2009/2/26 Marc Balmer <m...@msys.ch>: > > Am 26.02.2009 um 00:27 schrieb ropers: > >> 2009/2/25 Joseph C. Bender <jcben...@bendorius.com>: >>> >>> Marc Balmer wrote: >>>> >>>> I am using a TNC7multi. http://nt-g.de/de/tnc7multi/tnc7multi.php5 >>>> >>> >>> The venerable KPC-3 from Kantronics is always a good choice as well. >>> >>> http://www.kantronics.com/products/kpc3.html >> >> Apologies if this is very naive and thoroughly uninformed (it is) and >> possibly stupid, but seeing this on the above page -- >> >>> Data Rate (radio port) 1200 bps (default); 300, 400, 600 >> >> -- do these TNCs offer the same data transmission speeds that people >> used to get with early generation modems and acoustic couplers way >> back when? So what are people using TNCs for, then? What data are you >> actually exchanging this way? What are the modern-day practical >> applications of this technology? You're probably not using this to >> download install44.iso... > > Yes. The normal speed for packet radio over UHF/SHV is 1200 or 9600 > bps, over HF usually 300 bps. > > Heck, a very popular tranmission technique on HF, PSK31, uses 31 bps. > > Maybe you should google a bit a see what TNCs are used for ;)
My googling wasn't very successful (didn't use the right search terms, probably), but I found this at kantronics.com: http://www.kantronics.com/applications.html So if I get this right, then the advantages of communicating with a TNC via packet radio over cellular communications are lower cost and wider reach and coverage, and the advantages over sending the data via Iridium/satellite are much lower cost. Also, and correct me if I'm wrong, isn't it true that there are some regions even satellites don't reach? Maybe Antarctica? Presumably TNC packet radio could be used with longwave or medium wave and cover even such remote parts of the globe from very far away? I also gather that the combination of TNC packet radio with GPS equipment for instantly and continuously and cheaply available real time location data to let remote servers know just where you're at is a popular application? Don't feel pressed to answer unless you feel like it; I'm just wondering aloud; though if anyone would love to elaborate, that would be more than welcome. Thanks and kind regards, --ropers
