Wireless USB extenders -> why do they not seem to exist?

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For under $25 dollars that is.  In dongle form.

For example, say you've got some sort of USB device (camera) that has a
USB port.  You want to mount the camera a short distance away from your
computer (maybe 100 ft) but running a USB cable to the camera is not
possible (either physically or electrically).

So you buy this hypothetical two-piece wireless USB extender for $25.
You plug the receiver into your computer's USB port, and you plug the
camera into the transmitter.  Neither the camera or the computer knows
or "sees" this extender in the circuit.  The extender is transparent.

The extender makes a wireless connection between the camera and the
computer, as if the camera has a direct connection to the computer's USB

Does something like this exist?

And if not - why not?

Re: Wireless USB extenders -> why do they not seem to exist?

On 11/24/2012 10:51 AM, PC Guy wrote:
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It can be done but not at your price point. Not even close in fact. And it
probably won't work at that distance either if you want reliability. The
reason is pretty simple -- long-range wide-bandwidth bi-directional
wireless communication that rejects interference is difficult stuff and is
not to be bought cheaply. I suggest that you learn to live with cable and
buy a USB > CAT5 > USB solution which is cheap and can probably do the
100-foot distance for <$25 inclusive. A cheap solution is:

(Amazon.com product link shortened)

although I'm not suggesting that particular model, not having tested it.
There are loads of other similar items out there over a wide price range.

Re: Wireless USB extenders -> why do they not seem to exist?

On 24/11/2012 16:07, John McGaw wrote:
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I do like the idea of a USB to wifi adapter but it seems the tech can't
really support it. for a camera, you could just use an IP camera which
can be got at little money. Part of my job is designing the mechanical
side of them :)

you can then get a wireless to ethernet device, I can't for the life of
me remember the name. It's the opposite of an access point. Netgear make
one which I have lying about somewhere. This would allow you to connect
your cabled device to your wifi network.

Doesnt really solve you're problem but its at least another bit of info


Re: Wireless USB extenders -> why do they not seem to exist?

Pete wrote:
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I have been playing around with IP cameras now for the past 5 or so
years.  These are cameras that retail in the $80 to $120 range (Trendnet

What has royally pissed me off about those cameras is the lack of a
consistent protocal or method by which inexpensive / free monitoring
software (IPview and others) can be used to access ANY or ALL of these
cameras.  Even more recent Trendnet models can't be mixed with older
models because they are not compatible with IPview.

But that's a completely different issue.

The current project would be to take a $40 Wildgame Innovations
trail-cam and extend it's mini-usb port from my back yard into my house
(a distance of about 75 - 100 ft).  This would be to access the SDcard
in the camera and retrieve the pictures (not to perform any real-time
image streaming - something I don't think is possible with this camera

I don't even know if the USB interface on the camera is usb 1 or 2 (but
the SDcard is limited to 2gb max size - which would be some indication
of the age of the product).

The sneaker-net alternative is just to walk over the camera every few
days and pop the SDcard out and insert into SDcard reader in the house.

Another alternative I just might try is to make a long USB cable by
splicing/grafting USB ends onto cat5e cable.   Anyone know how long such
a cable could be?  Given the 4 twisted pairs, is there a best or
strategic way to use them for best S/N ratio, etc?

Re: Wireless USB extenders -> why do they not seem to exist?

On 24/11/2012 20:05, PC Guy wrote:
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 From memory is USB not limited to 3m generally? this is using a
standard cable and not twisted pair so if it was limited to 3m due to
noise interference then you may be onto an idea, though I'm not sure how
much further you would get.

You can however get HDMI to CAT5e/6 converters so if you could find a
camera with an HDMI/mini-HDMI output that could be an option.

Can't really speak for software engineering but with Mech Eng we
generally try to accommodate legacy parts where-ever possible. I don't
get to play much with final software builds much as by the time these
are finished we are generally getting ready to ship!

You could take a step back in tech terms and get something non-IP and
run the coax cable from the camera to a video capture card or IP encoder
in your house. Can't see the PCIe card costing much, the IP encoder
however could be quite costly.

I briefly looked into a few cheap IP cams last year and I got the
impression there were plenty on eBay that served a webpage and could
even push data out onto network storage... it's been so long you have me
doubting myself.

Re: Wireless USB extenders -> why do they not seem to exist?

Pete wrote:
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   "Cables and Long-Haul Solutions

    The cable length was limited by a cable delay spec of 26ns to allow
    for reflections to settle at the transmitter before the next bit
    was sent."

At 5.2ns/meter propagation delay allocation for the cable,
that is a 5 meter limit (16 feet). (You can get more details from
the USB_20.pdf document, which is 650 pages long.)

    "The best solution is ... a ... cable that had a one-port bus powered
     hub in the middle."

That would be a thing like this. Some cables are available which include
more than one of those repeaters in the cable. There is a limit to how
many hubs can be strung in a row. Power quality at the end of the
chain is likely to be poor, so a wall wart powered hub near the destination
is required for power-hungry devices. A mouse might run off the end of the
cable, without additional power. (Another note - when buying these,
*always* read the reviews, and make sure that some user has verified
that a long chain of cables works. Some of these repeater products,
it turns out they don't successfully concatenate. Only buy ones that
chain nicely, and deny the loser designs a place in the market! It's
unclear why some of these don't daisy-chain properly.)


So that's an example of a cabling solution, that only uses USB protocol.

The USBFaq also states:

    "I really need to put a USB device more than 30 meters away
     from my PC. What should I do?

     Build a USB bridge that acts as a USB device on one side and
     has a USB host controller at the other end. Use a long-haul
     signaling protocol like Ethernet or RS-485 in the middle. Using
     cables or short-haul fiber, you can get ranges upwards of a
     kilometer, though there's no reason why the long-haul link
     in the middle of the bridge couldn't be a pair of radio
     transceivers or satellite modems. Embedded host solutions
     capable of doing this already exist."

In other words, use a bridging protocol different than USB, for
the traversal of the longer-than-five-meter cable. Not USB
protocol itself. If you do find a USB bridge product, they're
unlikely to go into any technical details about how they do it.

When I show a product from this company, it's to show technical
capability. They hardly ever are price competitive. But if you
have pockets stuffed with cash, this'll solve your problem.


Note also, that naive implementations, they can claim the
product is USB2, but when you check the specs, the specs
only mention 12 megabits/sec. USB2 is 480 megabits/sec, so
I don't understand the labeling on this one, at all. If
you see some cheap Ebay product, they could pull the same
trick. I've seen this in the past, for some Laplink cables,
where some idiot claims they are selling a USB2 product,
only to discover the actual chip in the product is one
of the inferior USB 1.1 chips.



Re: Wireless USB extenders -> why do they not seem to exist?

PC Guy wrote:
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    "Wireless USB is based on the (now defunct) WiMedia Alliance's
     Ultra-WideBand (UWB) common radio platform, which is capable of
     sending 480 Mbit/s at distances up to 3 metres (9.8 ft)
     and 110 Mbit/s at up to 10 metres (33 ft). It was designed
     to operate in the 3.1 to 10.6 GHz frequency range, although local
     regulatory policies may restrict the legal operating range for
     any given country."

You might research UWB, and find out why the "wheels fell off".

It has excellent short range bandwidth, and only modest long
range bandwidth. There may have been concerns about what it
might do to the noise floor of other communications systems.
The initial idea was, the energy is spread over a huge
range of bandwidths, so to other transmission schemes, might
appear as a change in noise floor.

If that was a successful standard and means, we should have
been *buried* in that tech by now. And... we're not.

The basic USB protocol, has some time constants in it that
preclude extending the distance too far. That's where the
limit on existing cables come from, and requires the usage
of "in-line buffers". The buffers are one port hubs, that
basically terminate the protocol on a wire segment. The question
always comes up then, how extenders of any sort, manage to
defeat this time constant issue. And changing the protocol
used in the extender segment only, is one way.

If you look at the prototype in the Tomshardware picture,
it doesn't "look like a $25 item". It would probably be
priced similar to a wireless router, as the closest analogy.
And would you pay that kind of money, to be guaranteed
full bandwidth at only 9.8 feet ?

This is another example. HDMI over UWB. 30 feet. 1080p@30 ???
I'm guessing that's for movies or something. Only ~#1000.00
And, if you use the coax connector option on the box, you
can drive the signal over 1000 feet of coax, which is
just amazing. That there'd be any UWB signal left in the cable
at that distance. How is that even possible ? Still, 1000 feet
of coax might be cheaper than 1000 feet of fiber, and easier
to repair when needed.


A big question would be, whether this idea is FCC or DOC approved.
Wifi is approved for unlicensed usage, up to a certain EIRP. And
a tech like that, if you "splatter the airwaves", it too might
be subject to various restrictions on band usage. Like, a neighbor's
microwave dish is upset, and they trace it to your USB extender,
and the extender uses bands and power levels not allowed by FCC.

So this is a rich opportunity for some Googling...


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