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Broadband from World's Tallest Building
StarPie writes "The Chicago Tribune is reporting that Sprint Broadband will be broadcasting DSL from the top of the Sears Tower in Chicago. The range is said to be 33 miles -- a lot better than wire DSL. All you need is line of sight from the Sears Tower." I've spent the last couple minutes straining my eyes but try as I might, I can't see it. I'm stuck with 128kbits.
Since 1998, the Petronas Twin Towers in Kuala Lumpur, Malaysia have been the world's tallest building (not including tower structures like broardcast towers) - 1,483 feet vs 1,450.
Sprint is already doing this in a few other cities, such as Phoenix, where they have the MMDS license. Worldcom is doing it in Jackson, MS and a few other cities, and will be expanding it too (they have the NY and Boston licenses).
Note that "line of sight" for MMDS is much better than optical; it means "not over the horizon". Since Chicago is basically flatland, hills aren't the problem they would be in, say, New England. Which is why this Chicago rollout is so important; it could give the technology a real boost. MMDS operates around 2.5 GHz. It is not subject to significant rain fade, and passes easily enough through trees. (Contrast this to LMDS at 29 GHz, which has a typical reliable range of around 2 miles, because of rain fade, though it goes much farther on dry days.)
Each market has one MMDS licensee. This was the FCC's last pre-auction lottery, nicknamed "wireless cable". It was intended for pay-TV broadcast distribution. A bunch of shady operators took fees to enter people into the license lottery ca. 1993. The MMDS companies who bought up the licenses from the lottery winners discovered that there wasn't much of a market, so they went bankrupt or sold out to Sprint and Worldcom (who between them have most of the country's population covered by their licenses, but are just starting to offer service). Now it's viewed as a DSL alternative. Some other operators are also in business; Oxford Telecom, for instance, does MMDS data in Portland, Maine.
This is mostly two-way radio, something the FCC authorized a couple of years ago. (Early systems were dial-up return.) I don't really think there's enough bandwidth there to replace DSL or cable modems in urban areas, but it's a good alternative for people who are out of range of those services. Alas, with only one license per city (spectrum being a scarce resource), it's not totally competitive.
For example, where I'm located there is a ring of mountains directly in front of a satellite (Telstar IV). There is no line of site. Yet, I can get decent reception in some parts of town because the mountains form a knife edge and the resulting diffraction pattern alters the signal strengths in some spots.
In other places I have turned dish antenna at ninety degrees to the normal signal path because the reflections off a group of office buildings were stronger.
The only practical way to know is to get the guy with the field strength meter to come and see. Remember, higher is usually better, so now maybe there's a reason to get that apartment on the top of the building.
*whup* "Get along, little electrons. Heeyah!"
It's not DSL. It's MMDS -- Multichannel Multipoint Distribution Service.
Sprint Broadband is one of the largest customers of Hybrid Networks Inc.
In fact, there's even an interesting little press release on Hybrid's site regarding the whole deal in Chicago.
This isn't very new to me, as the majority of my work and home bandwidth is provided by a local ISP that has been deploying these systems since the Fall of 1998. As an individual subscriber I've pulled traffic nearing the 8Mbit/sec mark. Yep, that's something a little more than the equivalent of five T-1's.
MMDS has a lot of advantages over your typical "unlicensed" wireless gear operating in the 900MHz and 2.4GHz spectrum... namely the fact that MMDS is licensed by the FCC (in the US).
Businesses that build their existance and survival on the fragile structure of "unlicensed" wireless often don't spend the time to properly research what it is that they are getting into... a mess. The first "provider" in an area to deploy "unlicensed" equipment has great success... and then the second "provider" comes along... and things start to slow down a little... and then another provider comes along perhaps... and things start to break (more)...
And then an Amateur Radio Operator/ham comes along and decides to start using the spectrum for Amateur TV, and the FCC comes in and shuts the "providers" down as they are infringing on the rightful license of said ham to use the 2.4GHz spectrum. *poof* :)
Another thing to consider, and one of the other reasons I like my MMDS provider... They don't have that interestingly restrictive TOS that Sprint Broadband has.
That's the only real problem with XHF transmissions.. (XHF is basically anything above a gigahertz).. they are all line-of-sight.
.136 m / Hz.
.5 to 1.5 Mbps range.
;)
Clouds, though, shouldn't realy be a problem unless they're VERY thick. The wavelength of a 2.2 GHz wave (I'm assuming 2.2 GHz because I know 2.4 is occupied, and it's the same drek in a different package) is:
c / freq == 300Mm/s / 2.2GHz ==
The wavelength is 13 cm or so. That's mighty small (when you consider that AM 1000 is 300m and FM 100.0 is 3m), but they can pass through anything short of a heavy rainfall or a blizzard. (I have a DBS system and can receive in virtually all conditions. Idiot involvement, though, seems to screw everything up royally.)
The short wavelength dictates the LOS and the power of the frequency will determine the range.
I have to commend Sprint's good timing, since a lot of DSL'rs got screwed when northpoint Comms. went bankrupt.
And now, for the coup de grace that'll get me jacked on wireless broadband: It's two-way. According to this marketdroid page, it's completely free of the telephone grid.
However, for you QUAKErs, your ping time may be slightly slower than it would be on a comparable hard-wired connection. This appears (from what little data that's available) to be (at least in part) a party-line system.
According to the site (use zip 60625 if asked), the max d/l is 5 Mbps, and they project 'typical' to be in the
They have an upload cap of 256 kbps.
A few things worth keeping in mind:
1. It's running on RF frequencies, which means that, depending on your paranoia level, you may not want it since quality receivers are available that can receive above 2GHz. And it's not protected by the anti-cell-scanner bills (not like anyone interested in cracking t
2. IP Masquerade is probably the best way to go. They seem to be MScentric. (They are intending to charge an additional ten bucks a month per extra rig online. I didn't know IP's were that rare
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I used to be someone else. Now I'm someone better.
Real life is underrated.
... to a few of the questions I saw here: - mobile is really hard to do in this band. they're doing good to get fixed wireless working. that said, wireless does lend itself to portability and mobility; it's just a question of technology development. - upload is still limited; I think they claim like 32kbps or something. it should burst to ~200k though. - it's two-way wireless now, though it used to be dial-return back in the day. - it can burn through clouds, smog, rain, snow, etc., without much problem. trees and cars and walls start to cause trouble. - the hardware uses FreeBSD (not Linux) plus some fancy rf stuff from Intel. The vendor didn't ship a provisioning system, so one was written by a few chicago guys in perl/php/mysql on a va linux box and ported to to c++/perl/oracle on a sun e3500 - it's in 14 markets total (phoenix, tucson, san fran, san jose, colorado springs, denver, houston, chicago, detroit, melbourne, fresno, salt lake city, wichita, ok city) - it has nothing to do with pcs technology - the link is still unencrypted but the modems don't bridge, so they're slightly more secure than you'd think. then again, never underestimate the power of a bored ee student with a radio shack. - besides sprint and wcom, bellsouth and a company called nucentrix have a lot of mmds markets - people in most markets routinely get multi-mbps downloads