FCC Approves 802.11b Phased Array

n6zfx writes "802.11b Networking News is reporting that vivato received FCC approval for the 802.11b AP that has a range of 4 miles... This was discussed recently here on slashdot -- There were comments that it might not be totally legal. Hopefully, this paves the way for more WISPs, bigger hotspots, and replacement of outdated wireless technology that seemed to be the only competitor to DSL and tv-cable for the last mile."

Re:High effect

[AndrewMcG]

Actually, that's why it needed certification. It won't, it has very little different output to your laptop card. It works by actively steering antenna beams at associated users. Very cool for ISPs and big campuses.

Low-tech alternative

[icantblvitsnotbutter]

A company in Sweden conducted tests with a stratospheric balloon [theregister.co.uk]. They broke 300 km (187+ miles).

Not entirely salient, but a reminder that there's more than one way to skin a cat.

Re:High effect

[interiot]

Two watts? Are you on crack? Try 600 - 125 milliwatts [mcw.edu].

Re:wireless

[tigress]

This is already happening. Didn't you read any of the stories [slashdot.org] about [slashdot.org] wardriving? [slashdot.org]

The "standard" 300m outdoor-range of most APs are more than enough.

Re:High effect

[tigress]

Actually, on second thought...

Peak power output corresponds to 2 Watts or 2000 milliwatts (mW) which averages to 250 mW of continuous power. An analogue phone (AMPS system) has peak power limited to 600mW.

Source [arpansa.gov.au]

Re:Is it too powerful?

[Uller-RM]

I live in Portland, OR, home of PersonalTelco - a fairly well known volunteer group for WiFi access. We have more nodes listed on nodedb for the Portland metropolitan area than nearly any STATE - and take that to all states if you count all of Oregon.

We had a big landmark case here a while ago that's exactly what you're fearing. PersonalTelco's been providing a totally free 11Mb connection to Pioneer Courthouse Square (a major hotspot in downtown Portland), and the Starbucks on one corner of the square tried to compete with them, broadcasting their pay-to-use TMobile service on the same channel.

Starbucks ended up having to back down - they now broadcast on channel 11, and PT on 6.

PT's a great group to get involved with - not only do they have regular meetings and stay active with local politics, they also organize a lot of things like group buys on antenna connectors and workshops on Pringles can waveguides.

Re:Ho Hum...

[Effugas]

A few years back, a company came to my school to give a talk about SDMA -- Spatial Division Multiple Access. It was essentially based on the concept that, duh, a single cell phone is only one position, so the tighter a beam you could direct / detect from the phone, the more points could use the same frequency.

The cool thing about SDMA is that as your load increases, so too (to a limited degree) does your available bandwidth. As long as people are relevantly separated from eachother, their physical positioning relative to other hosts adds disambiguatable bandwidth. It ain't perfect -- node to node crosstalk is a real problem, since your wifi cards are omni -- but they're talking about such range that there's lots and lots of omni hexes to expand through.

Whoot to Vivato; hopefully they'll get a lower end antenna for fixed wireless clients!

Yours Truly,

Dan Kaminsky
DoxPara Research
http://www.doxpara.com

Re:Alot of problems solved, new ones created.

[Graymalkin]

What you describe was wat Metricom/Aerie/Whoever tried to do with Ricochet. Instead of a bunch of towers covering large cells they used their little repeaters to make micronetworks. Instead of having a huge swath of city not covered by a spot beam they just neglected to stick repeaters up in that area.

Smarter, not harder (same effect, better aims)

[Anonymous Coward]

Please guys, this techonology is NOT about splattering megawatts all over town!

It is about aiming a low power beam in the right direction using a smart antenna AND that same smart antenna is a better listener.

It's a high-tech equivalent of a parabolic antenna and it is adjusted to radiate the same power at a distance as a normal omnidiretional antenna would do. That's what the FCC require in order to approve an antenna.

It's a common mistake to think that range=power. Note that this is a two way operation.

You also have to be able to hear the other guy, right? That takes good listening skills = a directional antenna.

Re:Ewige Blumenkraft

[rjamestaylor]

What part of "Wi-Fi Switch" did you not understand? From the site [vivato.net]:

• Vivato's Wi-Fi switches deliver the power of network switching with Vivato genius radio antennas. Vivato's switches use phased-array radio antennas to create highly directed, narrow beams of Wi-Fi transmissions. The Wi-Fi beams are created on a packet-by-packet basis. Vivato calls this technology PacketSteering(TM). Unlike current wireless LAN broadcasting, Vivato's switched beam is focused in a controlled pattern and pointed precisely at the desired client device. These narrow beams of Wi-Fi enable simultaneous Wi-Fi transmissions to many devices in different directions, thus enabling parallel operations to many users - the essence of Wi-Fi switching. These narrow beams also reduce co-channel interference, since they are powered only when needed.

• Vivato's Wi-Fi switches significantly increase the range of Wi-Fi. Rather than transmit the radio energy in all directions, Vivato's PacketSteering concentrates the same amount of energy into a narrow, long beam. This beam is effectively a high-gain antenna that is formed for the duration of a packet transmission. The result is extreme range - extending the reach of Wi-Fi from tens of meters to kilometers.

  Another key attribute of switching is preserving compatibility with standard client devices. Vivato's Wi-Fi switches deliver increased capacity, range and security to standard Wi-Fi clients based on the IEEE 802.11b, 11a or 11g standards. With increasing capacity and range, Wi-Fi switches are more scalable than Wi-Fi traditional micro-cellular implementations and are managed in much the same way as Ethernet switches for easy adoption and widespread deployment.

Re:Sprint broadband

[praedor]

Last I heard/read, Sprint broadband was no longer accepting new customers (This was almost a year ago I read this on their site). If you have it now it is only because you got in before the locked down the system and stopped accepting new users. Doesn't bode well for its future does it?

Re:Alot of problems solved, new ones created.

[Alsee]

PD's, FD's, Hospitals, etc. are all considered to be zones absolutely off limits to any such interference this would cause... ...better solution would be to use smaller and cheaper arrays.

The point of the phased array is that it causes far less interference. It can get coverage to far more area while staying within the exact same limits to hospitals, PD's and FD's. It also gives you far more control of the coverage. Even if you have a "1 or 2 degree swath" on the far side of a hospital you can cover it with a second tower 3 miles away in a different direction.

The current implementation uses a fairly localized phased array to create beams. If they were to coordinate widely separated antennas they could do much better than beams, they could give pinpoint coverage. Almost like placing an ultra-weak antenna on the target's shoulder. It also becomes possible to actively zero-out the interference to hospitals with a pinpoint inverse signal.

They aren't up to pinpoint coverage level I described, but it will come. The current phased arrays are still far better than regular antennas.

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