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From: DuaneKaufman on 29 Jan 2008 13:37
Hi,

I'm investigating the feasibility of building myself the capability to
utilize the 'Wireless DSL' service that is being offered to the
citizens of a town about 2 miles away from where I live.

Unfortunately, I do not have line-of-sight to the town water tower
where my house is located, but I do own land that is high enough (with
the use of a tower) which can 'see' the water tower.

Hopefully the ASCII art will paint the picture:

< - 3-4 km ->
Municipal_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Solar-
powered
Tower
Repeater
/
/
/
/
(500 m)
/
/
/
/
House

What I am looking for is recommendations people have on the various
bits I'll need to assemble/acquire for this to happen.

Constraints:
There is no power available at the repeater site - any solar powered
gear people like?
A tower will be needed at the repeater site - again, any towers people
like (20-40 ft)

Will any hardware be required at the house? we'll have wireless
notebooks as clients there.

Any other suggestions?

Thanks in advance,
Duane
From: DTC on 30 Jan 2008 22:05
As I understand it, you will be a subscriber to the WISP and want
to repeat the signal from their client to you house that has inside
laptops.

*If* you had full control of their client, you could turn it into
a sequential repeater...but I don't think they would be keen on you
doing that to their equipment, so we'll assume you can't.

That means you'll need to connect their subscriber unit to your own
access point just to even get a signal down into you direction using
a full duplex repeater set up.

With that said...what are your expectations of reliability using solar
and supporting laptops inside a house.

Carrier grade solar starts off at $5,000 in the southern states. It
can run two radios for five days without sufficient sunlight for
charging. Those $200 solar powered MickyMouse mesh units can only store
enough to work over night, estimated price for the $100 unit and $100
solar add-on.

Indoor laptops...You can set up an AP at fifty feet up, and still not
connect reliably inside to a house a mere 1,00 feet away. So you'll
need more radios.


From: DuaneKaufman on 31 Jan 2008 09:56
Hi,

Thanks for the follow-up:

On Jan 29, 9:05 pm, DTC <m...(a)nothingtoseehere.zzx> wrote:
> As I understand it, you will be a subscriber to the WISP and want
> to repeat the signal from their client to you house that has inside
> laptops.
>
> *If* you had full control of their client, you could turn it into
> a sequential repeater...but I don't think they would be keen on you
> doing that to their equipment, so we'll assume you can't.
>
That is correct, I can't change the WISP (I _think_ they are doing
PPPoE)

> That means you'll need to connect their subscriber unit to your own
> access point just to even get a signal down into you direction using
> a full duplex repeater set up.
>
Yes.

> With that said...what are your expectations of reliability using solar
> and supporting laptops inside a house.
>
I am approaching this from a fairly reliable dial-up link, which is
being discontinued by that ISP. My
expectations are a faster link (when it is up). I can service this
device as needed.

> Carrier grade solar starts off at $5,000 in the southern states. It
> can run two radios for five days without sufficient sunlight for
> charging. Those $200 solar powered MickyMouse mesh units can only store
> enough to work over night, estimated price for the $100 unit and $100
> solar add-on.
>
If I can put one of these together myself, I imagine I could get a
fairly reliable set-up for between 5000 and 200, no?

> Indoor laptops...You can set up an AP at fifty feet up, and still not
> connect reliably inside to a house a mere 1,00 feet away. So you'll
> need more radios.

If I need an AP at the house, that would not be that bad.

Thanks,
Duane
From: DTC on 31 Jan 2008 22:47
DuaneKaufman wrote:
>> Carrier grade solar starts off at $5,000 in the southern states. It
>> can run two radios for five days without sufficient sunlight for
>> charging. Those $200 solar powered MickyMouse mesh units can only store
>> enough to work over night, estimated price for the $100 unit and $100
>> solar add-on.
>>
> If I can put one of these together myself, I imagine I could get a
> fairly reliable set-up for between 5000 and 200, no?

Depends how north you are and percent of overcast days.

Lets say you have two each 12 volt 1.5 Amp radios (18 watts apiece) that
will require 864 watts over 24-hours, and you have four hours of usable
sun in the lower latitudes (solar panels loose effectiveness past two
hours on either side of high noon).

If you have a solar array rated at 36 watts, it would only be sufficient
to power the radios for four hours a day. An 864 watt array would run
the units and charge the batteries with 720 watts to run them when the
sun gets lower and at night.

But an 864 watt array needs full sun everyday. If your area has up to
five consecutive days of overcast, then on the sixth day you need to
have an array that can dump charge the system in a mere four hours to
store another 4,320 watts for the next five consecutive overcast days
(4,320 = 864 watts per day x five days).

So to $500 might get you an array that can charge your batteries to
run your radios into the mid-evening each day.
From: Jeff Liebermann on 31 Jan 2008 23:40
On Wed, 30 Jan 2008 21:47:54 -0600, DTC <me(a)nothingtoseehere.zzx>
wrote:
>Depends how north you are and percent of overcast days.

I threw together a spreadsheet for calculating solar powered radio
installs. It was originally designed for running a ham radio repeater
site, but can be tweaked to do a simple wireless access point or
wireless repeater. See:
<http://802.11junk.com/jeffl/rf-calc/solar-repeater-207.xls>

I filled in my guess(tm) of the numbers for a WRT54G:
<http://802.11junk.com/jeffl/rf-calc/solar-wrt54g-v101.xls>

The bottom line, which is actually on the right side of the
spreadsheet, is the number of days it takes to recharge the batteries
from various states and conditions (full load, no load, etc). If the
recharge time is more than a day under full load, you stand an
excellent chance of running the batteries into the ground in a few
days. The WRT54G example above uses a proposed 50 watt array, which
takes about 3 days to recharge under full load, and is therefore
seriously under sized.



--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 jeffl(a)comix.santa-cruz.ca.us
# http://802.11junk.com jeffl(a)cruzio.com
# http://www.LearnByDestroying.com AE6KS
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