

Ask HN: How should I make a point-to-point wireless home system? - ivankirigin

This is a problem I think a lot of people have, including some smart hackers I know:<p>Your internet connection is at location X, and you want it at location Y. Wifi router at X and receiver at Y is okay for some applications, but the signal can get week if you're passing through lots of walls or floors. Also, if you're, say, streaming to an X-Box or a desktop PC used for gaming or streaming movies, a hit in speed is really noticeable.<p>Using a hard wire is great, but hard. Who wants to dig into walls or have lots of wires around?<p>Setting up wireless routers to act like repeaters or access points seems arcane, with questionable benefits.<p>So I thought I'd ask the smart folks here: how should I do this? If I really just want the X to Y speed maximized, is there good specialty hardware for this? Any hacks to take off the cap on broadcast strength on an easily available router?<p>[edits:
- Ethernet over power is horrible in my experience. I don't even think there is a connection between the two spots<p>- Laying down line is untenable currently because it is a rental, and the situation is dire: separate back office (converted garage) to a living room in the house. I won't dig into concrete and most certainly won't drape wires.<p>- Why isn't this just a product? Two routers with directional antennae + N repeaters long the route?
]
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iigs
_Any hacks to take off the cap on broadcast strength on an easily available
router?_

Yes, with certain firmwares you can. This adjustment is like turning up your
stereo: it might get a bit "louder" but beyond a certain point it begins to
clip and distort. The big difference is that unlike a stereo, the default
radio gain is usually set fairly high -- there's rarely much more headroom to
get.

A radio tuned for 100mw might have 200mw in it, if you're lucky. While this
sounds like a lot, it's only 3db, which is a small fraction of any signal
meter "bar" reading.

If you really want to increase your effective transmission power, your best
bet is a high-gain antenna:

<http://tinyurl.com/client-antennas> (no affiliation)

These will increase your effective signal strength by focusing the beam of the
antenna in the direction you wish to transmit/receive it. The down side is
that the antennas have to be pointed at each other, and the higher the gain
the closer they have to be aligned.

However, please keep in mind that increasing your effective radiation in one
direction above the initial design limit is likely to run afoul of your
government's (the FCC in the USA) rules about RF emissions.

In summary, yes you can do it, but it will take expensive, fidgety antennas,
is probably illegal, and at the end of it you still might not get the amount
of gain you need. I recognize your desire to use wireless but generally IMO
it's not worth the work.

~~~
cnvogel
Most often you don't want or need to increase your transmission power. What
you are looking for is a better signal to noise ratio (often written as SNR,
S/N). And a directional antenna will receive less noise from directions it's
not pointed at.

To stay within the valid "effective" output power of your regulatory domain,
you can lower the transmission power of the transmitter. Or you can spend your
excess gain by adding a little of high-quality cabling that puts your antenna
at a better suited location (but more often it will be easier to just move the
whole WLAN router/card/dongle).

A "pringles-like" design made out of stainless steel toilet-brush holders that
includes experimental and simulation results (in German):
<http://www.heise.de/netze/artikel/print/100565>

------
pudquick
Registered just so I could post it. Thanks for giving me the excuse.

If you're on Windows / OS X (and even under Linux, the Windows utility has a
Gold rating in wine), I'd recommend the Airport Express:
<http://www.apple.com/airportexpress/specs.html>

(The reason I mention the OSes is that it's got a software utility for
configuration - doesn't have a web interface in the unit)

802.11n (and a,b,g too), out-of-the-box WDS, pretty rock-solid little boxes,
Ethernet jack on each if you need to extend wired. Not much bigger than a
power supply.

I've got 3 at my house for exactly the reasons you posted and routinely stream
media from the upstairs AP through WDS to the downstairs unit or torrent with
200+ sustained TCP connections (and high turnover/churn) - it doesn't even bat
an eye.

$99 USD a unit. A little pricier than your average home wifi router but well
worth it (and if you're on Windows or OS X, you can stream music from iTunes
to individual APs' audio out jacks or share printers from them as well).
Highly recommend them.

Edit: And for those recommending dd-wrt / openwrt for WDS - don't you believe
it. The people using it aren't putting any decent loads on it. I tried it
(within this last year) before going all Airport Express. Too many issues with
random reboots in the APs - the firmware stability on those projects isn't
even remotely close to the Airports.

------
forkqueue
Did you consider homeplug networking?

I have two ZyXEL home plug devices and get ~ 60-70Mbps from them (they're
rated at 200Mbps for the whole network you can add them as you go). They're
pretty good, but latency is higher than I'd expected - ~4ms.

------
norkle
Why not use WDS on cheapo firmware-hacked routers, using dd-
wrt/openWRT/freeWRT (I use Tomato)? If you really want speed, you may be able
to find standard 802.11n routers that can do WDS, although if I really wanted
speed I would (and do) use cable. These firmwares usually also allow wireless
strength mods, although it may not be practial.

For info on WDS: <http://en.wikipedia.org/wiki/Wireless_Distribution_System>
or: [http://www.dd-
wrt.com/wiki/index.php?title=WDS_Linked_router...](http://www.dd-
wrt.com/wiki/index.php?title=WDS_Linked_router_network)

------
jvyduna
These used to be $50: <http://meraki.com/> (This company grew out of the MIT
Roofnet auto-configuring mesh technology)

Expensive, but these are what my dad's WISP uses:
<http://en.wikipedia.org/wiki/Motorola_Canopy> They are not not mesh, and they
involve config. You can buy them on licensed spectrum as well. Bulletproof,
amazing range and bandwidth.

------
dryicerx
There is the Ethernet-over-Power option (they seem to work a lot lower than
their rated speeds, but over longer distances / walls _might_ be better in
some cases compared to wireless). (Linksys PLK300, or D-Link DHP-301, etc).

Before shelling out that much, I would try getting a second router to act in
client mode and have high gain or directional antenna on both routers.

~~~
ivankirigin
Know of any good off-the-shelf directional antennae? Not sure I want to mess
with pringles cans. Also, any guides on setting a direction through a few
walls? Or do you just use it like a dowsing rod with some power sensor to
point it in the right direction?

Also, I've tried a network-over-power system, and it totally sucked when it
worked at all.

~~~
JimmyL
TigerDirect, surprisingly, has some decent directional antennas. I've had
decent luck with [http://www.tigerdirect.ca/applications/SearchTools/item-
deta...](http://www.tigerdirect.ca/applications/SearchTools/item-
details.asp?EdpNo=713934&CatId=374), but
[http://www.tigerdirect.ca/applications/SearchTools/item-
deta...](http://www.tigerdirect.ca/applications/SearchTools/item-
details.asp?EdpNo=4823733&CatId=374) looks pretty decent as well.

As for setting it up, I used it a pretty low-tech routine: set the antenna,
walk around with a power meter, adjust antenna, and repeat. If you really want
to get into it, put some thought into how the walls and other large objects
are laid out, and take that into account when setting up your antenna.

~~~
ivankirigin
I'm amazed someone hasn't made a 2 router + 2 directional antennae package for
people like me. Thanks

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adam_feldman
dd-wrt lets you change the broadcast strength on some routers. check out their
documentation for details - <http://www.dd-wrt.com/>

otherwise, unless you invested in commercial solutions (microwave
transceivers), i believe you are stuck chaining together repeaters or running
a cable.

~~~
ivankirigin
I don't mind spending a bit for a low end commercial solution, as long as I'll
spend less than, say, $800, and won't get cancer from sitting next to one for
a long period of time :)

Got any links or brands?

~~~
cdr
If you're willing to pay $800, why not just pay someone to run a wire?

~~~
ivankirigin
It's a rental and I'd rather have the equipment. I've lived in places where
running a wire isn't really an option. I've done it myself before too, but
that isn't even tenable. Also, I'd have to be pretty damn sure that I'm
getting what I want for that money.

