Interesting read on the Alfa site.
I see that their highest powered WiFi unit is rated at 30 dBm, that's 1 watt.
Not bad, but be careful to make sure that the maximum allowed EIRP (effective
isotropic radiated power) i.e antenna gain added to power output from the WiFi
adapter, minus any losses in between (i.e. coaxial cable losses, connector
losses, etc.), remains at 30 dBm or less at the antenna end.
Not that anyone is going to go around measuring the level probably, but you
can't just do-it-yourself with some of this stuff. And, all items are supposed
to be FCC type-approved, antennas included. I guess, shhhhh... don't advertise
if you do something not exactly kosher.
Incidentally, these power levels do not apply to amateur radio operators as
the 2.4 GHz spectrum is co-allocated to them in the US. So we are free to kick
it up as far as we wish to.
As to cellular modems, I still recommend the Sierra Wireless stand alone
modems. They do have various air-cards available, and these smaller devices
can be plugged into CradlePoint WiFi routers of various types, but no air-card
will perform as will a full-sized, and full-power dedicated cellular modem.
I have many thousands of these cellular modems deployed:
http://www.sierrawireless.com/productsandservices/AirLink/Configurable_Intelligent_Routers/AirLink_MP.aspx
They have either Ethernet (your best choice) or USB (less desirable) network
connections. They can be fed into a consumer router or router/WiFi AP via
their on-board Ethernet port to create a WiFi local LAN, or are available with
a built-in WiFi AP that does it all for you in one box. There is also a GPS
receiver option which we use for vehicle location. This has a standard serial
port option, or can be redirected via IP if desired.
These are the Cadillacs of mobile cellular based connectivity devices. If you
want the best, and want the longest range coverage possible, use one of these
on your favorite carrier. An omni-directional antenna can be used on these if
the signal strength of a tower is sufficient, or a multi-band directional
antenna can be added when you are not moving to give you far greater reach.
This is probably going OT, so unless I hear otherwise from Hunter :) bump me
off-list if you have any questions.
Rick Kunath
WBCCI #3060
This site is not sponsored by or affiliated in any way with Airstream Inc, Thor Inc, or the WBCCI.
0 comments:
Post a Comment