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Broadband from World's Tallest Building 195

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.
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Broadband from World's Tallest Building

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  • Is the upload still limited like other dish type Broadband?
  • by Dacta ( 24628 ) on Tuesday March 27, 2001 @06:29PM (#335553)

    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.

  • How does it send requests, the article only mentions a pizza sized receiver but doesn't mention anything about a transmitter. If you still need a phone line that would kind of suck, you wouldn't get a very good ping in Quake!
  • Just because you can't see the thing with your naked eye does not necessarily indicate that your location does not have 'line of sight' with the transmission tower.

  • I'm skeptical. I'm in Chicago (hence "CBoy") and about 12 miles from the sears tower. 90% of the time I can't see it because of low lying clouds or weather. Otherwise theres nothing blocking it.

    I don't put a lot of faith in this if it's line-of-site visibility
  • I just finished that project out at Sprint 2 months ago. What is sad, is that the system was running on a Linux box, with the provisioning system running perl/php with MySQL. The consultants I was working with (one a USMC Lt. Col) decided that it would be better if it ran on a Sun Sparc station with C++, tied to an Oracle database. Its part of the Broadband wireless group there. Each city has a cybermanager that maintains connections to and from the antenea in 30 degree radian chunks. It has only been rolled out in six or seven markets, but I think its the way of the future.
  • Great!! Now I will be able to sail on Lake Michigan and still get a broadband contection. I will not have to go home to read e-mail and check /.
  • by psocccer ( 105399 ) on Tuesday March 27, 2001 @06:38PM (#335559) Homepage
    We have wireless internet at work because it was available 2 years ago. That's 2 years before we got DSL access here, so it's all we could get for high-speed internet without grabbing a T1 or frame relay.

    Anyway, it was more like $150 a month or something and was still line of site, and I think it's 2GHZ. All I can say is, it sucks. A lot. I think we get about 80% uptime with it and the latency is horrible, dare I say it, even worse than a modem. We're talking anywhere from 30 to 300ms ping time to the first hop on the other side, usually in the mid 100's.

    The thing was though, the through put was still like 80K/sec or so, so as long as I wasn't streaming anything or playing games it was OK, say for like the web, except for that 80% uptime thing. Think about that, it doesn't sound too bad, but that means 1 in 5 times that I sit down to use the internet that the route is down.

    It was also tedious to program over the link since our webserver was co-located on the other side and with the link going down so much I spent lots of time banging on my keyboard waiting for my cursor to move again, only to see like 5 extra lines deleted in vi or something.

    We're getting a T1 now. I'm going to be very happy. :)

    PS: About the streaming thing, I stream video with real server to work from my house with DSL, and the best I can get is using the 56.6K setting, and usually that gets all out of sync so I actually use 33.6K. How's that for "High Speed?"

  • just as long as it isnt MLB :)
    Just one man beneath the sky,
  • The Petronas Towers are *not* taller than the Sears tower. If you were standing on the top floor of the Sears Tower, and the Petronas tower was next door, you would be looking down on the people on the top floor of the Petronas Tower.

    Its only by a quirk in the architectural definition of what is part of the building and what is not which makes some people think the Petronas Tower is taller. The decorative spire on the top of the Petronas tower, which is defined as being part of the building, rises above the roof of the Sears Tower, but it's merely decorative. However the Sears Tower's antennas which have a functional purpose for the building, including for the use mentioned in this article, but are not considered architecturally to be part of the building, top the Petronas Tower's spire.

    So there you have it. A useless piece of ornamentation hardly makes Petronas taller than the full functional height of the Sears Tower.

  • by bbillian ( 19067 ) on Tuesday March 27, 2001 @06:39PM (#335562)
    This is not entirely true. The Petronas Towers are the tallest buildings in one of the four categories for tallest building.

    The four categories are:
    • highest spire
    • highest observation deck
    • highest top floor
    • highest antenna
    The Sears tower holds the title for all of these except highest spire (which is held by the petronas towers in KL.)
  • by bink ( 87998 ) on Tuesday March 27, 2001 @06:39PM (#335563)
    Actually, the Sears Tower was dethroned by the Petronas Twin Towers in 1996, but regained the title in 1997. The way the Petronas Twin Towers gained the title was by putting decorative spires on top of the top floor of the buildings. In 1997 the Council of Tall Buildings and Urban Habitat met and declared the Sears Tower the tallest building again. You can read about it at this link [].
  • by joshv ( 13017 ) on Tuesday March 27, 2001 @06:39PM (#335564)
    It will be too cheap and oversold - resulting in shitty service, low bandwidth and spurious connections.

    Sorry, I will never ever ever buy a Sprint product or service every again. 'Crystal clear calling' my ass.

  • Wireless DSL is good and everything, but what sort of security is being put on this link? From what it sounds like, it isn't a directional link like most Microwave/Sat links...its more like radio.

    I know that there are a lot of good encryption techniques out there, and that they're widely adopted, but I still like the idea of having the privacy of a wire line, which not every freak-with-an-antenna can pick up.

  • Bah, thats semantics. The Petronas has the highest point off the ground basically. You could have an incredibly tall building, minus and observation deck, but no one would question whether or not its the tallest.

  • by Cerlyn ( 202990 ) on Tuesday March 27, 2001 @06:44PM (#335567)

    This has been argued actually; note there is only 33 feet difference between the two. Those measurements, if memory serves me right, do not include the antenna tower on top of Sears Tower, yet include the pinnacle* of Petronas. The logic here by the official raters is that the antenna tower can be easily removed, while the pinnacle is a permanent feature of the Petronas towers. Granted, I do not quite see the logic here; if you have a better explaination, please chime in.

    If you include both the pinnacle and the antenna tower, Sears Tower beats Pentronas by a foot or so, and the same holds true if neither the antenna tower or pinnacle is counted. Note I am recalling all this from memory, so I might have something incorrect.

    Still, the link you provide is intresting. Looks like something (two somethings, actually) may shortly beat Petronas.

    * A pinnacle is a fancy top piece for a building, typically with a large point on top of it. The concept dates back to at least Medival times.

  • by return0 ( 23978 ) on Tuesday March 27, 2001 @06:44PM (#335568)
    Sprintbroadband already offers service in Phoenix and Tuscon. $40/month for 1 Mbps bi-directional. The technology is called MMDS (multichannel multipoint distribution service) and it should work up to ~38 miles using a "pizza box" sized onnidirectional antenna. Very cool. Wish they offered it in Las Vegas.
  • What I have found with the wireless internet is that the provisioning and antena controlers are out of sync 20% of the time. People get de-provisioned becuase of the a faulty billing system, and then have to be reprovisioned by the call center.
  • o for gods sake, lighten up :)

    He was actually being funny for once...

  • ...though that wouldn't be hard. Sprint's Chicago cellular service was awful. I'd rather get a landline from Ameritheft than use those guys again.

    I'd be screwed without AT&T. (Hear that, RCN?)

  • I've posted this once in reply, but I think it bears repeating since there's already 10 posts concerning this topic... the Sears Tower IS the tallest building in the world. The Sears Tower once again became the tallest building in the world in 1997, when the Council on Tall Buildings met and announced new standards upon which the tallest building would be judged.

    The Petronas Towers were previously the world's tallest building, but only because of a decorative spire on top of both of the towers, the Empire State building is the tallest including the antenna, the Sears Tower is the tallest in the other two categories (highest occupied floor and highest to the top of the roof). You can read all about it here [].
  • It is also in CA, Seattle, Chi, and three other markets in New England (don't remember where). How long did it take you to get someone out there to hook it up after you ordered it?
  • Yea, any freak with a pair of kleins can get into your wire line. Security is relative. Crime rates are higher in cities. Vandalism is higher in cities. The air is something your run-of-the mill vandal can't touch. In that facet, it's somewhat better.
  • ... is that SBC is freezing out co-locaters -- and getting away with it.


  • by isdnip ( 49656 ) on Tuesday March 27, 2001 @06:51PM (#335576)
    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.
  • Amen to that , brother. I ditched thos e jerks last month after four months of "All Circuits Busy" messages to anyone who tried to get ahold of me on my cell. I pity the fool who tries to get decent service of another Sprint wireless servce.
  • by human bean ( 222811 ) on Tuesday March 27, 2001 @06:53PM (#335578)
    That which RF folks call "line of site" is a constantly shifting and variable thing. At microwave frequencies many different facets of physics come into play.

    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.

  • I find it hilarious that there is an actual Council on Tall Buildings.

    Once again, I'm finding life more and more like a monty python skit.
    minusthink [Code poet or super hero? (you decide)]
  • by Spy Hunter ( 317220 ) on Tuesday March 27, 2001 @06:55PM (#335580) Journal
    Now just wait a gosh-darned minute here!

    You can't beam DSL! Don't they even know what it stands for? It's a Digital Subscriber Line!

    I'm having visions of streams of thousands of cables shooting out of the top of the Sears tower...
  • With a 33 mile radius, the service would cover an area of over eight thousand square kilometeres. This is about the same size as the Sibayi Lake Lodge [] eco-tourism spot in Zululand, South Africa. If one of these towers was built there, then all the people who come to experience ecological wonders will be able to get wireless DSL while at the same time! It could be a tourism revolution!
  • >How long did it take you to get someone out there to hook it up after you ordered it?

    I live in Las Vegas where it isn't available yet. Worst part is that Sprint owns the FCC license for MMDS in my area so I'm screwed. Well not exactly screwed. I have a cable modem and DSL is available and Ricochet2 (128Kbps) is "comming soon" to LV.
  • Well that's what the 3G mobile hype is all about :)
  • I don't know where the poster got the idea that they were broadcasting DSL, but it doesn't say that anywhere in the article. That would be silly anyway.
  • This is really good for Chicago, my friend out in Naperville was laughed at when he wanted to order DSL. So he is the last one through the zone in EQ, on his dialup. Since he got ISDN (dual B channels) and a ISDN router, he is alot quicker. I hope Sprint takes off with this in Chicago.
  • it's Canada not canadia, and it's a tower not a building!

  • It is in fact worth noting that the article you linked to is a little out of date. The Sears tower now leads in the highest antenna category too.

    This is because the Sears tower replaced one of the two antennas on top of the building recently. The two antennas used to be the same height, but now the west antenna is taller the east one and it is higer than the one on the World Trade center.

    Incidently, here in Chicago, we call the spires on the Petronas towers "cheatsticks". :-)

  • by dorkstar ( 318427 ) on Tuesday March 27, 2001 @07:02PM (#335588)
    If you're willing to discard the "semantics", then you'll have to call the CN Tower [] the biggest. Right now it's the world's tallest "free standing structure", but it's taller that both the Sears Tower and the Petronas towers.
  • by AX.25 ( 310140 )
    I once ran 500 watts on 1296 MHz with a 55 element loop yagi from a mountain top in PA. I got a lot further than 33 Miles, but it would have taken days to download a typical /. comment page at 20 wpm cw.
  • by Anonymous Coward on Tuesday March 27, 2001 @07:06PM (#335590)
    We obviously need a new moderation category: (-1, Woo-fucking-hoo)

    Mr. AC
  • That's right - 'tallest building' and 'busiest airport' don't technically belong to us Chicagoans anymore, unless you start arguing semantics. Took my son to the observation deck of the Sears Tower last year when he had a day off school and I decided to skip work to spend the day with him. The people there said that the Sears was no longer the tallest free-standing structure anymore, but it is still has the highest occupied floor of any building in the world.

    Just like the airport. O'Hare [] used to be the 'busiest' until Atlanta's Hartsfield surpassed it in number of flights. That doesn't stop Chicago from still claiming it is the busiest, as long as you measure number of people who pass though each year instead of number of flights in and out. (although I thought Alanta passed Chicago for that too now).


  • Then get a telescope
  • The point I'm trying to make here is not about vandalism, its about privacy.

    Its the difference between having your box hacked by a script kiddie, as opposed to someone breaking in and stealing it.

    Its also a pretty serious vandal that would go around ripping up DSL lines....both in equipment and intent. The air equivalent would be someone broadcasting a tone in the DSL frequency range to interfere with transfers.

  • The author of the article doesn't says otherwise. The quote specifically mentions North America, which implies that it isn't the tallest anyways.
  • I can't wait until there's ubiquitous wireless broadband and we all have $50 5Ghz crusoe color handheld computer/cell phone/entertainment systems.

    Should be about another 18 months right?

    yeah baby.
  • by jeffg ( 2966 ) on Tuesday March 27, 2001 @07:12PM (#335596)

    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.

  • :: transmission initiated

    what is a real asian country? someone tell me? i bet you are someone who has never left your country thinking its the greatest country in the world. well... too bad.

    malaysia is not a third world country, and it consists of around 20% chinese (migrated from china), 10% indian (migrated from india), 69% malays (migrated from arab), and 2% natives of the land. their skin colors range from white, yellow, brown, to black.

    their factory workers have cell phones. and they have one of the widest selections of food in the world. i was there for almost 18 years and i have to tell you that you are horribly wrong if you think you don't need to leave your country. america is not that great after i discovered asia. we have tech. they have tech. we have little in terms of spirituality. they do. we have such boring food. they'll blow you away with their food, and our food. travel. open your eyes. america is what they want you to believe it is. but there are better, more balanced worlds out there.

    :: transmission terminated
  • That's the only real problem with XHF transmissions.. (XHF is basically anything above a gigahertz).. they are all line-of-sight.

    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 == .136 m / Hz.

    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 .5 to 1.5 Mbps range.

    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 ;)

    Ruling The World, One Moron At A Time(tm)
    "As Kosher As A Bacon-Cheeseburger"(tmp)
  • Oh, yeah... you bet. And don't think the City fathers in KL and Chicago didn't jump up and down a lot when this 'Council on Tall Buildings' met to decide how to measure.

    'Mine is bigger than yours!'

    'Is not!'

    'Is so!'

    'Wait, let's solve this objectively... do you measure from the pubic bone or from the base of the scrotum?'

    'We need a Council on Large Genitals to come up with a standard!'


  • While there are many different properties one could use to decide which is the "tallest building", the people who make it their business to keep track of records, namely the folks at Guinness, say that the "tallest building" is the CN Tower in Toronto, Canada. See their page [] on the subject.
  • by grapeape ( 137008 ) <mpope7 AT kc DOT rr DOT com> on Tuesday March 27, 2001 @07:32PM (#335601) Homepage
    I am part of the team that got the Chicago system for Sprint Broadband Wireless up and running. There has been a one way service there for some time but the two way in Chicago was just finished market acceptance.

    Its uses a fixed dish that connects to an external modem made by a company called Hybrid. The reciever and transmitter are combined and the unit works for the most part like any standard cable modem.

    On average you can expect in a fully subscribed market around t1 speeds down and isdn speeds up.

    The technology from the tower to the fixed wireless antenna at a subscriberes home is RF based cloud cover and rain fade do not have nearly the affect on RF as it does on satellite based systems, the only time weather really has much affect at all is when there is very heavy ice build up and even then its minimal.

  • Actually, yes it does. Right now Look Communications has been using the CN Tower for wireless broadband internet for quite sometime. However at the moment it's only downstream. They're working on two way wireless right now so that uploading won't be limited to 56k, but I don't know what the status of that is
  • Our doom is coming closer! Run for your lives! The beginning of the end has begun!

    Sprint is clearly symbolic for the four horsemen! We must prepare our souls for the war, before it is upon us. The plaque has hit already, and the pestilence is taking a new form... Slashdot Trolls and Crapflooders!

    Run! Run far away! Very, very far away!

    But don't tell my ex-boyfriend... he's a motherfucking asshole.

  • aren't you confusing them w/Verizon?

    try 1000+ pings to your gateway b/c they are daisychaining racks then telling you that it is not them that is causing the problem it is you!
  • 1.) The Canadian National tower is the world's tallest structure. It doesn't have occupied floors all up and down its interior. It's a essentially glorified TV antenna.

    2.) IMO, the Petronas Towers is essentially ripping-off the Sears Tower in the World's Tallest category. The Sears Tower has more occupied floors and the heighets occupied floor. As can be seen from a side-by-side to-scale comparison here [], the only reason the Petronas Tower is considered tallier is that the antenna on top is considered to be part of the art-deco cap, while the antennae on the Sears Tower aren't.

    So, now we have proof that architecs (sp?) smoke crack! :)

  • Someone on chi.internet already posted that the installers wanted to put a 25 foot tower on his roof to get his equipment above the neighbors trees. So what's the deal - is non-optical line of sight true?
  • by Anonymous Coward on Tuesday March 27, 2001 @07:42PM (#335607)
    ... 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
  • by HongPong ( 226840 )
    That's a lot of RF/microwave radiation! I bet there will be 2-headed pigeons and stuff. Or maybe just cooked pigeons. Oh, yeah, no birds that high.

    As long as I am rolling on a stream of consciousness, reminds me of a story, back in the day microwave station operators in the artic used to stand in front of their dishes to warm up. Maybe true, I don't know. Anyone can corraborate?


  • Recently a company has started construction on a new building in Chicago. When completed it will be the tallest building in the world. Coupled with the Sears Tower. That makes Chicago a pretty impressive area for tall buildings. Sorry, but the name of the new building escapes me.
  • Actually there is Sprint Broadband Wireless service in: Tucson, Houston, Phoenix, Detroit, Chicago, San Francisco, San Jose, Portland, Seattle, Wichita, Oklahoma City, Fresno, Denver, Colorado Springs, Melborne, and Salt Lake City. Sorry no new england states at the a matter of fact the florida pop is the only one on the atlantic coast. For the time being that is it....further launches are at least a year out. Most likely there will be expansion into other markets once the second generation product is available. The second generation product will offer near or non line of sight, better throughput and a cellular deployment...which could theoretically open the door for the mobile broadband wireless discussed earlier in later generations.
  • Trollicuous
  • Dude, if you're going to insist on sailing on Lake Michigan, the LAST thing you should be worrying about is your e-mail. You should be focused on trying to avoid all the industrial waste, fecal matter, and used hypodermic needles floating all around you.
  • Actually, there are four standards by which a building is considered the worlds tallest. The Petronas Towers wins out over the Sears Tower in only one category (that which includes spires). The other three (highest floor, highest occupied floor and something else) are still held by the Sears Tower. Speaking of which, I can see the Sears Tower from here. I've got line of site. I think I'll stick with the university's T3 line though.
  • what you say !!
  • No the empire state building is not the tallest in any category. Sorry, but you're wrong. and the truth.. shall whatever []
  • Trollicious, I say.
  • Don't know about the arctic guys, but I can tell you about the operators at WLW (AM 700 in Cinci, OH). Before the FCC regulated max wattage at 50kW, they operated at something like 500,000 watts... and according to two guys who are long retired from there, they used to warm up in winter by standing near what they called the "RF stacks", which were cooled by the pond that had prepetual steam rising from it.

    Oddly, many of their friends have long since died of cancer. I met these two at a HAM radio/Boy Scout thing many years ago. Couldn't tell ya if they're still around. But just knowing what the WLW tower and the VOA antenna were capable of causing (as in, your stove being hot when turned off, the ability to hear the broadcast on your fence, etc...), I have no reason NOT to believe them.

  • 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.

    Ya really, Taco, haven't you seen Entrapment []?
  • >
    is non-optical line of sight true?

    Think about what you just said. :)

    Line of Sight means there must be a more or less unobstructed path from you to the tower. The tower is one point, your antenna is another point, you have to be able to draw a straight line between the two withint intersecting any non-vaporous objects. No trees, no buildings, no Goodyear Blimps, no nothing.

    LOS changes in definition at some manufacturer's whim... but when it comes to the Hybrid equipment that Sprint Broadband is working with [], and when doing RF-return, the above definition certainly sticks.

    The world of RF is complex, and often things aren't as simple as pointing your antennas at each other... Just ask any RF engineer about water. Or hills. And the fun beast known affectionately as "multipath".

    Go do some research and reading on Multichannel Multipoint Distribution System (MMDS), QAM64, QPSK, and all kinds of other fun acronyms. And for some more information regarding MMDS peek at this comment, below [].

  • I'm sure it's going to head that way. You'll get a life-time IP address, and use it in everything. Your preferences will be able to follow you... and so will your email. (which, given the amount of spam i get these days, may not be so hot...)

  • I sorry to say but you are all wrong. The CN Tower is the tallest building in the world as recognised by the Guinness book of world records. While the counsel of tall buildings may say otherwise The Guinness book of world records has always been the definitive source of this type of information.
    | Cunning Pike... Good Guy...
  • Well, depending on the signal strength, the max range might be more that 33 miles. I am assuming that 33 miles is the distance to the horizon from the antenna on the sky scraper.

    If you are in an apartment building on a upper floor, you may have a clear shot at the transmitter from more than 33 miles. This is because the horizon is a 5 to ten miles away from the apartment window, and this adds to the horizon distance as seen from the sky scaper.

    Not accounting for trees, hills, and intervening objects, etc.

  • by StarPie ( 411994 ) on Tuesday March 27, 2001 @08:37PM (#335627)
    ...was with the title "Broadband from World's (second) Tallest Building", in deference to the fact that Petronas in Malyasia is technically the world's tallest, though that's only counting the spire, etc., etc.

    I don't think Taco realized the flamefest he was starting by deleting that little word in parentheses. Anyway, I do live in line-of-sight to the Sears Tower, but I'm a tad out of reach of the Petronas Towers, so I guess I'll have to live with the shame of getting broadband from the second banana in the skyscraper world.
  • Holy Crap - Look at the dates on that list. Empire state building built in nineteen thirty one. And it's still in the top ten! Wow! That must have been an incredible sight at the time it was built.


  • I think I heard the mooring mast was used once but I remember none of the details.
  • the building designed by the chief architect with the largest penis.

    This accolade goes to a strip mall in Minneapolis, by towering acting architect Benjamin Johnson, locally known as "The Big Johnson Building".

    There's another category for "highest architect", but the winning building fell down less than 2 weeks after official completion.
  • It just isn't Sprint. BeyonDSL [] and LanWaves [] both offer it, both have packages somewhere near consumer level. Same concept, don't know the details but it will at least get you connected. And bug me in the next few days, I should be able to get details on what Ricochet is doing here.

    Chris Cothrun
    Curator of Chaos
  • 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* :)

    Yeah, we have 902-928 Mhz and several slices in the 2.4 Ghz area.

    The thing that most people don't know is that their cordless phones and cell phones are often transmitting in plain FM on a public amateur radio band 902-928. They even have secondary allocation, so if I interfere with someone's oh-so-important cell phone call with my 1500 watts, they can't do anything about it, as long as I didn't do it "intentionally", but that is kinda a hard thing to prove.

    I don't do that type of thing of course, just pointing out the possibilities.

  • That's the only real problem with XHF transmissions.. (XHF is basically anything above a gigahertz)

    Uh no.

    ELF Extremely Low Frequency 3 - 30 Hz 100,000 - 10,000 km

    SLF Super Low Frequency 30 - 300 Hz 10,000 - 1,000 km

    ULF Ultra Low Frequency 300 - 3000 Hz 1,000 - 100 km

    VLF Very Low Frequency 3 - 30 kHz 100 - 10 km

    LF Low Frequency 30 - 300 kHz 10 - 1 km

    MF Medium Frequency 300 - 3000 kHz 1 km - 100 m

    HF High Frequency 3 - 30 MHz 100 - 10 m

    VHF Very High Frequency 30 - 300 MHz 10 - 1 m

    UHF Ultra High Frequency 300 - 3000 MHz 1 m - 10 cm

    SHF Super High Frequency 3 - 30 GHz 10 - 1 cm

    EHF Extremely High Frequency 30 - 300 GHz 1 cm - 1 mm

    And if it is some sort of marketing BS that made up "XHF", shame on you for perverting science with marketspeak.

  • I can't resist adding to this thread about tallness:

    Surely Mount Everest is the World's tallest free standing "structure" (in height above sea level). The CN tower only wins if you discount non manmade things.
  • by kfg ( 145172 )
    The broadcasting of digital signals using Pulse Code Modulation on an FM carrier is quite old tech, very highly developed, and for all practical purposes, including gaming, happens instantly.

    Look for your latency elsewhere.

  • And this probably has nothing to do with DSL, and everything to do with MMDS or something...

    It is entirely possible to use the modulation techniques of DSL over RF.... you simply modulate a different carrier. I know we've looked at using DSL chipsets to do wireless before.. I believe the spectrum required or something was just not feasible..

  • Nowhere does it say that this is 'wireless DSL'. The article mentions Sprint rolling out wireless (sounds like MMDS) and then goes on to talk about the DSL situation, two separate issues.

    Most wireless is either MMDS, or 2.4Ghz ISM band stuff (I know there is some 2.4Ghz ISM stuff going on in central IL,

  • But having worked with a lot of 2.4 Ghz stuff.. I wouldn't imagine the properties of 2.5Ghz are much different.
    You certainly cannot go through 'lots of trees'. 2.4 scatters like mad.. it doesn't penetrate worth crap.

    Is it just the power levels this operates at that make it work through obstacles?

    I think line-of-sight still means unobstructed view, though perhaps the odd tree or something will be okay.. but if you are underground, behind a hill, or something, you're probably out of luck.

  • You are referring to 802.11 devices that occupy the unlicensed ISM band I presume? Since its unlicensed spectrum the FCC imposes a power limit of 1 watt to keep interference under control.

    MMDS occupies regulated spectrum and thus can operate at much higher power and is able to penetrate obstructions like trees.
  • Trees don't help, but they don't absolutely block the signal. MMDS is licensed with more power than the 2.4 GHz unlicensed radios, so it has more fade margin to begin with. In some areas, trees could be a problem. But it's not like optical, where they cut you right off, or LMDS which is close.

    Multipath's a different story. Different radios survive it differently. Cisco, for instance, is quite vocal about how their OFDM radios for MMDS are multipath resistant (they work okay even if the signal is bounced off of a few buildings). Some others aren't. I don't know what radio Spring is using here but I suspect it's one of the newer, more multipath-resistant ones. That, btw, is what vendors are talking about when they say they support non-line-of-sight. Hills are a different story -- that's no path!

  • This is on anecdotal evidence, so take it for what it is worth.

    At the time I ordered and had installed Cox@Home (I know, I know - it sucks, but I can't get DSL where I am at, last I checked), I firewalled it, as recommended by just about every sane individual on the planet.

    When I had it installed, due to a couple of reasons I had to set up the firewall on a Windows 95 box. This box was also my GF's box, so I was a little nervous running both user apps and a firewall, but at the time I didn't have a choice.

    The firewall I chose was ZoneAlarm - simple to install, admin, and best of all, free. Today I would probably choose Tiny, but that wasn't available then (and I only recently learned about it). I searched for some kind of NAT solution (the box runs 95, not 98), but came up empty handed, so I opted for a proxy server: AnalogX's Proxy. This solution worked well for quite some time, and I never had many problems (occasionally the Win95 box would freak, and I would have to reboot), except for one thing - it seemed "slow", compared to my GF's box. All the apps on my GF's box ran through the firewall, while my box ran through the proxy, then the firewall. It was all still faster than a modem, to be sure, so I lived with it, figuring that I would be using a regular firewall later, and besides, what more should I expect from a free solution...?

    I always intended to set up a "real" firewall at a later point. I had thought about a Linksys router/NAT box, or possibly building it myself. Things dragged on, then recently I gained the oppourtunity to do what I wanted. I chose to build a box - to get the experience, number one, and because it was overall cheaper, plus I could expand it (unlike the Linksys router).

    I chose Freesco (which is based off of LRP), because it is easy to admin, has remote admin capability (telnet and web), good documentation, and support for a ton of NICs. After getting it setup, and running it, I found out a very good thing:

    Your speed is only as good as your routing software (or hardware, as the case may be)!

    I guess I should've known this - it is a good lesson to learn. The majority of people don't have to worry about this on a cable modem or DSL: they only run one machine, or a wide open network (the latter can be a risky situation, IMO). I run (or attempt to) a secure home network, so having the routing capability is a must.

    The speed improvement is incredible - I don't have hard numbers - but I know web page loads, mail downloads, everything is faster - much faster. So, if you are having speed issues (or you think you are), look into changing your routing/firewall software or hardware system - you may be surprised.

    Now, if I could only get rid of this upload cap (can anybody point me in a good direction - heck, I would even be willing to try to spoof being the BOOTP server for the cable modem, if it would work)...

    Worldcom [] - Generation Duh!
  • If we're talking about HAAT (height above average terrain), wouldn't a ship in the middle of the atlantic ocean qualify as tallest free-standing structure?
  • Shit yeah, they could do it off the Stratosphere. Think of all the people that would sign up JUST for conventions.
  • yes, but KL does NOT have decent Pizza, nor do they have the Bulls.
  • ST is also the world's largest office building. It's Mecca to Dilbert fans everywhere.
  • Yeah, and a taller one is planned in Chicago. SO what? That Chinese pile is vapor man.
  • Sorry, it's been years since I haven't been there. Maybe the Toronto's "council of tallest buildings" changed the definition of "building" recently? ;-)
  • The problem with that reasoning is that if you are going to measure starting from the sea floor, then what's to stop you from calling an entire continent a "mountain"? Then Everest is the "peak" of a very wide mountain known as "Asia".
  • Then there's the problem of timing. Special events change traffic patterns. If you measure by numbers of planes leaving and arriving per day, then modest little Wittman Field in Oshkosh, Wisconsin becomes the world's busiest airport during the one week that the Experimental Aircraft Association holds their annual fly-in convention there. Granted, most of those places are little private planes, but again, here we get into that "depends on what you measure" problem.

    If Oshkosh gets to be the "busiest" airport for one week, then can I temporarily build the "tallest man-made structure" by tying a long cable to a big rocket and firing it upward? Granted, it doesn't last long, but for a few brief seconds I've got the tallest "free standing" structure. It's made of one cable and a rocket, and it won't last more than a few seconds, but still...

    I don't consider the caveats put on the Sears Tower by Chicago to be "cheating". The spire of the tower in Toronto is just for show, as is the decrative structure at the top of the one in Malasyia. The Sears Tower actually has real, honest to goodness EMPLOYEES using those floors all the way up to the top. The reason the observation deck isn't at the top is because the top actually has offices in it.

    The Sears Tower has the highest floors that are actually USED by people for something.

  • Why measure hieght above "average" terrain? that gives unfair advantage to buildings on hills, where the hill itself is above "average" terrian. What's wrong with just measuring from the land at the base of the building?
  • Having spirituality isn't something to be proud of.
  • No, we don't take it into account because it's just a glorified transmitter tower. It's not much of a "building". It's more of a monument. It should be in the same category as radio towers and the Eiffel Tower. This doesn't mean it's something to be laughed at - making a spike that tall that has no wires to hold it is an amazing engineering feat. But it's not a building.
  • I was writing the above response on-the-fly on a less-than-reliable netfeed. (I use a laptop with a 14.4 modem. Heavy sites like slashdot, in addition to having other windows filled with graphics-heavy marketdroid drek, in addition to a few times getting kicked offline without getting my two cents worth in get to ya.

    So... AFA the units: Sorry to have offended you. Perhaps you can clarify if the SI unit is "cycle".

    And AFA the XHF notation:

    The way I've experienced the radio spectrum, and according to my ARRL Handbook, you can split the RF into three discrete parts. Note that the top and of each range overlap in characteristics at times with the bottom of the range of the next type; ex. a 60 MHz transmission is more likely to act like a VHF wave and duct tropospherically rather than get ionospheric bounce.

    Less than 60 MHz: These are long waves. These waves bounce off the ionosphere, which is between 50 and 650 clicks up. Some of the layers only work during daylight hours, and these higher levels bounce the higher frequencies. (You can listen to the BBS arounf 17500 kHz during the day and have to settle for somewhere in the 6000 kHz range at night.)

    Antennas are LARGE. From wire dipoles meters long to huge yagis and quads, the antennas need to be very large for any reasonable gain.

    60 - 1000 MHz: These can be 'ducted' in the troposhpere, which extends from where you are now to about cruising altitude, 10 clicks up. Ducting is pretty tough and pretty tricky unless you're either damn lucky or damn skilled. It's a really funky process.. these signals are weird that way. You can miss a friend's call from across town, but you can hear people from thousands of miles away on a lark. These signals, though, can be directed (useful in moonbounce communications) or broadcast in a spherical pattern (look at your TV or radio).

    Antennas for these frequencies are considerably smaller. Any kind of antenna can work, with the exception of bullhorn antennas (used for microwave work.. read on). Huge dishes, yagis, quads, hell, walkie-talkies use rubber-ducks!

    Above 1 GHz: These freqs are increasingly limited to LOS. You can get some propagation on the lower end, but the higher you go in freq, the smaller the stuff that conflicts with the signal. (Above 10 GHz, water vapor and O2 can affect the signal!)
    Bouncing off airplanes is possible, and done by some to, ex. communicate over a mountain.

    Directionality becomes important here. This increases the beam's focus, and you don't accidentally fry yourself with microwaves. That's why dishes and bullhorns are used with these signals.

    OK? Lather, rinse, repeat, chill!

    Ruling The World, One Moron At A Time(tm)
    "As Kosher As A Bacon-Cheeseburger"(tmp)
  • Vidi, Vici, Veni

    We saw, we conquered, we came.

    Cute. :)

  • Yes.. I indicated I suspected it was power levels.
    Yes, I was referring to ISM band devices, and yes, I know that MMDS occupies licensed spectrum.

    The whole spectrum, though, is regulated. The 2.4Ghz ISM band is also regulated. There are rules one must follow.

Each new user of a new system uncovers a new class of bugs. -- Kernighan