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New Wi-Fi, to cover 62 miles. Kills HD Radio!

w9wi said:
As for the backhaul, not only is there the issue of limited backhaul power, but there's also the issue of avoiding "collisions". What happens when you, and the guy on the other side of the ridge, both decide to send a byte of data at the same time? Do your transmissions clobber each other? There are ways of avoiding the collisions, but they reduce throughput.
Click to expand...

I haven't digested the full spec yet, but I'm sure it works just like 802.11 a/b/g/n does now, only on a much broader scale. Your home wireless network has to be able to take data from multiple wireless devices, some of which may not be able to "see" the other devices on the network if the range is great enough. The router handles collisions and that is already included in the 22 Mbps quoted speed as far as I can tell.

kenglish said:
Even on a large reservation (like the Navajo Nation), it's going to be hard to find a place where you need that kind of range between cities. Maybe the "bigger, better, newer, faster, more extreme" pundits of the industry need to look at realities, and promote the idea of having fiber or microwave access to much smaller areas, where a reasonable UHF transmission system can serve a county or a few adjacent communities. But, that doesn't have the "hype"-ability of these absurd claims they currently make.
Click to expand...

If this quoted range is a reality, you're looking at (un)wiring the entire Navajo and Hopi Nations with just 8 or 9 wireless access points. That's pretty incredible. I'm pretty sure DSL/cable is available in Tuba City, Page, Window Rock, Shiprock and probably Ganado, so those residents wouldn't need access. You could put the .22 towers in some more remote locations, assuming there's power available (solar?) and cover the minuscule number of people who really live out in the sticks. Of course, there's no guarantee those people even have power, themselves. Some people still live on the res without the most basic of amenities we take for granted.
 
Zach said:
w9wi said:
As for the backhaul, not only is there the issue of limited backhaul power, but there's also the issue of avoiding "collisions". What happens when you, and the guy on the other side of the ridge, both decide to send a byte of data at the same time? Do your transmissions clobber each other? There are ways of avoiding the collisions, but they reduce throughput.
Click to expand...

I haven't digested the full spec yet, but I'm sure it works just like 802.11 a/b/g/n does now, only on a much broader scale. Your home wireless network has to be able to take data from multiple wireless devices, some of which may not be able to "see" the other devices on the network if the range is great enough. The router handles collisions and that is already included in the 22 Mbps quoted speed as far as I can tell.
Click to expand...

Collisions aren't an issue on the "base"-to-remote side of the path; they won't affect download speed. (beyond delays in your ability to acknowledge receipt of data packets) Everyone can "see" the "base" station -- everyone will get their fair share of the 22M outgoing pipe. (again remember, this is shared with other users on the same base)

Collisions are a problem on the return path; they're going to affect your uploads, your ability to send large emails quickly, the latency of outgoing "clicks".

I don't know if we'll know whether this is a serious problem without deploying the system first!
 
Starbucks said:
The only other point is placing low power cells transmitting from a phone poles along the higways for long mobile coverages. But how much would that cost? A company in the Silicon Valley tried that as early as 1999-2000 , and went under.
Click to expand...

Ricochet - I see their modems at flea markets every now & then. But the Google Free WiFi in Mountain View works quite nicely. I'm sure they're not making money on it, but it works.

Dave B.
 
Are collisions a problem on your Wi-fi network or ethernet network? C'mon, guys, this is basic networking. Collision domains can be managed quite effectively in packet-based networks.

The bandwidth limitations can be managed. Each channel may carry 22MB, and you can dedicate multiple channels to a particular service area. Those channels can be redistributed by local access via another technology - Wi-Fi, or even DSL if you're close enough to the end users. Or, if you have a lone residence, you can put in the equivalent of a cable-modem with an external antenna that can get the upload side back to the main tower.

Studies have shown that typical users actually download data less than 10% of the time that they're on the Internet, and upload statistics are a fraction of that. Those percentages change if you have customers streaming HD video. Audio is not a high-bandwidth application.
 
I assumed they had it figured out, so I did a Google search for 802.22 collision avoidance. Yup. They do. As stated earlier, the real use for this will be for long-distance broadband fixed service. It will be interesting to see if these services have as much trouble operating in the VHF range as HD radio does. There's a good, fairly non-technical summary here:

http://ecee.colorado.edu/~ecen4242/802_22/general_info.html

It allows for a wide range of spectral efficiency - from 0.5 bits/hz to 6 bits/hz. HD radio is at the low end of that range and we all know how poorly it works in the real world, so it will be interesting to see how this system adapts. I also have to agree that this won't kill HD radio. Realistically, commercial deployment is probably at least 3 to 5 years away, and HD will most likely have run its course by then.

Dave B.
 
DaveBayArea said:
I assumed they had it figured out, so I did a Google search for 802.22 collision avoidance. Yup. They do. As stated earlier, the real use for this will be for long-distance broadband fixed service. It will be interesting to see if these services have as much trouble operating in the VHF range as HD radio does. There's a good, fairly non-technical summary here:

http://ecee.colorado.edu/~ecen4242/802_22/general_info.html

It allows for a wide range of spectral efficiency - from 0.5 bits/hz to 6 bits/hz. HD radio is at the low end of that range and we all know how poorly it works in the real world, so it will be interesting to see how this system adapts. I also have to agree that this won't kill HD radio. Realistically, commercial deployment is probably at least 3 to 5 years away, and HD will most likely have run its course by then.

Dave B.
Click to expand...

Look at it this way — if HD radio were strictly used by fixed applications with external antennas, the 1% power thing would be more than adequate for most stations. Once I find a 'sweet spot' I can leave the radio there for days and it never drops out. Eliminating the reflections of people and cars at ground level, HD radio from a rooftop antenna is much more stable.

Of course, few listen from a totally fixed location these days but they do internet from fixed locations (homes).

What seems to be disappointing, however, is the lack of symmetry between download and upload speeds, just like with DSL and cable. 1.5 Mbps down is quoted and 384 kbps up is all you get. With today's move towards social interaction and photo and video sharing, 384 kbps just ain't cutting it anymore.

A good example of this is my use of Dropbox to share my phone's camera and videos with my PC at home. I can take a set and upload them while still on the go, they're waiting for me when I get home. But with 3G's upload speed of about 20 kbps here, it takes forever for 5 MP pics to upload. And forget about my 4th of July fireworks shoot. 10 minutes of 720p video was something like 1 GB. That would take forever even at 384 kbps up.

Even if this is unusual, think of all the people uploading photos to Flickr, Twitter or Facebook; they're doing it at a pace much slower than 3G adverts (or DSL or cable) claim, because we only ever see the download speeds.

Hopefully 802.22 can be made to offer better upload speeds.

Sorry, this was just a rant, it had nothing to do with radio or HD!
 
Zach said:
Look at it this way — if HD radio were strictly used by fixed applications with external antennas, the 1% power thing would be more than adequate for most stations. Once I find a 'sweet spot' I can leave the radio there for days and it never drops out. Eliminating the reflections of people and cars at ground level, HD radio from a rooftop antenna is much more stable.
Click to expand...

You make a very good point, Zach. I wasn't really thinking of that. The power levels for 802.22 are much lower than for HD as well, and it will probably work just fine. I think this was mentioned somewhere in another thread, but it's interesting how the hobbyists and DX'ers are the ones that can make HD work, while they're the very people Ibiquity is criticizing.

Dave B.
 
pocket-radio said:
free access for a small fee
Click to expand...
Forgive me for stepping in so late(ly), but how much does free cost ???
 
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