Due to the lack of GSM coverage in many parts of the world (many countries and oceans) I looked for what global communications systems are available in the world.
The first I found is the HF Data Link band used by aeroplanes (3-30 MHz). It’s long range and covers the poles. Although it’s transmission speed is quite low it may be an option if permissions can be obtained and the antenna required is not too long.
The other system are satellite links, which allow voice and data exchange. The constellation INMARSAT provides much information about the products and services available. Nevertheless, they are mainly intended for industries, so M2M devices are hard to find (it exists something called IsatM2M that seems to be interesting). The device DMR-800D OEM looks good, since it’s designed for solar powered installations. Nevertheless I couldn’t find any information of prices, and in it’s weights is 190 grams.
With another constellation, called ORBCOMM, was much easier to find M2M devices.
According to Wikipedia the cheapest receivers cost around $100. Since I couldn't find it's exact price, the model I like most, the Stellar DS100, seems to be one of the simplest.
They say in its datasheet that it’s voltage input is 8 to 16 VDC, its max peak current consumption is 2.0 A (transmitting) and it’s nominal consumption receiving is 77 mA. It’s temperature range is also similar to the GM862-GPS (-40ºC to +85ºC).
Those are not the only constellations designed for communications (I also found GlobalStar, for example) but the devices I found in a brief research work with these two systems.
It’s good to know that this technology exists, but it’s still soon to consider the acquisition of any of those devices.
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