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Demystifying
Marine Wireless (.pdf)... |
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Updated 2009 - Check out
the
Presentation
(in .pdf ) |
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Wireless Networking:
Tips
and Tricks to stay connected afloat! |
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By popular request...here is my presentation
for the seminar on Marine Wireless
Networking. Many people have asked for
a copy, so here it is - Please feel free to
E-mail me
me with any questions you may have...and
have fun! |
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Test Your
Bandwidth Speed... |
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Go To SpeedTest.Net:
Click Here! |
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Speedtest.Net is a website base bandwidth
meter that will help you identify your
actual bandwidth, and help identify if your
having connectivity problems anywhere in the
world! Check it out, and see what
speed your REALLY getting! |
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Finding a
Hotspot... |
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Download NetStumbler:
Click Here! |
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A good practice is to use Network Stumble.
NetStumbler allows you to use your adapter
to "scan" for wireless networks while your
moving through a marina or anchorage.
It will also tell you where the strongest
signals are, and let you know if the AP's
are Open or Locked! |
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Get an
all-in-one WiFi Detector:
Click Here! |
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I like to use a WiFi detector. Place
it on the fly-bridge as your cruising to
find the strongest AP's and determine if
they're Public! |
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Adding An
Antenna To Your USB Adapter... |
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A lot of people ask me, "Can I just ad an
antenna to my USB adapter?" The simple
answer is yes. If you don't have an
adapter with an external antenna mount (RP-SMA),
Like the
Hawking HWUG1
(below), then you'll need to get your
soldering iron out... |
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Simply "pop" open your USB adapter (being
carful not to damage anything), locate the
antenna points and solder on your N-Type "Pigtail
Adapter" (a
multimeter
is
recommended for testing) - Done! Well,
you have to put it back together. ;)
Some, silicon glue and a zip-tie are good
for securing the new extension (below). |
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However, if you have a good antenna (like
the
Hawking 15dBi Outdoor
Omni-Directional, for example),
then you can weatherproof your newly
modified Franken-adapter and "stuff it" -
into an antenna mounting tube!. Then
lead your 5m (15ft) USB cable out the
bottom, seal it (w/ silicon, etc.)
and presto! - you now have a great, portable
extended USB antenna "light-saber". Drop it
in a backpack with your Netbook (running NetStumbler) and you can
"War-Walk" while your
strolling around the marina...but that's a
different story... |
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A Marine
Wireless (WiFi) Solution... |
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One of
the first questions I always get asked is, "what
should I buy?" Of course, this is a good and
pretty strait-forward question...with a somewhat
complicated answer. If you have not attended
one of my seminars, then this is a tough question to
answer because it all depends on what you need (or
want). It's a little like asking, "what type of VHF
radio should I buy?" It all depends on what range
you want, and you want the VHF to do (GPS, DSC,
etc). Do you want it portable like a handheld, or do
you want a more powerful "station"? and the all
important, how much do you want to spend? ;)
This is
a good analogy, because wireless does behave just
like (and actually is) radio (albeit at 2.4GHz!).
And it suffers the same limitations of radio (on a
somewhat more sensitive level). So, do you want to
sit on a dock and get WiFi from the (relatively
close) yacht club? Or do you want to be at anchored
and get good reception from a dozen Access points
(AP's) a couple miles out?
I've
broken the approach to good Wireless (WiFi)
connectivity into two basic categories (although
there are literally hundreds of configurations). One
a more "powerful" solution, and the other a good,
cheap extendable solution with far less range. On
Twixter, we have a few combinations of both (and
routers, and repeaters, and bridges, and, and,
and...). I highly recommend downloading the
presentation, "Wireless Networking Tips and
Tricks to stay connected afloat!" (above).
It addresses some specific issues that Mariners have
with reception; like those big metal towers (masts),
and those nifty little Radomes (which just happen to
pulse on 2-4GHz!).
I hope
this helps, and as always, feel free to
E-mail me with any
questions! |
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The High-Power
Antenna Route... |
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Going
with a high-power 2.4GHz antenna solution is little
complex (but probably no more difficult than a
VHF or HF\SSB install). It is a more costly
solution (ranging form $200 to $400), but it has
better range, performance and capabilities.
Your likely to get dozens of AP's from distances up
to 4 or 5 miles!
Also Note: This is the best solution if you
choose to use a router\hub based connection option
(as you can "swap" devices very easily at a central
consol!) |
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Omni-Directional |
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Directional |
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The
first thing you want to decide on is the type of
antenna to get, and as you can see there is a wide
variety. Keep in mind, although a directional
antenna has a better range (15-20%), it's focus is
very narrow (60-90%) and not conducive to movement
(i.e. - swinging at anchor). A good Parabolic
or Yagi directional antenna can get you a connection
from as far as 10 miles, but as soon as you move a
couple degrees you'll loose reception. Choose
wisely, and in this case size DOES matter - get a
15dBi over a 10dBi if the price is right! |
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Important: An
Adapter with an External Mount! |
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This is very important: no matter what your
connecting your antenna to (AP, Hub,
Adapter), it MUST have an external antenna
mount (usually RP-SMA). Power, in this case,
doesn't matter all that much (most adapters
are 40mW to 100mW). Keep in mind, too
powerful of an adapter could "burn out" your
booster, so keep it in-range. |
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Hawking
Hi-Gain ignal Amplifier ("Booster")
Link:
Click Here! |
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Now you need an amplifier. It should
be a two-way amplifier, and be adjustable
(usually between 100mW & 500mW). The
booster is utilized primarily to mitigate
signal loss due to cable length and insure a
strong Tx signal.
Note: Make sure you have the
right male-to-female connectors. |
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Radio Labs Amplifier (w/ DC Injector)
Link:
Click Here! |
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I like the DC injector type of amplifier. It allows
me to put the amplifier directly under the
antenna. However, the power of the
amplifier cannot easily be me modulated and
requires "weatherizing". Some inline
amplifiers can put out 1W (1000mW). However,
if your AP can't be received by your
antenna, it's doesn't matter how powerful
your amplifier is (which is why bigger IS
better!). |
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Two-Way N-type Splitter
Link:
Click Here! |
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A splitter is a great option that will allow
you to have both Directional and
Omni-directional antennas (at the same
time). This is a good addition (around
$30), and extends your range and coverage.
However, keep in mind that some splitters do
not work well with signal boosters, so make
sure you get a compatible splitter! |
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Cabling & Connections are VERY important!
Link:
Click Here! |
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Cable is very important. Standard
Low-Loss cable (LMR-200) can loose up to 0.6
dB per meter (@ 2.4GHz), and each connecter
is .3 dB loss (so get good connectors!).
I use LMR-400 for most of my wiring. It's
stiffer and harder to work with (and more
costly by 25-40%), but insures good signal
strength! |
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LMR-200 (10m =
$25) |
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LMR-Connectors
($3) |
LMR-400 (10m =
$40) |
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The Extended
USB Adapter Route... |
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An
extended USB solution is the way-to-go if you only
need to get a good (60/70%) connection from a local
AP. And if your strapped for cash ($30 to
$40), it's the only way to go! ;) |
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USB Adapters
www.radiolabs.com,
www.hawkingtech.com,
www.faculty-x.net,
www.ebay.com,
www.outpost.com |
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Of
course, a prerequisite of an extended USB adapter
solution, is the USB adapter. There are
hundreds to choose from, with a wide range of
prices. Key factors when choosing a USB
adapter are power (>50mA), Chipset (preferably
Atheros) and extendibility (external RP-SMA antenna
option). |
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EnGenius
Adapter
Link:
Click Here! |
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I like the EnGenius adapters (I have 2).
They are 200mW (very high for a USB
adapter), and they now come with two
external antenna mounts, perfect for adding
a couple extend antennas if needed (*see, "The
High-Power Antenna Rout" to the left). |
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Important Note: Do make sure
any adapter you purchase is WiFi certified
(this ensures QC and the quality of the
adapter!) |
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USB Extension Cable
Link:
www.faculty-x.net/usb-repeater |
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Once you have a good adapter, you may need
to extend it (via USB) to your PC. Due
to USB cable limitations (15ft) you will
need a USB Extension Cable. These are
usually fairly cheap ($15), and work very
well (you can use up-to 4 in-line). |
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USB Cable Length Limitations:
high speed (USB 2.0) devices to 5 meters
(15ft) and for low speed devices 3 meters
(9ft). This means you can't just connect a
bunch of USB cables together and run them 30
feet to another room (BUT you can connect
a 6 foot and 10 foot cable for a total of 16
feet). Most USB products are USB 2.0 and
have the 5 meter limit. Low speed devices
are generally keyboards and mice. |
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Use a Pole Mount! |
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Finally, you simply need to mount the
adapter. I prefer to mount all my adapters
and antennas on professional mounts ($50 to
$300 depending on quality). This is a
good way to insure that they are safe and
out of the way. Unfortunately, too many
sailors try to use the Mast or a Flag
Halyard to raise the adapters.
This is a very big mistake, as you are
significantly reducing reception due to the
mast (and interference of the Fresnel Zone).
You should find a nice long, unobstructed
mount (usually on the transom). |
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Weatherproof your Adapter
Link:
Click Here! |
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Important Note: Weatherize
your adapter! Adapters are very sensitive to
the environment. Any moister can destroy a
USB adapter very quickly. A smart idea
is to use an external plastic "electrical"
enclosure ($10-$20) or watertight container
with the antenna extended. This could
save your Adapter from a quick death! |
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