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This may sound over ambitious and silly but I think I should just ask. Lets assume a college campus (I mean a whole campus with buildings, gardens and workshops and stuff). I am thinking around 17 Acres of land. The signal of cellular phones is full just outside the campus, but just as you cross the first building you lose it totally. And then throughout the core of the campus, you don't have any signal at all.

Now how can I do a survey of such a situation for parameters like signal strength, causes of signal drop, places where I get a much better signal etc. There has to be some methodology to do it scientifically. What equipment will I have to use, are there any pre-existing DIY designs for these?

Also once I workout the cause of the signal drop, how can I boost it. Are there any signal booster for cellular network? I am thinking DIY type, something I would build myself and learning a lot of things in the process.

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When i saw the title of your question I thought of these: boost.org/doc/libs/1_43_0/doc/html/signals.html ... – J. Polfer Aug 4 '10 at 13:30
Practically: you may not have cell phone coverage, but you probably have lots of Wi-Fi coverage, so get a Skype/GV/SIP account and do internet calling. :) – endolith Oct 11 '12 at 1:10

3 Answers

up vote 3 down vote

What phone do you have?

If it's a smart phone, chances are there is a free app that can display RSSI (signal strength). You can use this number to make a map. You'll find that buildings and trees pose the most interference, and the higher you are the better the signal. You can even come up with a 3d map if you are ambitious :) Just use a smartphone to map the RSSI or SNR.

To boost the signal, the easiest approach is to attach a high gain antenna. A Yagi or even a parabolic dish antenna if you want to get the ladies' attention. :)

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I like the idea of attaching that antenna, I should look into that. – Rick_2047 Aug 4 '10 at 12:49
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How would you attach an antenna to a mobile if it does not have the RF extension port? – Rick_2047 Aug 4 '10 at 12:57
You can't, without a lot of work. You will need to know a lot about RF. – Leon Heller Aug 4 '10 at 16:44
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On the board there is usually a circular pad that looks like a target that is also the spot where you would connect your own antenna You could attach a small pigtail (see wrt54g pigtail) . On some devices, like my Motorola Droid there is a micro SMA connector. I'm not sure if it's for the phone or GPS receiver. I've seem similar sockets in many, if not all phones I've had in the past. I leave that research up to the question asker :) – Brad Hein Aug 4 '10 at 17:50
Another idea, something I wanted to build a while ago, is a parabolic dish and position the phone's antenna right at the focal point. It would require some hardware but if you use hands free, it could be pretty sweet :) – Brad Hein Aug 4 '10 at 17:51
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up vote 2 down vote

You will need some rather expensive equipment to perform those measurements, it's best left to the professionals. Boosting the signal as you propose isn't feasible and would be illegal, anyway.

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Why would that be illegal? I am just receiving a signal and boosting it, essentially just repeating it with more power. How is that illegal? – Rick_2047 Aug 4 '10 at 8:25
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You need a license to transmit a signal on the mobile phone band, which you won't get. – Leon Heller Aug 4 '10 at 10:08
ok I should have guessed that. Was a bit sleepy while writing that comment – Rick_2047 Aug 4 '10 at 12:47
up vote 2 down vote

As has already been said, transmitting within the mobile phone bands would be illegal and will almost certainly make matters worse with your signal interfering with the legitimate signal.

Some of the mobile phone companies (Vodaphone for example) will sell you an internet connected home base station that can allow your mobile phone to "connect" to their network using VOIP if you have no coverage at your home address.

Perhaps you should take this up with the mobile network concerned and they could ask the college for permission to place a repeater on site. On the other hand the college authorities may be quite pleased that there is no coverage over the campus as it prevents all sorts of disruption to lectures from student phones ringing.

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On the other other hand, the college authorities may be quite dismayed that there is no coverage over the campus, because it will make the college less attractive to incoming students, prevent emergency calls, and make it harder for students to connect. – Kevin Vermeer Aug 4 '10 at 12:37
Well the college I am talking about is sort of a all-you-can do college. It allows for total freedom in doing you work and there are no lectures as such.(Also its the best of the brand). – Rick_2047 Aug 4 '10 at 12:50

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