[Discuss-gnuradio] differences between usrps

[Walter Barmak]

hi,

as some of you already know, i have a usrp1 with 2 rfx1800 burned to
rfx900, two small antenas (13db, 60 watts) and a stock clock of 64mhz
which i'm planning to change for the external clocktamer. however,
before i do that, i'd like to know which is the best option for me.

1) as i understand, the main difference between usrp1 and usrp n210 is
the frequency range. does this have to do with the capacity for
concurrent calls? is this why the usrp1 can have 7 concurrent calls
while the usrp n210 can have up to 12 concurrent calls (without further
modification)?

2) also, i'd like to know what would be the reach of my system in open
field. i guess, as i now have it, would be around 200 meters, so if i
would like to improve that i would need either a filter (for transmit
and receive?) or a duplexer and a higher power antena?

3) what is the ethernet connection in the usrp n210 for?

4) if i would like to increase the number of concurrent calls, i guess i
would need to buy more usrps, which ones would be better to achieve a
higher number of concurrent calls? ie, which is designed to be able to
connect to other usrps and increase the number of concurrent calls?

thanks in advance,