You are probably at this page because you aren’t getting decent bandwidth and response from your mobile broadband connection. It’s worth noting that even if you use the most expensive ways of boosting the signal you may still receive poor bandwidth and response. This is because there is only so much data that can be carried on the frequencies available, so at times of heavy usage (particularly when there is also heavy phone usage as 3G shares the same radio waves) it doesn’t matter what you do, mobile broadband (or midband as it should really be referred to) will not work well.
Now I have dropped that bombshell I will list the ways of boosting the signal:-
1. Purchase a signal repeater. This comprises of a box which can sometimes be stuck to the window with suction cups for strongest signal. It will boost the frequency range you mobile broadband provider uses (and also other providers frequencies if it is an illegal device) on the way to your 3G modem. Typically these provide 60 – 70dbi of gain and cost several hundred euro.
2. Purchase an antenna which can be mounted in or outdoors (obviously outdoors will work better), being careful to restrict the length of coaxial cable used to connect to the modem, as the longer the cable the more resistance there will be and the more signal lost. If using a USB modem you can mitigate this by using a long USB cable to locate the modem closer to the antenna keeping the antenna cable as short as possible. It’s also worth noting that even if your mobile broadband modem doesn’t have an external antenna connector (or it is hidden internally like in a Huawei E220) you can still use a “magnetic coupler” to connect, see Panorama Antennas for more information. Typically these antennas are relatively low gain at 9 – 12dbi and between €50 to €100.
3. Use a small mountable antenna, these are little more than ornaments providing 2 to 3dbi and costing around €25. Save your money.
In addition to these off the shelf solutions there are a couple of DIY specials worth considering:-
1. Use an old satellite dish (or even an new one if you so desire) and mount your USB modem where the LNB would be. Obviously you will need to waterproof the modem, and here you are on your own. See http://www.silicon.com/technology/mobile/2008/07/15/peter-cochranes-blog-out-of-range-39259275/ for more info.
2. Carefully place the modem in the centre of a large steel saucepan. I have found this works as well as any of the indoor antennas so it is the most cost effective indoor option.