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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.
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.
eudas
Blessed is he who expects the worst, for he shall not be disappointed.
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.
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?"
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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.
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.
-josh
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.
-Scott
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.
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.
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!"
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.
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minusthink [Code poet or super hero? (you decide)]
"when life gets complicated, I like to take a nap in a tree and wait for dinner" - Hobbes.
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...
main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
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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Real life is underrated.
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'Is so!'
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Yeah, we seem to have the tour map.
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.
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! :)
... 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
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...)
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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.
"It is a greater offense to steal men's labor, than their clothes"
...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.
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.
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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
Bleh!
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.
KFG
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, http://www.illicom.net)
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.
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!
Reason is the Path to God - Anon
Yeah, and a taller one is planned in Chicago. SO what? That Chinese pile is vapor man.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
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".
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
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?
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
Having spirituality isn't something to be proud of.
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
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)
I used to be someone else. Now I'm someone better.
Real life is underrated.
Vidi, Vici, Veni
:)
We saw, we conquered, we came.
Cute.
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