I can get a range of ~3km for about R10 000 but thats cigarette box calculations.

The guys behind it test it at burning man in the states here is the link for a write up on last year's test: http://openbts.sourceforge.net/FieldTest/index.html

Ask away...
 

bdt

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Excellent read - 2.4km at 10m mast height (yes, on wonderfully FLAT ground!) off one radio ..and the unintended consequence of a handset-army DDoS is just funny.
 

floyd

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Mar 9, 2008
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ha ha yes. I definitely want to test it out on bigger scale than the people who switch on their phones on my floor in the engineering building :)

But it is funny when they connect unintentionally.

The first time it happened was when I was still struggling with the clock and connecting. All of a sudden a random SIM registered (I wrote a small auto-registration script). I thought it was a colleague trying to use my network so I called him (number "2008"). And I immediately asked "Wies jy, waar is jy". And it was a person at a conference at the department whose iphone 2G connected.
 

floyd

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Mar 9, 2008
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OpenBSC looks silly to me. But to be honest I havent looked at it for more than 5mins.

Looks like it's JUST a BSC. so you'll need a BTS etc for it to work... money... but I could be wrong...
 

pmbellis

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Jun 7, 2006
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Interesting

Hmm. Have to admit the technical aspects are way above my head, so I won't comment there.

Questions:
1.) Long term possibilities?
a.) Data
b.) Voice​
2.) What legislation / licensing concerns would there be?
3.) Equipment, etc ... are you thinking in terms of a competitor to the current telecoms contenders, or more along the lines of a community owned/funded/driven net?
 

floyd

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Voice and sms is working. Data in the form of GPRS is coming. No plans for UMTS.

There is two licenses. One is a telecoms license (to offer a telecoms service) and other one is to use the spectrum. But I haven't looked into any of this and can be wrong.

No I'm not thinking of in terms of competition, rather to work with them to offer communities who dont have a telecoms connection to contact the world
 

kilos

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Thanks for posting - it would get an extremely positive response. Leave the nanotechnology research ;) and pursue in fine tuning this open source project something that can really benefit SA using cheaper technology to deploy. Even with licensing issues,this can be deployed in remote locations where it will not interfere with the cellular networks.
I agree on thinking on the lines of a community network servicing rural areas that are not profitable for the telecoms, typical example is this posting by Geoffrey Grundling an ex Cape Townian - now a farmer in the Laingsburg district with no cell coverage, poor (noisy) telkom phone and no dialup possible and has to using also $$$ Telkom Spacestream satellite at R1700/month for 3Gb.

I estimate that he lives in the valley between Seweweekspoort Pass and Laingsburg, plenty of high ground for Wireless links to route the Voip calls from these possibly OpenBTS base stations, back to a Asterisk PBX sitting in town connected by Telkom ISDN PRI and Possible DSL Intenet access

Using Kannel as the SMS Gateway

http://www.businessday.co.za/articles/Content.aspx?id=77016
I farm in the Swartberg between Laingsburg and Ladismith, 300km from Cape Town — hardly a remote spot.

But the Telkom infrastructure is so obsolete that my only internet access apart from Telkom dial-up (34 minutes to download FNB log-in page) is Telkom’s VSAT satellite packages. There is also no cellphone coverage. If you want VSAT with 512k speed you have to opt for the three gig per month option at roughly a mere R1700 per month.

Globally, one of the benefits of satellite connectivity is that it is invariably uncapped — not when Telkom has a monopoly.

Down the road from me is a farm school — alas with no internet connectivity — and this is unlikely to change, Seacom or no Seacom.

For rural users outside of ADSL/ broadband/3G etc reach, surely Seacom’s arrival will not change our dependence on the dinosaur Telkom — and in reality the gap between what information access costs the urban user vs the rural user will merely widen.

Surely the whole idea is to make access to information more easily/ cheaply available to the poor and rural as well?

Or am I missing something?

Geoffrey Grundlingh

Laingsburg
 
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imel

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I for one will be watching this thread with interest, can think of lots of potential uses for this technology.
 

kilos

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Yes Imel we look forward to those ideas especially with your development skills, X10 home automation integration,SMS Apps from your phone to Asterisk.

This is what comes to my mind but you will have other ideas with implementing Asterisk PBX in the Garden Route

Prepay for electricity with a wallet system in the phone,or purchase units and use them to purchase items with no money exchange, in use in Africa already using Safaricom GSM network m-pesa in Kenya, free SMS within the same cellular network
 
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tco21

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I stand to be corrected but won't your network need more than 2 licenses?
 
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