Re: rooftop antenna range


[ Answering some old posts -wsr ]

Jeff Liebermann <jeffl@xxxxxxxxxxxxxxxxxxxxxx> writes:
More users mean more headaches and more intereference. Basically,
you're building a wireless ISP (WISP).

The twist that I was hoping would keep it manageable was to only have
the group concern itself with moving a users packets on the wireless
side. If someone wanted to route to the internet they would have to
use their own ISP connection by configuring their node to route for
them. If they are smart they'll have some secure mechanism such as a
vpn, ssh to their home machine etc to limit access to themselves and
the folks they specifically allow to gateway via them.

This also cuts out the question of someone calling to say "the
internet is down". It also removes the biggest cost (as you said in
another post) that of paying for a T-1 or more worth of backhaul.

Well, yeah. However, that leave your wireless network as some type of
dedicated game network. Good luck selling that idea. Everyone wants
(free) internet access.

Doesn't anyone want to just read email or their reach their own
systems from around town?

My gripe about paying someone for a for-pay wifi connection is that
the wifi folks have to price it as if it was someone's only internet
connection. Someone that is already paying $20-$70 or more for their
internet service isn't really going to want to add another $20-$70/mo
just so they can get and send mail from around town.

The standard construction method is a rather thick PTFE circuit board.
One side has the patch etched into the board. The back is all ground
plane and is covered with a vinyl sheet. The front is protected by a
vacuum formed plstic sheet. I don't think aluminum will impte the
weight.

I should really pull apart my laptop screen and see what they are
doing for an antenna. I assume they have a miniature dipole in there.
I may be possible to shove a larger patch behind the LCD. The case
looks like it has quite a bit of space.

Or if the plastic case would detune the antenna too much maybe
mounting it on the front of the case would be better.

Incidentally did you noice the power consumption in various modes at:
http://www.ubnt.com/super_range_cardbus.php4

Rate
1-24 Mbps 900mA, +/-100mA
36 Mbps 750mA, +/-100mA
48 Mbps 700mA, +/-100mA
54 Mbps 600mA, +/-100mA
Receive 350mA, +/-50mA

One would expect the power consumption to higher with higher
modulation rates. However, since the xmitter is on for a longer
period, for constant data amounts, the average power consumption is
higher for slower speeds.

I saw the funny power numbers and figured it must be something like
that.

I should be getting my card any minute now. It should be possible to
stick a 2dbi antenna on it and see if it is more sensitive than the
built-in wireless.


-wolfgang
--
Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/
.

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