Best 12V DC MIMO Router?

I am researching MIMO routers for use in a semi truck and figure the people
here might know one that will work in my situation.

I really prefer using a hardware NAT device as my first level of security,
especially when using a public network. The primary use will be at truck
stops and rest areas that offer a wireless feed. Most of the sites I've
seen so far only offer 802.11b or .11g so I see no need to get something
that also supports a pre-"N" standard unless it's all that is available.

I am looking for a unit that operates on 12 volts DC so I can run it
directly off of the truck electrical system. One possible problem is the
trucks voltage might swing between 12 to 14 volts depending on what the
battery charging system is doing. While on the subject, has anyone used a
good 12 volt spike suppressor/regulator for use in a truck or recreational
vehicle? I could add something like a 12 volt zener diode in series with
the power cable to control the higher voltage swings if nothing else turns
up.

Due to the shielding effect of metal trailers a unit that allows for using
external antenna(s) would be desired. I plan to mount one or two on
antennas on the top of the cab up in the wind deflector. The reason I was
looking for a MIMO device was so I could use it as a repeater while taking
my laptop outside the truck say at a picnic table.

Any help would be appreciated.

Hi,

I suggest the following link to start with:
www.networkingland.com/mimomain.htm

It might lead you to the correct router.

Panda

GlowingBlueMist wrote:
> I am researching MIMO routers for use in a semi truck and figure the people
> here might know one that will work in my situation.
>
> I really prefer using a hardware NAT device as my first level of security,
> especially when using a public network. The primary use will be at truck
> stops and rest areas that offer a wireless feed. Most of the sites I've
> seen so far only offer 802.11b or .11g so I see no need to get something
> that also supports a pre-"N" standard unless it's all that is available.
>
> I am looking for a unit that operates on 12 volts DC so I can run it
> directly off of the truck electrical system. One possible problem is the
> trucks voltage might swing between 12 to 14 volts depending on what the
> battery charging system is doing. While on the subject, has anyone used a
> good 12 volt spike suppressor/regulator for use in a truck or recreational
> vehicle? I could add something like a 12 volt zener diode in series with
> the power cable to control the higher voltage swings if nothing else turns
> up.
>
> Due to the shielding effect of metal traile
rs a unit that allows for using
> external antenna(s) would be desired. I plan to mount one or two on
> antennas on the top of the cab up in the wind deflector. The reason I was
> looking for a MIMO device was so I could use it as a repeater while taking
> my laptop outside the truck say at a picnic table.
>
> Any help would be appreciated.

From: "GlowingBlueMist" <(E-Mail Removed)>

| I am researching MIMO routers for use in a semi truck and figure the people
| here might know one that will work in my situation.
|
| I really prefer using a hardware NAT device as my first level of security,
| especially when using a public network. The primary use will be at truck
| stops and rest areas that offer a wireless feed. Most of the sites I've
| seen so far only offer 802.11b or .11g so I see no need to get something
| that also supports a pre-"N" standard unless it's all that is available.
|
| I am looking for a unit that operates on 12 volts DC so I can run it
| directly off of the truck electrical system. One possible problem is the
| trucks voltage might swing between 12 to 14 volts depending on what the
| battery charging system is doing. While on the subject, has anyone used a
| good 12 volt spike suppressor/regulator for use in a truck or recreational
| vehicle? I could add something like a 12 volt zener diode in series with
| the power cable to control the higher voltage swings if nothing else turns
| up.
|
| Due to the shielding effect of metal trailers a unit that allows for using
| external antenna(s) would be desired. I plan to mount one or two on
| antennas on the top of the cab up in the wind deflector. The reason I was
| looking for a MIMO device was so I could use it as a repeater while taking
| my laptop outside the truck say at a picnic table.
|
| Any help would be appreciated.
|

A 375watt DC-AC inverter can be obtained for as little as $40~45.00 US.
Then you will AC for "other" capabilities as well.

--
Dave
http://www.claymania.com/removal-trojan-adware.html
http://www.ik-cs.com/got-a-virus.htm

"GlowingBlueMist" <(E-Mail Removed)> hath wroth:

>I am researching MIMO routers for use in a semi truck and figure the people
>here might know one that will work in my situation.

Are you sure you're looking for a router and not for a "wireless
bridge" or "client radio"? A router is useful for running a server in
your truck for others to connect to. It's not useful for connecting
to a truck stop hot spot.

>I really prefer using a hardware NAT device as my first level of security,
>especially when using a public network.

Ummm... are you really running a server in the truck?

>The primary use will be at truck
>stops and rest areas that offer a wireless feed.

Ummm... looks like my guess(tm) is correct. You want your truck to
connect to the rest stop Wi-Fi feed. For that, you need a wireless
bridge or client adapter, not a router.

>Most of the sites I've
>seen so far only offer 802.11b or .11g so I see no need to get something
>that also supports a pre-"N" standard unless it's all that is available.

Purchasing a MIMO client radio will buy you nothing unless the truck
stop hot spot has a MIMO router. There are substantial benifits to
having a MIMO router, but they will mostly work with non-MIMO clients.
Also, there are now about 5 different MIMO implimentations, none of
which are compatible with each other. I suggest you drop the MIMO
requirement, at least until the 802.11n pissing match, er... standards
selection processes, is over and settled. Chances are very high that
anything you buy today, with MIMO or Pre-N scribbled on it, will not
be compatible with the inevitable 802.11n standards conglomeration.

>I am looking for a unit that operates on 12 volts DC so I can run it
>directly off of the truck electrical system. One possible problem is the
>trucks voltage might swing between 12 to 14 volts depending on what the
>battery charging system is doing. While on the subject, has anyone used a
>good 12 volt spike suppressor/regulator for use in a truck or recreational
>vehicle? I could add something like a 12 volt zener diode in series with
>the power cable to control the higher voltage swings if nothing else turns
>up.

Running something like a wireless bridge directly off the 12V vehicle
system is a bit risky. If you've ever attached an oscilloscope to the
cigarette igniter and watched the voltage when the vehicle starts,
you'll see 100v or more spikes. You can easily build a suitable
filter with some chokes, filter caps, MOV (metal oxide varistors),
fuse, and possibly a crowbar protection circuit. A zener or MOV can
protect against low energy spikes across the 12VDC line, but will not
protect against anything with substantial energy content (such as the
back-EMF from the starter). If your tractor starter runs on 24V from
two 12V batteries in series, and your accessories run on one of those
two batteries, you're going to see a substantial spike on startup.

Methinks a better way is to invest in a DC to DC converter. Most of
todays routers, bridges, and wireless contrivances run on 3.3VDC
internally. The external power can be anything from 3.3VDC to 12VDC
depending on the design of the internal regulator. Something like:
http://www.powerstream.com/dc5.htm
might be worth considering.

Someone suggested a 375watt 12v to 117VAC converter. Well, those get
hot, usually have a fan, and are not particularly efficient running a
device that only requires about 6-10 watts. Not recommended.

Finding the power requirements for various wi-fi hardware is difficult
without ripping open the package and reading it off the wall wart.
Sometimes, it's on the manufacturers web pile. More often, it's not.
In that case, dig through the disorganized mess on the FCC ID web
site. It's always listed on the test report with pictures of the wall
wart.

>Due to the shielding effect of metal trailers a unit that allows for using
>external antenna(s) would be desired.

That's going to be impossible with current MIMO technology unless you
want to install 3 antennas. Various forms of MIMO use beam forming,
beam stearing, or multi-wavefront technologies, that require 2 or more
antennas in a well controlled pattern. At this time, there are no
external MIMO antenna devices except for some contrivance I recently
saw that has the entire RF section in the antenna assembly with a
coax??? cable to the PCI board in the desktop computah. I forgot who
made it.

>I plan to mount one or two on
>antennas on the top of the cab up in the wind deflector. The reason I was
>looking for a MIMO device was so I could use it as a repeater while taking
>my laptop outside the truck say at a picnic table.

There's nothing about MIMO that would prevent you from using a
conventional 802.11g device as a repeater. If you drop the MIMO
requirement, you have what I've seen on a few trucks and campers. On
the roof or any place that's high up, there's a wi-fi repeater of some
sorts. In the cab, the owner has a laptop with internal wi-fi. When
he arrives at a hot spot, he determines the SSID using Netstumbler (or
just reads the sign in the window with the SSID inscribed). He then
programs the repeater to repeat that SSID and connects.

One nice feature is that everyone in the area "benifits" from the
repeater as other users can connect through it. The bad part is that
repeaters create double the number of packets in the air and IMHO
constitute a troublesome source of interference. There are also a
wide range of access points where repeaters just simply will not work.
Compatibility is always an issue with repeaters. I suspect you will
have some frustration running a mobile repeater. Not recommended.

What I suggest is you get a rather high gain panel antenna and mount
it on a motorized rotator type mount. Only one axis of rotation is
required. Install an "ethernet wireless bridge", "game adapter", or
"client bridge" type of radio near the antenna (to keep coax cable
losses to a minimum). Figure out some way to rotate and aim the
antenna. (Yeah, I know it won't work towards the rear if you have a
trailer). Plug your laptop into the ethernet (of USB) port of the
bridge and connect without a repeater in the way.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

I don't know if you can get them off the shelf, but I built a 5V 2A LDO
for use with a D-link WAP. The spec on the wall wart was 2A, but mine
ran around 1.3A. With a 7V drop, that is 9W. Not trivial, but I don't
like all the RF noise from most DC/DC converters.

Dittos on not using an inverter. More RF QRM, plus some devices don't
work well off the so-called modified sine wave. I swear I ruined the
DC/DC for my notebook by operating it off an inverter.

If you had to go DC/DC, perhaps this would be a better solution if you
can figure out the proper tip:
http://www.mobl.com/products.asp


Jeff Liebermann wrote:
> "GlowingBlueMist" <(E-Mail Removed)> hath wroth:
>
> >I am researching MIMO routers for use in a semi truck and figure the people
> >here might know one that will work in my situation.
>
> Are you sure you're looking for a router and not for a "wireless
> bridge" or "client radio"? A router is useful for running a server in
> your truck for others to connect to. It's not useful for connecting
> to a truck stop hot spot.
>
> >I really prefer using a hardware NAT device as my first level of security,
> >especially when using a public network.
>
> Ummm... are you really running a server in the truck?
>
> >The primary use will be at truck
> >stops and rest areas that offer a wireless feed.
>
> Ummm... looks like my guess(tm) is correct. You want your truck to
> connect to the rest stop Wi-Fi feed. For that, you need a wireless
> bridge or client adapter, not a router.
>
> >Most of the sites I've
> >seen so far only offer 802.11b or .11g so I see no need to get something
> >that also supports a pre-"N" standard unless it's all that is available.
>
> Purchasing a MIMO client radio will buy you nothing unless the truck
> stop hot spot has a MIMO router. There are substantial benifits to
> having a MIMO router, but they will mostly work with non-MIMO clients.
> Also, there are now about 5 different MIMO implimentations, none of
> which are compatible with each other. I suggest you drop the MIMO
> requirement, at least until the 802.11n pissing match, er... standards
> selection processes, is over and settled. Chances are very high that
> anything you buy today, with MIMO or Pre-N scribbled on it, will not
> be compatible with the inevitable 802.11n standards conglomeration.
>
> >I am looking for a unit that operates on 12 volts DC so I can run it
> >directly off of the truck electrical system. One possible problem is the
> >trucks voltage might swing between 12 to 14 volts depending on what the
> >battery charging system is doing. While on the subject, has anyone used a
> >good 12 volt spike suppressor/regulator for use in a truck or recreational
> >vehicle? I could add something like a 12 volt zener diode in series with
> >the power cable to control the higher voltage swings if nothing else turns
> >up.
>
> Running something like a wireless bridge directly off the 12V vehicle
> system is a bit risky. If you've ever attached an oscilloscope to the
> cigarette igniter and watched the voltage when the vehicle starts,
> you'll see 100v or more spikes. You can easily build a suitable
> filter with some chokes, filter caps, MOV (metal oxide varistors),
> fuse, and possibly a crowbar protection circuit. A zener or MOV can
> protect against low energy spikes across the 12VDC line, but will not
> protect against anything with substantial energy content (such as the
> back-EMF from the starter). If your tractor starter runs on 24V from
> two 12V batteries in series, and your accessories run on one of those
> two batteries, you're going to see a substantial spike on startup.
>
> Methinks a better way is to invest in a DC to DC converter. Most of
> todays routers, bridges, and wireless contrivances run on 3.3VDC
> internally. The external power can be anything from 3.3VDC to 12VDC
> depending on the design of the internal regulator. Something like:
> http://www.powerstream.com/dc5.htm
> might be worth considering.
>
> Someone suggested a 375watt 12v to 117VAC converter. Well, those get
> hot, usually have a fan, and are not particularly efficient running a
> device that only requires about 6-10 watts. Not recommended.
>
> Finding the power requirements for various wi-fi hardware is difficult
> without ripping open the package and reading it off the wall wart.
> Sometimes, it's on the manufacturers web pile. More often, it's not.
> In that case, dig through the disorganized mess on the FCC ID web
> site. It's always listed on the test report with pictures of the wall
> wart.
>
> >Due to the shielding effect of metal trailers a unit that allows for using
> >external antenna(s) would be desired.
>
> That's going to be impossible with current MIMO technology unless you
> want to install 3 antennas. Various forms of MIMO use beam forming,
> beam stearing, or multi-wavefront technologies, that require 2 or more
> antennas in a well controlled pattern. At this time, there are no
> external MIMO antenna devices except for some contrivance I recently
> saw that has the entire RF section in the antenna assembly with a
> coax??? cable to the PCI board in the desktop computah. I forgot who
> made it.
>
> >I plan to mount one or two on
> >antennas on the top of the cab up in the wind deflector. The reason I was
> >looking for a MIMO device was so I could use it as a repeater while taking
> >my laptop outside the truck say at a picnic table.
>
> There's nothing about MIMO that would prevent you from using a
> conventional 802.11g device as a repeater. If you drop the MIMO
> requirement, you have what I've seen on a few trucks and campers. On
> the roof or any place that's high up, there's a wi-fi repeater of some
> sorts. In the cab, the owner has a laptop with internal wi-fi. When
> he arrives at a hot spot, he determines the SSID using Netstumbler (or
> just reads the sign in the window with the SSID inscribed). He then
> programs the repeater to repeat that SSID and connects.
>
> One nice feature is that everyone in the area "benifits" from the
> repeater as other users can connect through it. The bad part is that
> repeaters create double the number of packets in the air and IMHO
> constitute a troublesome source of interference. There are also a
> wide range of access points where repeaters just simply will not work.
> Compatibility is always an issue with repeaters. I suspect you will
> have some frustration running a mobile repeater. Not recommended.
>
> What I suggest is you get a rather high gain panel antenna and mount
> it on a motorized rotator type mount. Only one axis of rotation is
> required. Install an "ethernet wireless bridge", "game adapter", or
> "client bridge" type of radio near the antenna (to keep coax cable
> losses to a minimum). Figure out some way to rotate and aim the
> antenna. (Yeah, I know it won't work towards the rear if you have a
> trailer). Plug your laptop into the ethernet (of USB) port of the
> bridge and connect without a repeater in the way.
>
> --
> Jeff Liebermann (E-Mail Removed)
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558

My thanks to all of you that replied to my questions.

It looks like the MIMO option is off the table for now as I'm sure most of
the sites I'll have access to would not actually support the MIMO standard
yet. As one mentioned, it sounds like a wireless bridge/repeater may be
better suited for what I plan to do anyway.

I can mount an entire wireless access point up on top in a water tight
container that is transparent to the proper frequencies.

Yes DC/AC converter might be an option for power but most are quite
inefficient and generate quite a bit of heat. I'll hit a few truck stops
and talk with drivers that have more than CB antenna's visible and see what
they are using. I forgot about the transients caused by the starter, among
other things, but they can be handled with the right handfull of components.

Again thanks for the feedback and suggestions.

GlowingBlueMist wrote:
> My thanks to all of you that replied to my questions.
>
> It looks like the MIMO option is off the table for now as I'm sure
> most of the sites I'll have access to would not actually support the
> MIMO standard yet. As one mentioned, it sounds like a wireless
> bridge/repeater may be better suited for what I plan to do anyway.
>
> I can mount an entire wireless access point up on top in a water tight
> container that is transparent to the proper frequencies.
>
> Yes DC/AC converter might be an option for power but most are quite
> inefficient and generate quite a bit of heat. I'll hit a few truck
> stops and talk with drivers that have more than CB antenna's visible
> and see what they are using. I forgot about the transients caused by
> the starter, among other things, but they can be handled with the
> right handfull of components.
> Again thanks for the feedback and suggestions.

Here's another thought. Friend of mine has an always on wap/router with a
pcmcia/cardbus data card in it, so he is always connected to the internet
via the cellular network (doesn't have to depend on hot spots), and has a
repeater mounted on the roof (he's in an rv, airstream - metal roof, wants
to be able to use his laptop outside and by the fire ) When on the road,
he's sort of a rolling hotspot As an added bonus, using the 1x network,
it's fast enuf for voip stuff/and videocalling. He uses it to talk to his
family. It's pretty cool/state of the art... for cost, figure about $200 for
the hardware, and $79 bucks a month for an always on data card... (powered
off a small inverter, $10 at walmart)


--
Practice safe eating. Use a condiment.

Peter Pan wrote:
> GlowingBlueMist wrote:
>> My thanks to all of you that replied to my questions.
>>
>> It looks like the MIMO option is off the table for now as I'm sure
>> most of the sites I'll have access to would not actually support the
>> MIMO standard yet. As one mentioned, it sounds like a wireless
>> bridge/repeater may be better suited for what I plan to do anyway.
>>
>> I can mount an entire wireless access point up on top in a water
>> tight container that is transparent to the proper frequencies.
>>
>> Yes DC/AC converter might be an option for power but most are quite
>> inefficient and generate quite a bit of heat. I'll hit a few truck
>> stops and talk with drivers that have more than CB antenna's visible
>> and see what they are using. I forgot about the transients caused by
>> the starter, among other things, but they can be handled with the
>> right handfull of components.
>> Again thanks for the feedback and suggestions.
>
> Here's another thought. Friend of mine has an always on wap/router
> with a pcmcia/cardbus data card in it, so he is always connected to
> the internet via the cellular network (doesn't have to depend on hot
> spots), and has a repeater mounted on the roof (he's in an rv,
> airstream - metal roof, wants to be able to use his laptop outside
> and by the fire ) When on the road, he's sort of a rolling hotspot
> As an added bonus, using the 1x network, it's fast enuf for voip
> stuff/and videocalling. He uses it to talk to his family. It's pretty
> cool/state of the art... for cost, figure about $200 for the
> hardware, and $79 bucks a month for an always on data card...
> (powered off a small inverter, $10 at walmart)
Oh, I forgot, heres a link to an article about it
http://www.smallbizpipeline.com/show...leId=169400342 and
that article links to the manufacturer site www.junxionbox.com (if you want
one, click on purchase, you can buy one and have it shipped to you)... The
small inverter was because of voltage transients, he didn't want to use the
12vdc built into it, afraid of starting spikes.
--
Practice safe eating. Use a condiment.

(E-Mail Removed) hath wroth:

>I don't know if you can get them off the shelf, but I built a 5V 2A LDO
>for use with a D-link WAP. The spec on the wall wart was 2A, but mine
>ran around 1.3A. With a 7V drop, that is 9W. Not trivial, but I don't
>like all the RF noise from most DC/DC converters.

In the wonderful land of power supplies, you can literally get any
combination of input and output voltage or current. Just don't ask
the price. The 2A spec on the wall wart is the nominal operating
current, at which the wall wart can operate continuously without
catching fire, violating the various certifications, or blowing a
fuse. That means it may get a bit warm, or even hot on the larger
wall warts, but won't start a fire.

There are many different types of DC to DC converters. The low weight
and high efficiency variety operate at 100KHz and up. These generate
some RFI which is a problem if you're a ham operator. However, if you
don't care about weight, low frequency DC-DC converters work quite
well. I once designed a variable pulse width charge pump DC-DC
converter, that ran at about 10 Hz. Yep, that's 10 pulses per second.
It was terrible at responding to changing loads, but generated no RFI
or conducted radiation. Later version used a V-F (voltage to
frequency) converter driving the charge pump, which has much better
transcient response. There's no magic in these, but they're not
commonly available.

>Dittos on not using an inverter. More RF QRM, plus some devices don't
>work well off the so-called modified sine wave. I swear I ruined the
>DC/DC for my notebook by operating it off an inverter.

I can believe that. A square wave has 33% of its energy in harmonics
of the basic 60Hz sine wave. That extra power has to go somewhere.
It's about half way dissipated in the low pass filter found on the
input circuit of almost all switchers. Get the phase just right, and
something is going to smoke. However, if you rip out the low pass,
the switchers actually prefer 60Hz square waves to running on 60Hz
sine waves. Unfortunately, that's not possible for assorted reasons
(switcher stability, tendency to ring, conducted EMI, etc).

With the advent of 3GHz P4 laptops, the power requirements of the
battery charger has dramatically increased. I recently had to replace
two customers Toshiblah chargers that has blown themselves up. 19VAC
at 6.2amps and the size of a small brick. That's about 120 watts. It
has to be so big because it should be able to run the laptop with the
battery removed. Previous generation of 1.6Ghz Pentium M laptops only
had chargers with about half the power output of this monster. If
that's what you're running, you don't need an AC inverter to blow one
up. They'll do it all by themselves.

>If you had to go DC/DC, perhaps this would be a better solution if you
>can figure out the proper tip:
>http://www.mobl.com/products.asp

That really depends on what the router/bridge/whatever requires. Some
of these require 5.0VDC regulated. That's not a typical commodity
unregulated 5VDC wall wart with just an xformer and diode inside the
case. It's a well regulated power supply, that puts out as close to
5.0VDC as possible.

Fortunately, most routers/bridges/whatevers have internal voltage
regulators that can handle a wide range of input voltage and are not
particularly critical. The WRT54G is amazing in that it will work
from about 4.0VDC to about 18VDC thanks to a nifty internal switcher.
I run mine on a 12VDC gel cell and charger. However, most other such
devices are not so tolerant.

It's easy enough to measure the input voltage range in the downward
direction with an external power supply. The upward direction is the
problem. Go too high and you blow it up. Therefore, I trace out the
circuit first, identify the components, try to guess the electrolytic
voltage rating, and then test the voltage range.

The iGo adapters are the industry standard for road warriors that
absolutely hate dragging around a mess of power supplies and cords for
their assortment of PDA's, wireless, laptops, cell phones, toys,
cameras, and such. One programmable power supply and a collection of
adapter tips is all that's required. It's a good system, but in my
opinion, rather expensive. It makes sense when one has a variety of
devices to power, but not for powering just one in a semi-permanent
installation.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"GlowingBlueMist" <(E-Mail Removed)> hath wroth:

>I forgot about the transients caused by the starter, among
>other things, but they can be handled with the right handfull of components.

This is what the railroads use to protect track side signaling.
Probably overkill for a vehicle.
http://www.transtector.com/productdetail?item=1101-707

A series inductor and fuse, with a zener or MOV, plus a BFC (big fat
capacitor) across the load should be sufficient.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558