Does anyone have some favorite transmitter chips (or even better a protocol) for sending 1MB pictures over long distances (mile or so)???
Any thoughts or ideas would be greatly appreciated!
Thanks!
other than cellular, the only thing I can suggest is if you live in No. America, get a pair of 1 Watt 902-928MHz freq. hopping data radios. Digi International sells some that have data rates of several hundred Kbits/sec. If you can use these with external directional antennas and get semi-line-of-sight, you can do it.
WiFi (802.11) - with high gain directional antennas and clear line of sight (rooftops) might make a half-mile, esp. if you force it to the lower bit rates (like 802.11b mode).
Otherwise, a mile in unlicensed bands at up to 1megabit/s is essentially not doable except as above. Time for cellular.
Transmitters are only only part of the solution. Antenna design and deployment for the local conditions is the other critical aspect. One mile can be easy to achieve or nearly impossible depending on what exists in the mile between the two antennas and what frequency you’re transmitting on. Check out http://www.dxzone.com/catalog/Antennas/WiFi/ for some wifi antenna ideas. There are also many websites that have directions for building homemade high gain antenna.
What about low earth orbit satellites? I know they used to be popular 10 years ago…are people still using them for commercial applications?
Yes, Iridium is DoD supported. Low speed.
Globalstar (Qualcom) is still there, barely.
Orbcomm is still up there (now Korean owned) - VHF, very low data rates.
So, the answer is no, these aren’t viable for your needs.
Cellular or for free, you need near line of sight, rooftops, hills, etc. Non-line-of-sight in unlicensed bands is not what you seek.